Regeneration and Population Dynamics of Quercus rugosa at the Ajusco Volcano, Mexico

Abstract

The knowledge of the interaction between gall-forming insects and oaks in Mexico is still very poor. However, the results presented in this chapter indicate that Mexican oaks have great gall morph diversity, and that external and internal gall morphology is structurally variable. More studies on gallwasp taxonomy, gall morphology and physiology are necessary to understand the adaptive significance of gall induction in oaks of temperate and tropical forests. Hybrids have the potential to act as new adaptive zones for the diversification of wasp species. Considering that hybridization is one of the main factors explaining the striking species richness of Mexican oaks, many gall-forming insects are also expected to have coevolved. Co-phylogenetic studies on Mexican oaks are now underway, and particularly aim at comparing endemic species with a restricted distribution to species with wider latitudinal and altitudinal distributions. This analysis is expected to contribute to our understanding of the co-evolutionary dynamics of this interaction at different spatial scales. Gall-forming insects associated to oaks may represent even greater species richness than found among oak species themselves. Therefore, this should be considered an important biodiversity component, which has its own specific conservation requirements within the diverse Mexican montane oak forests.