Arnott Shelley E, Keller Bill, Dillon Peter J, Yan Norman, Paterson Michael, Findlay David
Department of Biology Queen's University, Kingston, Ontario, Canada, K7L 3N6.
Environ Monit Assess. 2003 Oct-Nov;88(1-3):365-88. doi: 10.1023/a:1025537628078.
Climate change is expected to have important impacts on aquatic ecosystems. On the Boreal Shield, mean annual air temperatures are expected to increase 2 to 4 degrees C over the next 50 years. An important challenge is to predict how changes in climate and climate variability will impact natural systems so that sustainable management policies can be implemented. To predict responses to complex ecosystem changes associated with climate change, we used long-term biotic databases to evaluate how important elements of the biota in Boreal Shield lakes have responded to past fluctuations in climate. Our long-term records span a two decade period where there have been unusually cold years and unusually warm years. We used coherence analyses to test for regionally operating controls on climate, water temperature, pH, and plankton richness and abundance in three regions across Ontario: the Experimental Lakes Area, Sudbury, and Dorset. Inter-annual variation in air temperature was similar among regions, but there was a weak relationship among regions for precipitation. While air temperature was closely related to lake surface temperatures in each of the regions, there were weak relationships between lake surface temperature and richness or abundance of the plankton. However, inter-annual changes in lake chemistry (i.e., pH) were correlated with some biotic variables. In some lakes in Sudbury and Dorset, pH was dependent on extreme events. For example, El Nino related droughts resulted in acidification pulses in some lakes that influenced phytoplankton and zooplankton richness. These results suggest that there can be strong heterogeneity in lake ecosystem responses within and across regions.
气候变化预计将对水生生态系统产生重大影响。在北方盾地，预计未来50年年平均气温将上升2至4摄氏度。一个重要的挑战是预测气候和气候变率的变化将如何影响自然系统，以便能够实施可持续管理政策。为了预测与气候变化相关的复杂生态系统变化的响应，我们使用长期生物数据库来评估北方盾地湖泊生物群的重要元素如何响应过去的气候波动。我们的长期记录跨越了二十年，期间有异常寒冷的年份和异常温暖的年份。我们使用相干分析来测试安大略省三个地区（实验湖区、萨德伯里和多塞特）气候、水温、pH值以及浮游生物丰富度和丰度的区域运行控制。各地区间气温的年际变化相似，但降水量在各地区间的关系较弱。虽然每个地区的气温都与湖面温度密切相关，但湖面温度与浮游生物的丰富度或丰度之间的关系较弱。然而，湖泊化学性质（即pH值）的年际变化与一些生物变量相关。在萨德伯里和多塞特的一些湖泊中，pH值取决于极端事件。例如，与厄尔尼诺相关的干旱导致一些湖泊出现酸化脉冲，影响了浮游植物和浮游动物的丰富度。这些结果表明，湖泊生态系统在区域内和区域间的响应可能存在很强的异质性。
