PARENT SESSION
Poster Session 19: Biodiversity
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Impact of nitrogen addition on biodiversity and productivity of grasslands.
Bai, Yongfei1, Wu, Jianguo1, 2, Pan, Qingmin1, Zhang, Lixia1, Huang, Jianhui1, Han, Xingguo1, 1 Institute of Botany, the Chinese Academy of Sciences, Beijing2 School of Life Sciences, Arizona State University, Tempe, Arizona
ABSTRACT- Understanding the relationship between biodiversity and ecosystem functioning is of fundamental and practical importance in ecology. Recent studies have generated several interesting findings on the effects of nitrogen addition on grassland biodiversity and ecosystem functioning. However, essentially all of these studies were carried out in localized and artificial grasslands in North America and Europe, and their results need to be tested in natural grasslands that occupy vast geographic regions (e.g., the Eurasia Steppe). To address this issue, here we report on the results of a 4-yr field experiment of nitrogen addition in the Inner Mongolia Grassland, a representative area of the Eurasia Steppe. In general, our results corroborated the previous finding that nitrogen addition decreases plant species richness while it increases grassland biomass production and soil nitrogen losses. However, we found that the shift in the relative dominance of plant functional groups in mature steppe communities was in sharp contrast with that reported for North America grasslands. In addition, although their general response patterns were similar, undisturbed mature and degraded steppe ecosystems differed in terms of the details of species turnover and dominant functional group dynamics. Our results shed new light on the biodiversity-ecosystem functioning relationship and have important implications for managing and restoring the vast degraded grasslands in Inner Mongolia steppe region and elsewhere.
Key words: nitrogen addition, biodiversity, productivity, grassland