Ecological genomics of niche exploitation and individual performance in tropical forest trees

Understanding characteristics, causes and consequences of biodiversity is a fundamental challenge in ecology and evolution. Biodiversity presents three nested levels, from individuals, over species, to ecosystems. Intraspecific variability affects the individual level of biodiversity. High levels of intraspecific variability, notably in ecologically important traits has been reported. Intraspecific variability is shaped by the interaction between (1) genetic variability, (2) environmental heterogeneity and (3) stochastic factors. However, we still know little about the effects of this variability on population dynamics, species interactions and ecosystem processes. Interestingly though, variability at the level of genotypes and traits has been suggested to promote local adaptation of populations and to promote species coexistence at the community level, thus suggesting a role for this variability in the origin and maintenance of biodiversity. We here present the conceptual framework of the recently started PhD thesis of S. Schmitt. The main objective of the thesis is to further explore the genotype-environment interactions in shaping the intraspecific trait variability of biodiversity. The study site for the thesis is the lowland rainforest in the research station of Paracou, French Guiana, where detailed inventory and tree growth data, as well as environmental characterization are available. We specifically wish to consider the intraspecific genomic variability as a continuum within structured populations of closely related species, and measure its role on individual tree performance through growth over time, while accounting for effects of a finely-characterized environment at the abiotic and biotic level. Eventually, we expect to help building a theory of community ecology starting with individuals, because interactions with environment is based at the individual level