Slowing Down in Spatially Patterned Ecosystems at the Brink of Collapse
Slowing Down in Spatially Patterned Ecosystems at the Brink of Collapse
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DOI：
10.1086/659945
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发表时间：
2011-06-01
影响因子：
2.9
通讯作者：
Scheffer, Marten
中科院分区：
文献类型：
--
作者：
Dakos, Vasilis;Kefi, Sonia;Scheffer, Marten
预测人口崩溃等关键过渡的风险对于指导管理工作至关重要。在任何接近临界转变的系统中，小扰动的恢复变得缓慢，这种现象称为临界减速。有人认为，这种减缓可以通过空间和时间相关性和方差的增加间接检测到。在这里，我们在干旱的生态系统中测试了这个想法，由于水资源限制的增加，植被可能会崩溃成为沙漠。我们使用了三种描述荒漠化的模型，但它们产生的空间植被模式不同。在所有模型中，扰动后恢复率下降之前植被崩溃。然而，在其中一个模型中，放缓未能转化为方差和相关性的上升。这是由该模型产生的规则的自组织植被格局造成的。这一发现意味着一个重要的限制的方差和相关性的关键转变的指标。然而，这种自组织模式本身的变化是即将到来的过渡的可靠指标。我们的研究结果表明，虽然临界减速可能是一个普遍的现象，在关键的过渡，其检测通过间接指标可能有局限性，在特定的系统。
Predicting the risk of critical transitions, such as the collapse of a population, is important in order to direct management efforts. In any system that is close to a critical transition, recovery upon small perturbations becomes slow, a phenomenon known as critical slowing down. It has been suggested that such slowing down may be detected indirectly through an increase in spatial and temporal correlation and variance. Here, we tested this idea in arid ecosystems, where vegetation may collapse to desert as a result of increasing water limitation. We used three models that describe desertification but differ in the spatial vegetation patterns they produce. In all models, recovery rate upon perturbation decreased before vegetation collapsed. However, in one of the models, slowing down failed to translate into rising variance and correlation. This is caused by the regular self-organized vegetation patterns produced by this model. This finding implies an important limitation of variance and correlation as indicators of critical transitions. However, changes in such self-organized patterns themselves are a reliable indicator of an upcoming transition. Our results illustrate that while critical slowing down may be a universal phenomenon at critical transitions, its detection through indirect indicators may have limitations in particular systems.