Beginning in April, young explorers delve into the landscape through five educational programs designed for hands-on learning. The youngest participants—pre-schoolers from Head Start and kindergarten students—discover plants, animals, and habitats in the Explorations program. Boston’s first-grade students explore living things and their habitats in the Organisms program, and second-grade students compare plants grown in the classroom with the Arboretum’s mature tree specimens in Old Plants. Upper elementary school grades investigate how flowers make seeds in Flowers Change, and compare evergreen conifers and deciduous flowering trees and their cultural uses in Native Trees/Native Peoples.

All of the more than 15,000 accessioned plants at the Arnold Arboretum are mapped, recorded, and tracked digitally with the help of a collections database, BG-BASE. Arboretum Explorer allows users to tap into this information by harnessing the GIS (geographic information system) capabilities of their mobile phones and tablets to locate and identify specific plants in the landscape. Arboretum Explorer also significantly enhances how visitors interact with plants they encounter in the collection, from taking self-guided tours to finding information on Tree Mobs and sharing plants on social media.

Among the “class of 2013” are young specimens birch (Betula spp.), hornbeam (Carpinus spp.), and holly (Ilex spp.), to name just a few. Many new accessions of species and ornamental roses will enhance new beds established last fall at the entrance to the Bradley Rosaceous Collection. Plants obtained on a 2008 staff expedition to the Adirondack Mountains are also finding their way into the landscape this spring, including red maple (Acer rubrum), mountain maple (A. spicatum), and two species of cherry (Prunus serotina and P. virginiana). The red maple, Accession #567-2008*B, was planted on Arbor Day during a special gathering and tour in the Maple Collection, an honors those who lost their lives or were injured in connection with the Boston Marathon bombing on April 15.

The first event in the 2013 series is Magnificent Maples on April 21 from 1 to 3 p.m. According to Julie Warsowe, manager of visitor education, “Collections Up Close events focus attention on plants at their peak—though perhaps not the ‘peak’ you would expect. While some might think of maples during sugaring season or in the fall when their leaves change color, the delicate beauty and complexity of maple flowers inspires wonder as well. Once you look closely, you begin to notice details that reveal the wonderful diversity of these trees.”

Sir Peter Crane, dean of forestry and environmental science at Yale; William “Ned” Friedman, Arnold Professor of Organismic and Evolutionary Biology at Harvard, and director of the Arnold Arboretum; and Peter Del Tredici, senior research scientist at the Arnold Arboretum and ginkgo specialist, will lecture on their combined 50 years of ginkgo investigations and lead a tour of the Arboretum’s ginkgo collection. The program will spotlight the history, culture, biology, and conservation of ginkgo, and include displays of artifacts and illustrations from the Arboretum Archives, examples of ginkgo bonsai created by Peter Del Tredici, and more.

The award recognizes Del Tredici’s extensive work on numerous aspects of both botany and horticulture over the past forty years. His wide ranging interests include new plant introductions from China, the root systems of woody plants, the natural and cultural history of ginkgo, and urban ecology and vegetation, a subject he explores in his recent book, Wild Urban Plants of the Northeast: A Field Guide (Cornell University Press, 2010). He has lectured widely in North America and Europe and has authored more than 130 scientific and popular articles. Del Tredici joins the select company of five other Arboretum staff members who received the Veitch Memorial Medal: Founding Director Charles Sprague Sargent (1896), plant explorer and keeper of the Arboretum Ernest Henry Wilson (1906), propagator William H. Judd (1944), horticulturist Donald Wyman (1968), and curator and horticultural taxonomist Stephen A. Spongberg (1996).

On April 11, 1925, a portable phonograph began blaring the Italian opera “Rigoletto” through the dusty village of Ch’ing-shui, China, prompting curious listeners to pour into the streets and onto nearby rooftops.

Botanist Joseph Rock had brought the phonograph on his three-year collecting expedition for Harvard’s Arnold Arboretum and the Museum of Comparative Zoology. In mounting his simple concert, Rock was adding in a small way to Harvard’s nascent educational exchange with Asia, which had begun in 1879 when scholar Ko K’un-hua became the first instructor to teach Chinese at Harvard.

Over the last century, the connections between Harvard and Asia have grown from such early trickles to a broad torrent of ideas, information, and people. Harvard now exchanges students and scholars with dozens of Asian nations, including three of the world’s four most populous: China, India, and Indonesia. Harvard conducts research across Asia into energy, business, health, government, history, art, and culture. The University also offers its expertise to everyone from farmers in Myanmar to Khmer Rouge justice-seekers in Cambodia to fledgling democratic leaders in Indonesia.

To encourage this exchange, Harvard maintains several offices in the region, including posts in Mumbai, Hong Kong, Singapore, Tokyo, and Shanghai. The University leans on and, in turn, supports local partners at a host of Asian institutions. And in collections that delight the public even as they enlighten scholars from around the world, Harvard also is a careful steward of thousands of items from Asia that are of historic importance, radiant beauty, and natural wonder.

Harvard’s Reischauer Institute of Japanese Studies is named for Edwin Reischauer (standing), who pioneered Japanese studies at a time when both knowledge and interest in the country were lacking. Photo courtesy of Harvard University Archives

‘World of universities without borders’

This Harvard-Asia exchange now is part of the endlessly evolving knowledge economy, where information — global and nearly instantaneous — drives economic growth and in which universities play pivotal roles. Rock and Ko planted seeds not only for the knowledge economy but also for what Harvard President Drew Faust described during a 2010 speech in Shanghai as a “world of universities without borders.”

“Universities exchange faculty and students as never before, and engage in an increasingly porous world of international problem-solving and collaboration,” Faust said in the speech, which marked the opening of the new Harvard Center Shanghai. “Higher education is developing a global meritocracy.”

Asian nations today, led by the global titans China and India, are roaring ahead, gaining importance both economically and politically. Likewise, Harvard’s engagement with Asia has grown rapidly in recent decades. The emergence of China and India as global economic titans has only increased the attraction of countries whose ancient civilizations, art, music, and culture have long made them objects of fascination for scholars in many fields.

“I’ve always felt that globalization is upon us and many countries in Asia were going to emerge very strongly,” said Venkatesh Narayanamurti, former dean of Harvard’s School of Engineering and Applied Sciences (SEAS) and Peirce Professor of Technology and Public Policy, who has had partnerships with Indian institutions in Mumbai and Bangalore.

Harvard’s recent venture into online education, edX, has diminished borders even further. Students from Asia and elsewhere around the world have gained increased access to courses at Harvard, Massachusetts Institute of Technology, and other universities. Though it launched its first course just last fall, edX already has drawn 677,000 students, 40 percent from outside the United States.

In March, Faust will deepen her own engagement with the region (which already has included trips to Japan, India, and China) during a spring break trip to South Korea and Hong Kong. There, she’ll visit with alumni groups, deliver a speech to students of Ewha Women’s University, and spend time with current Harvard students visiting Ewha.

Faculty members have played important roles over the decades in building bridges between Harvard and Asia, fostering not only teaching and learning at Harvard but also understanding more broadly among the United States, Japan, and China.

For instance, Edwin Reischauer pioneered Japanese studies at a time when both knowledge and interest in the country were lacking. He became ambassador to Japan under President John Kennedy, and today is the namesake for Harvard’s Reischauer Institute of Japanese Studies. John Fairbank was widely known for his scholarship on China and also has a research institute here named for him, the Fairbank Center for Chinese Studies. Fairbank’s legacy extends through the scholars he trained who went on to teach others.

“Fairbank really deserves enormous credit for not only sustaining and nurturing the study of China at Harvard, but, through his students, creating a scholarly basis for the study of China in the U.S.,” said Jorge Dominguez, Harvard’s vice provost for international affairs.

Professor Diana Eck’s Harvard Divinity School students had been studying elements of Kumbh Mela for months. In February, Eck (second from left) was able to bring her students to India for an unforgettable hands-on experience. Photo by Isaac Dayno

Likely to have been born in those regions

Harvard scholars of particular regions today are as likely to have been born in those regions as not. In its search for academic excellence, Harvard recruits faculty members around the world and, once they are here, takes advantage of not just their academic skills but their leadership talents, as illustrated by Nitin Nohria’s tenure as dean of Harvard Business School (HBS) and Xiao-Li Meng’s as dean of the Graduate School of Arts and Sciences (GSAS).

International students have become a far larger part of Harvard’s student body. The Harvard International Office, founded in 1944 to help foreign students with the transition to the University’s various campuses, teaching hospitals, and research institutions, began with just 250 students and scholars. Today it serves more than 7,000.

China, with 686 students, has the largest non-U.S. student contingent at Harvard. Of the top 10 countries that send students to Harvard, five are from Asia, including South Korea, third overall; India at fourth; Singapore at seventh; and Japan, which is 10th.

Once here, students can select from hundreds of classes on Asia-related topics ranging from language instruction to religion to history, from governance to business to global health, from art to energy to engineering to a host of others.

Most other Harvard students don’t stay put for their entire academic careers, either. Harvard students travel abroad with increasing frequency, with China the most popular destination by far, according to Dominguez.

Research opportunities are numerous and are supported by several regional centers and institutes that cover Asia and South Asia, including China, through the Fairbank Center, Japan, through the Reischauer Institute, and Korea, through the Korea Institute. Chinese studies are fostered further through the China Fund, an academic venture effort that promotes research on topics important to the nation. These regional programs can help to coordinate work from researchers across the University. In January, for example, the South Asia Institute (SAI) spearheaded a cross-disciplinary, University-wide effort to visit and conduct research at India’s Kumbh Mela, a religious gathering that occurs only every 12 years.

Perhaps the grandfather of such efforts at American universities also resides on Harvard’s campus: the Harvard-Yenching Institute. Founded in 1928 as an independent foundation with close ties to Harvard, the institute was begun in collaboration with Yenching University and several other Chinese colleges that were closed by the government in the 1950s. The Institute at Harvard survived closing by broadening its attention to other East Asian countries before again including China after it reopened to the United States in 1979.

Today the Institute, whose Harvard-run library has the most East Asian materials of any university outside East Asia, sponsors some 50 scholars from Asia to study at Harvard each year. The institute is headed by a Harvard faculty member, Rosovsky Professor of Government Elizabeth Perry, and also supports faculty and advanced graduate research and training programs, both at Harvard and at its 50 partner universities in Asia.

“China is one of the world’s great civilizations and today boasts the second-largest economy in the world, in terms of importance and status,” Perry said. “It’s absolutely important, critical that students have the opportunity to learn about China and about East Asia more broadly.”

Across Harvard, in museums and collections, thousands of objects from Asian nations are on display and used by researchers. This watercolor (above, detail) is from Rajasthan, the largest state in India. Courtesy of Harvard Art Museums/Arthur M. Sackler Museum

Significant exchange of material

In addition to the exchange of knowledge between Harvard and the countries of Asia, a significant amount of material has also been exchanged. Across Harvard, in museums and collections, thousands of objects from Asian nations delight viewers when put on display and enlighten researchers who study the collections.

Those collections extend beyond the arts to science. The fruits of Rock’s three-year collecting trip are still available to scholars nearly 90 years later, in the dried plant collections at the Harvard University Herbaria, the prepared bird skins at the Museum of Comparative Zoology, and at the Arnold Arboretum, where the living specimens Rock brought back — butterfly bushes, cotoneasters, and dragon spruce among them — still grow and fruit each fall. Rock would return to China, working there while a research associate and fellow with the Harvard-Yenching Institute in the 1940s.

The Arboretum itself is something of an East Asian botanical stronghold, and in it Harvard’s commitment to Asia literally grows each year. The Arboretum is a living collection of tree and shrub specimens from around the world, with an emphasis on the United States and East Asia. In fact, specimens from China, Japan, and South Korea together outnumber U.S. specimens more than 2,800 to 2,094 — a slice of East Asia in Boston’s Emerald Necklace.

To read more Asia coverage, visit Global Harvard.

While the sixteen plants that currently make up the Larz Anderson Collection are not the oldest dwarfed plants in the United States, they have been under cultivation longer than any other examples currently growing in North America—with the lone exception of three plants at the Brooklyn Botanic Garden that were imported in 1911. The Arboretum plans a number of special events this fall to celebrate the beauty and historical importance of this singular collection of dwarfed plants; details will be announced this spring. Currently off display for the winter, the collection will return to public view in April.

“Plants have a wonderful way of reminding us how lucky we are to be here, how lucky we are to sit on 3.5 billion years of evolutionary history and be here to have this conversation,” William Friedman, director of the Arnold Arboretum, said Monday during a talk at the Hunnewell Building.

The world we live in was produced by many evolutionary steps, and some of those steps have been taken many times by different organisms. Arborescence — changes in plants that create towering trees — evolved five times over 20 million years, for example. But there were two important changes that have occurred only once in the evolutionary record, and we have the precursors of plants to thank for both, Friedman told an audience of about 100.

The first happened early in Earth’s history, when the atmosphere contained no oxygen. Bacteria used photosynthesis to harvest energy from the sun, but the process was different from what we see today in plants, Friedman said. Early photosynthesis used hydrogen sulfide instead of water and gave off sulfur instead of oxygen. The key evolutionary step, Friedman said, was the switch to a process that used water and released oxygen into the atmosphere. The switch eventually created oceans full of photosynthetic bacteria — cyanobacteria — that pumped oxygen into the atmosphere.

Algae from Rwandan water lilies is examined under a microscope in one of the Arnold Arboretum’s labs.

“That was a major event in the history of the Earth,” Friedman said. “Cyanobacteria, they set the agenda for everything that comes afterward.”

The second major evolutionary jump, Friedman said, was the leap of an aquatic plant onto land, some 475 million years ago. Microbial life had colonized the land earlier, but it was the movement of plants onto land that created a food source that allowed animal life to follow. That movement occurred just once, Friedman said, when a single lineage of green algae survived on the ocean’s edge. It evolved into primitive plants like today’s liverworts and mosses, and gave rise to the large variety of land plants we know today.

“Our history is tied to these rare, extraordinary events,” Friedman said.

Friedman’s talk was the first in the Arboretum’s spring Director’s Lecture Series. He showed slides of some of the diversity of microbial photosynthetic life and also talked about the importance of another process, symbiosis, in complex plant life.

Modern plants owe their existence to an ancient act of symbiosis, when an early single-celled ancestor engulfed a photosynthesizing cyanobacterium. In this instance, the cyanobacterium was not digested and instead became part of the cell. It eventually became the chloroplast that performs photosynthesis in plant cells today.

“All the acquisition of photosynthesis in eukaryotes was not an innovation in chemistry, it was an innovation in symbiosis,” Friedman said.

The next talk in the Director’s Lecture Series, “Biodiversity 2013: Crisis and Opportunity” by Harvard Professor of Biology and Alexander Agassiz Professor of Zoology James Hanken, will be held on Feb. 25 at 7 p.m. The lecture is free, but registration is requested. Visit the website to register and view upcoming lectures.

For Iñaki Hormaza, a research associate of the Arnold Arboretum and professor at the Mayora Research Station of the Spanish Council for Scientific Research (CSIC), this phenomenon provides an opportunity to study how plants regulate their biological functions. “As temperatures start to drop after summer,” he explains, “flower buds enter a dormant stage to help them to survive harsh winter conditions.” The duration of this dormancy is specific for each plant, but usually lasts the entire winter. “Once the plant has accumulated its required number of cold hours,” he adds, “warmer temperatures induce flowering.”

There are living fossils and dying icons. There are locusts and larch, hackberry and holly, Kentucky coffee and catalpas. There are colors in autumn, rebirth in the spring, and shade in the summer.  Even amid winter’s winds, rough bark reminds us of the life asleep inside as we scurry past.

