Data from: High temporal variability in the occurrence of consumer–resource interactions in ecological networks

Ecological networks have been used to represent interactions between species as fixed linkages despite that populations naturally oscillate over time and space. As such, the influence of the persistence of linkages between species in communities has been overlooked. Unfortunately, empirical analysis of the temporal variation of trophic networks is constrained by the lack of data with high spatial, temporal and taxonomic resolution. Here, we evaluate the spatiotemporal variability of multiple consumer-resource interactions to quantify the relative dominance of highly persistent versus poorly persistent interactions, the commonness of the interaction persistence patterns, and the effect of biotic and abiotic conditions on these patterns. We took advantage of a dataset from four large marine intertidal rocky-shore networks monitored seasonally for three years along 1000 km of the coast of northern Chile. Our results showed that the communities were characterized by few persistent interactions and a large number of transient trophic interactions, which was well described by a common exponential decay in the rank-frequency relationship of consumer–resource interactions despite dissimilarities in environmental conditions among sites. These results were independent of the degree of consumer–resource co-occurrence. Our results stress the need for more long-term studies that evaluate the temporal variability of ecological networks.

生态网络（ecological networks）常被用于将物种种间相互作用表征为固定的联结关系，然而自然种群的丰度本就会随时间与空间动态波动。正因如此，群落内物种种间联结的持续性对生态系统的影响长期被忽视。遗憾的是，针对营养网络（trophic networks）时间动态的实证分析，往往受限于缺乏兼具高空间分辨率、时间分辨率与分类学分辨率的数据集。本研究针对多种消费者-资源相互作用（consumer-resource interactions）的时空变异展开评估，旨在量化高持续性与低持续性相互作用的相对占比、相互作用持续性模式的普遍程度，以及生物与非生物环境条件对这些模式的影响。我们借助了智利北部1000公里海岸线上的4个大型海洋潮间带岩岸网络（marine intertidal rocky-shore networks）数据集，该数据集以季度为监测频率，历时三年完成采样。研究结果显示，这些群落的特征为仅存在少量持续性相互作用，而大量为暂时性营养相互作用；尽管各监测位点的环境条件存在差异，但消费者-资源相互作用的秩频关系普遍呈现指数衰减模式，这一规律能够很好地契合上述群落特征。上述结果不受消费者-资源共现（co-occurrence）程度的影响。本研究结果强调，亟需开展更多长期研究以评估生态网络的时间动态变异。