A multilevel mechanistic model of diversity change
AbstractChanges in biodiversity reflect processes acting on the success of
individual species at multiple spatial scales, including in communities,
biogeographic regions, and globally. This complexity makes it difficult
to analyse the mechanisms shaping diversity change using traditional
approaches. To resolve this, we propose a novel approach to partition
total biodiversity changes according to mechanisms reflecting species'
success at multiple scales. We apply this approach to study changes in
the diversity of invertebrate herbivores from a large-scale, plant
community experiment. This partitioning showed that rapid changes in the
relative abundances of individual species resulted in surprisingly small
changes in diversity across scales. Our novel analytical method reveals
how strong ecological effects at different hierarchical levels can
counteract each other, resulting in weak effects on diversity across
broad spatial scales.