Responses of mediterranean forest phytophagous insects to climate change

Abstract

The present characteristics of the Mediterranean forest ecosystems are the results of millennia of human action under a particular climate. As in all forested ecosystems, insects play an essential role in their functioning. Consequently in these regions, tree insect relationships are extremely dependent on both social and climatic factors. Because these later two parameters are expected to largely change along the twenty-first century, considerable changes in the functioning of Mediterranean forest ecosystems are also expected, partly as results of modification of tree-insect interactions. Our reflection in that chapter is to try and foresee how the characteristics of phytophagous insects and their relationships with host tress could evolve during the twenty-first century, as results of climate changes in relation with social factors. Our starting point is a description of the present biological characteristics of Mediterranean forests and their phytophagous insects. Considering then the various scenarios of climate change, we present what the consequences for the Mediterranean trees and forests could be, and then the consequences for the phytophagous insects in terms of abundance, survival, phenology, spatial range, host tree quality, and biodiversity. We conclude by replacing the tree-phytophagous insects’ relationships in the context of complex interactions, reality of forest ecosystem functioning.