文献类型：会议论文

英文题名：Density-dependent effects of snail grazing on the growth of a submerged macrophyte, Vallisneria spiralis

作者：Li, Kuan-Yi[1,2];Liu, Zheng-Wen[1,3];Gu, Bin-He[4]

机构：[1]Chinese Acad Sci, State Key Lab Lake Sci & Environm, Nanjing Inst Geog & Limnol, Nanjing 210008, Peoples R China;[2]Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China;[3]Jinan Univ, Inst Hydrobiol, Guangzhou 510630, Guangdong, Peoples R China;[4]Guangdong Ocean Univ, Fishery Coll, Zhanjiang 524000, Peoples R China

会议论文集：Eco Summit 2007

会议日期：MAY 22-27, 2007

会议地点：Beijing, PEOPLES R CHINA

语种：英文

外文关键词：Radix swinhoei; Grazer density; Vallisneria spiralis; Growth

外文摘要：In order to better understand the role of herbivorous snails in freshwater ecosystems, we conducted experiments investigating food preference of the snail Radix swinhoei on leaves of the submerged plant Vallisneria spiralis with and without periphyton coverage. The effects of snail grazing on the growth of V. spiralis were assessed in a no-snail control and at three snail densities (80, 160, 240 individuals m(-2)). Results showed that the snails chose preferentially leaves covered by periphyton. Grazing activity at low snail density (80 individuals m(-2)) was found to stimulate V. spiralis growth, but at higher snail density (240 individuals m(-2)), plant growth was apparently suppressed. An increase observed in nutrient concentrations in water column with increasing snail density may be attributed to nutrient release by snails. This study suggests that the nature of the relationship between herbivorous snails and macrophytes in freshwater ecosystems depends on the abundance of the snails. At low snail density, the relationship may be a mutualistic one, but at high density snail herbivory may impact negatively on macrophyte biomass in lakes. (C) 2009 Elsevier B.V. All rights reserved.