Verlässliche Daten über unsere Lebens­grundlage

The species–area curve is generated by niche-related factors and stochastic factors like neutral processes or dispersal. Even though the use of environmental variables is widespread to predict the spatial distribution of species richness, it remains difficult to distinguish the relative importance of habitat heterogeneity and the area effect on total species richness. In our study, we used different types of species–area curves to disentangle the habitat heterogeneity effect and the area effect on vascular plant species richness. We generated three types of sample rarefaction curves: (1) a randomly aggregated rarefaction curve, (2) a rarefaction curve for which areas of similar habitat types were aggregated and (3) a rarefaction curve, for which areas of dissimilar habitat types were aggregated. These analyses were made on three data sets separately with different grain sizes to investigate if this had an effect on the observed pattern. The classification of the habitat types was based on three environmental variables (mean annual temperature, mean moisture index and the slope of the terrain). A consistent pattern of sample rarefaction curves was found with all three data sets. While the aggregation of dissimilar habitat types showed the highest species accumulation rates and saturation levels, the lowest accumulation rates and saturation levels were found when similar habitat types were aggregated. Depending on the grain size, the habitat heterogeneity effect accounted for 20–30% to the total species richness. However, this effect was not statistically significant. The results indicate, that effects of niche related factors on the species–area curve are scale dependent and that effects related to the area are at least as important in explaining the species richness.

Steinmann, K., Eggenberg, S., Wohlgemuth, T., Linder, H. P., & Zimmermann, N. E. (2011). Niches and noise—Disentangling habitat diversity and area effect on species diversity. Ecological Complexity, 8(4), 313–319. https://doi.org/10.1016/j.ecocom.2011.06.004

Baetis pentaphlebodes Ujhelyi, 1966, a species new for the Swiss fauna (Ephemeroptera: Baetidae)

In the framework of the MEPT project (red list of Mollusca, Ephemeroptera, Plecoptera, Trichoptera, supported by the Federal Office for Environment), the first author had the opportunity to identify material from the Aare River, containing a single larva belonging to Baetis gr. buceratus (Müller-Liebenau 1969). New samples were made in this locality confirming the presence of Baetis pentaphlebodes Ujhelyi, 1966 in Switzerland. Additional samplings in similar habitats allow the discovery of three new localities. We suspect that this species could be in expansion in Switzerland in the next years.

Wagner, A., Mürle, U., & Ortlepp, J. (2011). Baetis pentaphlebodes Ujhelyi, 1966, (Ephemeroptera: Baetidae) une espèce nouvelle pour la faune de Suisse. Bulletin de la Société Entomologique Suisse 84: 35-44.

Sown wildflower strips are increasingly being established in European countries within agri-environmental schemes to enhance biodiversity, especially in intensively used agricultural areas.

The regulations vary between countries regarding the seed mixture, intensity of management and period of time over which subsidies are given. Insects in particular are intended to benefit from these schemes.
This review treats studies of insect diversity and abundance in sown wildflower strips. Schemes on wildflower strips in several countries in Central and Northern Europe are compared.

In a significant majority of studies, sown wildflower strips support higher insect abundances and diversity than cropped habitats. In general, numbers and diversity also tend to be higher than in other margin types such as sown grass margins and natural regeneration, but pollen- and nectar-rich flower mixtures may outperform them.
Common species are the main beneficiaries of the establishment of wildflower strips, although some studies point out the presence of rare or declining insect species.

Insect groups respond differently to particular characteristics of the strips. Flower abundance, seed mixture, vegetation structure, management, age and landscape have been identified as factors influencing insect abundance and diversity.

Future work should address under-represented comparisons, such as with pollen- and nectar-rich seed mixes, and neglected groups, in particular parasitoids. Nevertheless, sown wildflower strips can already be seen as a beneficial measure to enhance insect diversity. This is especially the case, where schemes for sown strips vary within a region to favour different species groups.

Haaland, C., Naisbit, R. E., & Bersier, L.-F. (2011). Sown wildflower strips for insect conservation: A review: Wildflower strips for insect conservation. Insect Conservation and Diversity, 4(1), 60–80. https://doi.org/10.1111/j.1752-4598.2010.00098.x

Question: How many vegetation plot observations (relevés) are available in electronic databases, how are they geographically distributed, what are their properties and how might they be discovered and located for research and application?

Location: Global.

Methods: We compiled the Global Index of Vegetation-Plot Databases (GIVD; http://www.givd.info), an Internet resource aimed at registering metadata on existing vegetation databases. For inclusion, databases need to (i) contain temporally and spatially explicit species co-occurrence data and (ii) be accessible to the scientific public. This paper summarizes structure and data quality of databases registered in GIVD as of 30 December 2010.

Results: On the given date, 132 databases containing more than 2.4 million non-overlapping plots had been registered in GIVD. The majority of these data were in European databases (83 databases, 1.6 million plots), whereas other continents were represented by substantially less (North America 15, Asia 13, Africa nine, South America seven, Australasia two, multi-continental three). The oldest plot observation was 1864, but most plots were recorded after 1970. Most plots reported vegetation on areas of 1 to 1000 m²; some also stored time-series and nested-plot data. Apart from geographic reference (required for inclusion), most frequent information was on altitude (71%), slope aspect and inclination (58%) and land use (38%), but rarely soil properties (<7%).

Conclusions: The vegetation plot data in GIVD constitute a major resource for biodiversity research, both through the large number of species occurrence records and storage of species co-occurrence information at a small scale, combined with structural and plot-based environmental data. We identify shortcomings in available data that need to be addressed through sampling under-represented geographic regions, providing better incentives for data collection and sharing, developing user-friendly database exchange standards, as well as tools to analyse and remove confounding effects of sampling biases. The increased availability of data sets conferred by registration in GIVD offers significant opportunities for large-scale studies in community ecology, macroecology and global change research.

Dengler, J., Jansen, F., Glöckler, F., Peet, R. K., De Cáceres, M., Chytrý, M., Ewald, J., Oldeland, J., Lopez-Gonzalez, G., Finckh, M., Mucina, L., Rodwell, J. S., Schaminée, J. H. J., & Spencer, N. (2011). The Global Index of Vegetation-Plot Databases (GIVD): A new resource for vegetation science: Global Index of Vegetation-Plot Databases (GIVD). Journal of Vegetation Science, 22(4), 582–597. https://doi.org/10.1111/j.1654-1103.2011.01265.x