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Climate and land‐use change jointly affect the future of biodiversity. Yet, biodiversity scenarios have so far concentrated on climatic effects because forecasts of land use are rarely available at appropriate spatial and thematic scales. Agent‐based models (ABMs) represent a potentially powerful but little explored tool for establishing thematically and spatially fine‐grained land‐use scenarios. Here, we use an ABM parameterized for 1,329 agents, mostly farmers, in a Central European model region, and simulate the changes to land‐use patterns resulting from their response to three scenarios of changing socio‐economic conditions and three scenarios of climate change until the mid of the century. Subsequently, we use species distribution models to, first, analyse relationships between the realized niches of 832 plant species and climatic gradients or land‐use types, respectively, and, second, to project consequent changes in potential regional ranges of these species as triggered by changes in both the altered land‐use patterns and the changing climate. We find that both drivers determine the realized niches of the studied plants, with land use having a stronger effect than any single climatic variable in the model. Nevertheless, the plants' future distributions appear much more responsive to climate than to land‐use changes because alternative future socio‐economic backgrounds have only modest impact on land‐use decisions in the model region. However, relative effects of climate and land‐use changes on biodiversity may differ drastically in other regions, especially where landscapes are still dominated by natural or semi‐natural habitat. We conclude that agent‐based modelling of land use is able to provide scenarios at scales relevant to individual species distribution and suggest that coupling ABMs with models of species' range change should be intensified to provide more realistic biodiversity forecasts. [ABSTRACT FROM AUTHOR]

Pleistocene climate fluctuations had profound influence on the biogeographical history of many biota. As large areas in high mountain ranges were covered by glaciers, biota were forced either to peripheral refugia (and possibly beyond to lowland refugia) or to interior refugia (nunataks). However, nunatak survival remains controversial as it relies solely on correlative genetic evidence. Here, we test hypotheses of glacial survival using two high alpine plant species (the insect‐pollinated Pedicularis asplenifolia and wind‐pollinated Carex fuliginosa) in the European Alps. Employing the iDDC (integrative Distributional, Demographic and Coalescent) approach, which couples species distribution modelling, spatial and temporal demographic simulation and Approximate Bayesian Computation, we explicitly test three hypotheses of glacial survival: (a) peripheral survival only, (b) nunatak survival only and (c) peripheral plus nunatak survival. In P. asplenifolia the peripheral plus nunatak survival hypothesis was supported by Bayes factors (BF> 100), whereas in C. fuliginosa the peripheral survival only hypothesis, although best supported, could not be unambiguously distinguished from the peripheral plus nunatak survival hypothesis (BF = 5.58). These results are consistent with current habitat preferences (P. asplenifolia extends to higher elevations) and the potential for genetic swamping (i.e., replacement of local genotypes via hybridization with immigrating genotypes [expected to be higher in the wind‐pollinated C. fuliginosa]). Although the persistence of plants on nunataks during glacial periods has been debated and studied over decades, this is one of the first studies to explicitly test the hypothesis instead of solely using correlative evidence. [ABSTRACT FROM AUTHOR]

Aim The rate of climate change might exceed the migration capacity of plants, particularly where habitats became fragmented by human land use. Except for some tree species, the extent to which habitat fragmentation decreases migration rates has nevertheless been little evaluated. Here, we compare simulated migration rates of understorey herbs, which comprise the big part of temperate forest plant diversity, under varying levels of fragmentation at a continental scale. Location Europe. Methods We combined simulations of demography and seed dispersal to simulate migration of 16 hypothetical forest herb species through a virtual, continuously forested landscape of 50 × 50 km and through 1179 50 × 50 km regions spanning most of the European Union's territory plus Norway and Switzerland. Each region was subdivided into a 250-m raster of sites, which were rated as suitable to a species if covered by forest according to current land cover maps and future land cover scenarios. The 16 hypothetical species were defined by combinations of those trait values that control demographic and dispersal processes. Results In continuous forests, simulated migration rates of the 16 species varied between ~95 and ~225 m/y. Current forest fragmentation was predicted to reduce migration rates to about 70% on average across the continent, but to below 25% in many parts of western and southern Europe. Under future land use, migration rates might slightly increase in economically marginal regions. Main conclusions Our results indicate that even on a continuously forested continent most understorey herbs would be unable to track climate warming and that habitat fragmentation will reduce migration rates to values an order of magnitude lower than expected climate velocities in parts of Europe. We conclude that, instead of concentrating conservation efforts in protected areas, facilitating the movement of species through the average countryside should become a conservation priority. [ABSTRACT FROM AUTHOR]

