The effect of tropical dry forest seasonality on the diversity of insects associated with ferns

Abstract

Seasonality is one of the main characteristics of a tropical dry forest that affects the structure of ecological communities. In this context, we evaluated the seasonal diversity of ferns and insects in the tropical dry forest of Morelos, Mexico, to determine whether a relationship exists between the presence of each of these two groups. Hill’s numbers indicated differences in the diversity of both groups according to season. In the rainy season, we recorded the highest diversity of ferns, with 6,471 individuals. In contrast, in the dry season, we recorded only 293 individuals. Regarding the insects, we collected 723 individuals in the rainy season and 171 individuals in the dry season. The order Orthoptera was the most abundant (50%). The best-represented functional group according to feeding guild was that of chewing herbivores. Correlation analysis revealed a positive relationship between insect and fern abundances since, for both groups, the minimum abundance was presented in the dry season and the maximum abundance in the rainy season. We recorded 12 orders of insects associated with eight ferns in the rainy season. Seasonal studies that consider different biological groups are necessary to understand how changes in resource availability shape temporal patterns of species diversity.

Key words:
alpha diversity; functional groups; herbivorous insects; tropical forest