Special Profile: Functional diversity.
This special issue includes six papers that examine how management activities or policy could benefit from consideration of the functional contributions of species. Focusing on species richness, management activities may unintentionally reduce functional diversity (FD), with detrimental consequences for ecosystem services or stability. Two of the studies included in this issue show that grassland management (e.g. mowing or grazing) can result in loss of FD, which may result in an unintended loss of ecosystem services. The third paper reviews how species extinction and environmental change can negatively affect FD and, potentially, ecosystem function. At the individual species level, invasions offer insight into the importance of species traits. The fourth paper describes how an invader is successful because of unique trait values, underlining the importance of examining FD when considering management options. The fifth paper, eutrophication is shown to drastically affect lichen functional groups (some decreasing and some increasing) with a minor effect on overall richness. The final paper demonstrates that the ability of aquatic plants to maintain biomass production in changing environments is determined by their complementary contributions to productivity. These complementary contributions to ecosystem function, especially given that they are more important in fluctuating environments - need to be included in evaluations of diversity.