Connecting local and regional scales with stochastic metacommunity models: Competition, ecological drift, and dispersal
Connecting local and regional scales with stochastic metacommunity models: Competition, ecological drift, and dispersal
复制标题
将地方和区域尺度与随机元群落模型联系起来：竞争、生态漂移和扩散
DOI：
10.1002/ecm.1591
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发表时间：
2023
影响因子：
6.1
通讯作者：
Klausmeier, Christopher A.
中科院分区：
文献类型：
--
作者：
Lerch, Brian A.;Rudrapatna, Akshata;Rabi, Nasser;Wickman, Jonas;Koffel, Thomas;Klausmeier, Christopher A.
尽管众所周知，生态相互作用具有尺度依赖性，但人们对不同空间尺度之间动态相互作用的理解却相对较少。这在元群落理论中尤其显著，其中出生和死亡主导着斑块内的动态（局部尺度），而分散和环境随机性主导着斑块之间的动态（区域尺度）。通过考虑元群落中局部和区域尺度的相互作用，群落生态学的基本过程——选择、漂移和分散——可以统一到一个单一的理论框架中。本文在经典的两种Lotka-Volterra竞争模型的基础上，分析了三种相关的空间模型。两个开放系统模型关注的是单个斑块通过扩散与更大的固定景观耦合。前者是决定性的，而后者则增加了人口统计学的随机性，以允许生态漂移。最后，第三个模型是一个真正的元群落模型，它在大量局部斑块之间分散，允许局部和区域尺度之间的反馈，并将研究得很好的元群落范式作为特殊情况。与以往的模拟模型不同，我们的元群落模型允许对均衡和入侵标准进行数值计算，以精确地确定区域尺度上的竞争结果。研究表明，分散性和随机性都可能导致不同于经典Lotka-Volterra竞争模型预测的区域结果。当非空间模型预测共存或方正控制时，分别由于生态漂移或吸引力盆地之间的不对称随机转换而发生区域排斥。区域共存可以通过局部共存机制或竞争-殖民化或演替-生态位权衡来实现。较大的扩散速率通常具有竞争优势，但局部创立者控制的情况除外，后者有利于中间扩散速率。从广义上讲，我们的模型证明了竞争元群落中地方和区域尺度之间反馈的重要性，并为理解选择、漂移和扩散如何共同塑造生态群落提供了一个统一的框架。
Despite the well known scale‐dependency of ecological interactions, relatively little attention has been paid to understanding the dynamic interplay between various spatial scales. This is especially notable in metacommunity theory, where births and deaths dominate dynamics within patches (the local scale), and dispersal and environmental stochasticity dominate dynamics between patches (the regional scale). By considering the interplay of local and regional scales in metacommunities, the fundamental processes of community ecology—selection, drift, and dispersal—can be unified into a single theoretical framework. Here, we analyze three related spatial models that build on the classic two‐species Lotka–Volterra competition model. Two open‐system models focus on a single patch coupled to a larger fixed landscape by dispersal. The first is deterministic, while the second adds demographic stochasticity to allow ecological drift. Finally, the third model is a true metacommunity model with dispersal between a large number of local patches, which allows feedback between local and regional scales and captures the well studied metacommunity paradigms as special cases. Unlike previous simulation models, our metacommunity model allows the numerical calculation of equilibria and invasion criteria to precisely determine the outcome of competition at the regional scale. We show that both dispersal and stochasticity can lead to regional outcomes that are different than predicted by the classic Lotka–Volterra competition model. Regional exclusion can occur when the nonspatial model predicts coexistence or founder control, due to ecological drift or asymmetric stochastic switching between basins of attraction, respectively. Regional coexistence can result from local coexistence mechanisms or through competition‐colonization or successional‐niche trade‐offs. Larger dispersal rates are typically competitively advantageous, except in the case of local founder control, which can favor intermediate dispersal rates. Broadly, our models demonstrate the importance of feedback between local and regional scales in competitive metacommunities and provide a unifying framework for understanding how selection, drift, and dispersal jointly shape ecological communities.