Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Ziyang Road 99, 330022 Nanchang, People's Republic of China.
Statistics and Actuarial Sciences, School of Mathematics, University of Kent, Parkwood Road, Canterbury, CT2 7FS, UK.
Proc Biol Sci. 2020 Dec 9;287(1940):20201571. doi: 10.1098/rspb.2020.1571. Epub 2020 Dec 2.
Recent studies have suggested that intransitive competition, as opposed to hierarchical competition, allows more species to coexist. Furthermore, it is recognized that the prevalent paradigm, which assumes that species interactions are exclusively pairwise, may be insufficient. More importantly, whether and how habitat loss, a key driver of biodiversity loss, can alter these complex competition structures (and therefore species coexistence) remain unclear. We thus present a new, simple yet comprehensive metapopulation framework that can account for any competition pattern and more complex higher-order interactions (HOIs) among species. We find that competitive intransitivity increases community diversity and that HOIs generally enhance this effect. Essentially, intransitivity promotes species richness by preventing the dominance of a few species, unlike the hierarchical competition, while HOIs facilitate species coexistence through stabilizing community fluctuations. However, variation in species' vital rates and habitat loss can weaken or even reverse such higher-order effects, as their interaction can lead to a more rapid decline in competitive intransitivity under HOIs. Thus, it is essential to correctly identify the most appropriate interaction model for a given system before models are used to inform conservation efforts. Overall, our simple model framework provides a more parsimonious explanation for biodiversity maintenance than the existing theory.
最近的研究表明，与等级竞争相反，非传递竞争允许更多的物种共存。此外，人们认识到，普遍存在的假设，即认为物种相互作用是完全成对的，可能是不够的。更重要的是，生境丧失（生物多样性丧失的主要驱动因素）是否以及如何改变这些复杂的竞争结构（因此物种共存）仍然不清楚。因此，我们提出了一个新的、简单而全面的复合种群框架，可以解释任何竞争模式和更复杂的物种间高阶相互作用（HOI）。我们发现，竞争的非传递性增加了群落的多样性，而高阶相互作用通常会增强这种效应。本质上，非传递性通过防止少数物种的主导地位来促进物种丰富度，而不像等级竞争那样，而高阶相互作用通过稳定群落波动来促进物种共存。然而，物种关键率的变化和生境丧失可能会削弱甚至逆转这种高阶效应，因为它们的相互作用可能导致在高阶相互作用下竞争的非传递性更快下降。因此，在使用模型来为保护工作提供信息之前，必须正确识别给定系统中最合适的相互作用模型。总的来说，我们的简单模型框架比现有理论提供了对生物多样性维持的更简洁的解释。
