Conclusion
Trees may find themselves back in a distantly related neighbourhood if niches were conserved in the past and at present (i) environments change rapidly, requiring colonization of sites still occupied by distantly related trees, or (ii) environments remain constant and individuals leave their ancestral niche and converge with niches of distantly related species. Such coexistence of trees with distant relatives appears to impede and severely re-organize carbon and nitrogen recycling. Processes involved operate through above- and belowground mechanisms, appear to involve abiotic drivers of decomposition in some cases, and biotic drivers in many others, notably fungi for aboveground effects and Acari and Collembola for belowground effects of phylogenetic isolation. Such mechanisms driven by local phylogenetic isolation might ultimately contribute to feedbacks between niche-evolution and ecosystem functioning (Srivastava et al . 2012; Prinzing et al . 2017): they might prevent trees from tracking and conserving niches under environmental change.