Moreno-Spiegelberg Pablo, Rietkerk Max, Gomila Damià
Institute for Cross-Disciplinary Physics and Complex Systems (Consejo Superior de Investigaciones Científicas - Universitat de les Illes Balears), Palma de Mallorca E-07122, Spain.
Copernicus Institute of Sustainable Development, Section Environmental Sciences, Utrecht University, Utrecht 3508 TC, The Netherlands.
Proc Natl Acad Sci U S A. 2025 Mar 18;122(11):e2412522122. doi: 10.1073/pnas.2412522122. Epub 2025 Mar 13.
We study how self-organization in systems showing complex spatiotemporal dynamics can increase ecosystem resilience. We consider a general simple model that includes positive feedback as well as negative feedback mediated by an inhibitor. We apply this model to meadows, where positive and negative feedbacks are well documented, and there is empirical evidence of the role of sulfide accumulation, toxic for the plant, in driving complex spatiotemporal dynamics. We describe a progressive transition from homogeneous meadows to extinction through dynamical regimes that allow the ecosystem to avoid the typical ecological tipping points of homogeneous vegetation covers. A predictable sequence of distinct dynamical regimes is observed as mortality is continuously increased: turbulent regimes, formation of spirals and wave trains, and isolated traveling pulses or expanding rings, the latter being a harbinger of ecosystem collapse, however far beyond the tipping point of the homogeneous cover. The model used in this paper is general, and the results can be applied to other plant-soil spatially extended systems, regardless of the mechanisms behind negative and positive feedbacks.
我们研究了表现出复杂时空动态的系统中的自组织如何提高生态系统的恢复力。我们考虑一个一般的简单模型，该模型包括正反馈以及由一种抑制剂介导的负反馈。我们将此模型应用于草地，在草地中，正反馈和负反馈都有充分的记录，并且有经验证据表明，对植物有毒的硫化物积累在驱动复杂的时空动态中发挥了作用。我们描述了一个从均匀草地到灭绝的渐进转变，该转变通过一些动态状态实现，这些动态状态使生态系统能够避免均匀植被覆盖的典型生态临界点。随着死亡率不断增加，可观察到一系列可预测的不同动态状态：湍流状态、螺旋和波列的形成，以及孤立的行进脉冲或扩展环，后者是生态系统崩溃的先兆，无论其距离均匀覆盖的临界点有多远。本文中使用的模型具有通用性，其结果可应用于其他植物 - 土壤空间扩展系统，而无需考虑正负反馈背后的机制。
