Trees are rarely most abundant where they grow best

A common assumption in ecology is that where a species is found to be most abundant must correspond to the environmental context in which the species performs the best (i.e. optimal niche space). This assumption is central to common conservation and management tools such as habitat suitability assessment and species distribution modeling. I test this hypothesis. I use the US Forest Inventory Assessment data for the abundance of trees across eastern North America. I use the FORAST tree-ring dataset for ontogenetic growth rate (tree-ring increment), a measure of niche performance and correlated with intrinsic rate of increase, r. I find that across 15 species, there are significantly more negative correlations than expected by chance. This negative correlation between abundance and performance across space contradicts common assumptions but is consistent with an inclusive niche structuring of the community.