Thursday, August 5, 2010 - 3:20 PM

COS 99-6: Edge effects of roads on forest plant diversity and ecosystem properties: A case study from Southern China

Ting Zhou1, Shaolin Peng2, Jianguo Wu3, Jingang Liu2, and Keke Wu2. (1) Sun Yat-Sen University, Arizona State University, (2) Sun Yat-Sen University, (3) Arizona State University

Background/Question/Methods Roads create edge effects on plant community structure and ecosystem properties through fragmenting habitat and introducing disturbances.  These effects may vary with the width of roads as well as the specifics of ecosystems under consideration.  We assessed the edge effects of wide (6-8m) and narrow (2m) roads on plant species diversity, biomass, and soil properties in the Dinghushan Nature Reserve and the Baiyun Mountain, Guangdong, China.  Data were collected at different distances along transects running from the roads to the interior of the forests.  

Results/Conclusions  Our results showed that wide and narrow roads had different edge effects.  For the wide roads, plant diversity and soil moisture tended to increase, whereas herbaceous biomass tended to decrease, from the road edge to the forest interior.   Tree biomass and soil pH at the road edges were significantly higher than those in the forest interior.  No significant difference between the edge and the interior was found, however, in terms of soil microbial biomass carbon, available phosphorus, organic matter content, and total soil nitrogen.  For the narrow roads, none of the measured variables showed a statistically significant difference between the edge and the interior.  Our study suggests that forest roads tend to increase plant biomass mainly because of increased light availability, but reduce plant diversity probably due to increased competition, in the edge zone of a forest.  It also suggests a threshold width of roads for edge effects to take place, which is between 2 and 8 m for the study forests.  These findings have important implications for forest conservation and landscape planning in this region so as to maximize biodiversity and minimize habitat fragmentation and edge effects.