古湖沼学研究揭示湖泊生态系统服务变化的过程

Using paleolimnology to reconstruct historic processes of lake ecosystem services

当今在气候变化和人类活动等多重压力影响下,作为地表过程重要组成部分的湖泊生态系统正遭受着巨大威胁,其服务功能急剧退化.如何客观地评价湖泊生态系统服务的现状,并科学地预测其发展趋势,是当前亟待解决的问题.开展长期生态系统服务变化过程与机理的分析,有助于未来生态系统服务变化趋势的预测.然而,现有的观测数据往往时间较短(通常小于50年).连续的湖泊沉积记录为研究生态系统服务变化的长期过程提供了可能.本文结合前人研究成果,列举了可反映湖泊生态系统服务变化的一些古湖沼学指标,依据这些指标相对明确的生态和环境指示意义,将其与各项服务关联起来.最后,结合巢湖实例分析来说明这些指标在评估湖泊生态系统服务方面的具体应用,研究表明当今巢湖生态系统服务供应能力的持续增加是以调节服务的丧失为代价的.尽管目前的研究尚处于起步阶段,但古湖沼学手段无疑为今后湖泊生态系统服务历史状况的评估提供了途径,为古湖沼学的应用提供了一种新的思路,并为今后生态系统的保护和可持续利用提供重要的决策依据.

With the impacts of climate change and human activities, lake ecosystem nowadays is suffering from multiple threats and its services function becomes degenerated. It is urgent to evaluate objectively the value of the lake ecosystem services and to predict their future state. Understanding the historical evolution process of ecosystem services and its mechanism is crucial for predicting the future changes of ecosystem service. However, most of the existing instrumental record on ecosystem service is too short （ 〈50 a）. With continuous sedimentation, lake sediments can provide detail information on the long-term changes of the lake eco- system services. With a review on previous studies, this paper introduced a few palaeolimnology indexes that can be linked to vari- ous forms of lake ecosystem service. We also presented a case study of Lake Chaohu to demonstrate how the implementation of these proxies could indicate the lake ecosystem services. This study showed that the growth in economy and production supply capacity is always at the cost of the loss of regulating services of lakes. Although such kind of research is still in its infancy, there＇s no doubt that it will be of great benefit to palaeolimnology development and can provide a scientific basis for decision making in the protection and sustainable utilization of lake ecosystem in the future.