Relationships between traits of organisms and the structure of their metacommunities have so far mainly been explored with meta-analyses. We compared metacommunities of a wide variety of aquatic organism groups (12 groups, ranging from bacteria to fish) in the same set of 99 ponds to minimise biases inherent to meta-analyses. In the category of passive dispersers, large-bodied groups showed stronger spatial patterning than small-bodied groups suggesting an increasing impact of dispersal limitation with increasing body size. Metacommunities of organisms with the ability to fly (i.e. insect groups) showed a weaker imprint of dispersal limitation than passive dispersers with similar body size. In contrast, dispersal movements of vertebrate groups (fish and amphibians) seemed to be mainly confined to local connectivity patterns. Our results reveal that body size and dispersal mode are important drivers of metacommunity structure and these traits should therefore be considered when developing a predictive framework for metacommunity dynamics.

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Pollen diagrams from mountain lakes and marshes in SW Turkey show evidence of intensive anthro pogenic influence in the landscape between 3500 and 1300 BP. Three cores from within the territory of the classical city Sagalassos (Western Taurus, Pisidia) were palynologically analysed to make a reconstruction of the past vegetation in the territory of Sagalassos and to estimate the impact of its inhabitants on the landscape in Pisidia. Two cores originate from an intramontane marsh (Gravgaz; elevation 1215 m) and one from a seasonal intramontane lake (ÇanaklK; elevation 1030 m). Human acitivity is apparent from c. 2530 BP in the pollen diagrams. A deforestation phase/‘disturbance’ phase (from c. 2530 BP/c. 2480 BP till c. 2280 BP/c. 2270 BP), anthropogenically or climatologically driven, precedes a cultivation period (arboricultural phase) (from c. 2280 BP/2270 BP till c. 1480 BP/c. 1270 BP). The results of the pollen analyses of the three cores are compared and show many similarities. There are also similarities with other cores from SW Turkey, although the arboricultural phase (mainly olive cultivation) occurs later in the cores from the Sagalassos territory than in other cores from SW Turkey.

In large parts of Western Europe agricultural intensification after World War II has led to an increased use of fertilisers. The resulting nutrient enrichment (=eutrophication) has a huge impact on the occurrence and distribution of plant species and is one of the main pressures on native plant communities. We used the distribution maps (grid size: 16 km(2)) of individual plant species, obtained through two consecutive survey projects (1939-1971 and 1972-2004) in Flanders (northern Belgium), to estimate the relative change in their distribution area. The comparison of changes in range size among groups of taxa classified according to habitat preference and Ellenberg indicator values, demonstrated a marked decline in distribution area in species that are characteristic for nutrient-poor habitats. To assess geographic patterns in the change of species assemblages, we calculated the mean Ellenberg N- and R-values for every grid cell during each of both survey periods. Differences between these values were analysed in relation to soil type and estimates of atmospheric nitrogen deposition. The largest shifts in Ellenberg N-values, reflecting a decline of species from nutrient-poor conditions and/or an increase of nitrophilous plants, were observed in areas with nutrient-poor, acid sandy soils and high nitrogen deposition rates. Hence, shifts in species composition were modulated by geographic variation in soil type and levels of nitrogen deposition. As the levels of atmospheric nitrogen deposition are still very high in Flanders, it is likely that species from nutrient-poor habitats such as heathlands, will further decline in the near future

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