Data from: Feeding environment and other traits shape species' roles in marine food webs

Food webs and meso-scale motifs allow us to understand the structure of ecological communities and define species' roles within them. This species-level perspective on networks permits tests for relationships between species' traits and their patterns of direct and indirect interactions. Such relationships could allow us to predict food-web structure based on more easily-obtained trait information. Here we calculated the roles of species (as vectors of motif position frequencies) in six well-resolved marine food webs and identified the motif positions associated with the greatest variation in species' roles. We then tested whether the frequencies of these positions varied with species' traits. Despite the coarse-grained traits we used, our approach identified several strong associations between traits and motifs. Feeding environment was a key trait in our models and may shape species' roles by affecting encounter probabilities. Incorporating environment into future food web models may improve predictions of an unknown network structure.

食物网（food web）与中尺度基序（meso-scale motif）可助力我们解析生态群落的结构，并明确物种在群落内的生态位角色。这种基于物种层面的网络视角，使得我们能够检验物种性状与其直接、间接互作模式之间的关联。此类关联可使我们基于更易获取的物种性状信息，对食物网结构进行预测。本研究中，我们在六个解析度较高的海洋食物网内，以基序位置频率向量的形式计算了物种的生态位角色，并识别出与物种角色变异程度最高相关的基序位置。随后我们检验了这些基序位置的频率是否随物种性状发生变化。尽管本研究使用的物种性状属于粗粒度类别，我们的分析方法仍识别出了若干性状与基序间的显著关联。摄食环境是本研究模型中的关键性状，其可通过影响物种间的相遇概率，进而塑造物种的生态位角色。将环境因素纳入后续的食物网模型，或可提升未知群落网络结构的预测精度。