The trees of Harvard Yard have for centuries shielded student travels. They’ve roofed the Yard and framed its iconic image. All one has to do is imagine the Yard barren and treeless to understand that trees are as much a part of that landscape as its historic buildings and John Harvard’s brass toe.

And, like much of the University in this globalized age, the trees of the Yard are changing.

The Yard is approaching the end of an era, when elms — once thought the perfect trees for civic plantings because of their vaselike shape — graced and dominated the Yard.

The sad story of America’s elms is well known. Loved for their high-branching pattern that creates a shady canopy above and a parklike setting below, the tree was planted everywhere, making fertile ground for Dutch elm disease when it arrived in the 1920s.

In the disease’s wake, the Yard has undergone a quiet renovation over the past several decades. As elms have died, they’ve been replaced with other trees that will retain the Yard’s parklike setting. In the old Yard, large oaks stand side by side with the elms. In Tercentenary Theatre, where Commencement and other ceremonial events occur, large honey locust trees mix with maples and elms to provide a ceiling for campus affairs.

There are still elms left, but hundreds have given way to tens. Harvard groundskeepers fight the good fight, deploying fertilizer, fungicide, and careful pruning, but the Yard’s remaining elms are locked in a battle that will likely claim even the strongest of them.

“They’re survivors, but as survivors, they show their wear,” said Donald H. Pfister, the Asa Gray Professor of Systematic Botany. “They’re trimmed very severely. They’re pampered. Fungicides are used to treat them. Each year, there are fewer elms in the Yard.”

The result is a Yard that today looks a lot more like the forests surrounding it. American species have dominated the replanting, Pfister said, which has proceeded with an eye toward diversity in creating a mixed stand resistant to pests and diseases, and toward uniformity in retaining the Yard’s historic look.

“There’s a collective [reaction of visitors], that is, ‘Of course this is what it’s supposed to look like. You’re supposed to be able to see students walking through. You’re supposed to be able to look across from Johnson Gate to see John Harvard,’ ” Pfister said. “Those are characteristics of the Yard and how the Yard has been illustrated in its iconic past.”

Though planting native American trees has been emphasized as the Yard is remade, not all the plantings are native. In the small area between Robinson Hall and the Memorial Church is a stand of dawn redwoods, which Pfister called “living fossils.” The trees, conifers that lose their needles in the fall and whose brown trunks look almost muscled, were first known from fossils and were thought extinct until living specimens were found in China in the 1940s. Harvard played a role in the tree’s resurgence. Seeds were collected and cultivated at the Arnold Arboretum. Specimens today have been planted around the world.

The Yard’s trees change on a smaller, more expected scale as well. In his travels across the Yard, Pfister marks the seasons by the changes he sees, whether leaves are budding out and flowers blooming, whether fruits are growing or falling on the ground. He even gets a kick out of the walnuts’ ongoing battle with the automobile, acted out each fall as trees overhanging Quincy Street bombard the cars parked below.

“The Yard is ever-changing,” Pfister said. “One sees different things, depending on the season.”

For Pfister, the Yard’s trees are as much a part of Harvard as its buildings and people. They frame the activities of students and faculty, and perhaps should join the Yard’s ghosts in their “long winding train reaching back into eternity,” spoken of by writer Ralph Waldo Emerson in his verse inscribed near Meyer Gate.

“You can think about the Yard that way too … the trees under which people played,” Pfister said. “The activities of the College take place under them, Commencement takes place under them. [Students] leave, we [faculty] stay for a while. The trees are here for much longer.”

Behold, the noble pigeons.

Students taking the “Getting to Know Darwin” freshman seminar visited the home of Jim Spring, a pigeon fancier in Sutton, Mass., to observe his “Birmingham Roller” pigeons in action. Rollers are competitive birds whose talent involves completing a series of continuous tumbles in a midair free fall. Spring has been breeding, flying, and competing through his birds for more than 50 years.

“Pigeons have probably been around for millions of years,” Spring said. “Over the years, mutations have resulted in unique differences, and man has cultivated those mutations for his benefit and his pleasure. There are different types of competitions for pigeons — birds bred to race hundreds of miles to their homes, for example — but my competition birds are tasked to fly up in the air, conduct a certain gymnastic move, and then awarded points based on how well they execute those moves.”

In organizing the trip to Spring’s home, William “Ned” Friedman, Arnold Professor of Organismic and Evolutionary Biology and director of the Arnold Arboretum, was in a way mirroring the research of legendary biologist Charles Darwin himself. In the 19th century, coal miners in Birmingham, England, began to capture, breed, and compete using pigeons that were adept at initiating and then pulling out of sudden, tumbling falls.

Friedman’s interest in Spring’s Birmingham Rollers dovetails with the in-depth research that Darwin gathered from pigeon fanciers across Britain, research that helped him eventually to write “On the Origin of Species.” In reading Darwin’s extensive correspondence — many letters from which are now online as part of the Darwin Correspondence Project — the students got a glimpse into the important connection between Darwin’s work and the hobby of pigeon fanciers.

“Darwin not only wrote about pigeons, he bred them himself,” Friedman said. “The first chapter of ‘On the Origin of Species’ has a whole section on pigeons. He was trying to convince the world that natural selection occurs, so he used the extensive domestication histories of pigeon fanciers. ‘On the Origin of Species’ opens with an argument that asks: If you can do this much with pigeons in mere hundreds of years, what could be possible with tens of thousands and millions of years? He was gathering his evidence and preparing his arguments so that they would be accessible to a broad swath of British society.”

After examining the Sutton birds’ markings and wings, the Harvard class gazed heavenward as Spring released about 20 pigeons from their coop. The birds immediately flocked together and began to climb ever higher as a group. When 10 birds broke free from the flock as one, tumbling wing-over-claw in an acrobatic plummet toward the earth, the freshmen gasped in chorus. As one pigeon suddenly rolled about 50 feet, Spring likened the bird’s spontaneous decision on when to roll to a school of fish suddenly turning as a group.

Asked how he got the birds to perform, Spring responded, “Breeding, training, and flying Rollers presents many challenges. One must be, to a degree, a veterinarian, nutritionist, personal trainer, sanitarian, geneticist, weatherman, and animal husbandman in order to achieve the desired result in the air. Constant observation of the birds and making changes in feed and flying frequency as deemed necessary are paramount to a successful program. It is these challenges that keep Rollermen around the world striving to improve the breed.”

As the class prepared to return to campus, Friedman and the students remained transfixed by the birds’ spectacular showcase. “Thank you for an extraordinary experience,” Friedman said to Spring. “Your explanations, showing us the birds, seeing them in action — that was more than I dreamed possible. None of us will ever forget it.”

The disruption and recovery of an ecosystem after the introduction of a new pest species is a natural process that has played out before in the region, according to Harvard Forest Director David Foster. Reconstructions of the region’s forested past have shown dramatic declines of hemlock and oak 5,000 years ago, likely related to the interplay of climate change and insect pests.

The historical evidence, however, also indicates that forest-transforming diseases and pest outbreaks are also naturally rare, giving forests time to recover between episodes. That leisurely pace has been lost since the mid-1800s. Since then, 400 new species of insects have been introduced into the region, and new diseases have taken an enormous toll.

Northeastern forests have lost what was a dominant tree, the American chestnut, a forest giant that stood up to 150 feet tall and 10 feet in diameter. Chestnut blight, imported from Asia, killed billions of trees and eliminated what had been an important food source for a host of animals. Similarly, Dutch elm disease has devastated American elms, another large forest tree that had been heavily planted in cities and towns.

“Many towns have Elm Streets. Most Elm Streets have no elms on them,” said David Orwig, a researcher at Harvard Forest specializing in invasive species.

Orwig and Foster spoke about invasive species’ effects on New England forests during a Sept. 19 talk at the Harvard Museum of Natural History. The session, co-sponsored by the Arnold Arboretum, took place in the Geological Museum building.

New England forests face a veritable “who’s who” of pests and pathogens, Orwig said. Front and center are insects that have been in the news recently, including the hemlock woolly adelgid, the Asian long-horned beetle, the winter moth, and the emerald ash borer.

The hemlock woolly adelgid, a tiny, sap-sucking insect originally found in Japan, is spreading across New England and attacking another of the forest’s large trees. The evergreen hemlock, which grows to 100 feet tall and 5 feet in diameter, has shown no resistance to the pest, which also has no known native predators.

The loss of the hemlock is important, Orwig and Foster said, because it is a species that controls the nature of the forest around it. Loss of hemlocks creates an opening that black birch seem to be most commonly filling, triggering a cascade of changes in soil, vegetation, and animal composition. The only control on the pest has been northern winters, but temperatures have to be well below zero to kill the bug. The pest has “really blown up” this summer owing to last winter’s warm temperatures, Orwig said.

The Asian long-horned beetle has been in the news a lot recently, with an outbreak near Worcester causing the felling of 30,000 trees, and a smaller outbreak in Boston leading to the felling of six trees. The beetle’s ability to infest several host species worries officials, though drastic control measures have so far appeared to be effective. The difference in the number of trees felled in Worcester, where the infestation was advanced, and Boston, where it was just beginning, illustrates the importance of catching infestations early, Orwig said.

The emerald ash borer might be the most worrisome pest today, Orwig said. It is a good flier that rapidly kills ash trees. In just 10 years, it has killed millions of trees in 18 states, including Massachusetts, where an outbreak was detected in the southwestern part of the state this summer. Eight billion trees are threatened.

“That’s an incredible spread in 10 years,” Orwig said. “The emerald ash borer, in my opinion, is out of control.”

The winter moth is another worrisome pest that infests hardwood trees. It is found in Massachusetts and has spread from 15,000 acres in 2009 to 88,000 acres in 2011.

Responses have taken a variety of forms, including biological controls that focus on finding native predators or diseases from their home country and introducing them to the area. That doesn’t always work, however, and carries the risk of unexpected side effects, such as the newly introduced control insect also feeding on other native species. Control with chemical pesticides and fungicides can also work, but is usually limited to smaller landscaping uses rather than forest-scale preservation efforts.

Cutting infested trees, either to remove the threat or salvage wood, can be effective, as it appears to have been with the Asian long-horned beetle, but it can also backfire, removing potentially resistant individual trees, which might be the foundation for a recovering population, along with those infected.

“Sometimes our choices can make the situation worse. We need to be cautious about knee-jerk reactions,” Orwig said.

It was a final action project in a food justice initiative at the Mission Hill Summer Program, which is supported by Harvard College students. The initiative brought together camp counselors, gardeners, local chefs, and other community organizations, like the Roxbury Environmental Empowerment Project (REEP), to create a meaningful summer experience for young people.

“It’s powerful for kids when they see teens and adults from their own community who are engaged around important issues like bringing healthier food to the neighborhood,” said camp director Jane Wang Williams ’13, who brought the idea of food justice to the camp this summer and fostered partnerships with community members to create the project.

The seed bombing was one of the learning moments at 12 Phillips Brooks House Association Summer Urban Program camps peppered across Boston and Cambridge. The camps were coordinated, run, directed, and taught by about 120 college students, offering summer learning and community building activities for 850 children. The camps also employed more than 100 local teens in partnership with the Boston Youth Fund and the Cambridge Mayor’s Summer Youth Employment Program. (Harvard employed more than 150 local youths this summer.)

Even though it was summer, Boston and Cambridge neighborhoods and the campus were alive with Harvard activity. Students, faculty, and staff from the University brought community members and students into classrooms, performing spaces, and parks — extending teaching and learning beyond Harvard Yard in partnership with local organizations and neighborhood schools.

On campus, the Harvard School of Engineering and Applied Sciences (SEAS) hosted “Kids’ Science and Cooking,” a new program that built upon the popular undergraduate “Science and Cooking” course. Boston and Cambridge students from ages 9 to 12 attended a two-week day summer program, learning from Harvard scientists, mathematicians, and top chefs about pickling, emulsion, fermentation, and more.

Kathryn Hollar, director of educational programs at SEAS, said the goal of the program was to “give these kids the tools and empower them to make good decisions, and to teach that science and math is everywhere. We want to show that our scientists are very curious, and want our young people to be curious too.”

For the ninth straight year, the Crimson Summer Academy (CSA), a program that helps talented, low-income high school students gain access to top colleges and universities, hosted a class of local sophomores, juniors, and seniors on the Harvard campus. While the average family income of most scholars is $28,000, all 158 program graduates have gone on to college. Some scholars, such as Suryani Dewa Ayu ’15, who graduated from the program in 2010, have gone on to attend Harvard.

“CSA is such a phenomenal program,” Ayu said. “It’s a network of people who really support each other, who are constantly in contact, checking up on you, encouraging you, and seeing how you’re doing. I’m so glad to be here as a mentor, interacting with the kids.”

While Crimson Scholars were delving into science, qualitative reasoning, and writing, even pitching their original prose at a poetry slam, nearly 300 local high schoolers were getting an academic boost up the street at Cambridge Rindge & Latin School.

The Cambridge Harvard Summer Academy (CHSA) is a free summer school, a partnership between the Harvard Graduate School of Education (HGSE) and the Cambridge Public Schools, where students work closely with teachers-in-training and veteran teachers as they prepare classwork and get ahead for the next school year.

In Allston, the Harvard Allston Education Portal offered mentoring in science, math, and writing to Allston-Brighton children and youth for the fifth consecutive summer. In addition, community outreach and programming for the Harvard Allston Farmers’ Market and the Ed Portal Annex healthy eating series continued, with participation from Harvard Medical School and Harvard College undergraduates.

Deeper into Boston, the Arnold Arboretum of Harvard University invited local citizens to participate in “tree mobs,” which are 20-minute, in-depth information sessions about individual trees in the arboretum. “It’s about getting back to learning about the biology of plants in a fun way,” said Arboretum Director William (Ned) Friedman. “This is about meeting an organism — to be in a spot and open people’s eyes to an aspect of the collection they may have never noticed before.”

“From college prep courses to continuing education, community partnerships to summer jobs, Harvard offers a broad range of opportunities to local residents during the summer,” said Christine Heenan, vice president for Harvard Public Affairs & Communications. “Over three short months, thousands of people of all ages came together to learn, explore, and build community, making the summer a little livelier on campus and strengthening our ties with our neighbors.”

— Jennifer Doody contributed to this story.

Already a part of the Arboretum’s equipment arsenal, the air knife requires the use of a large tow-behind air compressor for its operation, which until now has been rented for specific projects. With the acquisition of the air compressor unit, the horticulture staff can exercise greater flexibility and efficiency in using the air knife as a part of its standard operations for plant care and health.

“The Arboretum’s collections represent an invaluable resource to science as well as the visiting public,” said William “Ned” Friedman, the Arboretum director. “Everything we do in research and education revolves around the 15,000 curated organisms in our landscape, so ensuring their vigor and long life is absolutely essential. We’re delighted to have the kind support of the Arnold Arboretum Committee to help us make the most of our efforts to improve the condition of our plants.”

They know it was rooted and planted by Peter del Tredici, who in 1989, as a Boston University doctoral student, took a four-inch cutting directly from one of the few remaining wild ginkgos in eastern China. They know it is one of 55 ginkgos growing in the Arboretum today. They also know it has the potential to live 1,000 years.

But even del Tredici, now a senior research scientist at the Arboretum, doesn’t know everything about the tree. That’s why del Tredici and Arboretum Director William (Ned) Friedman are collaborating with counterparts at the University of Colorado to learn more. Scientists in late June spent three days high off the ground, hoisted by the Arboretum’s bucket truck. Head arborist John Del Rosso and Colorado research associate Jon Leff collected 100 samples of the tree’s microbial life, the location of each swab painstakingly recorded with 10 different variables by Colorado graduate student Samantha Weintraub.

