Assessing community assembly along a successional gradient in the North Adriatic Karst with functional and phylogenetic distances.

Recently, two approaches to account for ecological differences in community composition have been developed: one based on trait differences (functional diversity) and another based on evolutionary history (phylogenetic diversity). Combining them allows an integrated view of processes structuring communities. The North Adriatic Karst is covered by species-rich grasslands, but land abandonment has resulted in replacement by woodlands. This creates a successional gradient along which environmental conditions may change, and different community assembly rules may apply. We sampled 56 plant communities in the Karst and used functional-phylogenetic distances to assess assembly along a successional gradient, from grasslands to shrublands and woodlands. We found 146 species, for which we measured functional traits and built a phylogenetic tree. The three successional stages were floristically different, with grasslands having species that are typical of harsher soil conditions and woodlands with species preferring milder soil conditions. All communities had higher functional than phylogenetic distances, implying that closely related species tended to be phenotypically dissimilar. When more importance was given to functional distances, most grasslands and some shrublands were underdispersed; when more importance was given to phylogenetic distances, only one grassland was underdispersed and one woodland was overdispersed. Combining functional and phylogenetic distances provided us with better estimates of ecological differences in a successional gradient, where environmental filters seem to be the dominant force in early stages and competitive exclusion becomes more important in later stages. Taking into account that sucessional stages are assembled by different rules is essential to predicting their behaviour under future environmental scenarios.

Political systems affect mobile and sessile species diversity--a legacy from the post-WWII period.

Political ideologies, policies and economy affect land use which in turn may affect biodiversity patterns and future conservation targets. However, few studies have investigated biodiversity in landscapes with similar physical properties but governed by different political systems. Here we investigate land use and biodiversity patterns, and number and composition of birds and plants, in the borderland of Austria, Slovenia and Hungary. It is a physically uniform landscape but managed differently during the last 70 years as a consequence of the political "map" of Europe after World War I and II. We used a historical map from 1910 and satellite data to delineate land use within three 10-kilometre transects starting from the point where the three countries meet. There was a clear difference between countries detectable in current biodiversity patterns, which relates to land use history. Mobile species richness was associated with current land use whereas diversity of sessile species was more associated with past land use. Heterogeneous landscapes were positively and forest cover was negatively correlated to bird species richness. Our results provide insights into why landscape history is important to understand present and future biodiversity patterns, which is crucial for designing policies and conservation strategies across the world.