Verlässliche Daten über unsere Lebens­grundlage

Rising temperatures are leading to increased prevalence of warm-affinity species in ecosystems, known as thermophilisation. However, factors influencing variation in thermophilisation rates among taxa and ecosystems, particularly freshwater communities with high diversity and high population decline, remain unclear. We analysed compositional change over time in 7123 freshwater and 6201 terrestrial, mostly temperate communities from multiple taxonomic groups. Overall, temperature change was positively linked to thermophilisation in both realms. Extirpated species had lower thermal affinities in terrestrial communities but higher affinities in freshwater communities compared to those persisting over time. Temperature change’s impact on thermophilisation variedwith community body size, thermal niche breadth, species richness and baseline temperature; these interactive effects were idiosyncratic in the direction and magnitude of their impacts on thermophilisation, both across realms and taxonomic groups. While our findings emphasise the challenges in predicting the consequences of temperature change across communities, conservation strategies should consider these variable responses when attempting to mitigate climate-induced biodiversity loss.

Khaliq, I., Rixen, C., Zellweger, F. et al. (2024). Warming underpins community turnover in temperate freshwater and terrestrial communities. Nat Commun 15, 1921. https://doi.org/10.1038/s41467-024-46282-z

We adopted a landscape-scale approach to analyze the genetic patterns (diversity, structure, and differentiation) of the Marbled White (Melanargia galathea). This butterfly species is characteristic of semi-dry grasslands, which have substan­tially declined in Switzerland during past decades. We sampled individuals on a regular grid of the established Biodiversity Monitoring program of Switzerland over five consecutive years, obtaining 1639 genotyped individuals from 185 locations. Results showed that M. galathea populations cluster into five spatially aggregated clusters that largely coincide with the biogeographic regions of Switzerland. Genetic diversity (allelic richness) was higher in the South of the Alps, likely related to immigration dynamics that suggest recolonisation from the South after the last glaciation. Demographic history resulted in distinct isolation by distance (IBD) and by cumulative elevational difference (isolation by altitude, IBA) at large scale, while regional IBD and IBA were less pronounced. This pattern was likely induced by the barrier effect of the high mountains of the Alps impeding continuous northward migration after the last glacial maximum. A temporal analysis revealed that regional genetic diversity did not change strongly during the five sampling years. This result indicates that the genetic diversity pattern in M. galathea has not been noticeably affected by historical land-use change or that the sampling period of five years is too short to detect any changes. Our findings highlight the regionally, topography-induced distinct genetic clusters, relevant for consideration as conservation units and likely reflecting genetic structures similar to those found in other butterfly species of conservation concern.

Terzer, E., Schmid, M., Bauert, B. et al. (2023). Distinct spatial patterns of genetic structure and diversity in the butterfly Marbled White (Melanargia galathea) inhabiting fragmented grasslands. Conserv Genet. https://doi.org/10.1007/s10592-023-01593-4

Reusser, J. E., Siegenthaler, M., Winkel, L. H. E., Wächter, D., Kretzschmar, R. & Meuli, R. G. (2023). Geochemischer Bodenatlas der Schweiz: Verteilung von 20 Elementen in den Oberböden. Agroscope / Bundesamt für Umwelt (BAFU), ,Zürich / Bern. 5. Dezember, 2023, 154 S.

The objective of the Biodiversity Monitoring in Switzerland programme (BDM) is to identify changes in Switzerland's biodiversity. These data can help to ensure that the country's nature conservation policy is made more effective and more efficient and to scrutinize the efficacy of national policies affecting biodiversity. The BDM allows Switzerland to meet one of the requirements of the Convention on Biological Diversity signed in Rio.

Although biodiversity means not only species diversity but also genetic diversity and habitat diversity, financial and methodical constraints have forced the BDM to focus on monitoring species diversity.

A comprehensive picture of species diversity can only be obtained if changes are monitored on the three levels of diversity. Different pressures come to bear at each level, and different protective strategies need to be pursued to maintain and promote biodiversity.

The change in the species diversity of a country (y-diversity) depends predominantly on the occurrence of rare (and possibly threatened) species. The a-diversity of defined area types, in contrast, depends on the occurrence of common species, regional Bidiversity on widespread species. The BDM employs a separate indicator for each of these three levels. It thus monitors not only rare and threatened species but also common and widespread species. This is done through two coordinated sampling grids. The presence or absence of all the species in selected species groups is recorded in both grids. These samples will allow conclusions to be drawn for Switzerland as a whole, for specific regions and (for a-diversity) for certain types of land use.

In addition to indicators showing the state of biodiversity, the BDM includes indicators for main factors probably affecting biodiversity and for measures that have been implemented. These indicators are presented using the "'Pressure-State-Response model", which allows hypotheses to be developed about possible cause-effect relationships.

The annual results will be presented in a form, accessible to the various target groups and made available to users who need this information. The most important recipients of this information are nature conservation offices, agriculture and forestry, decision makers in politics, environmental organizations and the media.

Hintermann, U., Weber, D., & Zangger, A., 2000: Biodiversity monitoring in Switzerland. Schriftenreihe für Landschaftspflege und Naturschutz 62: 47-58.