Explaining coexistence in species-rich communities of primary producers remains a challenge for ecologists because of their likely competition for shared resources. Following Hutchinson’s seminal suggestion, many theoreticians have tried to create diversity through a fluctuating environment, which impairs or slows down competitive exclusion. However, fluctuating environment models often only produce a dozen of coexisting species at best. Here, we investigate how to create richer communities in fluctuating environments, using an empirically parameterized model. Building on the forced Lotka-Volterra model of Scranton and Vasseur (Theor Ecol 9(3):353–363, 2016), inspired by phytoplankton communities, we have investigated the effect of two coexistence mechanisms, namely the storage effect and higher intra- than interspecific competition strengths (i.e., strong self-regulation). We tuned the intra/inter-competition ratio based on empirical analyses, in which self-regulation dominates interspecific interactions. Although a strong self-regulation maintained more species (50%) than the storage effect (25%), we show that none of the two coexistence mechanisms considered could ensure the coexistence of all species alone. Realistic seasonal environments only aggravated that picture, as they decreased persistence relative to a random environment. However, strong self-regulation and the storage effect combined superadditively so that all species could persist with both mechanisms at work. Our results suggest that combining different coexistence mechanisms into community models might be more fruitful than trying to find which mechanism best explains diversity. We additionally highlight that while biomass-trait distributions provide some clues regarding coexistence mechanisms, they cannot indicate unequivocally which mechanisms are at play.

中文翻译：

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自我调节，存储效应及其相互作用如何在随机和季节性环境中共存

对于生态学家来说，解释物种丰富的初级生产者社区中的共存仍然是一个挑战，因为他们可能会争夺共享资源。遵循哈钦森的开创性建议，许多理论家试图通过波动的环境来创造多样性，这种环境会削弱或减缓竞争排斥。但是，波动的环境模型通常最多只能产生十二种共存物种。在这里，我们研究如何使用经验参数化模型在动荡的环境中创建更丰富的社区。基于Scranton和Vasseur的强迫Lotka-Volterra模型（理论Ecol 9（3）：353–363，2016），在浮游植物群落的启发下，我们研究了两种共存机制的影响，即存储效应和较高的内部共存机制。比种间竞争优势（即 ，强大的自我调节能力）。我们基于经验分析调整了竞争内部/竞争比，其中自我调节主导种间相互作用。尽管强大的自我调节功能可以使物种（50％）多于存储效应（25％），但我们发现，所考虑的两种共存机制均无法确保所有物种单独共存。现实的季节性环境只会加剧这种情况，因为它们相对于随机环境而言会降低持久性。但是，强大的自我调节能力和储藏效果超级叠加地结合在一起，因此所有物种都可以在两种机制下均能持久存在。我们的研究结果表明，将不同的共存机制组合到社区模型中可能比尝试找到哪种机制能最好地解释多样性更有效。