河蚬(Corbicula fluminea)对霍甫水丝蚓(Limnodrilus hoffmeisteri)生物扰动的抑制效应

Inhibiting effect of Corbicula fluminea on the bioturbation of Limnodrilus hoffmeisteri

近年来太湖局部区域水体富营养化仍有加剧趋势,这可能与底栖动物生物扰动促进沉积物营养盐释放有关.耐污种霍甫水丝蚓(Limnodrilus hoffmeisteri)与常被用于生态修复的河蚬(Corbicula fluminea)均为太湖底栖动物优势种类,本文设计了双因素4组处理(对照组、河蚬组、霍甫水丝蚓组和混合组(霍甫水丝蚓和河蚬))的室外受控实验,研究在太湖2种种群分布交错区,河蚬能否对霍甫水丝蚓的生物扰动产生抑制效应.结果表明:霍甫水丝蚓扰动能显著增加水体总氮、总磷浓度,同时促进浮游植物生长;河蚬通过滤食和生物沉降作用显著降低水体总氮、总磷和悬浮物浓度,抑制浮游植物生长,从而促进了底栖藻类的生长;河蚬对霍甫水丝蚓生物扰动效应有抑制作用.

In recent years, eutrophication in partial areas of Lake Taihu still had a tendency to become worse which may attributed to the release of internal nutrient loading promoted by the bioturbation of zoobenthos. Corbicula fluminea and Limnodrilus hoffmeisteri were the dominant species in Lake Taihu. In order to explore whether C. fluminea had inhibiting effect on the bioturbation of L. hoffmeisteri, a mesocosm experiment including four treatments (control, C. fluminea, L. hoffmeisteri, C. fluminea & L. hoffmeisteri) was carried out from September 22 to October 12, 2014. The results showed that the bioturbation of L. hoffmeisteri could increase the concentration of total nitrogen and total phosphorus in water column remarkably, meanwhile stimulated the growth of phytoplankton. C. fluminea could decrease the concentration of total nitrogen, total phosphorus and total suspended matter remarkably by filter-feeding and biodeposition. Besides, C. fluminea had inhibiting effect on the growth of phytoplankton which in turn promoted the growth of benthic algae. Our results confirmed that C. fluminea had inhibiting effect on the biotubation of L. hoffmeisteri. © 2016 by Journal of Lake Sciences.