Biodiversity can affect the functioning of ecosystems and the services ecosystems can provide for

humans. A better understanding of the relationships between biodiversity and ecosystem

functioning will support conservation and sustainable management of nature. In the proposed

research, we will examine how tree species diversity affects the growth of young trees in two tree

species diversity experiments. The experiments consist of young trees planted in small parcels that

differ in tree species richness, ranging from monocultures to two-, three-, and four-species

mixtures. We will investigate the tree growth above and below the ground. Competition between

roots may be lower where different tree species grow together as their roots may grow in different

parts of the soil. Consequently, the uptake of water and nutrients from the soil might be higher in

mixed plantations, which might in turn improve the aboveground growth of the trees. We will

combine measurements of root biomass and distribution, leaf nutrient content and photosynthetic

efficiency, and tree height and diameter growth to study the effects of the neighbourhood’ tree

species diversity on the growth of individual trees. As the tree species in the plantations are

functionally different –they differ in, for instance, shade tolerance –we will look for effects of

both species richness and species identity.