Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
School of Environment, University of Auckland, Auckland, New Zealand.
J Anim Ecol. 2020 Sep;89(9):2145-2155. doi: 10.1111/1365-2656.13274. Epub 2020 Jun 25.
Niche and neutral processes jointly influence species interactions. Predictions of interactions based on these processes assume that they operate similarly across all species. However, species characteristics could systematically create differences in the strength of niche or neutral processes for each interspecific interaction. We used national-level records of plant-frugivore interactions, species traits, biogeographic status (native vs. exotic), phylogenies and species range sizes to test the hypothesis that the strength of niche processes in species interactions changes in predictable ways depending on trophic generalism and biogeographic status of the interacting species. The strength of niche processes (measured as trait matching) decreased when the generalism of the interacting partners increased. Furthermore, the slope of this negative relationship between trait matching and generalism of the interacting partners was steeper (more negative) for interactions between exotic species than those between native species. These results remained significant after accounting for the potential effects of neutral processes (estimated by species range size). These observed changes in the strength of niche processes in generating species interactions, after accounting for effects of neutral processes, could improve predictions of ecological networks from species trait data. Specifically, due to their shorter co-evolutionary history, exotic species tend to interact with native species even when lower trait matching occurs than in interactions among native species. Likewise, interactions between generalist bird species and generalist plant species should be expected to occur despite low trait matching between species, whereas interactions between specialist species involve higher trait matching.
生态位和中性过程共同影响物种相互作用。基于这些过程的相互作用预测假设它们在所有物种中都以相似的方式发挥作用。然而，物种特征可能会系统地在每个种间相互作用中对生态位或中性过程的强度产生差异。我们使用全国范围内的植物-传粉者相互作用记录、物种特征、生物地理地位（本地与外来）、系统发育和物种范围大小来检验以下假设：物种相互作用中生态位过程的强度会根据相互作用物种的营养特化和生物地理地位发生可预测的变化。当相互作用的伙伴的特化程度增加时，生态位过程的强度（通过特征匹配来衡量）会降低。此外，对于外来物种之间的相互作用，这种特征匹配与相互作用伙伴的特化之间的负相关关系的斜率（更负）比本地物种之间的相互作用更为陡峭。在考虑中性过程的潜在影响（通过物种范围大小估计）后，这些结果仍然显著。在考虑中性过程的影响后，生态位过程在产生物种相互作用方面的强度变化可以提高从物种特征数据预测生态网络的能力。具体而言，由于它们较短的共同进化历史，外来物种与本地物种相互作用的可能性很大，即使发生的特征匹配程度低于本地物种之间的相互作用。同样，尽管物种之间的特征匹配程度较低，但是广食性鸟类物种和广食性植物物种之间的相互作用也应该会发生，而专门物种之间的相互作用则需要更高的特征匹配程度。
