Effects of Climatic Variations on Plant–Pollinator Interactions: Implications for Biodiversity Conservation

Abstract

Field evidence of the effects of local climatic variation on pollination processes is not consistent and climate change is altering the availability, abundance and quality of floral resources to which the insects rely. The present study was designed based on a quantitative field approach to gain insight into the effects of climatic variation on plant–pollinator interactions over a four-month period across three ecological sites with different environmental conditions. Thirty 10 × 10 m plots (10 plots per site) were chosen in a stratified random fashion, and along with temperature, relative humidity and rainfall, pollinator visitation frequency, plant diversity, flowering abundance and flowering duration were measured. Diversity was calculated with the Shannon – Wiener index and associations were explored with Pearson correlation analysis and negative binomial generalized linear mixed models (GLMMs) in R. The intermediate site had the greatest diversity of plants and pollinators, plant flowering, and visitation, while the warmest and driest site had shorter flowering and lower visitation. A positive correlation was found between visitation and both flowering abundance and length, and there was a curvilinear correlation between visitation and temperature. The results indicate that climatic variability can mostly be mediated through floral resources availability and phenology and strongly endorse the conservation approach based on the maintenance of heterogenic microclimates and floral continuity.