Changes in land use and its intensity are major determinants of biodiversity. Currently, biodiversity experiences a general decline due to ongoing large- and small-scale changes in land use. However, while the relationship between land use and biodiversity is well-established for some taxa including studies on the effects on genetic diversity, it is not for others. Also, it is not known how diversities of different taxa are related to each other, and whether they, and their genetic diversities respond similarly to variation in land use. Recent model experiments with manipulated plant species diversity demonstrated negative effects of biodiversity loss on ecosystem functioning and services. Other model experiments with manipulated microbial, fungal, animal, and genetic diversity are further exploring functional consequences of biodiversity change, and they appear to confirm the observations made with plants. However, for natural systems the functional importance of biodiversity is unclear because of the overriding effects of different management strategies. Therefore, research in real landscapes on feed back loops between landscape change, diversity of genes, species and biological interactions, and ecosystem services through combinations of monitoring approaches and measurements of functional diversity with designed experiments will be conducted.