Community assembly processes vary during the course of succession: stochastic processes can be important during the early phase of succession, whereas deterministic ones might be so during the later phase. These predictions assume a community with a single trophic level, and trophic interactions are rarely considered.
We aim to broaden these predictions to a community with two trophic levels such as a plant and herbivorous insect community. We studied whether the deterministic assembly of a plant community leads to the similar assembly of the corresponding insect community, and whether the association between the plant and insect communities becomes increasingly stronger during the course of succession.
We investigated the plant and insect communities in semi-natural grasslands, in which mowing initiates a new course of succession. The relative importance of the deterministic and stochastic processes was quantified based on the beta-deviation which is the magnitude of deviation from the expected beta-diversity.
We found no relationship between the beta-deviations of plant and insect communities, implying a different community assembly between the two trophic levels. We also found that the correlation between beta-diversity of plant and insect communities became stronger after the mowing, suggesting more stochastic assembly at the beginning of succession.