Friedman said the project is part of the first-ever effort to define the entire community of microbes — the “microbiome” — of a tree. Microbiome research made headlines this spring when a consortium of scientists published the first human microbiome, detailing the microbial community of healthy humans. That research emphasized that the trillions of microbes from some 1,000 species aren’t just along for the ride, they play important roles in digestion, immunity, and other bodily functions.

The microbiomes of plants are largely unknown, Friedman said, and the project will help scientists understand what kinds of microbes are living on the tree and whether the microbial communities vary according to location (trunk versus leaves, for example), amount of sunlight (north versus south side), or other factors. Comparisons with wild ginkgos in China and with other tree species should show whether geographic location — New England versus China — or species identification — ginkgos versus pines, for example — plays a role in determining microbial community.

The Arboretum, which holds an extensive collection of East Asian trees, is an ideal location for samples to be collected, Friedman said. Much of the analysis will be done in the Boulder lab of Noah Fierer, an assistant professor of biology with whom Friedman worked before leaving the University of Colorado for Harvard in January 2011.

“We’re at such an early stage of microbiome work, we really don’t know what we’ll find,” Friedman said. “I won’t be surprised if we find some new species, maybe some whole new groups.”

On a day off, Jack Wittenberg briefly joined the “Tree Mob” with senior research scientist Peter Del Tredici at the Stewartia collection, which dates from 1918. Wittenberg, a fan of Harvard’s Arnold Arboretum since the years when his mother convalesced nearby, didn’t have to sign up in advance or make a big time commitment.

“I come to interesting things here and you know with Peter it’s the final word,’’ he said.

Amy Galblum said she decided to swing by the 5:30 p.m. gathering en route from her job in Brookline to her home in Roslindale. “I bike through here, and I didn’t realize there were so many Stewartias and that they are so varied.”

Many botanical gardens give tours and offer classes about their collections, but that is not enough for Arboretum Director William (Ned) Friedman, who took the helm of the oldest public arboretum in North America in January 2011.

“You can go to collections and see everything has a binomial [scientific name] and be around people who know the name of every cultivar, but that’s not the same as rejoicing in the biology and the stories of these plants,” said Friedman.

Friedman took the whimsical concept of a flash mob — a social media–driven spontaneous gathering — and applied it to outreach to the public to encourage interaction with the scientists, curators, and horticulturalists who work on the Arboretum’s 265 acres.

“I just hatched it, I’ve never heard of anything quite like it,” Friedman said of the Tree Mob concept. “It goes at what I’m trying to do — move away from some of the formality in the collection that comes with a tour, a lecture, or children’s education.”

Tree Mob attendees may be alerted by a sign or may notice a group gathered. They may drift by for only a few minutes of the presentation or they may stay for its entirety.

“It’s about getting back to learning about the biology of plants in a fun way,” said Friedman, who led a mob on the evolutionary development of thorns on a rainy 40-degree day. The 20 people in attendance asked him questions well after the expected 15-minute duration.

“This is about meeting an organism, to be in a spot and open people’s eyes to an aspect of the collection they may have never noticed before.”

The next Tree Mob, “Locust, Legumes, and Nitrogen Fixation,” is 5:30 p.m. July 19 and is hosted by horticulturalist and Arnoldia Editor Nancy Rose. Rose will discuss how plants and bacteria partner to produce fertilizer. For more information, visit the Arnold Arboretum website.

Henry Young '52 and his wife Chris Young of Andover, Mass., join others for the Arboretum's Tree Mob event last week.

Friedman’s plan is to increase the number of tree mobs so that they remain intimate and spontaneous.

Del Tredici, an Arboretum scientist since 1979, admitted he was dragged “kicking and screaming” into Friedman’s initiative of Tree Mobs and the mobile tour concept that lets anyone with a cell phone give themselves an informative tour of the prestigious collection.

But his deep knowledge about the collection in general and specifically about the new hybrid of Stewartia — Scarlet Sentinel — developed in the Arboretum, is compelling for mob attendees.

“You can come here and see these plants, but you don’t know anything about them. You could hold your cell phone up [to the bar codes on the signs posted by many plants]. But it’s better to have someone tell you,” said Del Tredici.

He showed the group a half dozen varieties of the camellia-like flowers that were blooming on the woodland trees, with anthers — the filaments holding the stamen — that vary from lavender to mustard yellow. And the bark of the trees, which hail from China, Japan, Korea, and North America, ranges from a mottled desert camouflage to the thick, scaly husk typically seen on deciduous trees.

The white or pink blooms and interesting bark make the Stewartia a sought-after garden acquisition, but many did not survive until plant propagators at the Arboretum unlocked some of the mysteries of growing them. That’s why Del Tredici found himself fielding questions from his group about how to ensure their survival in a typical garden. “It is kind of ‘miffy,’ like it is easily miffed if something is not quite right.”

The Tree Mob participants range from ardent gardeners to city dwellers seeking refuge from the blazing asphalt of a summer day. But one reality that has come with promoting the events is that participants are apparently not Facebook and Twitter devotees.

Pamela Thompson, manager of adult education, said attempts to use social media to invite people to the Tree Mobs largely fell flat. But success has come from posting signs close to the event on the Arboretum grounds and notifying the email list of more than 7,200, she said.  Without the need for much lead time, the Arboretum can respond to weather and blooming patterns to come up with a last-minute mob, she said.

The rewards of that spontaneity hit home for Thompson one evening when she was in a tiny mob with Friedman that spent 20 minutes watching a magnolia open.

“You look at it and you think nothing’s moving and then it’s like, ‘Wait a minute, did that petal move?’ and then it just popped open.”

Though many people take in the scene without a second thought, a group of 10 students from Norfolk County Agricultural High School wanted to learn about the work behind it. So they listened intently despite Wednesday’s heat as Paul Smith of Harvard’s Landscape Services talked about organic techniques implemented in recent years that are not only more environmentally sustainable but also ensure a healthier Yard.

Smith showed students how Harvard landscapers brew organic “tea” — a mix of compost and other ingredients — in a large water drum near Phillips Brooks House, and talked about soil compaction and root growth and soil microbes. When spread on the Yard’s grassy lawns, the tea promotes a healthier microbial community in the soil.

The students were part of a four-week program — a partnership between their high school and Harvard’s Arnold Arboretum — providing a capstone for their junior year. It blended hands-on work at the arboretum, lectures at a nearby community college, and excursions like Wednesday’s to the Yard and a recent visit to Franklin Park Zoo to see the nearly five-foot-high “corpse flower” in all its stinky glory.

“It’s been a wonderful experience,” said Marc Mertz, an urban forestry instructor at the school and one of the program’s organizers. “The goal is to expose the kids to real-world working conditions and to have an educational component. It makes sense to work with one of the world’s foremost arboretums.”

Kieran Clyne (left) and Paul Smith of Harvard Landscape Services showed the visiting students organic landscaping techniques.

Stephen Schneider, the arboretum’s manager of horticulture and another organizer, said the kids spent most of their time at work in two of the arboretum’s collections. Directed by experienced horticulturalists, the students put in new beds and tended existing beds in the three-acre Leventritt Shrub and Vine Garden and also tended the arboretum’s crabapple collection, in the last year of a major refurbishment.

Schneider was impressed with the students’ enthusiasm and focus during the four weeks.

“I wasn’t this focused as a high school junior. These guys are like lasers,” he said. “This is the prime time to grab their attention — this time of their lives. We know their basic interest is in plants and we want to cultivate that one way or another.”

Though tending the trees and other plants spread across its 265 acres is a major focus, the arboretum also has research and educational goals. Programs such as the one with the Norfolk County Agricultural High School help the arboretum meet the educational portion of its mission, Schneider said.

Sam Sternweiler, a junior who plans to pursue a business degree after high school, said he was interested in landscaping techniques used at the arboretum and in learning more plant identification.

“The arboretum is a world-class place to learn landscape techniques and plant identification,” Sternweiler said. “It was amazing. I wish I didn’t have to leave.”

The Katharine H. Putnam Fellowships in Plant Science are made possible by the generosity of George and Nancy Putnam through the Putnam Fellows Fund.

Born in China, Hu graduated from Ginling College in Nanking in 1933 and received her master’s degree from Lingnan University in 1937. In 1949, she became the first Chinese female to obtain a doctoral degree in botany at Harvard, and worked as an herbarium assistant at the Arboretum. Named a research assistant by Arboretum Director Richard Howard in 1953,  Hu devoted herself full time for the next four years to the Flora of China Project. In 1968, Hu took up the position as senior lecturer in the Department of Biology of Chung Chi College and continued her work investigating the botanical diversity of Hong Kong. She was appointed adviser to the Sunyatsen Botanical Garden in Nanjing, honorary professor of South China Agriculture University in Guangzhou, adviser to the Fairy Lake Botanical Garden in Shenzhen, and honorary professor of Chinese medicine at the Chinese University of Hong Kong in 1999.

They set out on the provincial sloop, under orders from Massachusetts Bay Gov. Francis Bernard to convey them to Newfoundland, North America’s easternmost settlement, so that Winthrop could view one of nature’s rarest astronomical phenomena: Venus’ passage across the face of the sun.

Called a “transit of Venus,” the event is an eclipse of the sun by Venus. In this case, however, Venus appears as a black dot that tracks a line across the sun’s face for several hours. On June 5 of this year, skywatchers around the world will watch the sun to catch a glimpse of the same event, which remains a curiosity for many, even if it has lost much of the scientific importance it bore when Winthrop voyaged to Newfoundland.

“As an amateur astronomer as a kid I read about this thing that was so far in the future,” said Owen Gingerich, professor of astronomy and of the history of science emeritus. “I thought, wouldn’t it be neat to see something so rare?”

Transits of Venus occur in pairs, eight years apart, separated by more than a century. Winthrop’s transit in 1761 was followed by one in 1769. The next pair occurred in 1874 and 1882, and the most recent was in 2004. The next transit after this month’s won’t occur until 2117.

Gingerich traveled to Sicily with his wife to view the 2004 transit because it could be viewed in its entirety in Europe. This year, Gingerich is traveling to California to view it. Here at Harvard, the Harvard-Smithsonian Center for Astrophysics (CfA) is holding an event at 6 p.m. on June 5 to view the first part of the transit, which will begin just before sunset. The Arnold Arboretum is also marking the occasion on May 30, with a talk by historian Andrea Wulf on her book about the 1761 and 1769 transits.

The 2004 transit had some scientific merit and was used to test techniques to find planets circling other stars. But the earlier transits were international scientific events. In particular, the transits in the 1700s generated an enormous amount of interest because, if observed carefully, the passage of Venus across the sun could be used to determine the then-unknown size of the solar system.

“This would give us a just idea of the vast dimension of the solar system and the mighty globes which compose it,” Winthrop wrote in his account of the Newfoundland expedition, “Relation of a Voyage from Boston to Newfoundland for the Observation of the Transit of Venus.”

Before the 1761 transit, the event had been observed only in 1639. In the intervening years, Edmond Halley had proposed a way to determine the distance from the Earth to the sun using measurements of the transit of Venus from two distant places on Earth. A key factor in the calculations was the difference in the time it took Venus to cross the sun’s surface, as viewed at the two locations.

Halley died before the 1761 transit, but his exhortations to his scientific colleagues were heeded.

“From a sense of the advantages to be derived from this observation, Dr. Halley recommended it in the most emphatical terms, and inforced it with all the energy of language, on the Astronomers and others of the present day, that they would by no means let slip an opportunity,” Winthrop wrote. “And to put the matter beyond all hazard, he advised to have a number of Observators stationed in different parts of the Earth, that some of them might be sure to succeed; as a single person might be frustrated by the intervention of clouds.”

That 1761 transit was invisible to most of North America, because it occurred before sunup over large swaths of the land. Winthrop’s trip to Newfoundland was spurred by his desire to see the last part of it, visible only from the continent’s easternmost part.

Winthrop’s account details landing at St. John and searching for a suitable home where his group could set up, only to be stymied by hills to the east. They ultimately hiked over the hills and set up tents to wait for the event, amid an unrelenting horde of insects that “persecuted us severely, without intermission, both day and night, with their venomous stings.” Because accurate timekeeping was of the essence, they brought a large grandfather clock from Harvard — on display today in the Science Center’s Putnam Gallery — which they fixed to a post driven into the ground, and set to wait.

“Thus prepared, we waited for the critical hour, which proved favorable to our wishes,” Winthrop wrote. “The morning of the 6th of June was serene and calm. The sun rose behind a cloud that lay along the horizon but soon got above it; and at 4h 18m [4:18 a.m.] we had the high satisfaction of seeing that most agreeable sight, Venus on the Sun.”

Winthrop took his measurements, sharing the view with “gentlemen of the place, who had assembled very early on the hill to behold so curious a spectacle.”

Science would be stymied, however, by the inexactness of the instruments of the day. The global scramble would be repeated in 1769 by a group that included, among others, Capt. James Cook, who voyaged to Tahiti to view the transit. A 1771 estimate of the distance from the Earth to the sun employing multiple measurements from both transits came in not too badly, at 95 million miles. The estimates would be refined to very close to the known value of 93 million miles a century later, after the 1874 and 1882 transits, the latter of which was observed at Harvard by a group of astronomers led by Observatory Director Edward Pickering.

The Center for Astrophysics will hold a special rooftop viewing of the Venus transit beginning at 6 p.m. June 5. No reservations are required. The transit will be visible from 6:03 until the sun sets at 8:19 p.m. (If weather is inclement, the center will still show the transit via webcast in Phillips Auditorium.)

The Arnold Arboretum will have a talk by historian Andrea Wulf on her book about the 1761 and 1769 transits, “Chasing Venus: The Race to Measure the Heavens.” Pre-registration is required to attend the  7-8:30 p.m. Wednesday event.

“I’ve lived in Jamaica Plain for about six years, but this was my first visit to the Arnold Arboretum,” she said. “I had such a wonderful morning with my kids, Kingston and Khalesi, and it was great to be surrounded by so many other families enjoying the day.”

Now in its 104th year, Lilac Sunday has become a time-honored tradition for families to celebrate Mother’s Day at the Arboretum, which boasts more than 15,000 woody plants on its 265-acre landscape. This year, the event included tours of the Arboretum’s other collections, including the Bradley Rosaceous Collection, the Leventritt Shrub and Vine Gardens, and the Explorers Garden.

Maggie Redfern, Explorers Garden tour guide and visitor education assistant, said the day was an opportunity to connect with multiple generations of Bostonians, some of whom were new to the Arboretum. “Half the people on my tour had never been here before,” Redfern said. “We had two teenage girls in our group, as well as their mother and grandmother.”

It’s that opportunity to encourage lifelong learning, and expand the understanding of the Arboretum in the community, that William “Ned” Friedman, director of the Arnold Arboretum and Arnold Professor of Organismic and Evolutionary Biology, finds so rewarding.

“It’s incredibly important for the Arnold Arboretum of Harvard University to be much more than a collection to come and look at,” Friedman said. “We are part of a university whose mandate is to share and educate with all of the incredible resources that Harvard can bring to bear. We’d like our visitors to learn more about the evolution that underpins all modern biology, the dangers of invasive species that can destroy entire ecosystems, as well as benefit from the aesthetics of our biodiversity collections. Our evening public lectures, guided tours, volunteers, and scientists are central to sharing our unique resources and insights with our neighbors of all ages in the Greater Boston area and beyond.”

