Intraspecific genetic diversity along plant species diversity gradients

Relationships between diversity among species and genetic diversity within species are only poorly understood. Levels and patterns of genetic diversity within a population are the result of historical processes, part of them being adaptive. Thus, it is far from being obvious that today’s species diversity of an ecosystem has a direct impact on the genetic diversity of its keystone species or vice versa. However, simulations of the interacting effects of immigration rate (gene flow) and environmental heterogeneity on the correlated diversity of genes and species led to positive and sometimes strong correlations.
Recent studies have shown that plant species diversity and genetic diversity in keystone species may have significant effects on the diversity of associated herbivores and ecosystem processes.
We want to test the hypotheses that levels of genetic diversity (adaptive and neutral) within populations of keystone species and tree species diversity are correlated and that the genetic diversity in keystone tree species has an effect on the diversity of associated organisms (e.g. microbes, phytophagous insects) in temperate and tropical forest ecosystems.