Spanbauer Trisha L, Allen Craig R, Angeler David G, Eason Tarsha, Fritz Sherilyn C, Garmestani Ahjond S, Nash Kirsty L, Stone Jeffery R
Department of Earth and Atmospheric Sciences and School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
U.S. Geological Survey, Nebraska Cooperative Fish and Wildlife Research Unit, School of Natural Resources, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.
PLoS One. 2014 Oct 3;9(10):e108936. doi: 10.1371/journal.pone.0108936. eCollection 2014.
Regime shifts are generally defined as the point of 'abrupt' change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia.
regime转变通常被定义为系统状态发生“突然”变化的点。然而，看似突然的转变可能是系统重组的产物，这种重组持续的时间比在系统单个组成部分的统计分析中所显示的要长得多。我们使用单变量和多变量统计方法，对一个已知物种组合发生变化的长期高分辨率古生态数据集进行了 regime转变测试。用Fisher信息和多变量时间序列模型对该数据集进行分析表明，在 regime转变之前有一个约2000年的不稳定期。这个不稳定期和随后的 regime转变与区域气候变化相吻合，表明该系统正在经历外部强迫。古生态记录提供了一个独特的机会来测试检测阈值和稳定状态的工具，从而检验数千年时间尺度上生态系统的长期稳定性。