Julie Warsowe, manager of visitor education at the Arboretum, agreed. “Beyond Lilac Sunday, we want to reach a broad audience. We have fun science activities for families, interpreters in the landscape who can help visitors learn more about plants – we want to reach all those casual visitors who may have come for a social experience, and give them the opportunity to connect and have a deeper, richer, and more informative experience.”

To that end, the Arboretum has launched several new programs to engage and educate the community. Two mobile applications provide information on many of the Arboretum’s trees. Next month, the Arboretum will roll out a new international month program, which will provide tours of the living collections in 10 languages. The Arboretum has also launched a “tree mob” program offering 15-minute lessons on its amazing organisms.

The initiatives, Friedman said, are all “part of our effort to exceed expectations and surprise. When you come to the Arboretum, whatever you were expecting, we want you to get even more.”

Saint’s first Lilac Sunday made such an impression that she’s already considering options for the 105th celebration next year. “I might even start a tradition of having a picnic with other moms and their families,” she said. “I’ll definitely come back.”

All accessioned plants at the Arnold Arboretum are mapped, documented, and tracked by staff with the help of a collections database, BG-BASE. Until recently, availability of this data was restricted to complex software systems used by Arboretum curation staff, or locked away in paper files. Last fall’s launch of Collections Researcher represented a leap forward in sharing this information globally by linking Arboretum data with a powerful GIS (geographic information system) for desktop explorations of the Arboretum. This week, the Arboretum marks a further milestone in this effort with the release of test versions for two software applications that map the Arboretum’s accessioned plants on mobile devices.

These mobile applications are Arnold Arboretum Navigator and Mobile Collections Researcher, and are introduced for public testing as part of festivies celebrating Lilac Sunday on May 13. Arnold Arboretum Navigator allows users to locate plants in the collection and and is compatible with most smartphones currently available. Though limited in functionality at this time, future versions will deliver features consistent with those available in our second application, Mobile Collections Researcher. This second tool is optimized to function using the latest technology from Android manufacturers and Apple’s iOS platforms for iPhone and iPad. Mobile Collection Researcher enables you to search the collection, view seasonal plant highlights, and link to individual plants at the Arboretum.

Instead, it was the latest public lecture by a Harvard researcher during the Cambridge Science Festival.

Crone, who leads a team of researchers at Harvard Forest, has been studying the reproduction of sugar maples and pollination strategies, including the kinds of bees that visit flowers in tree canopies.  During the lecture, she outlined her team’s research, which points to a correlation between the amount of seeds a tree sets the previous fall — sugar maples are mast seeders, producing heavy seed production followed by years of larger seed crops — and the sugar content of the sap produced.  Given last fall’s heavy seed crop and analysis of maple syrup production, she said, syrup production could be light this year.

“The idea that Harvard has everything from maple syrup to the genomes of plants covered is a reminder of the collective power of the plant resources at Harvard,” said Ned Friedman, director of the Arnold Arboretum, who invited Crone to share her research as part of the festival.  In addition to work at Harvard Forest and the Arboretum, University specialists conduct important research on plant life in the Department of Organismic and Evolutionary Biology and at Harvard University Herbaria.

“Basic science has an implication on the economy of states … we’re talking about science having a societal impact,” added Friedman.  “And sharing the science and its impact is part of our job, what we, as academics, should always be doing.”

It’s that spirit of sharing — both research and excitement — that is the hallmark of Cambridge Science Festival.

The 10-day festival taps researchers, scientists and innovators across Cambridge to share their love of science, technology, engineering, and math at nearly 100 events geared to people of all ages.  The Massachusetts Institute of Technology and Harvard are among the festival’s founding sponsors. And this year, more Harvard affiliates than ever before are sharing their research with the public.

“Harvard faculty, researchers, and students are involved all the way through the festival,” said P. A. D’Arbeloff, director of the Cambridge Science Festival.  “It’s exciting to see how its has taken off organically in Harvard departments.”

Harvard researchers joined forces with stand-up comedians to explain episodes of the history of science at the Harvard Museum of Natural History.  Last Friday night, researchers at the Harvard-Smithsonian Center for Astrophysics set up a cluster of telescopes offering passersby a chance to look at the stars in the urban sky and learn that you really could see the rings of Saturn in the city with the right equipment and a little guidance.  And Harvard affiliates, including HMNH staff, participated in the opening Science Carnival.

Given last fall’s heavy seed crop and analysis of maple syrup production, she said, syrup production could be light this year, explained Harvard Forest Senior Ecologist Elizabeth Crone. Photo by Jon Chase/Harvard Staff Photographer

“All kinds of people are walking up to Harvard researchers and learning about science,” said D’Arbeloff.

Cambridge resident Bragadees Madambakkampa was one of them. He happened to stumble on the Harvard Smithsonian Center for Astrophysics’ urban stargazing in Harvard Square last Friday.   “I was pleasantly surprised to find telescopes pointed at Venus, Mars, and Saturn at Brattle Square,” he posted on the Cambridge Science Festival’s Facebook page. “Thank you so much, I’m proud to call Cambridge home.”

“There’s tremendous value for residents who get a glimpse inside local universities and learn about the remarkable research that’s happening there and its important for universities to explain their science to a broader audience,” said D’Arbeloff.  “Plus, who knows where the next great Eric Landers will come from,” she added.

“The idea that Harvard has everything from maple syrup to the genomes of plants covered is a reminder of the collective power of the plant resources at Harvard,” said Ned Friedman, director of the Arnold Arboretum. Photo by Jon Chase/Harvard Staff Photographer

Upcoming Harvard events at the Cambridge Science Festival:

On Friday, from 7:30 to 9:30 p.m. at First Parish in Cambridge, Harvard Square, David Haig, professor of biology and Edward Glaeser, director of the Rappaport Institute for Greater Boston and Fred Eleanor Glimp Professor of Economics, will join faculty from MIT and BU for “Big Ideas for Busy People,” Cambridge’s fast-paced answer to “Ted Talks,” where prominent researchers deliver five-minute talks and take five minutes of questions.

Also on Friday, the MIT/Harvard Center for Ultracold Atoms opens its doors to sixth- and ninth-graders to learn about experimental physics.

On Saturday, Svante Paabo will discuss human pre-history at 2 p.m. in Science Center B.

Also on Saturday, Harvard-Smithsonian Center for Astrophysics scientists at Rocket Day will teach children about solar physics projects and launch 30 to 50 bottle rockets in Danehy Park.

See the full festival schedule here.

But Hanrahan isn’t a recent college graduate in her first job, or even a newcomer to Harvard. Rather, as she tells two co-workers in an apology for a reporter’s unplanned interruption, hers is a tale of starting over.

“I’m part of a story about old people making a comeback,” she says with a self-deprecating shrug.

Going from head of exhibition design and installation at the Harvard Art Museums to a curatorial assistant at an herbarium — from handling the works of major artists to carefully preserving and cataloging humble leaves and twigs — might seem an unusual move. But landing a job at the Herbaria allowed Hanrahan, a longtime lover of both art and science, to pursue the career path not taken.

After 30 years in the art world, 22 of them at the Fogg Museum, she resolved to try something new.

“I decided to jump off the edge of the cliff and see where I was going to land,” she said.

In 2008, the Fogg (which shared a home with the Busch-Reisinger Museum) closed in preparation for a move to a new building, projected to open in the fall of 2014. The next year, Hanrahan was offered the option of working half-time or being laid off.

“It seemed like a really good transition point in my life,” she said. “Things were ending, and I wanted to go down that other road I didn’t go down as a youngster, to pursue something in the natural world.”

She left the museum in 2009 with a plan: to stay at Harvard, to find a job in natural history, and to work in a fun environment. She took classes on plant identification at the Arnold Arboretum (which houses one of the six herbaria that make up the HUH consortium) to familiarize herself with the plant world’s complex taxonomy.

“I sure wish I’d taken Latin in school,” she joked.

She’d long been involved with conservation projects as a volunteer, most recently by acting as a weekend ranger and tending to bluebird boxes at Appleton Farms, one of the oldest continually operating farms in the country. (Just like Harvard, it was established in 1636.)

Last July, she took a temporary job at the Herbaria, mounting new specimens, and was then brought on permanently. She is now working on a collaborative project with the University of California, Berkeley, building a database of California plants that will help scientists track the effects of climate change on different plants’ dispersal across the state.

The job offers constant learning opportunities, she said. The work combines history, geography, and botany, and requires an archivist’s attention to detail. With more than 5 million specimens in the HUH collections, some of them hundreds of years old, nothing can be mishandled or misplaced.

“My colleagues are very generous with sharing their vast knowledge about the plant world,” she said. “They’re supportive and kind. I think that’s really important in a work environment.”

She recognizes how rare her opportunity was. The recession, she said, exposed the difficulties of job seekers like herself: too young and energetic to truly retire, but often viewed by prospective employers as too old to start over in a new field.

“I feel lucky,” she said. “I really do think that a lot of it was being in the right place at the right time. But you have to put the energy out there for anything to come back.”

Hanrahan still makes time for art. She runs her own design and color consulting business, makes and sells bluebird nesting boxes, and serves on the board of Mobius, a local, artist-run nonprofit that supports experimental work.

“I think it’s important to follow your passions,” she said. “They’ll lead you to where you need to be.”

The Deland Award for Student Research was presented to Laura Lagomarsino, a Ph.D. student in the Davis Lab in the Department of Organismic and Evolutionary Biology at Harvard University. Lagomarsino is studying the evolution of secondary woodiness in the Lobelioideae, a primarily temperate group of herbaceous plants. Award funds will enable Lagomarsino to travel to Peru to collect plant specimens for the Herbarium of the Arnold Arboretum (A) and to advance her studies of wood anatomy. The Deland Award was established in 1992 through the generous bequest of F. Stanton Deland Jr., Harvard c’36, and supports research on the comparative biology of woody plants conducted by graduate and advanced undergraduate students.

Collaborating with the BTU School has opened avenues of discovery for both students and their instructors, and both teachers and parents have noticed a spike in the children’s enthusiasm for learning science. In addition to engaging students in the classroom, the Arboretum hosted the students for field studies in the landscape, creating opportunities for students to expand on their indoor experiments through an exploration of the Arboretum’s living collection of plants. Some of the students will learn elementary botany by growing plants in their classrooms this spring, and all will return to the landscape when the weather warms to continue to learn about science in the field. Whether in the classroom or on the Arboretum grounds, students and educators both look forward to the continued flowering of this unique educational partnership.

Learn more about the Boston Teachers Union School and its partnership with the Arnold Arboretum.

Opened in January 2011, the Arboretum’s research and administration facility at Weld Hill was designed and constructed to LEED (Leadership in Energy and Environmental Design) specifications, incorporating many technologies designed to minimize the building’s impact on the environment and its surrounding neighborhood. Leveraging energy-efficient mechanical systems and innovative water management technologies, the facility reflects the Arboretum’s strong interest in conservation and sustainability. LEED certification also acknowledges the Arboretum’s choice of “green” construction methods, such as clearing only the land required for construction and employing on-site soil management and erosion control techniques.

LEED is the nation’s preeminent program for the design, construction, and operation of high performance green buildings. By using less energy and water, LEED certified buildings save money, reduce greenhouse gas emissions, and contribute to a healthier environment. Weld Hill incorporates water-saving technologies not only in the interior of the building, such as dual flush toilets and low-flow showers for bicycle commuters, but also through the design of its surroundings. The landscape around the building consists mainly of a “cosmopolitan meadow mix,” a selection of hardy perennials developed by Arboretum Senior Scientist Peter Del Tredici. Requiring only yearly mowing and no irrigation, this sustainable alternative to grass reduces typical water requirements by half.

Recently, the Arnold Arboretum has focused more technology on recording its local weather events, deploying an array of small weather stations across the landscape in 2008 and establishing a new permanent weather station a few months ago. Collected data allow arboretum staff to better document conditions in the landscape, and to even identify microclimates, or small fluctuations in climate, due to terrain, aspect, or proximity to buildings. While overall the arboretum landscape is nestled in Zone 6b (-5° to 0°F), there are a number of microclimates that offer slightly warmer lows. This gives curatorial and horticultural staff areas to cultivate plant species that are more tender and would typically perform best in Zone 7.

Combining the tools of cutting-edge GIS technology with the resources of modern curatorial practice, Collection Researcher was created through the collaborative efforts of the Arboretum’s curation and information technology staffs, in partnership with Harvard’s Center for Geographic Analysis.

Central to this initiative has been the Arboretum’s longstanding commitment to provide staff, scientists, and visitors with access to the depth and richness of its plant collections. “Bringing Collection Researcher online signifies a giant step in our efforts to share our remarkable collections with the world,” states Arboretum Director Ned Friedman. “We aim to ensure that everyone—from genomicists to environmental biologists, and citizen scientists to the visiting public—can access our plants and the biology that lies behind them.”

They have no appreciation for other noise either, since they pretty much simply lie in the dirt despite students’ shouts, drumming, and repeated playing of a piano note, loudly.

“Worms do not possess any sense of hearing, I think we confirmed that,” said Ned Friedman, Arnold Professor of Organismic and Evolutionary Biology and leader of the freshman seminar “Getting to Know Charles Darwin.”

Friedman, five students, a research assistant, and a teaching fellow were in an unlikely location to replicate a Darwinian experiment involving earthworms: the Music Building.

Crammed into a small basement room that itself was jammed with chairs and two pianos, Friedman and teaching fellow Jesse Weber on Nov. 16 re-created one of Darwin’s last experiments, to see if earthworms can hear. He detailed the experiment in his book “The Formation of Vegetable Mould Through the Action of Worms, With Observations on Their Habits,” published in 1881, a year before his death.

Though the book might seem an odd finale for a man known for a sweeping theory explaining the fundamental mechanism guiding the development of life on Earth, Friedman said the book actually was right up Darwin’s alley, espousing the important theme of gradual changes over long periods — in this case describing the worms’ ability to build layers of soil.

In addition, partly because of a writing style that appealed to a popular audience and partly because by then Darwin was a “rock star,” as Friedman put it, the book was a runaway hit, outselling even “On the Origin of Species.”

The course, offered for the first time this fall, results from Friedman’s own passion for Darwin coupled with his arrival in January from the University of Colorado to become director at the Arnold Arboretum. A botanist whose research focuses on the evolution of plants and relationships between them, Friedman over the years has become increasingly fascinated with the man whose theories underlie his own work.

Friedman designed the seminar to familiarize freshmen with Darwin, who was a towering figure in modern science, yes, but also a dedicated family man, a tireless correspondent, and a scientist whose theories were informed not just by deep thinking about his journey aboard the ship Beagle, but also by experiments conducted throughout his life.

“It’s probably the class that I look forward to every week. It’s fun, and very innovative,” said freshman Tess Linden. “I had a lot of misconceptions about Darwin, coming in. The class is called ‘Getting to Know Darwin,’ and that’s what we did.”

Classmate Ned Whitman echoed Linden’s sentiment. It was surprising “how much he used evidence and observation,” Whitman said of Darwin. “He wasn’t just a fanatic, thinking we evolved from bacteria without evidence.”

To learn more about Darwin the experimentalist, students re-created 10 of Darwin’s experiments over the semester. They also read his letters and selections from his books, including the passage that describes worms and music.

“Worms do not possess any sense of hearing,” Darwin wrote. “They took not the least notice of the shrill notes from a metal whistle, which was repeatedly sounded near them; nor did they of the deepest and loudest notes of a bassoon. They were indifferent to shouts, if care was taken to ensure that the breath did not strike them. When placed on a table close to the keys of a piano, which was played as loudly as possible, they remained perfectly quiet.”