Question How does the plant species composition of Pontic- Pannonian salt-rich habitats vary on a large geographical scale? Do the floristic differences between Pannonia and the Balkans correspond to the current phytosociological classification? Location Pannonia ( Hungary, Slovakia, Austria, Czech Republic, Croatia, Serbia, Romania) and the Balkans ( Bulgaria, Macedonia, Greece). Methods Two thousand four hundred and thirty-seven relevés from halophytic and sub-halophytic habitats were classified using a modified TWINSPAN. The crispness of classification was checked. DCA and CCA with climate data as explanatory variables were applied. Results The classification was best interpreted at the level of 15 clusters. The vegetation changed along the salinity gradient from sub-halophytic grasslands (including Trifolion resupinati alliance of the Molinio- Arrhenatheretalia class and Beckmannion eruciformis and Festucion pseudovinae p. p. alliances of the Festuco- Puccinellietea class) and reed beds ( Bolboschoenion maritimi p. p. alliance; the Phragmito- Magnocaricetea class), through steppe and wet inland halophytic vegetation ( Festucion pseudovinae p. p. , Puccinellion limosae, Pucinellion convolutae, Bolboschoenion maritimi p. p. and Juncion gerardii of the Festuco- Puccinellietea class) towards the extreme halophytic vegetation of the Thero- Salicornietea, Crypsietea and Juncetea maritimi classes. This gradient was longer in the Balkan region, where it spanned from the sub-mediterranean salt-rich grasslands to the extremely halophytic vegetation at the Black Sea coast. The second most important gradient coincided with the water regime. Some vegetation types appeared to be confined to either the Pannonian or the Balkan region (especially within dry sub-halophytic and steppe halophytic grasslands), while others were distributed across the entire study area. The above-mentioned pattern did not always correspond with current classification systems. Conclusions Variation in salt-rich vegetation predominantly follows the salinity and water regime gradients. Geographical variation, generally coinciding with climatic and historical effects, is also important, especially in drier salt-rich habitats. Our large-scale analysis of the floristic variation of salt-rich habitats might be useful for the unification of classification systems that differ substantially between the countries involved. In addition, the analysis may be useful for adjustment of a classification system in the poorly explored Balkan region, where particular vegetation types were identified with, or delimited from, Central European vegetation types without detailed comparative analysis until now. [ABSTRACT FROM AUTHOR]

Background: The divergent glacial histories of southern and northern Europe affect present-day species diversity at coarsegrained scales in these two regions, but do these effects also penetrate to the more fine-grained scales of local communities? Methodology/Principal Findings: We carried out a cross-scale analysis to address this question for vascular plants in two mountain regions, the Alps in southern Europe and the Scandes in northern Europe, using environmentally paired vegetation plots in the two regions (n = 403 in each region) to quantify four diversity components: (i) total number of species occurring in a region (total γ-diversity), (ii) number of species that could occur in a target plot after environmental filtering (habitat-specific γ-diversity), (iii) pair-wise species compositional turnover between plots (plot-to-plot b-diversity) and (iv) number of species present per plot (plot a-diversity). We found strong region effects on total γ-diversity, habitatspecific γ-diversity and plot-to-plot b-diversity, with a greater diversity in the Alps even towards distances smaller than 50 m between plots. In contrast, there was a slightly greater plot a-diversity in the Scandes, but with a tendency towards contrasting region effects on high and low soil-acidity plots. Conclusions/Significance: We conclude that there are strong regional differences between coarse-grained (landscape- to regional-scale) diversity components of the flora in the Alps and the Scandes mountain ranges, but that these differences do not necessarily penetrate to the finest-grained (plot-scale) diversity component, at least not on acidic soils. Our findings are consistent with the contrasting regional Quaternary histories, but we also consider alternative explanatory models. Notably, ecological sorting and habitat connectivity may play a role in the unexpected limited or reversed region effect on plot adiversity, and may also affect the larger-scale diversity components. For instance, plot connectivity and/or selection for high dispersal ability may increase plot a-diversity and compensate for low total γ-diversity. [ABSTRACT FROM AUTHOR]

