Ardichvili Alice Nadia, Loeuille Nicolas, Dakos Vasilis
Sorbonne Université, Université de Paris-Cité, UPEC, CNRS, INRA, IRD, Institute of Ecology and Environmental Sciences, Paris, France.
Université de Montpellier, IRD, EPHE, CNRS, Institut des Sciences de l'Evolution de Montpellier, Montpellier, France.
Ecol Lett. 2023 May;26(5):692-705. doi: 10.1111/ele.14180. Epub 2023 Mar 9.
Ecosystems under stress may respond abruptly and irreversibly through tipping points. Although mechanisms leading to alternative stable states are much studied, little is known about how such ecosystems could have emerged in the first place. We investigate whether evolution by natural selection along resource gradients leads to bistability, using shallow lakes as an example. There, tipping points occur between two alternative states dominated by either submersed or floating macrophytes depending on nutrient loading. We model the evolution of macrophyte depth in the lake, identify the conditions under which the ancestor population diversifies and investigate whether alternative stable states dominated by different macrophyte phenotypes occur. We find that eco-evolutionary dynamics may lead to alternative stable states, but under restrictive conditions. Such dynamics require sufficient asymmetries in the acquisition of both light and nutrient. Our analysis suggests that competitive asymmetries along opposing resource gradients may allow bistability to emerge by natural selection.
处于压力下的生态系统可能会通过临界点做出突然且不可逆转的反应。尽管导致替代稳定状态的机制已得到充分研究，但对于此类生态系统最初是如何形成的却知之甚少。我们以浅水湖泊为例，研究沿资源梯度的自然选择进化是否会导致双稳态。在那里，根据养分负荷，临界点出现在由沉水植物或漂浮大型植物主导的两种替代状态之间。我们对湖泊中大型植物深度的进化进行建模，确定祖先种群多样化的条件，并研究是否会出现由不同大型植物表型主导的替代稳定状态。我们发现生态进化动态可能会导致替代稳定状态，但条件较为苛刻。这种动态需要在光和养分获取方面有足够的不对称性。我们的分析表明，沿相反资源梯度的竞争不对称性可能会使自然选择导致双稳态的出现。