Darwin went on to say that worms, while stone-deaf, are very sensitive to vibrations and pulled back into their burrows when their pots were placed on top of the piano that was then played.

The worms in the Music Building may not have read Darwin’s book. Kept on ice for freshness, they were a bit sluggish, barely responding to vibrations when placed on the piano. They also forgot to ignore the music entirely, as Darwin had observed. Of course, they could have also been responding to the excited faces gathered around the pots, or the wisecracks that flew about.

Besides worms, students re-created experiments involving everything from barnacles to a visit to Boston-area pigeon fanciers. They planned to cap off the semester with a grand feast, using recipes from Darwin’s wife Emma’s cookbook. Though this last event was more meal than science experiment, students understood enough about Darwin to know the perilous ground they were planning to tread: Darwin regularly complained of stomach and digestive ills, perhaps traceable to Emma’s delicacies.

In the eyes of a botanist, the year’s biggest meal is a celebration not so much of our feathered friends, but of the plants in our lives: the potatoes, carrots, cloves, lettuce, celery and sage, of all the holiday foods that people savor, from stuffing to cranberry sauce to pumpkin pie.

Pamela Diggle, a visiting professor of organismic and evolutionary biology, took a lecture hall full of Arnold Arboretum visitors on a botanical tour of America’s favorite food holiday on Wednesday (Nov. 16). She explained that though the turkey is the star of the day, the plants on the menu give it that extra oomph.

“A lot of the textures, flavors, and aromas come from the plants in that dinner,” Diggle said.

Diggle can be forgiven if she views the nation’s annual poultry pig-out through a plant perspective. After all, as a botanist from the University of Colorado and a visiting professor at Harvard, she has made a career of studying plant development and evolution.

Thanksgiving’s plants are just doing what we all do, Diggle said: making a living, setting something aside for a rainy day, and looking for love. It’s the strategies that particular plants employ in those pursuits that make them delectable.

Potatoes, which are really just modified stems that have lost their way and burrowed underground, are the plant’s way of getting through hard times, namely, the long, cold winter when their leaves have withered and photosynthesis’ sugar factory is shut down.

Carrots employ the same strategy — storing sugars for the winter — but in a different body part. A carrot’s sweet, orange, edible tissue is basically the same as the wood and bark of a tree, modified to store sugar. Sweet potatoes and onions are saving for a rainy day, only each with different strategies. Sweet potatoes are actually modified roots of a vine, while onion bulbs are modified leaves. An onion leaf is green on the top, but the bottom stores food for the cold months, swelling and wrapping entirely around the tiny stem (the hard part we cut out).

Leaves — the site of photosynthesis — are where a plant makes a living and are full of nutrients. Lettuce, of course, is just a leaf that we eat. We discard the leaves of celery, however, and eat instead the leaves’ petiole, or stalk, fleshy and swollen all out of proportion, but still containing the stringy tubes that carry water up and sugars down from the leaves.

Flowers — a plant’s advertisement for love — are the one part that we don’t eat a lot, Diggle said. But Thanksgiving’s bounty does include a flower: clove, which flavors pies and other foods.

Most of these examples are parts that the plant would rather we didn’t eat, thank you very much. In fact, many flavors come from the plants’ ongoing chemical warfare against insect pests, animal browsers, and even other plants, Diggle said. The flavors and oils are an effort by the plant to preserve its winter stores and leafborne nutrients from raiders just like ourselves. In cabbage and Brussels sprouts, for example, the ingredients that provide the tangy taste and smelly aroma are isothiocyanates, a relative of cyanide. From the standpoint of cabbage and Brussels sprouts, they may not have quite gotten the formula right.

Fruits, on the other hand, are the part that plants want us to eat. Fleshy fruits are a plant’s way of attracting animals and birds to eat and disperse the seeds that were contained within. Humans, always a troublesome lot, have worked out a way to ruin even that. Just ask wheat. Bread flour, of course, comes from wheat. But instead of dispersing wheat seeds, we destroy them, grinding them up and separating the contents. We make the endosperm, which is intended to nourish the seed’s embryonic wheat plant, into white flour. We strip off the seed coating, which is tough and intended to protect the seed from predators like us, and we call it wheat bran. As for the baby plant itself, we separate it out and sell it as wheat germ.

“Poor wheat, just trying to raise a family, and then we come along,” Diggle said.

Pumpkins and cranberries are other fruits employed to round out the Thanksgiving feast. Pumpkins have added an extra set of tubes that carry sugar from the leaves to the fruit, enabling them to grow to impressive sizes over just three months, while cranberries have an extra dose of pectin, making cranberry sauce a snap.

Despite a botanists’ passion, however, turkey is still king at Thanksgiving. So as her talk ended, Diggle’s attention finally moved from the plants to the bird. Even there, we have plants to thank, she pointed out. But no, unlike a carrot, a turkey is not modified tree bark. And unlike potato or celery, it’s not a stem or a stalk. It’s not a modified root or leaf or flower. But farmers do feed grain to turkeys, Diggle pointed out, and turkeys do turn that grain into meat.

“Turkeys are just reprocessed endosperm,” Diggle said.

Peter Del Tredici, senior research scientist at Harvard’s Arnold Arboretum, said that New England’s forests grow differently from pre-colonial woodlands. They’re missing towering, iconic trees such as chestnuts and mature elms. They’re peppered with invasive species and decimated by introduced pests and diseases. They’re fragmented by ongoing human impact and still affected by past farming practices that altered the soil. Watersheds have been changed too, with dams built on rivers and streams.

Many of these changes are permanent, said Del Tredici. Some native trees, for example, can only grow in the natural, layered soil laid down over centuries by decomposing organic matter in the forest. These species, Del Tredici said, will never grow on farm fields even if they were there before the land was cleared because plowing churns the soil, disturbing its natural structure.

“Soil characteristics are radically different from undisturbed sites,” Del Tredici said. “Canadian hemlock will only be found on land that has never been plowed.”

Del Tredici spoke at the Geological Museum in a lecture sponsored by the Harvard Museum of Natural History. The talk, “Deeply Disturbed: The Emergent Forests of New England,” was part of a fall series marking the opening of the museum’s “New England Forests” exhibit in the Zofnass Family Gallery.

Disturbance will be a hallmark of the region’s future forests, Del Tredici said. While natural disturbance from hurricanes, tornadoes, and ice storms have always affected the region’s woods, humans have increased the pace of disturbance, clearing land for roads and for buildings, clearing tracts for logging, and introducing pests and disease.

While forests will regrow from some types of disturbance, such as logging, other types, such as road and home building, permanently fragment forests, increasing the ratio of edge zones to interior forest segments. These edges favor plants adapted to grow quickly and take advantage of disturbance. Many such plants are invasive species, favored by humans because they grow rapidly in fields, pots, and gardens. Once they escape into the wild, they can grow prolifically, gaining a toehold and then penetrating the forest interior.

The problem of invasive species occurs not just close to major urban centers like Boston, Del Tredici said. He showed pictures of Japanese knotweed, a species that thrives in disturbed areas, along a riverbank in Vermont. Following this year’s floods from Hurricane Irene, he said, there should be more disturbed places for the plant to take root.

Del Tredici recounted 11 major introductions of pests and diseases, including chestnut blight, which has reduced the former giant of the forest to a shrubby understory plant; Dutch elm disease, which cuts down another former forest giant after 20 or 30 years, before it’s fully grown; hemlock woolly adelgid, which has devastated stands of that tree; and the Asian longhorned beetle, whose recent arrival in Worcester has prompted the destruction of 30,000 trees so far.

In such disturbed areas, some species are winners and some losers. One major victor, Del Tredici said, is black birch, a fast-growing species that can take over disturbed plots rapidly. A study of forest composition comparing early colonial times and today shows declines in beech, hemlock, oak, and chestnut and increases in birch, maple, and pine.

Animal life within the forest is also different now. Though deer, beaver, and other species have rebounded, some, such as the wolf, haven’t, and others that were not here before, like the coyote, have come in their place. The absence of top predators has allowed deer populations to explode to levels likely never seen even in pre-colonial forests, Del Tredici said, resulting in overgrazing in some areas and exerting their own pressure on forest structure.

Though some observers may desire to restore forests to their original state, Del Tredici said that forests have always been changing. Even if researchers knew precisely the composition of forests when the first Europeans arrived, that picture should not be viewed as the description of a steady state that was disrupted by humans, but rather as a moment in time in forests that have always been changing.

Ongoing changes include climate warming that is pushing species like spruce and fir northward, and fewer killing frosts that provide protection from some pests, allowing species like the hemlock woolly adelgid to survive and spread. Introduced species like honeysuckle will continue to spread because the region’s animals view them as resources, not invaders. Birds, for example, feed on honeysuckle berries for food, spreading the seeds further.

“You may not like it, but that’s sort of irrelevant,” Del Tredici said. “Species that can take advantage of disturbance will be prevalent.”

Each July 4, as night falls, the Roslindale neighbors who live near Peters Hill in Harvard’s Arnold Arboretum walk to the top. Someone brings a radio, and they listen to the Boston Pops Orchestra play the “1812 Overture” while they watch the fireworks burst brilliantly over the Charles River. Near the base of the hill, among tall trees and along narrow dirt paths, lies a little-known cemetery containing the remains of veterans of the American Revolution and early settlers — an ideal place for pondering the meaning of the nation’s birthday.

The little cemetery, hidden at the far end of the 265-acre Arboretum, holds several headstones and a crypt and was once part of the Walter Street “Berrying” Ground. The “Jamaica End” settlers of the early 1700s belonged to the distant Roxbury town church on Meeting House Hill. The long walk to services was especially difficult during the cold winters, so a group of 44 petitioned to establish a second parish. In 1711 when their petition was ignored, they quietly broke away. Alongside their Walter Street church they built the cemetery, now part of the Arboretum, which was established in 1872.

Under giant Hawthorn trees are the crude, chipping headstones etched with old New England names like Baker, Weld, and Child. The epitaph on the stone of Capt. John Baker underscores the importance of religion to the early Americans. The inscription reads, “Life is uncertain, Death is sure, Sin is the wound, Christ is the cure.” One of the earliest markers is a double headstone for Grace and Benjamin Child, husband and wife. Nearby is the stone marking Benjamin’s brother, Joshua, whose wife Elizabeth is also buried in the area. (According to the 1961 edition of the Arboretum publication “Arnoldia,” Joshua and Benjamin were brothers, born a year apart and baptized the same day, and Elizabeth and Grace were sisters. Each couple had 12 children.)

Around 1902, when the city of Boston was widening Walter Street, workers found 28 other bodies. A marker above the sidewalk reads, “In memory of Soldiers of the Revolution who died in the hospitals at Jamaica Plain and were buried in this lot. 1775-1776.” One account is that the soldiers were killed fighting in the Revolution; another is that they died from smallpox while stationed at nearby Loring-Greenough House, which had been converted to a hospital.

The ancient burial site is a hidden space within a hidden space, far afield from the main Harvard campus. Arnold Arboretum is the second-to last-link in Boston’s Emerald Necklace, a series of connected parks. The views of Boston from this southernmost tip of the park are remarkable. So are the stories of those buried in the tiny cemetery.

Path to paradise

The pathway from Walter Street at the entrance to Peters Hill in Harvard University's Arnold Arboretum leads to an 18th-century burial ground of early settlers and Revolutionary War soldiers.

'Rev. War'

The weathered stone of Capt. Jonathan Hall is decorated with a small contemporary American flag and a 1776 commemorative marker. Hall fought against the British and the words "Rev. War" are crudely engraved on his stone.

Age of leniency

An aging headstone no longer stands at attention, finally permitted some leniency.

Dog days

Dogs and people share the grassy lawn on Peters Hill where early settlers are laid to rest.

From hill to orchard

A large expanse of lawn at the top of Peters Hill dips down to an apple orchard.

Words of wisdom

In 1776, Hannah Baker, who lived until the age of 95, was buried beside her husband, John, who had died at the age of 83. His epitaph reads: "Life is uncertain. Death is sure. Sin is the wound. Christ is the cure."

Sacred spot

The ancient burial site is a hidden space within a hidden space, far afield from the main Harvard campus.

Remains of the day

The remains of 28 Revolutionary War soldiers were discovered in this area around 1902 and a marker was erected at the base of Peters Hill in remembrance.

Wooden frame

Trees frame two aged markers at the 18th-century burial site on Peters Hill.

Side by side

Grace and Benjamin Child, husband and wife who died just over a year apart in the 1790s, are buried side by side under a double headstone on Peters Hill.

Walk this way

A narrow and natural pathway borders the burial site.

Setting sun

The sun sets through the trees on Peters Hill in Harvard’s Arnold Arboretum.

Photo slideshow: Hidden Spaces: Arboretum cemetery

Photos by Rose Lincoln/Harvard Staff Photographer

The effort kicked off earlier this month, when scientists from the Center for Tropical Forest Science (CTFS), a collaboration between the Smithsonian Tropical Research Institute and Harvard’s Arnold Arboretum, participated with Chinese scientists in a 17-day workshop, followed by a three-day symposium.

Leading the effort is Stuart Davies, director of the Arboretum’s Asia Program. According to program manager Liz Delaney Lobo, the collaboration became a reality largely because of a five-year National Science Foundation grant that will help to finance workshops, travel, and other costs. In addition to the workshops, the grant provides for 10 graduate students or early-career researchers from the United States to visit China for scientific exchanges.

The project ties the efforts of center researchers managing 41 similar plots in forests around the world to a similar effort underway in China. The plots in both networks are exhaustively documented using the same methodologies so that information can be compared and used to better understand both the basic functioning of the forests and how their diversity affects their resilience in the face of global climate change.

Though led by Smithsonian and Harvard botanists, the center’s effort involves hundreds of scientists around the world. Harvard Professor Peter Ashton, the Charles Bullard Professor of Forestry Emeritus, helped to create the network during the early 1990s. The plots are between 25 and 50 hectares in size and hold about 4.5 million trees, from 8,500 species. All trees with a diameter larger than a centimeter on the plots are identified, documented, and tracked in recurring censuses every five years. Though the center network’s first plots were tropical, in recent years concerns about climate change have prompted researchers to expand the network to temperate sites, such as the Harvard Forest in Petersham, Mass.

In recent years, scientists affiliated with six institutes that are part of the Chinese Academy of Sciences have begun their own network of forest plots. Called the Chinese Forest Biodiversity Network, it involves researchers using the same methodology as the center, allowing them to compare data between the two networks, furthering their understanding of forest dynamics.

Delaney Lobo said the grant will help to support annual 20-day workshops involving both groups of scientists. The first workshop, just concluded, took place in China. Future sessions will take place at the Harvard Forest, at Michigan State University, and at two Chinese botanical institutes.

“Without this grant, it would be very difficult for such a large group of scientists to collaborate this comprehensively or effectively on such an enormous scale,” Delaney Lobo said.

Scientists have settled on a handful of likely factors that might have driven this blizzard of diversification, including competition between males to fertilize the egg cell hidden at the base of every flower.

This male competition is familiar to anyone who has seen rams butt heads or stags lock antlers. It is a decidedly quieter process among plants, although the stakes are just as high. The competition occurs between pollen grains deposited on a flower.

Each pollen grain holds three cells, two being the plant’s sperm cells and the third a tube-growing cell that rapidly creates a pathway to the egg, along which the sperm can travel. Scientists believe that competition to grow the fastest pollen tube is the vegetative equivalent of male-male combat in the animal kingdom, a measure of fitness of the father plant that is one of several factors that drives flowering plant evolution.

