The majority of forests in Europe are managed and underwent considerable changes in tree species richness, species
composition and genetic diversity over the last few centuries. However, sound scientific evidence of the impact of these
changes in tree species and genetic diversity on how the ecosystems work and the services provide including human wellbeing,
is still lacking. Boreal forests are particularly species-poor, and therefore addition or loss of a single tree species
may be expected to have larger effects on the ecosystem. In addition, the variation within tree species has also been
recently shown to be an important determinant of ecosystem functioning, but the relative importance of variation between
tree species and within a single species has not yet been addressed in a single study. This project will take advantage of
two unique long-term experiments previously established by our team in boreal forests of SW Finland in 1999-2000 (www.sataforestdiversity.org). These experiments manipulate both tree species diversity and tree within-species genetic diversity. The project will examine how this tree-based biodiversity affects the range of ecosystem process and services, including production of timber and non-timber forest products (berries and mushrooms), understorey vegetation, herbivory etc. The relative importance of tree species vs intraspecific diversity and potential trade-offs and synergies between the above services and process will also be explored.