PARENT SESSION
Poster Session #50: Climate Change.
Thursday, August 8. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC

The effects of habitat fragmentation and climate change on the range of forest plant species.

Honnay, Olivier^*,1, Verheyen, Kris¹, Bossuyt, Beatrijs¹, Butaye, Jan¹, Jacquemyn, Hans¹, Hermy, Martin¹, ¹ Laboratory for Forest, Nature & Landscape Research, Leuven, Belgium

ABSTRACT- Global circulation models predict an increase in mean annual temperature between 2.1 and 4.6 degrees C by 2080 in the northern temperate zone. The associated changes in the ratio of extinctions and colonisations at the northern and southern boundaries of species ranges are expected to result in northward range shifts for many species. At the southern range boundary, the climate induced changes in the species physiology, phenology and ecology inevitably cause net extinction. Simultaneously, however, net species colonisation at northern boundary ranges, necessary for a northward shift and for range conservation, may be hampered due to severe habitat fragmentation in the agricultural and urban landscapes of Europe, as evidenced for some butterfly species. Here we provide evidence that habitat fragmentation can also prevent plant colonisation and will prohibit northward range shifts. We report the results of forest plant colonisation studies in two representative fragmented landscapes in central Belgium. We show that 85% of all forest plant species had an extremely low success of colonising spatially segregated empty forest habitats after 42 years. In the landscape with higher forest connectivity, colonisation success was higher, but still highly insufficient to ensure large scale colonisation. Under the hypothesis of net extinction at southern range boundaries, forest plant species dispersal limitation will prevent net colonisation at northern range boundaries required for range conservation.

KEY WORDS: climate change, habitat fragmentation, plant dispersal