全球变暖与富营养化的协同作用研究：以湖泊沉积物为例

Freshwaters are particularly vulnerable to climate change because (i) many species within these fragmented habitats have limited abilities to disperse as the environment changes; (ii) water temperature and availability are climate-dependent; and (iii) many systems are already exposed to numerous anthropogenic stressors. Most climate change studies to date have focused on individuals or species populations, rather than the higher levels of organization (i.e. communities, food webs, ecosystems). This study will mimick experimentally a scenario of global warming in sediment system of shallow lakes located in the middle and lower reaches of Yangtze River. The aim is to investigate whether a predicted temperature rise in the next century can change the structure and function of the sediment system. Questions to be addressed include (1) how metabolism balance in different trophic level of lake sediment system is response to global warming? (2) will global warming interact with increased nutrient supply to alter response mechanisms and variation characteristics of metabolism balance in lake sediment system? (3) will changing climate aggravate eutrophication symptoms

淡水生态系统极易受到气候变化的影响，其主要原因为（1）破碎化生境中的许多物种已很难应对各种环境的改变；（2）水温与水资源的可利用性与气候变化紧密相关；（3）生态系统已经受到许多人为因素的干扰。目前，大多数气候变化的研究多集中在个体和种群的水平，而对更高组织水平，如群落、食物网及生态系统影响的研究则相对较少。本研究拟选择长江中下游地区典型湖泊沉积物系统作为研究对象，采用实验生态学手段，模拟该地区百年后气候变暖的情景，探讨气候变暖是否会改变湖泊沉积物系统的结构与功能，以期揭示不同营养水平沉积物系统水平代谢平衡在全球变暖趋势下的响应特征；阐明气候变暖与富营养化的协同作用下，湖泊沉积物系统结构与功能的响应机制；揭示气候变暖在水体富营养化进程中的地位与作用。

浅水湖泊是生物圈的重要组成部分，但其也极容易受到流域范围内人类活动的破坏，如营养物质的过量输入导致的水体污染，同时浅水湖泊也可能面临气候变暖趋势的威胁。本研究利用长江中下游地区典型湖泊沉积物系统作为研究对象，采样实验生态学手段，模拟该地区百年后气候变暖的情景。结果表明，变暖导致低营养水体沉积物-水界面间营养物质释放强度更加显著，而对高营养水平水体界面间营养物质释放影响较小。变暖与富营养化的协同作用加速了水体中磷含量的升高，促进水体中藻类生物量的增加；通过协方差分析发现，螺类的周长在不同温度条件下有显著性差异。同时，升温能促使铜锈环棱螺的复苏时间提前以及生物量增大。综合回归分析和协方差分析，螺类的面积能够最大程度预测不同环境下螺类种群生物量。