Now, researchers at Harvard’s Arnold Arboretum and the Department of Organismic and Evolutionary Biology have shown that females in an ancient lineage of woody vines also duke it out for reproductive rights, employing a practice that may give researchers a glance back in time at a strategy that helped to foster today’s diversity.

While most flowering plants develop a single egg cell in each seed and sit back and wait for the winning pollen tube to reach it, some species develop not one egg, but many, that are located far enough from the site of fertilization that they must also grow tubes, tangling with rivals as they do for the right to produce the next generation.

The research, published online Monday (June 20) in the Proceedings of the National Academy of Sciences, was conducted by Arnold Arboretum Director William Friedman, the Arnold Professor of Organismic and Evolutionary Biology, and postdoctoral fellow Julien Bachelier.

Bachelier and Friedman studied Trimenia moorei, a woody vine native to Australia that is part of an ancient group of flowering plants called Austrobaileyales. The research, which took a year and a half and was begun when the two were at the University of Colorado, involved microscopic analysis of thousands of Trimenia flowers, painstakingly tracing the delicate paths of pollen tubes and those from Trimenia egg cells.

Bachelier, who did much of the microscopic analysis, said competition is nature’s way of ensuring that the most fit genes are passed on to the next generation. From a fitness standpoint, the more competition the better.

Once Bachelier looked at specimens under the microscope, he saw many flowers that had just a few pollen grains or even just a single one.

“A lot of flowers were sectioned; there were very few pollen grains in them,” Bachelier said. “The presence of female competition may be a way to compensate for low levels of male competition in Trimenia and other members of ancient lineages of flowering plants.”

Trimenia’s flowers are small and not very showy and Trimenia’s female competition strategy may serve as a way to increase the fitness of the next generation.

“These early lineages of plants had small, simple flowers,” Friedman said. “They sort of had the training wheels on.”

In the millions of years of flowering plant evolution, many types have developed large, showy flowers and partnered with efficient insect and bird pollinators, greatly increasing the number of pollen grains that settle on a single flower and, hence, the level of competition that leads to the next generation. That process may have allowed the species to discard competition between egg cells.

The work, Friedman said, grew out of a larger effort to understand plant strategies to nourish their young by storing carbohydrates in their seeds. Though scientists have in the past recognized that some plants have multiple egg cells that produce pollenlike tubes, they’ve generally described the phenomenon and moved on. Friedman credited Bachelier with recognizing that what he was observing may have deeper implications about the early evolution of flowering plants.

“It’s one of the wonderful things about doing biology,” Friedman said. “Once you start looking, amazing and unexpected things happen.”

The Arboretum is so serene and languid it seems imaginary. On a warm summer day, dogs and runners and bicyclists all share the nearly silent space under the shade of giant and rare trees of odd shapes and sizes. On Conifer Path, raspberries grow under a Ponderosa pine. The tree’s five arms jut out from its central trunk, looking oddly like the spokes on the wheels of the bicycles that pass by. The crimson-colored trunk of a Japanese red pine is conspicuous in the depth of its color yet at home amongst other rare conifers on Bussey Hill.

In 1872, Benjamin Bussey bequeathed the land to Harvard College “for the creation of an institution for instruction in farming, horticulture, botany, and related ?elds.” This philosophy continues today. Signs along pathways say “Experiment in progress” and “What’s going on?” instructing visitors who might be curious about why branches of bushes are wrapped in plastic bags, or why newly planted moss shouldn’t be stepped upon.

If you listen carefully, you can hear the cars buzzing along the Arborway, but mostly you hear the birds, the wind, and the soft laughter of the other visitors, transformed by the beauty of the Arboretum and our shared good fortune of experiencing an aaah moment in the middle of a crowded city.

The reader

A quiet spot beneath a tree is the perfect place to indulge in a good book.

Behind the locked gate

Majestical plants await behind the Hunnewell Building's spiraled gate.

White oaks

These white oaks jut out from this diaphanous field.

Japanese red

This Japanese Red Pine frays and splinters in the sun.

Roll away the stone

Moss and stones in Arnold Arboretum.

Branching out

A tree with many branches.

Juicy

A raspberry plant bears fruit.

Dewy

These blossoms stretch for the honeyed light at the Arnold Arboretum.

Lover's lane

A couple meanders through the Arboretum.

Photo slideshow: Afternoon delight

Rose Lincoln/Harvard Staff Photographer

“Specialization,” the science fiction author Robert Heinlein once wrote, “is for insects.” He could have been talking about Samimi. The 33-year-old Iranian American may be the most overqualified trash collector around.

“I think it was a necessity-is-the-mother-of-invention situation,” said Samimi, who struck out on his own at 17, reflecting on his many mini-careers. “But also, I think like most children I was born with a natural curiosity about all things.” Unlike most kids, he never grew out of it.

Samimi is the only gardener at the Arnold Arboretum, but his title is somewhat misleading. He’s responsible for maintaining and protecting the Arboretum’s 265-acre grounds, from its gates and benches to its roads to its precious flora. For some, the job might invite tedium — it involves a lot of trash.

But Samimi has used garbage as an unlikely muse for the kind of creativity and resourcefulness learned after a lifetime of odd jobs. In his four years at the Arboretum, he has devised a number of inventive solutions to reduce waste and litter and promote recycling on the grounds, earning him the first-ever Arnold Arboretum Director’s Innovation Award in 2009.

“The crux of my job is trash,” he said as he made his rounds on a warm, overcast April morning. “You’ve got to get it when you see it.” He paused midsentence and hopped out of his beat-up Chevy to grab a discarded tissue off the side of the road.

“It’s a nightmare,” he continued. “In my off time, all I see is trash.” His days, which begin at 7 a.m., often find him roaming the Arboretum like a modern-day Thoreau. He quickly noticed ways in which the Arboretum’s trash collection could be improved.

First, he researched and installed recycling bins around the Arboretum. Another problem he noticed, however, was more intractable. The park’s many dog walkers would leave spare plastic bags hanging from the Arboretum’s gates for anyone who had forgotten their own.

While the thoughtful gesture did reduce dog waste, Samimi said, “the bags would blow off the gates into the grounds, and I’d be running around picking them up.” One day, he began to sketch a design for a mesh basket to attach to the front of a trash bin, like a large tissue box. He took his design to the Arboretum’s welder, and the Arboretum’s dog walkers now have “take a bag, leave a bag” drop points all around the grounds.

Perhaps most impressive, he figured out a little-known way to recycle Styrofoam, a process that has taken him three years.

“I called over to [the main Harvard campus] to ask how they recycle Styrofoam, and they told me there was no such way,” he recalled. Samimi researched the issue and found Conigliaro Industries, a Framingham company that would recycle the Arboretum’s Styrofoam — but only in 1,000-gallon increments. Because the material is 90 percent air, Samimi said, the company only deals in large quantities.

Samimi began collecting Styrofoam in a spare room at 1090 Centre St., a former dormitory for the Arboretum’s interns. Last month, he finally hauled 20 50-gallon bags to Framingham.

In addition to allowing him to dream up new ideas, Samimi’s job gives him the freedom to pursue his real passion: Middle Eastern history. He lobbied aggressively for a job at the Arboretum so he could take advantage of Harvard’s libraries and its Tuition Assistance Plan.

He was offered the job in 2007, shortly after finishing his bachelor’s degree in history at the University of Massachusetts Boston. He had started college at 24, putting himself through by working full time as a waiter, mover, and assistant building manager.

Working so many jobs meant he had already “learned how to learn,” Samimi said. “Surprisingly, I was a pretty good student, and it occurred to me for the first time in my life that I was interested in scholarship.” He has since taken classes at the Harvard Extension School, where he hopes to earn a master’s degree.

Samimi may not fit the mold of a typical grounds worker, but the position suits his rather offbeat sensibility, he said.

“This is a great place to work,” he said. “I can’t imagine any other job where people would have supported me to do the things I’ve done.”

The 44,000-square-foot building received final approvals from Boston in December, and since then has been awash in moving boxes and crates. One of the first occupants was the arboretum’s new director, William “Ned” Friedman, the Arnold Professor of Organismic and Evolutionary Biology.

Friedman, an esteemed botanist who came to Harvard from the University of Colorado, took over the arboretum’s leadership in January, his start dovetailing nicely with that of the building that will be his new home.

During a walk through the building shortly after his arrival, Friedman enthusiastically showed the new labs and equipment, and spoke of the community he hopes will grow among scientists who work in the open, shared laboratory spaces.

“By getting the walls out of here, there’s a social component. The goal is to have people mixing,” Friedman said. “If you’re in your own office and the door is closed, you can’t have a conversation with someone else.”

The building allows the arboretum’s researchers, who moved from offices at the Cambridge campus, to share space with those in charge of managing the collections, who had been based at the arboretum.  Researchers and graduate students began moving to their new offices in January, even as the new laboratory equipment was arriving.

“The most joyful thing in the world is having a new microscope,” Friedman said. “My postdoc is a microscopist; he’s just about passing out with all the new equipment.”

The new building has enough extra room, Friedman said, that there is space for visiting scholars from other institutions and for undergraduates pursuing plant science research.

In order to bridge the physical distance between the arboretum, which is in Boston’s Jamaica Plain and Roslindale neighborhoods, and the Cambridge campus, a shuttle van will be used to ferry students or entire classes for lessons that draw on the arboretum’s resources.

“Without students here, this wouldn’t be a University,” Friedman said. “There are chances to do undergraduate honors theses based on these resources. My goal is that every undergraduate honors project should be publishable and should lead to a next step.”

An advantage of the new building is its proximity to the arboretum’s living collection, Friedman said. While the arboretum doubles as a city park and an important part of Boston’s string of parks called the Emerald Necklace, it also is one of the world’s pre-eminent collections of woody plants. As a living collection, the arboretum also includes other forms of life, such as fungi and insects, that can be studied by researchers at Weld Hill.

“Out there are not just lots of plants, but incredible numbers of insect, fungal, and microbial species. We have 275 acres of biodiversity,” Friedman said.

The building also has a dozen greenhouses where some specimens can be grown and others collected from the field can be raised, including for Friedman’s own research into the origin of flowering plants, collected in New Caledonia.

Doctoral student Becky Povilus and postdoctoral fellow Julien Bachelier moved to Harvard from the University of Colorado to continue their work with Friedman and were among the first to settle into the new building. Bachelier said it was “everything we heard, but better,” while Povilus said having the arboretum nearby was a plus, as it is a place to both collect samples and to walk around and get ideas for new avenues of research.

For the next few months, Friedman said, the staff will focus on getting researchers situated and their work under way. A major emphasis, Friedman said, is to further develop relationships with the community through activities such as open houses and the new director’s lecture series.

The North American Collections Assessment (NACA) — conducted collaboratively by Harvard’s Arnold Arboretum, Botanic Gardens Conservation International U.S., and the U.S. Botanic Garden — found that only 3,681 of North America’s 9,494 most threatened plant species are maintained in 230 collections across the continent.

Although the protection of natural habitats remains the highest priority, maintaining rare species in seed banks or living collections — such as those in public gardens and conservation organizations — provides an insurance policy against future loss. Such collections have also been valuable in restoring natural populations.

“Until this point, nobody knew which rare North American plants were safeguarded in collections,” said Michael Dosmann, curator of living collections at the Arnold Arboretum and one of the report’s authors. “Perhaps even worse is that we didn’t have a clue which ones were not in cultivation. These are the species of greater priority for collection and preservation.”

“This report is a wonderful illustration of the Arboretum’s critical role in shaping the national and international agenda for the preservation of rare and endangered biodiversity,” said William “Ned” Friedman, director of the Arnold Arboretum and Arnold Professor of Organismic and Evolutionary Biology.

Assessment results indicate that North America did not reach the Global Strategy for Plant Conservation’s (GSPC) Target 8 goal set in 2002, which called for 60 percent of threatened plant species to be protected in collections by 2010. While botanical organizations across Canada, Mexico, and the United States are making progress to achieve this, the report found that 3,500 or more additional threatened plant species will need to be added to collections to meet the new GSPC goal of conserving 75 percent of known threatened species in North America by 2020. This will require nearly doubling the current capacity.

“These assessment results are hopeful, but also a call to action,” said Andrea Kramer, Botanic Gardens Conservation International (BGCI) U.S. executive director and the report’s senior author. “For many public gardens, this marks the first time their potential to assist in the conservation effort has been recognized. We hope this is a watershed moment.”

To address the need to increase capacity, the assessment calls for the strengthening of conservation networks and collaboration in conservation planning and data sharing. One solution is for institutions to contribute plant lists to BGCI’s PlantSearch database and update them regularly. It is also crucial to increase cooperation and coordination among a broad and diverse network of gardens and conservation organizations with different expertise and resources.

The Arboretum’s role

Reflecting on the Arboretum’s contributions to the assessment, Friedman said, “The strong emphasis on the curation of the Arboretum’s living collections, along with the many fellowships offered to train the next generation of plant and conservation biologists, was central to making this seminal study come to fruition.”

Said Dosmann: “Another one of the lessons we learned from this assessment is just how important it is to curate for conservation. Curators and horticulturists have not always considered conservation value as they go about their routines. Yet by participating in this assessment, many for the very first time saw the direct value of their plants in bolstering efforts to conserve our threatened flora. We hope this becomes a new paradigm in collections management.”

This new paradigm — fully integrating the conservation ethic into curatorial practices —stems out of recent work at the Arboretum. Its living collection is one of the world’s most diverse and well-documented assemblages of trees, shrubs, and vines. Roughly 15,000 accessioned plants are cultivated in the outdoor museum, representing some 4,000 different taxa, or kinds (e.g., species, subspecies, or cultivated varieties), from temperate regions of the world — particularly Asia and North America. While it is obvious that some of these are threatened in their native habitat, determining their conservation value is not always simple.

Why the challenge?  For one, threat rankings are assigned by many organizations around the world, and can be applied at a range of scales. For instance, the Red Lists compiled by the International Union for Conservation of Nature are at the global level, while individual countries may maintain their own. Complicating things further is that definitions of conservation status among international, national, and regional groups are not always uniform. Lastly, some rankings are unreliable because of data deficiencies.

In 2008, Dosmann hired Abby Hird as a Putnam Research Fellow to address this issue at the Arboretum.

“When I came to the Arboretum,” said Hird, who now works for BGCI U.S. and was a co-author on the report, “Michael asked me to answer one little question: ‘What is the conservation value of the living collections?’ Little did we know that it would take nearly two years to build a pragmatic conservation assessment model for living plant collections.”

Hird’s work at the Arboretum determined that when a wide net is cast (looking at threats from global to local scales) approximately 11 percent of the species growing in its living collections are threatened with extinction. This knowledge is now applied at multiple levels of collections management, from setting new acquisition targets to elevating horticultural maintenance and curatorial regimes for those plants in greatest peril.

Applying the Arboretum’s approach more broadly seemed a logical next step, and when the chance to collaborate on the NACA with BGCI U.S. and the U.S. Botanic Garden came up, Dosmann and Hird were on board. Hird, whose fellowship was just ending, went to work for BGCI U.S. yet remained at the Arboretum as a research associate.

“It was exciting to extend the collections assessment I did as Putnam Fellow to the continental scale for BGCI’s NACA,” said Hird.

And just how many of the Arboretum’s plants contributed to the NACA report?  “Forty-seven of the North American species in our collections are threatened in their native range,” notes Dosmann. “We not only will work to preserve and research these rarities, but we can set our eyes upon additional species not in our collection — yet.”

More information and the full North American Collections Assessment report.