The post-glacial migration of European beech Fagus sylvatica has been addressed by many studies using either genetic or fossil data or a combination of both. In contrast to this, only little is known about the migration history of beech forest understorey species. In a review of phytosociological literature, we identified 110 plant species which are closely associated with beech forest. We divided the distribution range of European beech forests into 40 geographical regions, and the presence or absence of each species was recorded for each region. We compared overall species numbers per region and numbers of narrow-range species (species present in <10 regions). A multiple regression model was used to test for the explanatory value of three potential diversity controls: range in elevation, soil type diversity, and distance to the nearest potential refuge area. A hierarchical cluster analysis of the narrow-range species was performed. The frequency of range sizes shows a U-shaped distribution, with 42 species occurring in <10 regions. The highest number of beech forest species is found in the southern Alps and adjacent regions, and species numbers decrease with increasing distance from these regions. With only narrow-range species taken into consideration, secondary maxima are found in Spain, the southern Apennines, the Carpathians, and Greece. Distance to the nearest potential refuge area is the strongest predictor of beech forest species richness, while altitudinal range and soil type diversity had little or no predictive value. The clusters of narrow-range species are in good concordance with the glacial refuge areas of beech and other temperate tree species as estimated in recent studies. These findings support the hypothesis that the distribution of many beech forest species is limited by post-glacial dispersal rather than by their environmental requirements. [ABSTRACT FROM AUTHOR]

In the phytosociological literature, there are numerous different approaches to the designation of diagnostic species. Frequently, this results in discrepancies between the lists of diagnostic species published for one and the same community. We examined different approaches to determining diagnostic species using as an example Picea abies forests within the broader context of all Central European forests. Diagnostic species of spruce forests were determined from a data set of 20,164 phytosociological relevés of forests from the Eastern Alps, Western Carpathians, and the Bohemian Massif, which included 3,569 relevés of spruce forests. Phi coefficient of association was used to measure species fidelity, and species with the highest fidelities were considered as diagnostic. Diagnostic species were determined in four ways, including (A) comparison of spruce forests among the three mountain ranges, (B) comparison between spruce forests and other forests, performed separately in each of the mountain ranges, (C) simultaneous comparison of spruce forests of each of the mountain ranges with spruce forests of the other two ranges and with the other forests of all ranges, (D) comparison of spruce forests with the other forests, using pooled data sets from the three mountain ranges. The sets of diagnostic species of spruce forests yielded in comparisons A and B were sharply different; the set resulting from comparison C was intermediate between the first two and comparison D resulted in similar diagnostic species as comparison B. In comparison A, spruce forests of the Eastern Alps had a number of diagnostic species, while the spruce forests of the other two mountain ranges had only few diagnostic species. In comparison B, by contrast, the number and quality of diagnostic species decreased from the Bohemian Massif to the Eastern Alps. This exercise points out that lists of diagnostic species published in phytosociological literature are dependent on the... [ABSTRACT FROM AUTHOR]

Mountain plant species shift their elevational ranges in response to climate change. However, to what degree these shifts lag behind current climate change, and to what extent delayed extinctions and colonizations contribute to these shifts, are under debate. Here, we calculate extinction debt and colonization credit of 135 species from the European Alps by comparing species distribution models with 1576 re-surveyed plots. We find extinction debt in 60% and colonization credit in 38% of the species, and at least one of the two in 93%. This suggests that the realized niche of very few of the 135 species fully tracks climate change. As expected, extinction debts occur below and colonization credits occur above the optimum elevation of species. Colonization credits are more frequent in warmth-demanding species from lower elevations with lower dispersal capability, and extinction debts are more frequent in cold-adapted species from the highest elevations. Local extinctions hence appear to be already pending for those species which have the least opportunity to escape climate warming. Mismatches between the pace of climate change and plant responses may lead to delayed upslope shifts or extinction of mountain species. Here the authors investigate 135 alpine plant species, finding that extinction debts are more common among cold-adapted plants and colonization credits among warm-adapted plants. [ABSTRACT FROM AUTHOR]