(PhysOrg.com) -- An agricultural method dating back millennia could be the key to species conservation. For the past 2,000 years, farming practices of the areca nut palm in southwestern India have not changed much. Surprisingly, neither has bird diversity in tropical forests near areca palm plantations.
Survey records dating back over 100 years indicate that more than 90 percent of species found in the Western Ghats region of India still exist today, according to a study published Nov. 3 in the Proceedings of the National Academy of Sciences. The conservation success is largely due to a supportive role that forests play in local agriculture production.
"If it wasn't for the areca nut palm, the forests wouldn't be there," said Jai Ranganathan, lead author of the article, who earned a PhD in biology at Stanford in 2007. He is now a postdoctoral fellow at the National Center for Ecological Analysis and Synthesis.
Fallen branches and leaves from nearby forests are collected and transported to areca nut plantations where they are used as fertilizer and mulch to prevent soil erosion. Because farmers rely on these natural materials to maintain their land, the forests stay intact.
"This could be an important part of the conservation story for the entire Western Ghats region," Ranganathan said. The region extends 1,000 miles from north to south, running parallel to the west coast of India.
The area is a biodiversity hotspot, host to more than 1,000 animal species, including birds, mammals, reptiles and amphibians. More than a third of those species are only found in that part of the world.
The areca nut palm not only supports species biodiversity by conserving bird communities, but also supports the economic livelihoods of local inhabitants, Ranganathan said. He called this a win-win situation for conservationists.
People living in the region's two towns, Kumta and Honavar, maintain economic sustenance by harvesting and selling the fruit produced by the palm.
The areca nut, also known as the betel nut, grows in small, coconut-size clusters at the top of a slender palm tree. It is used by 10 percent of people in the world, primarily in Southeast Asia, who chew the nut to release chemicals that produce a mild, coffee-like alertness.
A high-value cash crop, it provides people living in the region with an economic incentive to keep the forests intact, Ranganathan says, instead of developing the land for other human use that would result in wiping out large numbers of species.
Without incentives, people are inclined to follow the economic drivers that prevail today without thinking about what effects it might have on the future, said Gretchen Daily, a biology professor and co-author of the paper.
In partnership with the Center for Conservation Biology, Daily, who is also a senior fellow at the Woods Institute for the Environment at Stanford, has been researching tropical biodiversity conservation for more than 15 years by conducting studies around the world in places such as Hawaii and Costa Rica.
She advocates a "game-changing view" of conservation that gets people thinking about going beyond nature reserves to contemplating ways of harmonizing human activities with conservation.
Traditional conservation philosophy supposes that in order to protect species from extinction, habitat areas have to be fenced in and locked away from human contact. But according to Daily, this strategy alone is "doomed to fail."
"Even if we ambitiously expand reserve areas in the future, it is likely that we'd protect in the long run only 3 to 5 percent of the Earth's plants and animals," Daily said. "That's such a tiny fraction, no one would call that a success."
People need to get away from the idea that human activity and biodiversity preservation cannot go together, Ranganathan said. "What we have shown in our research is that there is some level of coexistence."
The research was funded by a David L. Boren Graduate Fellowship, the Winslow Foundation and Peter and Helen Bing.
Provided by Stanford University
Explore further: Lichen to thrill as rare Golden-eye is discovered in South Wales