Isolated forest patches can lose species and biological diversity

Washington, June 12 (ANI): A new study has revealed that the increasing fragmentation of forest patches by roads and development are making them isolated green islands, which can lose species and biological diversity.

The study, by University of Wisconsin-Madison researchers, is revealing that decades of fragmentation of Wisconsin's forests have taken a largely unseen toll on the sustainability of these natural ecosystems.

The long generation times of trees and other plants have masked many of the ecological changes already under way in the patches of forest that remain, according to study co-author Don Waller, a professor in the Department of Botany and Nelson Institute for Environmental Studies at UW-Madison.

"Things may look healthy, but over time we see an erosion of biodiversity," he said.

To better catalog the changes at work, he and colleagues looked beyond the trees to the forest understory - the shrubs, grasses and herbs covering the forest floor - to witness how Wisconsin's forests are really faring.

Their results show that fragmentation is reducing the abundance and diversity of native plants in southern Wisconsin forests.

The findings highlight the effects of increasing urban development and road density, especially in the southeastern part of the state.

Land use changes have a pronounced impact on the islands of forest that remain, even when these are protected as parks or natural areas.

"These forest patches are not just losing species - their whole biological nature is changing," said David Rogers, an assistant professor of biological sciences at UW-Parkside who led the study while a UW-Madison graduate student.

"Surrounding landscape factors, like urbanization and agricultural dominance, are now determining which species can survive in these little patches," he added.

According to the researchers, though negative effects of fragmentation on biodiversity have gone largely unrecognized in the past, the impacts appear to be intensifying over time.

Nearby cities and towns now strongly affect local woodlots, causing smaller plots in particular to lose species.

"When we isolated these forest patches 50 or 100 years ago, we were dooming species to extinction," said Waller. "It may not happen right away - and in that sense it's an 'extinction debt' - but it will accumulate over time," he added. (ANI)