全球变暖对淡水湖泊浮游植物影响研究进展

摘要

The impact of global warming on lake ecosystems has been of central and growing interests to limnologists recently . Here, we describe the strengths and weaknesses of the multi-faceted approaches that are presently available for elucidating the effects of climate change on phytoplankton, including time series, space-for-time substitution, remote sensing, experiments, mod-eling and palaeolimnology.Phenology has been impacted due to rising temperatures, earlier thermal stratification and the disap-pearance of ice-covers on some lakes.These changes have greatly favored increasing dominance by cyanobacteria in lakes globally . Species-specific changes have been observed in response to global warming in different regions around the globe .In lakes where nu-trient supplies are sufficient, primary production of phytoplankton has been enhanced by global warming.However, primary pro-duction might be more inhibited when nutrients are limiting .Because environmental factors invariably interact with each other , knowing how to evaluate the effects of a single factor on phytoplankton composition and activity is the key research challenge . Changes in wind speed and patterns caused by global warming may affect nutrient releasing , as well as the light regimes in the wa-ter column in shallow lakes .Therefore studies on wind-driven effects of sediment and nutrient resuspension events induced by glob-al warming on phytoplankton community succession in large shallow lakes are a future research frontier in limnology .%全球变暖对湖泊生态系统的影响已经成为近年来湖沼学领域的研究热点。本文首先列举了目前研究全球变暖对淡水湖泊浮游植物影响的常用方法：监测数据分析、时空转换、遥感信息提取、控制实验、模型预测和古湖沼学技术等。研究结果表明气候变暖导致的气温升高、湖泊热力分层提前破坏以及无冰期提前等因素可导致春季物候提前；在全球变暖大背景下浮游植物群落结构正朝着蓝藻占优的方向发展，但是不同地区以及不同物种对全球变暖的响应不一致。在营养盐充足的湖泊中，由于全球变暖延长了浮游植物生长季节等，从而能提高浮游植物初级生产力；但在贫营养湖泊中，浮游植物初级生产力与变暖趋势甚至可能呈负相关。由于生态系统往往是多因子的共同作用，这也使得全球变暖对浮游植物群落的影响效应复杂化，区分各因子的净影响份额是目前研究的一个难点；全球变暖引起的风场改变会促进浅水湖泊中营养盐从底泥的释放，同时也会增加水体中悬浮物的浓度而影响水下光场，因此开展气候变化对再悬浮及浮游植物群落结构的影响可能是将来研究的一个切入点。