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，却忽略了种群本身会随时间与空间发生自然波动。正因如此，群落内物种种间联结的存续性所产生的影响长期遭到忽视。遗憾的是，针对营养网络（trophic networks）时间变异的实证分析，往往受限于缺乏兼具高空间分辨率、高时间分辨率与高分类学分辨率的数据。本研究依托智利北部沿岸1000公里范围内、经三年季节性监测的四个大型潮间带岩岸网络（intertidal rocky-shore networks）数据集，评估了多组消费者-资源互作（consumer-resource interactions）的时空变异性，以量化高存续性互作相较于低存续性互作的相对优势、互作存续模式的普遍性，以及生物与非生物环境条件对这些模式的影响。研究结果显示，这类群落以少量持久互作与大量瞬时营养互作为特征；尽管各监测点的环境条件存在差异，但消费者-资源互作的秩频关系（rank-frequency relationship）呈普遍的指数衰减（exponential decay）趋势，可很好地契合这一特征。这一结果与消费者-资源的共存程度无关。本研究强调，亟需开展更多长期研究以评估生态网络的时间变异特性。