My principal research interest lies in the field of biodiversity, ecology, and conservation of tropical rain forest ecosystems. Lately I have been focusing on the consequences of land-use change and forest degradation on plant diversity. Another focus of my work includes carnivorous plants and epiphytes. I have carried out extensive vegetation surveys in Indonesia (Sumatra), Kenya, and Uganda, and have participated in ecological and experimental studies in Madagascar, Brunei, and Malaysia. While I have so far mainly been working in tropical ecosystems, I am generally extremely interested in the fields of botany, biodiversity, ecology, and conservation biology worldwide, including temperate regions.