„Wild bees in urban grasslands: Urbanisation, functional diversity and species traits“ has been published in Landscape and Urban Planning. We found that urbanisation was not related to neither taxonomic nor functional diversity in bee communities of urban grasslands. However, endangered bee species responded negatively to the isolation of grasslands but positively to flower coverage. Urbanisation, previous restoration efforts and site type filtered the functional composition of bee communities in terms of species traits related to diet and nesting. Our results substantiate the role of urban habitats for functionally diverse bee communities, including rare and endangered species, and indicate pathways towards enhancing habitat functions of urban grasslands for wild bees by improving the connectivity of urban grassland patches within the urban matrix, and more locally by adjusting management to maintain flower coverage in grasslands.
Assessing spider diversity in grasslands – does pitfall trap color matter? has been accepted in Journal of Arachnology.
Authors Möller M & Buchholz S
We analyzed effects of pitfall trap color (white, yellow, green, brown) on spider catches and found differences in alpha-diversity and one biological trait, namely hunting type. Attractiveness of different trap colors may arise due to differences in biological preconditions, albedo and microclimate which in turn can affect diversity and community structure of spiders. Trap color has a significant impact on spider catches and should be considered when planning surveys.
Grasshopper diversity of urban wastelands is primarily boosted by habitat factors has been published in Insect Diversity and Conservation.
Authors Eckert S, Möller M & Buchholz S
Abstract Urban wastelands are considered to be valuable habitats for biodiversity conservation, but empirical evidence for several poorly investigated taxa such as grasshoppers is still pending – although urgently required for reasonable habitat management and urban planning. For the first time, we analysed grasshopper diversity of urban wastelands at different diversity levels, namely, alpha and functional diversity. In 2014, we selected 24 urban wastelands in the city of Berlin (Germany).
We analysed the relationships between local and landscape factors and different measurements of diversity (species richness, Simpson diversity, functional dispersion, functional evenness and functional divergence). We sampled 21 species, which represented about 45% of the entire grasshopper fauna of Berlin and numerous species of conservation interest were present at the investigated sites. Grasshopper diversity was best explained by local factors, with herb cover having a positive effect on alpha and functional diversity. Human impact and accessibility increased the conservation value of urban wasteland sites.
Late successional stages are very important for a high grasshopper diversity in general but early stages are mandatory to promote species of conservation concern. Urban wastelands can be turned into most promising transition zones for city-dwellers that fulfil the needs of conservationists and specialised species at the same time. To achieve this goal we recommend minimum requirements for successful habitat management.
Trait composition and functional diversity of spiders and carabids in linear landscape elements has been published in Agriculture, Ecosystems and Environment.
Authors Schirmel J, Thiele J, Entling MH & Buchholz S
Abstract Agricultural intensification is a cause of global biodiversity decline. Seminatural linear landscape elements (LLE) within agricultural landscapes can considerably mitigate these declines, but their effects on functional properties of biodiversity are poorly known. We analyzed trait composition and functional diversity (functional dispersion) of spiders and carabids in woody and herbaceous LLE. We expected that species assemblages of woody LLE are more diverse and K-selected compared to herbaceous LLE, and that effects of environmental parameters vary between LLE types. We selected 58 LLE in an agricultural landscape in Northwest Germany. We sampled carabids and spiders by pitfall trapping and measured landscape connectivity, landscape-wide land-use diversity, local land-use diversity, and local plant richness as explanatory variables. The trait composition of arthropods in woody LLE was more K-selected (lower dispersal ability, a higher food specialization or trophic level) than in herbaceous LLE. Moreover, spider functional diversity was higher in woody LLE. Spider functional diversity and proportion of predatory carabids in woody LLE increased with increasing connectivity of the habitats. In contrast, in herbaceous LLE local plant richness and landscape-wide land-use diversity were most important drivers for spider and carabid diversity and traits. Our results show that species richness and functional diversity of spiders and carabids were differently affected by landscape and local factors. Therefore, the importance of landscape connectivity was higher in woody LLE, suggesting that their inhabitants are more sensitive to habitat fragmentation than the highly mobile generalist species living in herbaceous habitats.
Conference talk in Greifswald
Last weekend the conference of the German Arachnological Society took place in Greifswald. I gave a talk on trait-based approaches and functional diversity in arachnology and presented progresses and perspectives within this research topic (see slides). Trait-environmental relationships and functional diversity are very important components within biodiversity research and several studies have successfully applied these concepts to spiders. Unfortunately, a consensus how to select appropriate morpho-physiological, phenological and ecological traits and to define trait categories is missing yet. Therefore, my talk intended to encourage the development of a standardised and expert-based open-access trait database for spiders. It was great to have some fruitful discussions afterwards. We agreed on organising an expert workshop soon to work out a first proposal for a meaningful trait selection.
New research project on urban ecology
Back in Berlin, I am now working as scientist in the new research project „Bridging in Biodiversity Science (BIBS)“ which is established at the Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB) and the TU Berlin. Rapid transitions in land use patterns are often very conspicuous in the process of urbanization: within the central European landscape, large urban areas have emerged within the past two centuries. By ignoring them as islands of unnatural, novel landscapes, traditional research on ecology and biodiversity did not predict that numerous mammalian wildlife species would invade, stay and flourish within urban areas, or that cities would emerge as biodiversity hotspots. Since I am now responsible for the work package „Rural-urban coupling“ I am going to work on the following research topics:
- understanding the effect and spatial reach of matrix heterogeneity and configuration,
- measuring the temporal dynamics of urban landscapes to reveal effects of landuse legacy, historical connectivity and current land use,
- identifying key functional traits of successful species that meet the challenges created by urban environments, and
- exploring the consequences of increased contact for both people and wildlife