期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：15
页码：E1828-E1836
DOI：10.1073/pnas.1414708112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceCatastrophic shifts such as desertification processes, massive extinctions, or stock market collapses are ubiquitous threats in nature and society. In these events, there is a shift from one steady state to a radically different one, from which recovery is exceedingly difficult. Thus, there is a huge interest in predicting and eventually preventing catastrophic shifts. Here we explore the influence of key mechanisms such as demographic fluctuations, heterogeneity, and diffusion, which appear generically in real circumstances. The mechanisms we study could ideally be exploited to smooth abrupt shifts and to make transitions progressive and easier to revert. Thus, our findings could be of potential importance for ecosystem management and biodiversity conservation. Transitions between regimes with radically different properties are ubiquitous in nature. Such transitions can occur either smoothly or in an abrupt and catastrophic fashion. Important examples of the latter can be found in ecology, climate sciences, and economics, to name a few, where regime shifts have catastrophic consequences that are mostly irreversible (e.g., desertification, coral reef collapses, and market crashes). Predicting and preventing these abrupt transitions remains a challenging and important task. Usually, simple deterministic equations are used to model and rationalize these complex situations. However, stochastic effects might have a profound effect. Here we use 1D and 2D spatially explicit models to show that intrinsic (demographic) stochasticity can alter deterministic predictions dramatically, especially in the presence of other realistic features such as limited mobility or spatial heterogeneity. In particular, these ingredients can alter the possibility of catastrophic shifts by giving rise to much smoother and easily reversible continuous ones. The ideas presented here can help further understand catastrophic shifts and contribute to the discussion about the possibility of preventing such shifts to minimize their disruptive ecological, economic, and societal consequences.
