My main research interests are in the mechanisms behind species diversity patterns and in the effects of land use on biodiversity.
On the broadest scale I (together with Roland Jansson) develop and test a new theory about the evolutionary consequences of climatic fluctuations caused by variations in Earth’s orbit. On the regional to local scale I study boreal diversity of vascular plants, liverworts, mosses, and lichens. Fundamental questions concern the wide range of species richness attained in different parts of the landscape and along the course of rivers as well as the occurrence of spatial correlations in species richness among organism groups.
My work on effects of land use include effects of river regulation, conventional forestry, slash removal from clear-cuts for energy production, and wood ash recycling. I have also studied the efficiency of buffer strips of riparian forest for bryophyte conservation. I also work with assessments of the fragmentation by dams and degree of regulation in the World’s large river systems.
Previously, I have evaluated methods to date when a tree was uprooted and applied these methods to reconstruct the long-term dynamics of this natural forest floor disturbance.