Popular causes not necessarily best

Conservation policies favoring keystone animal species are insufficient to conserve the world’s biodiversity because many of these target animals don’t live in the world’s most bio diverse spots: lowland tropical forests under pressure from agriculture, logging, and other human activities.

“We need a completely different approach to conservation, particularly if these [tropical forest] plants are proxy for overall biodiversity,” said former Arnold Arboretum director and Charles Bullard Professor of Forestry Emeritus Peter Ashton.

Ashton made the comments as the kickoff speaker in the Harvard Museum of Natural History lecture series “Plants Matter” on Tuesday (Oct. 16) in the Geological Lecture Hall.

Ashton used conservation efforts on the heavily deforested island of Borneo, where he spent years doing fieldwork, to illustrate his point.

Today, organizations are looking to conserve remnant upland forests in Borneo’s mountains as habitat for a variety of animal species. The effort is a reflection of a widespread emphasis on conservation of wide-ranging birds and mammals popular with the public. The reasoning of these programs, he said, is that by conserving these animals, they’ll also conserve their habitats, helping less-charismatic plants, animals, insects, and fungi.

Though those animals and their forests are certainly worth protecting, Ashton said, if the goal is to save as many of the world’s species as possible, then efforts have to target the forests containing the most biodiversity. And those forests are often not home to the charismatic animals and birds that are the target of both public interest and many of today’s conservation efforts.

“It’s a worthwhile project, even from a botanist’s point of view, but it’s not sufficient,” Ashton said. “We’ve got to go for these tiny little places that yet remain along the coast … because it’s there that the great concentration of biodiversity is to be found.”

These lowland patches are difficult to conserve, Ashton said, because they don’t generate income for their owners unless they’re utilized in some way. Logging and agriculture extract resources, but are destructive. Ecotourism can generate revenue without damaging the forest, but tourists are more interested in exotic animals than they are the trees and understory plants that make up most of the species diversity in these areas.

“Ecotourists come and say, ‘Where are the elephants? Trees? No, no, no, you’ve seen one tree, you’ve seen them all,’” Ashton said.

Developed countries ought to play a role and contribute financially to the preservation of these last species-rich spots, Ashton said. Conservation of the world’s remaining biodiversity is at least as pressing an issue as reducing greenhouse gases in the atmosphere responsible for global warming.

Ashton said the genes of all the varied species of plants and animals constitute a library of the planet’s genetic information. He likened the tropical forests to the Library of Congress — full of books few people read on a day-to-day basis, but a potentially critical resource to someone looking for the key to an important discovery.

The good news, Ashton said, is that because rainforest trees are immobile and long-lived, they can persist in relatively small patches of forest for some time. Unlike a wide-ranging animal that faces extinction if it loses part of its range, patches of rainforest can hold as many as 700 different tree species — more than in all of Canada and the United States — and, if not cut, persist for a long time even as neighboring forests disappear.

Ashton has spent decades working in the forests of Southeast Asia. His research has focused on the taxonomy and biogeography of tropical tree species. A critical milestone was his work establishing a network of tropical forest plots around the world used to study the forests and their response to global climate change. Earlier this year, Ashton received the Japan Prize, one of biology’s top honors.

“Species and individuals are unique. There are no copies. When you’ve lost a species, you’ve lost them forever,” Ashton said. “In my opinion, we have a special responsibility to regard biodiversity as an asset and protect it. It is as important as getting carbon out of the atmosphere and we’ve got to start … putting more money into its protection. Otherwise, it’s gone.”