Species-to-species and species-to-environment interactions are key drivers of community dynamics. Disentangling these drivers in species-rich assemblages is challenging due to the high number of potentially interacting species (the ‘curse of dimensionality’). We develop a process-based model that quantifies how intraspecific and interspecific interactions, and species’ covarying responses to environmental fluctuations, jointly drive community dynamics. We fit the model to reef fish abundance time series from 41 reefs of Australia's Great Barrier Reef. We found that fluctuating relative abundances are driven by species’ heterogenous responses to environmental fluctuations, whereas interspecific interactions are negligible. Species differences in long-term average abundances are driven by interspecific variation in the magnitudes of both conspecific density-dependence and density-independent growth rates. This study introduces a novel approach to overcoming the curse of dimensionality, which reveals highly individualistic dynamics in coral reef fish communities that imply a high level of niche structure.

中文翻译：

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高响应多样性和同种密度依赖性，而不是物种相互作用，驱动珊瑚礁鱼类群落的动态

物种与物种以及物种与环境的相互作用是群落动态的关键驱动因素。由于存在大量潜在相互作用的物种（“维数诅咒”），在物种丰富的组合中解开这些驱动因素具有挑战性。我们开发了一个基于过程的模型，该模型量化了种内和种间相互作用以及物种对环境波动的共变反应如何共同驱动群落动态。我们将该模型与澳大利亚大堡礁 41 个珊瑚礁的珊瑚礁鱼类丰度时间序列进行拟合。我们发现相对丰度的波动是由物种对环境波动的异质反应驱动的，而种间相互作用可以忽略不计。长期平均丰度的物种差异是由同种密度依赖性和密度无关增长率的种间差异驱动的。这项研究引入了一种克服维度灾难的新方法，揭示了珊瑚礁鱼类群落中高度个体化的动态，这意味着高水平的生态位结构。