Rising variance: a leading indicator of ecological transition
Rising variance: a leading indicator of ecological transition
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DOI：
10.1111/j.1461-0248.2005.00877.x
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发表时间：
2006-03-01
期刊：
影响因子：
8.8
通讯作者：
Brock, WA
中科院分区：
文献类型：
--
作者：
Carpenter, SR;Brock, WA
制度变迁是复杂系统（如生态系统）的实质性、持久性重组。大型生态系统变化，如富营养化、植被类型的变化、珊瑚礁退化和区域气候变化，往往令人惊讶，因为我们缺乏制度变化的领先指标。生态系统变异性的增加被认为预示着生态系统的变化。然而，由于即将发生的制度转变与影响生态系统的外源驱动因素的变化，可能很难辨别出变异性。我们使用湖泊富营养化模型来解决这个问题。湖泊受到与制度转变相关的循环波动以及营养投入波动的影响。尽管嘈杂的输入的并发症，增加变化的湖水磷是可辨别的富营养化条件下转移之前。模拟显示，标准差（SD）的上升可能预示着大约十年前即将发生的变化。通过研究一个简单的时间序列模型预测的变异性来检测SD的上升，并不依赖于实际生态系统动态的详细知识。
Regime shifts are substantial, long-lasting reorganizations of complex systems, such as ecosystems. Large ecosystem changes such as eutrophication, shifts among vegetation types, degradation of coral reefs and regional climate change often come as surprises because we lack leading indicators for regime shifts. Increases in variability of ecosystems have been suggested to foreshadow ecological regime shifts. However, it may be difficult to discern variability due to impending regime shift from that of exogenous drivers that affect the ecosystem. We addressed this problem using a model of lake eutrophication. Lakes are subject to fluctuations in recycling associated with regime shifts, as well as fluctuating nutrient inputs. Despite the complications of noisy inputs, increasing variability of lake-water phosphorus was discernible prior to the shift to eutrophic conditions. Simulations show that rising standard deviation (SD) could signal impending shifts about a decade in advance. The rising SD was detected by studying variability around predictions of a simple time-series model, and did not depend on detailed knowledge of the actual ecosystem dynamics.