Carroll E. Wood, Jr., Professor of Biology, Emeritus, brought a mind of great precision to the field of plant systematics, focusing on the diverse flora of the southeastern United States.  Making use of the unexcelled resources at Harvard—which include the largest private herbarium in the world, several outstanding botanical libraries, the extensive living collections of the Arnold Arboretum, and many specialized collections in paleobotany, economic botany, and plant anatomy—he developed a broad biological approach to plant description that emphasized the genus rather than the species as the unit of study.  The result of his work was a floristic synthesis of the diverse flora of the southeastern United States, ranging both latitudinally and altitudinally from the Carolinas to Florida and westwards to include Arkansas and Louisiana.

Wood is remembered affectionately by his students for his encyclopedic knowledge and seriousness of purpose, which were leavened in the classroom by his mischievous, sometimes wry, humor, comic anecdotes, and play on words.  In recognition of his editorial precision in matters of style and grammar, his associates awarded him the title of “Supervisor of Punctuation.”  Yet, for someone who was dedicated to sound scholarship, botantical order, and semantic precision, his office was a curious masterpiece of untidiness, referred to by his students as “Wood’s Hole.”

Wood grew up in Salem, Virginia, where his father was a pharmacist and his mother was a teacher.  His early interest in natural history, which was encouraged by his parents, evolved after high school, into an inclination towards botany but with a sustained interest in butterflies, first as an undergraduate at Roanoke College and subsequently as a Masters student at the University of Pennsylvania.  During this period, he was already collecting extensively, working on a local county flora with a special emphasis on carnivorous plants.  His academic career was interrupted by military service with distinction in Europe towards the end of World War II, although he continued to collect plants—in military uniform—during periods of leave.  Upon returning to graduate school, he rapidly completed a Ph.D., working at the University of California at Berkeley and under Professor Merritt Fernald at Harvard University.

Having already established a large network of fellow botanists throughout the United States, he first took a position as Assistant Professor at the University of North Carolina and then began his long affiliation with Harvard as Associate Curator at the Arnold Arboretum, rising to Professor in 1972.  His innovative research project, the Generic Flora of the Southeastern United States, which continues to this day, takes a biological approach to the description of plants involving all aspects of biology, including their evolutionary history, ecology, geographic distribution, and economic uses.  Funded extensively from external sources, the project requires a contributor to look deeply into the biology of a plant group throughout its total range.  Although Wood wrote many of the early descriptions himself, he soon recruited a host of collaborators, including graduate and postdoctoral students, his herbarium colleagues inside Harvard, and professional colleagues from outside institutions.  Over time, his involvement became increasingly editorial, a suitable application of his extensive botanical knowledge and his insistence on the precise application of style and grammar.  A selection of drawings from the Generic Flora of the Southeastern United States, based on Wood’s dissections of fresh or fluid preserved material, was published as a Student’s Atlas of Flowering Plants.  Perhaps his most visible legacy was Plant Systematics: A Phylogenetic Approach, a textbook of plant classification produced by a cohort of his students whom he had shepherded into the modern era of molecular and phylogenetic systematics.  His knowledge of the principles of plant nomenclature was deployed internationally and recent botanical monographers have used his generic approach for large tropical families.

As a teacher, Wood was known for accommodating individual student needs through personalized tutorials, his enthusiasm for field study (especially at the Arnold Arboretum), and his willingness to make material available at all hours for his courses in plant systematics.  This tradition of the open laboratory still continues in the Herbarium.  Wood was affiliated with several scientific societies, notably the New England Botanical Society.

In retirement, Wood continued his editorial work in the company of his cat, named Birnham.  He also remained interested in horticulture, an enthusiasm originally nurtured by his mother, becoming a valued source of information about gardens and gardening among his friends and neighbors in Boston’s South End.  An avid hiker, he climbed to the top of Mount Washington in his late eighties.  When Carroll Wood died of a heart attack at the age of eighty-eight, people of all walks of life mourned his passing, but remember him with great affection.  He is survived by one brother but left no issue.

Respectfully submitted,

Robert E. Cook

Norton G. Miller

Donald H. Pfister

P. Barry Tomlinson, Chair

By his senior year in high school, Friedman knew he loved biology, but in that freshman college course he wasn’t feeling the love from cutting up the pig. The love came the next semester, when he sampled botany.

“Dissecting that fetal pig, steeped in formaldehyde, I just couldn’t get into it,” Friedman said during an interview. “Then, during the plant half of the course, I felt this connection with these organisms. I couldn’t imagine doing anything else.”

Friedman, who took over as director of Harvard’s famed Arnold Arboretum in January and is the Arnold Professor of Organismic and Evolutionary Biology in the Faculty of Arts and Sciences, followed that blooming passion for 30 years with an enthusiasm that’s still apparent as he shows visitors around the new Weld Hill research building.

Striding through the still-empty facility just weeks after officially starting his directorship, he envisions not only the lab benches and spaces where equipment will soon sit, but a vital center for plant science, crowded with research scientists, graduate students, and undergrads interacting over samples drawn from the field, from the facility’s greenhouses, and even from the Arboretum’s trees themselves, cultivated over the 139 years since the Arboretum’s founding. Friedman also wants to infect neighbors with his excitement, reaching into the community with open houses and events like the already-begun Director’s Lecture Series.

Friedman, who conducted his doctoral work at the University of California, Berkeley, focused his attention on the reproductive structures of plants and on the rise of the dominant group on Earth today, flowering plants. Flowering plants appeared relatively recently in evolutionary history and diversified broadly, becoming everything from familiar garden plants to trees to grasses to aquatic plants like the water lily.

“I look out the window at the Arnold Arboretum and see conifers and flowering plant trees. Conifers, as a group, are nearly 300 million years in age, while flowering plants are a mere 130 million years old. Yet conifers currently number in the hundreds of species, while flowering plants contain well over a quarter of a million living species,” Friedman said. “Clearly, flowering plants have been very busy diversifying and speciating.”

His work, conducted from the fields of New Caledonia to the Arboretum itself, has helped to illuminate flowering plants’ diversification from more ancient lineages of seed plants such as gymnosperms, which include pines and ginkgo trees. The work of Friedman and his research team has overturned more than a century of widely held views about the earliest phases of flowering plant diversification 130 million years ago. His studies of the process of sexual reproduction in ancient lineages of flowering plants have revealed a number of key stages in the evolutionary establishment of the tissue in all flowering-plant seeds nourishing the embryo.

Friedman also has long been interested in the history of biology, and so studied the father of evolutionary biology, Charles Darwin, whose book “On the Origin of Species” was a foundational document. Friedman taught courses on Darwin while at the University of Colorado, where he taught before coming to Harvard. He has written about Darwin’s troubled thoughts on the evolution of flowering plants, which Darwin termed an “abominable mystery” because the fossil record known at the time showed an uncomfortably rapid evolution.

Darwin, a proponent of slow, gradual evolution, was concerned that flowering plants’ apparently rapid rise and diversification would be used as an argument against his views. He hypothesized that perhaps flowering plants began their evolution in an out-of-the-way place where fossils had not yet been discovered. Subsequent finds have since extended the timeline of flowering plant evolution, making the mystery not quite so great.

While Friedman has remained intrigued by the structure, function, and origin of plants, he is also enamored by the beauty he sees as he examines them.

“The science — you should be passionate about it,” Friedman said. “If you don’t appreciate that you’re in the midst of incredible beauty, you’re missing something.”

William “Ned” Friedman, the Arnold Professor of Organismic and Evolutionary Biology who took over as arboretum director Jan. 1, has studied Darwin’s writings as well as those of his predecessors and contemporaries. While Darwin is widely credited as the father of evolution, Friedman said the “historical sketch” that Darwin attached to later printings of his masterpiece was intended to mollify those who demanded credit for their own, earlier ideas.

The historical sketch grew with each subsequent printing, Friedman told an audience Monday (Jan. 10), until, by the 6th edition, 34 authors were mentioned in it. Scholars now believe that somewhere between 50 and 60 authors had beaten Darwin in their writings about evolution. Included was Darwin’s grandfather, Erasmus Darwin, a physician who irritated clergymen with his insistence that life arose from lower forms, specifically mollusks.

Friedman’s talk, “A Darwinian Look at Darwin’s Evolutionist Ancestors,” took place at the arboretum’s Hunnewell Building and was the first in a new Director’s Lecture Series.

Though others had clearly pondered evolution before Darwin, he wasn’t without originality. Friedman said that Darwin’s thinking on natural selection as the mechanism of evolution was shared by few, most prominently Alfred Wallace, whose writing on the subject after years in the field spurred Darwin’s writing of  “On the Origin of Species.” Alhough the book runs more than 400 pages, Friedman said it was never the book on evolution and natural selection that Darwin intended. In 1856, three years before the book was published, he began work on a detailed tome on natural selection that wouldn’t see publication until 1975.

The seminal event in creating “On the Origin of Species” occurred in 1858, Friedman said, when Wallace wrote Darwin detailing Wallace’s ideas of evolution by natural selection. The arrival of Wallace’s ideas galvanized Darwin into writing “On the Origin of Species” as an “abstract” of the ideas he was painstakingly laying out in the larger work.

This was a lucky break for Darwin, Friedman said, because it forced him to write his ideas in plain language, which led to a book that was not only revolutionary, despite those who’d tread similar ground before, but that was also very readable.

Though others thought about evolution before Darwin, Friedman said scientific discovery requires more than just an idea. In addition to the concept, discovery requires the understanding of the significance of the idea, something some of the earlier authors clearly did not have — such as the arborist who buried his thoughts on natural selection in the appendix of a book on naval timber. Lastly, Friedman said, scientific discovery demands the ability to convince others of the correctness of an idea. Darwin, through “On the Origin of Species,” was the only thinker of the time who had all three of those traits, Friedman said.

“Darwin had the ability to convince others of the correctness of the idea,” Friedman said, adding that even Wallace, whose claim to new thinking on evolution and natural selection was stronger than all the others, paid homage to Darwin by titling his 1889 book on the subject, “Darwinism.”

The tradition of AAAS Fellows began in 1874. Currently, members can be considered for the rank of fellow if nominated by the steering group of their respective sections, by three fellows, or by the association’s CEO. Each steering group then reviews the nominations of individuals within its respective section and forwards a final list to the AAAS Council, which votes on the final aggregate list.

Harvard faculty named AAAS Fellows for 2011 follow:

Frederick W. Alt, Harvard Medical School, for distinguished contributions to the field of genome stability, particularly for elucidating the mechanisms of immunoglobin gene rearrangement and nonhomologous end joining in mammalian cells.

Barry R. Bloom, Harvard School of Public Health, for his many contributions to and leadership in the areas of infectious diseases, vaccines, and global health.

Lewis Cantley, Harvard Medical School, for distinguished contributions to the field of signal transduction and control of cell growth.

Nicholas A. Christakis, Harvard Medical School, for foundational research on the relationship between social networks and health, applying network science and mathematical models to understand health dynamics in longitudinally evolving networks.

R. John Collier, Harvard Medical School, for distinguished contributions to our understanding of how bacteria cause disease, particularly for elucidating the structures and actions of bacterial toxins.

William Friedman (nominated for the fellowship while a professor at the University of Colorado), Arnold Arboretum, for important contributions to the study of angiosperm evolutionary development biology.

Vadim Gladyshev, Harvard Medical School, for distinguished contributions to the fields of redox regulation, signaling, and the biochemistry, bioinformatics, and biology of the trace element selenium.

Michael E. Greenberg, Harvard Medical School, for the study of activity dependent processes whose dysfunction can lead to the development of diseases of cognitive function.

Roberto Kolter, Harvard Medical School, for distinguished contributions to understanding the genetics of and signaling in bacterial stationary phase and biofilm production.

Bjorn R. Olsen, Harvard School of Dental Medicine, for distinguished research contributions to cell, matrix, and developmental biology and to dental academics through innovative leadership at the Harvard School of Dental Medicine.

Stuart H. Orkin, Harvard Medical School, for distinguished contributions to the understanding of the development and function of the blood system, particularly the mechanistic basis of lineage selection and hemoglobin switching.

Hongkun Park, Faculty of Arts and Sciences, for his distinguished contributions to nanoscience, particularly for pioneering work in single-molecule transistors and nanodevices, and the exploration of their utility in electronics, optoplasmonics, and biology.

Charles N. Serhan, Harvard Medical School, for distinguished contributions to medical sciences (pathology), with the identification of novel mechanisms in resolution of inflammation via structural elucidation of endogenous anti-inflammatory-pro-resolving chemical mediators.

Yang Shi, Harvard Medical School, for seminal contributions to the field of epigenetics by identifying the first histone demethylase, thus disproving the long-held view that histone methylation is irreversible.

Cornelis P. Terhorst, Harvard Medical School, for distinguished contributions to the characterization of the CD3/T cell receptor complex, SLAM molecules, and highly innovative studies on X-linked lymphoproliferative and inflammatory bowel diseases.

For more information.

Friedman, also the Arnold Professor of Organismic and Evolutionary Biology at Harvard University, has established the Director’s Lecture Series in which nationally recognized experts will examine an array of contemporary topics related to Earth’s biodiversity and evolutionary history, the environment, conservation biology, and key social issues associated with current science. Lectures are free and registration is required.

For a schedule of events; to register for these events.

During nearly a decade in the post, Hyman put significant emphasis on intellectual activities that cross disciplines and School boundaries, and played a key role in founding major institutes and academic centers that forged new approaches to scientific research.

“Being Harvard provost is undoubtedly one of the greatest privileges in American higher education,” Hyman said. “Working with Harvard’s talented deans, faculty, and other University leaders, I have had an opportunity to nurture their high aspirations for some of the world’s greatest academic departments, professional Schools, museums, and libraries, as well as for their extraordinary students.”

Hyman, a neurobiologist and past director of the National Institute of Mental Health (NIMH), said he would take a one-year sabbatical at the Broad Institute of Harvard and Massachusetts Institute of Technology (MIT) to refocus on his academic work. He also plans to create an undergraduate course on the implications of neuroscience for ethics, policy, and law.

Harvard’s longest-serving provost in modern times, Hyman broadened the scope of the role through programmatic expansions that served all of the Schools, including the modernization of the University’s technology transfer programs, and the establishment of policies to support international research and collaborations.

“I have deeply valued my partnership with Steve,” said President Drew Faust. “He has spurred fresh thinking and important initiatives in areas ranging from the sciences to the humanities, from the museums to the libraries … In all of these areas and more, he has approached his role with intelligence, passion, and wit, and with a devotion to the highest academic standards.”

Faust said the search for a new provost would begin early next year.

“Steve has done an outstanding job as provost, especially in helping the University navigate a decade full of change and in creatively pursuing ways to make Harvard more than the sum of its parts,” said Robert D. Reischauer, senior fellow of the Harvard Corporation. “He’s contributed a great deal to the Corporation’s deliberations on a wide range of issues, and he’s consistently been a positive force for academic and organizational innovation. More than that, he’s been a pleasure to work with, and all of us on the Corporation join in thanking him for his leadership, his insight, and his dedication.”

Hyman oversaw the reorganization of the American Repertory Theater, supported the renovation of the Fogg Art Museum, and appointed the current directors of those two institutions, as well as the Arnold Arboretum and Villa I Tatti, Harvard’s Renaissance research center in Italy. He is currently leading the search for a new curator of the Nieman Foundation and, having overseen a review of the University’s vast library system, also is chairing the new Harvard Library Board that will establish a more closely coordinated management structure to strengthen Harvard’s position as the pre-eminent university library of the 21st century.

