Two of IDENT sites (Auclair, QC, Canada and Cloquet, MN, USA) were specially designed to identify the effects of species native and exotic species on productivity.
The effect of species provenance on the biodiversity-ecosystem functioning relationship has not yet been studied on trees. We hypothesize that productivity increases with functional diversity is age-dependent and that exotic species should be more productive than native species.
We grew a total of 12 species (six native and six exotic) in different combinations of 1, 2 and 6 species mixtures. The exotic species were selected based on their functional similarity to the native ones.
We showed an increase in species productivity due to an interaction between functional diversity and exotic species but not for native species. We also showed a positive effect of species richness and plot functional identities. We revealed that the effect of functional diversity and provenance of species become more pronounced with time.