A growing body of evidence suggests that processes of upward treeline expansion and shifts in vegetation zones may occur in response to climate change. However, such shifts can be limited by a variety of non-climatic factors, such as nutrient availability, soil conditions, landscape fragmentation and some species-specific traits. Many changes in species distributions have been observed, although no evidence of complete community replacement has been registered yet. Climatic signals are often confounded with the effects of human activity, for example, forest encroachment at the treeline owing to the coupled effect of climate change and highland pasture abandonment. Data on the treeline ecotone, barriers to the expected treeline or dominant tree species shifts due to climate and land use change, and their possible impacts on biodiversity in 11 mountain areas of interest, from Italy to Norway and from Spain to Bulgaria, are reported. We investigated the role of environmental conditions on treeline ecotone features with a focus on treeline shift. The results showed that treeline altitude and the altitudinal width of the treeline ecotone, as well as the significance of climatic and soil parameters as barriers against tree species shift, significantly decreased with increasing latitude. However, the largest part of the commonly observed variability in mountain vegetation near the treeline in Europe seems to be caused by geomorphological, geological, pedological and microclimatic variability in combination with different land use history and present socio-economic relations.

Abiotic factors often are the most important factors influencing a species' distribution. Nevertheless, when investigating the underlying causes of a species' distribution, it is important to assess both the abiotic and the anthropogenic factors (land-use variables) that might have influenced the species' distribution. That is especially true in the Mediterranean Basin, where natural ecosystems have undergone significant changes in response to anthropogenic pressures in the region. In this study, we examined the effects of abiotic and anthropogenic factors on the distribution of Quercus faginea in the Spanish Central Pyrenees. Information on the presenceabsence of Q. faginea, and abiotic and anthropogenic variables, were derived using GIS based on digital maps and aerial photographs. To identify and quantify the factors that have affected significantly the spatial distribution of Q. faginea, we used Bayesian Model Averaging and hierarchical partitioning. In the Spanish Central Pyrenees, on a broad scale, abiotic variables; i.e. climate and lithology, were the factors that had the greatest effect on the spatial distribution of Q. faginea; however, recently introduced pine plantations and previous livestock pressure have had a negative effect on the distribution of Q. faginea in the region.

Achieving social equity among local stakeholders should be a key objective for ecosystem service (ES) governance in Europe's ecologically fragile treeline areas. The ES literature tends to be biased towards distributional equity and market-based instruments when assessing social equity of ES governance. In this study, we analyze a wide range of social equity procedures that have been applied in Europe, using 11 synthesized case studies of governance-related challenges and 75 proposals for governance enhancement from 8 European countries provided by researchers with expertise on treeline area governance. The proposals were grouped by inductive clustering into 10 procedural or distributional equity-related policy recommendations: (1) increase stakeholder collaboration, (2) balance interactions between horizontal and vertical governance levels, (3) increase ES education, (4) use science to guide decisions, (5) start collaboration at an early stage, (6) enhance transparency, (7) aim to mitigate negative impacts, (8) use an ES approach to identify synergistic goals for governance, (9) enhance balanced multi-functional land use, and (10) use market-based instruments to balance benefits and costs deriving from governance decisions. Finally, we discuss 5 more general proposals on how regulatory and market-based ap proa ches could be linked to enhance both procedural and distributional equity of treeline area governance.

This case study assessed changes in vegetation composition of a 0.8 ha rangeland site over the past four decades, in relation to changes in temperature and to an increase in grazing pressure. The frequency and standing crop (biomass) of species and functional groups were sampled in the spring of 1979 and 2016. Mean annual temperature increased, whereas changes in frequency varied between species and functional groups. Species that decreased included perennial plants, whereas species that increased were comprised mostly of annuals and unpalatable herbaceous plants. An NMDS ordination showed significant differences in species composition between 1979 and 2016. Total biomass, as well as the biomass of annual and perennial grasses and forbs did not differ between 1979 and 2016. Shrub biomass, however, decreased by 60% between years. Biomass of the 'graminoids' (e.g. Carex divisa), on the other hand, increased fourfold between 1979 and 2016. Species richness and the Shannon-Weaver diversity index H′ declined in 2016. This, together with a decline in the frequency of palatable species and a shift in species composition, could signal a decline in resilience over the long term. Changes in vegetation were most likely driven by a combination of higher temperatures and increased grazing pressure.

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