Hyman also worked to elevate the Harvard Humanities Center to the status of a University-wide center. “Steve Hyman is in many ways a Renaissance man, and I don’t use the term lightly,” said Homi Bhabha, director of the Mahindra Humanities Center and the Anne F. Rothenberg Professor of the Humanities, who noted that Hyman helped him to organize seminars that explored the intersection of the humanities and the sciences. “He has deep interests, of course, in the neurosciences and in the sciences more generally, but he is also very interested in the classics and in contemporary debates in the humanities.”

At a time when difficult questions were being asked about diversity in the ranks of Harvard’s faculty, Hyman established the Office of Faculty Development & Diversity, whose mission has been to improve the faculty experience while taking steps to ensure that the evolving faculty more closely reflects the increasing diversity of the student body.

“Steve’s background in medicine, his passion for the liberal arts, and his experience in leading the NIMH gave him the perfect set of skills to be an extraordinary provost,” said Harvard College Dean Evelynn Hammonds, who was the first vice provost for faculty development and diversity. “Steve never lost sight of the University’s goals and priorities. He’s been a wonderful mentor and friend to me.”

Many of Hyman’s most far-reaching accomplishments revolve around research and education in the sciences and engineering. He was integrally involved in elevating Harvard’s Division of Engineering to School status, and in founding such entrepreneurial and interdisciplinary ventures as the Wyss Institute for Biologically Inspired Engineering, a collaborative venture of Harvard Medical School (HMS), the School of Engineering and Applied Sciences, and the Faculty of Arts and Sciences; the Broad Institute, of MIT and Harvard, which takes a systematic, collaborative approach to genomics and the life sciences more generally to dramatically accelerate the treatment of disease; and the Ragon Institute of Massachusetts General Hospital, MIT, and Harvard, which supports nontraditional partnerships among experts to accelerate the search for an HIV/AIDS vaccine.

Gary Gottlieb, president and chief executive officer of Partners HealthCare, said Hyman had been “a visionary in creating a single campus for Harvard University.”

“His office has allowed the development of close collaboration among the hospitals and the HMS quadrangle faculty and the great scientists and teachers at the main campus of the University,” Gottlieb said. “He is passionate, brilliant scientifically, yet he’s a true physician who grew up in the hospitals. He really understands the great strength of all the parts of the University.”

Hyman established the Harvard University Science and Engineering Committee, which brings together faculty and deans from all of Harvard’s Schools that support science and engineering, along with leaders of the University-affiliated hospitals, to take an integrated approach toward priority setting and initiating new collaborative ventures. He played a key role in creating the Department of Stem Cell and Regenerative Biology, Harvard’s first cross-School department, and the Harvard Stem Cell Institute, which has been a world leader in the growing field of stem cell research.

“Steve Hyman has been a very strong voice for science and innovation at Harvard, working to support new structures for research and teaching within our community,” said Doug Melton, co-director of the Harvard Stem Cell Institute. “A notable success was his ability to foster and coordinate new research initiatives within Harvard, as well as making stronger connections with Harvard’s affiliated hospitals. I was delighted to learn that he is returning to experimental science for his next challenge, and look forward to watching his discoveries at Harvard.”

“I thought, my God,” he recalled, “the room is full of old people.”

Little did Hamilton realize that this group of distinguished senior citizens, all former Harvard employees like himself, would become, in his words, “The most energized, creative, and interesting group of people I have ever worked with.”

“It’s been a great delight to work with them, and for the hundreds of retirees I have come to know so well,” said Hamilton, who is now president of the association.

Established in 1991, HURA is a nonprofit organization for former Harvard employees at all levels. With partial financial backing from the University, the group offers a range of programs and services for retired Harvard faculty and staff who are eager to stay connected to the University. For this dynamic group, age is just a number.

Eighty-year-old tango dancer Anne Atheling, who retired as business manager at the Arnold Arboretum in 1997, loves the Argentine art form and the fact that HURA helps her publicize her Tango Society of Boston events.

“It’s a wonderful resource,” Atheling said.

As a longtime University library administrator and human resources officer, Hamilton followed a simple mantra during his 37 years at Harvard, one he relies on as HURA president: “Set goals, secure the resources people need to reach those goals, and then stay out of their way.”

His philosophy has “worked very well with HURA,” said Hamilton, who has led HURA for six years and helped usher the organization into the computer age. There is a new website on HARVie and a robust electronic mailing list that the organization uses to convey information to 1,000 subscribers.

The group coordinates trips to the ballet, behind-the-scenes visits to Symphony Hall and Fenway Park, and of course, outings to Harvard football and hockey games, as well as popular “rambles” ­­— leisurely walking tours of local reservations and parks. Through HURA, members can also connect with volunteer groups and other enrichment opportunities, as well as to each other.

What began as a small group of retirees in the 1980s — brought together initially to help organize Harvard’s 350th anniversary celebration — has blossomed into a network of more than 1,200 members. The group, which has officers and a board of directors, also hosts three major yearly gatherings: a holiday party, an annual meeting, and HURA Day in the spring.

Each March during spring break, the group commandeers the Science Center for a day of meetings and discussions with Harvard’s faculty and University administrators. During the event, Harvard-affiliated organizations like Outings & Innings, the Harvard University Employees Credit Union, and Harvard University Health Services set up information tables.

“We try to give people some impression of all of the services that the University offers to all of its retirees,” said Hamilton.

HURA also produces a newsletter five times a year containing information of interest to retirees, along with cultural and educational happenings, HURA activities, and updates on retiree benefits. HURA members also receive the “Harvard Resources for Retirees” handbook, which describes the services and resources available to them.

“It’s a very vibrant, caring group,” said its longtime secretary and former human resources administrator Carole Lee. “I have stayed with it this long because I enjoy it so much.”

Membership costs $15 a year and is open to all benefits-eligible Harvard retirees.  For more information, contact Carole Lee, 15 Yerxa Road, Cambridge, MA 02140. You also can call 617.864.8694, or email caroleandjack@comcast.net.

Designs must be original artwork for the front of a T-shirt, suitable for men and women. The competition is open to all ages, and each artist may submit up to three designs. The deadline for all submissions is Jan. 31.

For the complete guidelines, visit the arboretum’s website.

Friedman, set to start on Jan. 1, will be the eighth director of the Arboretum, which is administered by Harvard’s Office of the Provost. He also will be a tenured professor in the Faculty of Arts and Sciences. His priorities include strengthening ties between the Arboretum and the Cambridge campus and working closely with the Arboretum’s neighbors in Jamaica Plain and Roslindale.

“Ned’s appointment underscores Harvard’s commitment to integrating the incredible resources and opportunities presented by the Arboretum with the important work of our scientists here in Cambridge,” said Provost Steven E. Hyman. “As an FAS faculty member, Ned will be a part of the Harvard community. As director of the Arboretum, he will seek closer ties, not only with our Cambridge campus, but also with the city of Boston, the Arboretum’s home.”

Friedman has been a professor of ecology and evolutionary biology at the University of Colorado since 1995. As professor of organismic and evolutionary biology at Harvard, he will conduct research in the new Weld Hill Research and Administration Building at the Arboretum and teach at Harvard’s Cambridge campus.

Part of Boston’s Emerald Necklace of parks, the 265-acre Arboretum, founded in 1872 and designed by Frederick Law Olmsted, is free and open to the public every day of the year. Its programs and events include lectures and community outreach initiatives in neighboring schools.

“Professor Friedman’s appointment creates an exciting opportunity to connect the unique resources of the Arnold Arboretum in Boston to the plant science research and education occurring on our Cambridge campus,” said Jeremy Bloxham, FAS dean of science. “Ned’s teaching and leadership will facilitate closer linkages between the educational and research possibilities the Arboretum presents and the innovative scholarship of our faculty and students.”

Friedman’s research has focused on patterns of plant morphology, anatomy, and cell biology. He was recently acclaimed for his discovery of a new type of reproductive structure in an ancient flowering plant that may represent a critical link between flowering plants and their ancestors.

Friedman also has a keen interest in the history of science, particularly the intellectual history of evolutionism. He has designed and taught courses on the life and work of Charles Darwin and other historical figures, and lectured on the subject at natural history museums and other venues.

On Nov. 4, Friedman will deliver a lecture at the Harvard Museum of Natural History on “Darwin’s ‘Abominable Mystery’ and the Search for the First Flowering Plants.” He plans to launch a Director’s Lecture Series at the Arboretum that will make accessible to the public cutting-edge research by leading scientists from Harvard and around the world.

“I am thrilled to be able to welcome a diverse group of audiences to the Arnold Arboretum, one of the world’s leading resources for the study of plants, and help integrate it more deeply into the research and teaching missions of Harvard University,” said Friedman. “I am also deeply committed to building on the Arboretum’s robust history and its ongoing programs to enhance a neighborhood resource that brings the world of biodiversity to Greater Boston.”

Friedman is the author or co-author of more than 50 peer-reviewed publications, and serves on editorial committees for the American Journal of Botany, the International Journal of Plant Sciences, the Journal of Plant Research, and Biological Reviews. He is a member of the Botanical Society of America.

Friedman received a bachelor’s degree in biology from Oberlin College in 1981, and a doctorate in botany from the University of California, Berkeley, in 1986. He is a fellow of the Linnean Society of London, and a 2004 recipient of the Jeanette Siron Pelton Award, granted by the Conservation and Research Foundation through the Botanical Society of America. In 1991, he received the Presidential Young Investigator Award from the National Science Foundation. Friedman spent his early career in the Botany Department at the University of Georgia before joining the faculty at the University of Colorado.

With plenty of rain.

At the dedication of the Harvard Community Garden on Mt. Auburn Street on Sunday (April 18), well-wishers huddled gratefully under a blue tarp noisy with rain. Nearby, green lawn chairs sat empty.

But the garden at 27 Holyoke Place offers sunny messages: that food can grow in an urban backyard; that a garden is a living laboratory for diverse academic pursuits; and that an open garden encourages community.

The plot in front of Lowell House — 560 square feet of growing space — is a lesson in local food and sustainability that matches the University’s environmental ethic, said Zachary Arnold ’10. “Our tagline is: a beautiful and productive space.”

The Eliot House senior is one of a dozen or so undergraduates who helped to organize a new club, the Harvard College Garden Project, a year in the making.

The garden, consisting of 25 raised beds spaced along stone-dust patios, is supervised by the Center for Health and the Global Environment (CHGE) at Harvard Medical School. Collaborators include the Office for Sustainability (OFS), the University Planning Office, Landscape Services, the Faculty of Arts and Sciences, and the Food Literacy Project, a division of Harvard University Hospitality and Dining Services.

Food harvested from the garden — lettuce, onions, peas, and other traditional New England kitchen crops — will be used in on-site tastings and demonstrations, consumed at undergraduate dining halls, sold at the Food Literacy Project’s two farmers’ markets, or donated to the Greater Boston Food Bank.

Within a year, organizers say, the garden will expand. On the wish list are trellises, more raised beds, work stations, storage, and a system for harvesting rainwater.

The site will also serve as an outdoor classroom and as a gathering place. Arnold called the new garden a “multiuse space.”

This summer, two full-time interns will tend the garden, said the project’s acting director, Kathleen Frith, who is assistant director at CHGE. They also will develop protocols for how the garden might be used in current Harvard courses.

In the fall, she said, faculty will be invited to a forum on ways to bring the garden into the classroom. The hope is to get faculty to use the garden in existing courses, said Frith, not just in the sciences, but for poetry, languages, and the arts.

Over time, courses will emerge that are specific to the garden, said Frith. Lessons in urban agriculture will include growing on vertical surfaces, composting, and water-conservation strategies.

“When you look out here, you see a garden,” said botanist Donald Pfister, who made brief remarks from the shelter of the tarp. “I see a whole lot of thesis projects.”

He said there is academic work to be done, for instance on integrated pest management, urban habitats, and the microbial composition of the garden’s soils.

Pfister, an authority on the biology of fungi, is Harvard’s Asa Gray Professor of Systematic Botany and acting director of the Harvard University Herbaria. He told the small crowd, “I want you to think about this as your laboratory.”

Pfister is also dean of the Harvard Summer School, which runs during a peak season for studying plants. “To be able to be out in it,” he said of the garden-as-classroom, “is the great thing.”

Six decades ago, Harvard had a full-scale botanical garden at Garden and Linnaean streets. “That was the ultimate,” said Pfister, and included classroom space, plant displays, greenhouses, and outdoor growing beds.

But the intent of the Harvard Community Garden is wider than plant science, making it a kind of first at Harvard. “Our center works at the intersection of human health and environmental issues,” Frith said. “For me, growing food locally fits right in that intersection.”

It will be a boon to social well-being, she added, and has already brought students, faculty, staffers, and neighbors together. “That’s going to be the healthiest part of this garden: learning and getting to know and working with everybody.”

Ilana Cohen stood nearby. She was one of eight landscape architecture students at the Graduate School of Design who helped to design the garden. (The others were Erin Kelly, Rebecca Bartlett, Amy Whitesides, Dorothy Tang, Abhishek Sharma, Xue Zhou, and Athens Qin.)

The project — including a design charrette this winter — brought the benefits of community and collaboration, agreed Cohen. “It’s been great to meet people from other institutions within the University. We wind up in our separate silos quite easily.”

Evelynn M. Hammonds, dean of Harvard College, spoke from under the tarp, with a crimson-striped umbrella furled at her side. “It’s really a great start for Harvard and the College,” she said of the garden. “This will be the first space, but it won’t be the last space.”

Afterward, in a raised garden bed nearby, Joshua Wortzel ’13 scattered radish seeds. It was the new garden’s first planting. In another raised bed, seeds were scattered for arugula and rhubarb chard. Helping out was Jaclyn Olsen, assistant director at OFS.

“It’s amazing to see the students come together for something’s environmental, community, and social benefits,” she said. “It shows that Harvard is really trying to apply what the students are learning and what the faculty are teaching.”

Designing the garden came with challenges, said Cohen, who graduates this year. For one, the garden could not be planted in the lawn soils, so raised beds were a necessity. And those raised beds had to be accessible, even to gardeners in wheelchairs.

So the designers drew up flat pathways and settled on varied heights for the beds: 34, 20, and 16 inches, a “stepped condition,” said Cohen. “You wind up with these very dynamic spaces.”

The garden also had to encourage social interaction. So seating was built into some of the beds, which are arranged to create nooks. Visitors can “gather,” said Cohen, “and be surrounded by growing.”

And the garden probably will be expanded someday, so it was important to create an expandable design. “It’s a very modular system,” she said. “You could always add beds in the future and still have them fit with the same design language.”

Executing the design took hands-on work. Arthur Libby and Ryan Sweeney of Landscape Services started at the site March 18. They installed the patio first, with its border of wood and surface of stone dust. Then they put in a fresh asphalt access walk. They framed the 25 garden beds off-site, and installed them last Friday (April 16).

“The fact that we were able to work with the students one-on-one was pretty exciting,” said Libby, who took a moment to shelter from the rain in his truck. “They’re out there, hands-on, learning the importance of sustainability.”

On Sunday morning, Libby, Sweeney, and a group of students filled the raised beds with heavy dark soil, shoveling them full and raking the surfaces flat.

The soil is made from compost seasoned in windrows at the Arnold Arboretum of Harvard University in Jamaica Plain, Mass. It’s a loamlike mix of what was once food waste, grass clippings, leaves, and other organic matter.

The garden dedication, hurried by intermittent rain, wrapped up fast. “Soggy cookies?” Frith asked, holding out a plate to students walking by.

“See,” she added, “we’re feeding people already.”