Dispersal ecology of deadwood organisms and connectivity conservation

5 years ago

Dispersal ecology of deadwood organisms and connectivity conservation

Atte Komonen, Jörg Müller

Limited dispersal knowledge for most organisms hampers effective connectivity conservation in fragmented landscapes. In forest ecosystems, dead-wood dependent organisms (i.e. saproxylics) suffer from forest management and degradation globally. We review the empirical evidence on dispersal ecology of saproxylic insects and fungi. We focus on direct studies (e.g. mark-recapture, radio telemetry), field experiments and population genetic analyses. Our review revealed two somewhat opposite results: based on direct methods and experiments dispersal is limited within a few kilometers, whereas genetic studies generally find little genetic structure over tens of kilometers, indicating long-distance dispersal. Direct dispersal studies and field experiments, however, suffered from a small study extent and thus could not have detected long-distance dispersal. Particularly for fungi there is obvious need for more studies at management-relevant scales (1 to 10 km). Genetic studies in turn suffered from now outdated markers, small number of loci investigated, and the inherent difficulties in inferring dispersal from genetic population structure. Although there were systematic and species-specific differences in dispersal ability, fungi being better dispersers than insects, it seems that in both groups colonization and establishment, not dispersal per se, are limiting their occurrence at management relevant scales. Because most studies were from forest landscapes in Europe, particularly from the boreal region, more data are needed from non-forested landscapes, in which fragmentation effects are likely to be more pronounced. Given the potential for long-distance dispersal and the logical necessity of habitat area being a more fundamental landscape attribute than the spatial arrangement of habitat patches (i.e. connectivity sensu strict), retaining high quality dead-wood habitat is more important than explicit connectivity conservation in many cases. This article is protected by copyright. All rights reserved

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/cobi.13087