Urban sprawl not as harmful to wildlife as previously thought? / by urbanexus

Barn Owl in flight

On December 20, 2006, the online science journal PLoS One posted an article entitled "Depauperate Avifauna in Plantations Compared to Forests and Exurban Areas"[i]  The three authors are David G. Haskell and Jonathan P. Evans, who are affiliated with the Landscape Analysis Lab at the University of the South in Sewanee TN, USA, and  Neil W. Pelkey who is  an environmental science professor at Juniata College in Huntington, PA, USA. 

Using field surveys and digital maps of habitat, the authors compared the diversity of bird populations in natural forests, tree plantations and "exurban" (urban sprawl) areas along the Cumberland Plateau in Tennessee. They found that tree plantations had substantially less bird population diversity than did native forests and exurban areas. In some cases, exurban areas had more diversity than did the native forests.  “These findings suggest that urban sprawl is not all bad for wildlife,” Haskell says. “This turns conventional wisdom about wildlife conservation on its head.”

For years scientists have been concerned with the loss of biodiversity resulting from worldwide deforestation. Governments and private organizations have implemented conservation programs that discourage sprawl and promote tree plantations to replace deforested areas.  “Scientists had assumed that tree plantations were preferable to exurban areas for wildlife conservation,” Haskell says. “This study firmly refutes this assumption, and has important implications for government policies, many of which subsidize plantations and penalize sprawl in the name of wildlife conservation.”

For estimates of forest cover, the U.S. government classifies forest converted to tree plantation as “no loss of forest”, and classifies wooded areas where houses have been built as “loss of forest.”  “Yet our data show that plantations have much lower levels of biodiversity than do native forests and that exurban areas can retain much of the biodiversity of native forests,” the researchers write. “Therefore, current methods of accounting for forests give potentially misleading results for biodiversity analyses.” 

[i]The article can be found at:http://www.plosone.org/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1371%2Fjournal.pone.0000063#aff1