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Extensively cultivated permanent grassland with a high species diversity has strongly decreased in Switzerland over the last decades owing to agricultural intensification and abandonment. The question arises which diversity of species can still be found in the current ‘usual’ cultural landscape of Switzerland and how it differs from extensively cultivated permanent grasslands.

The study presented analyses the species diversity and species composition in select extensively cultivated permanent grasslands, and it compares the findings with average values of the species diversity of vascular plants, mosses and snails according to the ‘Biodiversity Monitoring Switzerland’.

Currently cultivated permanent grasslands in the Swiss average still show a high species diversity in the three species groups compared to traditional land use forms. Whilst for vascular plants the average number of species in extensively used grasslands is higher than the national average on comparable sites, the analysis showed no difference for mosses and snails. Additionally, the vascular plants included more indicator and character species and more plant species of the Red List on extensively cultivated grassland. The differences of the species composition of vascular plants between extensively cultivated permanent grassland and the nationwide average values can be ascribed to nutrient gradients.

Schlup, B., Stalling, T., Plattner, M., & Weber, D. (2013). Die Artenvielfalt des durchschnittlichen Dauergrünlands der Schweiz. Ein Vergleich zu naturschutzfachlich wertvollen Wiesen und Weiden. Naturschutz und Landschaftsplanung 45: 013-020.

Aim

Spatial dynamics and habitat connectivity affect community composition and diversity in many ecosystems. For many decades, diversity patterns in riverine ecosystems were thought to be related to local environmental conditions. Recent theoretical work, however, suggests that diversity in rivers is strongly affected by dispersal along the dendritic landscape structure and that environmental conditions are intrinsically linked to the network position. In this study we tested hypotheses on network position by relating river network geometry and connectivity to multi-level biodiversity patterns across large scales.

Location

Three major alpine drainage basins in Switzerland were studied (Rhine, Rhone, Ticino), extending over an elevational gradient of > 2500 m and covering a total area of 41,285 km2km2.

Methods

We sampled all may-, stone- and caddisfly species at 217 sites which representatively cover the three river networks. Using generalized additive models, we related diversity patterns in aquatic insects to centrality within the network as a direct river network property, and to catchment area and elevation , which are related to network position.

Results

Centrality within the river network, and catchment area and elevation had significant and interacting effects on α-diversity and community similarity. Alpha diversity was lowest in peripheral headwaters and at high elevations. Species richness generally increased with increasing catchment area. Well-connected, central communities within the river network had greater α-diversity than more peripheral communities did. Elevation was a strong predictor of α-diversity, with the most diverse communities found at mid-elevation sites. Community similarity decreased with increasing along-stream distance between sites.

Main conclusions

Our results highlight the fact that diversity patterns of aquatic insects in river systems are related to local factors such as elevation, but interact with network properties and connectivity along waterways, and differ among insect orders. These findings are consistent with dispersal-limited processes and indicate that riverine diversity should be addressed and protected taking the river network structure into account.

Altermatt, F., Seymour, M., & Martinez, N. (2013). River network properties shape α-diversity and community similarity patterns of aquatic insect communities across major drainage basins. Journal of Biogeography, 40(12), 2249–2260. https://doi.org/10.1111/jbi.12178

Aim Understanding the stability of realized niches is crucial for predicting the responses of species to climate change. One approach is to evaluate the niche differences of populations of the same species that occupy regions that are geographically disconnected. Here, we assess niche conservatism along thermal gradients for 26 plant species with a disjunct distribution between the Alps and the Arctic.

Location European Alps and Norwegian Finnmark.

Methods We collected a comprehensive dataset of 26 arctic-alpine plant occurrences in two regions. We assessed niche conservatism through a multispecies comparison and analysed species rankings at cold and warm thermal limits along two distinct gradients corresponding to (1) air temperatures at 2 m above ground level and (2) elevation distances to the tree line (TLD) for the two regions. We assessed whether observed relationships were close to those predicted under thermal limit conservatism.

Results We found a weak similarity in species ranking at the warm thermal limits. The range of warm thermal limits for the 26 species was much larger in the Alps than in Finnmark. We found a stronger similarity in species ranking and correspondence at the cold thermal limit along the gradients of 2-m temperature and TLD. Yet along the 2-m temperature gradient the cold thermal limits of species in the Alps were lower on average than those in Finnmark.

Main conclusion We found low conservatism of the warm thermal limits but a stronger conservatism of the cold thermal limits. We suggest that biotic interactions at the warm thermal limit are likely to modulate species responses more strongly than at the cold limit. The differing biotic context between the two regions is probably responsible for the observed differences in realized niches.

Pellissier, L., Bråthen, K. A., Vittoz, P., Yoccoz, N. G., Dubuis, A., Meier, E. S., Zimmermann, N. E., Randin, C. F., Thuiller, W., Garraud, L., Van Es, J., & Guisan, A. (2013). Thermal niches are more conserved at cold than warm limits in arctic-alpine plant species: Thermal limits in arctic-alpine plants. Global Ecology and Biogeography, 22(8), 933–941. https://doi.org/10.1111/geb.12057

Purpose: Land use is a main driver of global biodiversity loss and its environmental relevance is widely recognized in research on life cycle assessment (LCA). The inherent spatial heterogeneity of biodiversity and its non-uniform response to land use requires a regionalized assessment, whereas many LCA applications with globally distributed value chains require a global scale. This paper presents a first approach to quantif land use impacts on biodiversity across different world regions and highlights uncertainties and research needs.

Methods: The study is based on the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) land use assessment framework and focuses on occupation impacts, quantified as a biodiversity damage potential (BDP). Species richness of different land use types was compared to a (semi-)natural regional reference situation to calculate relative changes in species richness. Data on multiple species groups were derived from a global quantitative literature review and national biodiversity monitoring data from Switzerland. Differences across land use types, biogeographic regions (i.e., biomes), species groups and data source were statistically analyzed. For a data subset from the biome (sub-)tropical moist broadleaf forest, different species-based biodiversity indicators were calculated and the results compared.

Results and discussion: An overall negative land use impact was found for all analyzed land use types, but results varied considerably. Different land use impacts across biogeographic regions and taxonomic groups explained some of the variability. The choice of indicator also strongly influenced the results. Relative species richness was less sensitive to land use than indicators that considered similarity of species of the reference and the land use situation. Possible sources of uncertainty, such as choice of indicators and taxonomic groups, land use classification and regionalization are critically discussed and further improvements are suggested. Data on land use impacts were very unevenly distributed across the globe and considerable knowledge gaps on cause–effect chains remain.

Conclusions: The presented approach allows for a first rough quantification of land use impact on biodiversity in LCA on a global scale. As biodiversity is inherently heterogeneous and data availability is limited, uncertainty of the results is considerable. The presented characterization factors for BDP can approximate land use impacts on biodiversity in LCA studies that are not intended to directly support decision-making on land management practices. For such studies, more detailed and site-dependent assessments are required. To assess overall land use impacts, transformation impacts should additionally be quantified. Therefore, more accurate and regionalized data on regeneration times of ecosystems are needed.

de Baan, L., Alkemade, R., & Koellner, T. (2013). Land use impacts on biodiversity in LCA: A global approach. The International Journal of Life Cycle Assessment, 18(6), 1216–1230. https://doi.org/10.1007/s11367-012-0412-0