Could the tree diversity pattern in Europe be generated by postglacial dispersal limitation?

Abstract

The relative importance of contemporary climate and history as controls of geographical diversity patterns is intensely debated. A key example is the controversy over the extent to which temperate tree distributions and diversity patterns reflect postglacial dispersal limitation. Here, we focus on Central and Northern Europe, and show that recent estimates of tree migration rates < 100 m year(-1) imply that many species have probably not reached equilibrium with climate in this region. We then demonstrate that geographical accessibility from glacial refuges explains 78% of the geographical variation in the region's tree diversity and is a much stronger diversity predictor than climate. Finally, we show that realistic estimates of migration rates can be derived from the observed tree diversity pattern by assuming it to be purely dispersal driven. In conclusion, the tree diversity pattern in Central and Northern Europe could, to a large extent, be a result of postglacial dispersal limitation.

Woody plants and the prediction of climate-change impacts on bird diversity

“…Many additional unknowns remain in forecasting future patterns of biodiversity (Davis et al 1998;Pearson & Dawson 2003;Thomas et al 2004;Araú jo & Rahbek 2006). Current forecasting techniques often assume that species' distributions are at or near equilibrium with current climate (Pearson & Dawson 2003) and the potential effects of dispersal and recruitment limitation on current and future species distributions remain understudied (Davis et al 1998;Nathan 2006;Svenning & Skov 2007). Even when the response of species richness to climate change can be adequately predicted, other attributes of ecological communities might not respond in a similar or predictable way (La Sorte et al 2009).…”

Geothermal activity helps life survive glacial cycles

“…We used this dataset and spatial modeling approaches to assess diversity patterns in Antarctica in relation to the locations of geothermal areas. Postglacial population expansion away from LGM refugia is typically marked by a distinct reduction in diversity in recolonized vs. refugial regions (36)(37)(38)(39) [including intraspecific genetic diversity (15,31,32)]. Under a hypothesis that geothermal refugia allowed persistence of Antarctic species throughout recent glacial periods, species richness is predicted to be highest close to geothermally active areas and lower in nonactive regions, with significant nestedness (40) of taxa from high-to low-richness areas, consistent with postglacial recolonization of more distant sites by a subset of the refugial taxa.…”

The postglacial recolonization of Northern Europe by Rana arvalis as revealed by microsatellite and mitochondrial DNA analyses

“…However, the withdrawal of the ice enabled two routes of recolonization into Fennoscandia, often leading to the formation of secondary contact zones (for example Hewitt, 2004) and thus increasing the overall genetic diversity found. These phylogenetic patterns have had implications not only for the patterning of within-species diversity, but also for the between-species interactions and community composition (Taberlet et al, 1995;Hewitt, 1996;Comes and Kadereit, 1998;Svenning and Skov, 2007). Therefore the identification of divergent intraspecific lineages constitutes an important element in our understanding of the biogeography, evolutionary history and sometimes even adaptation of a given species.…”