Responses of trophic structure and zooplankton community to salinity and temperature in Tibetan lakes: Implication for the effect of climate warming
Responses of trophic structure and zooplankton community to salinity and temperature in Tibetan lakes: Implication for the effect of climate warming
复制标题
西藏湖泊营养结构和浮游动物群落对盐度和温度的响应：对气候变暖影响的启示
DOI：
10.1016/j.watres.2017.07.078
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发表时间：
2017-11-01
期刊：
影响因子：
12.8
通讯作者：
Han, Bo-Ping
中科院分区：
文献类型：
--
作者：
Lin, Qiuqi;Xu, Lei;Han, Bo-Ping
气候变暖对湖泊生态系统产生了明显的影响，要么直接导致温度升高，要么间接导致盐度变化。对西藏沿着海拔2300 m、盐度梯度76的45个湖泊的浮游动物群落和营养结构现状进行了调查。淡水-低盐湖泊主要有浮游植物、小型浮游动物和鱼类/钩虾3个营养级，而中盐-高盐湖泊只有浮游植物和大型浮游动物2个营养级。浮游动物物种丰富度随盐度的升高而显著下降，但与温度无关。此外，在两个营养级的湖泊中，物种丰富度随盐度的下降远不如在三个营养级的湖泊中来得突然。浮游动物群落结构的变化取决于食物链的长度，并显着解释盐度作为关键的环境变量。浮游动物群落由低盐度3个营养级湖泊的桡足类和小型枝角类优势种向高盐度2个营养级湖泊的大型盐滤食性叶足类优势种转变。浮游动物与浮游植物的生物量比在两营养级系统中与温度呈正相关，在三营养级系统中与温度呈负相关。由于青藏高原的变暖速度比全球平均速度快三倍，我们的研究结果表明，变暖可能会对西藏湖泊生态系统的结构和功能产生相当大的影响，无论是通过盐碱化/脱盐对物种丰富度，组成和营养结构的间接影响，还是通过水温对营养相互作用的直接影响。(C)2017爱思唯尔有限公司版权所有
Warming has pronounced effects on lake ecosystems, either directly by increased temperatures or indirectly by a change in salinity. We investigated the current status of zooplankton communities and trophic structure in 45 Tibetan lakes along a 2300 m altitude and a 76 salinity gradient. Freshwater to hyposaline lakes mainly had three trophic levels: phytoplankton, small zooplankton and fish/Gammarus, while mesosaline to hypersaline lakes only had two: phytoplankton and large zooplankton. Zooplankton species richness declined significantly with salinity, but did not relate with temperature. Furthermore, the decline in species richness with salinity in lakes with two trophic levels was much less abrupt than in lakes with three trophic levels. The structural variation of the zooplankton community depended on the length of the food chain, and was significantly explained by salinity as the critical environmental variable. The zooplankton community shifted from dominance of copepods and small cladoceran species in the lakes with low salinity and three trophic levels to large saline filter-feeding phyllopod species in those lakes with high salinity and two trophic levels. The zooplankton to phytoplankton biomass ratio was positively related with temperature in two-trophic-level systems and vice versa in three-trophic-level systems. As the Tibetan Plateau is warming about three times faster than the global average, our results imply that warming could have a considerable impact on the structure and function of Tibetan lake ecosystems, either via indirect effects of salinization/desalinization on species richness, composition and trophic structure or through direct effects of water temperature on trophic interactions. (C) 2017 Elsevier Ltd. All rights reserved.