New paper on urban pollinators

Disentangling urban habitat and matrix effects on wild bee species has been published in PeerJ.

Authors Fischer LK, Eichfeld J, Kowarik I & Buchholz S

Abstract In face of a dramatic decline of wild bee species in many rural landscapes, potential conservation functions of urban areas gain importance.  Yet effects of urbanization on pollinators, and in particular on wild bees, remain ambiguous andpollinators not comprehensively understood. This is especially true for amenity grassland and extensively managed wastelands within large-scale residential housing areas. Using Berlin as study region, we aimed to investigate (a) if these greenspaces are accepted by wild bee assemblages as foraging habitats; (b) how assemblage structure of bees and individual bee species are affected by different habitat (e.g., management, flower density) and urban matrix variables (e.g., isolation, urbanization); and (c) to what extend grassland restoration can promote bees in urban environments. In summer 2012, we collected 62 bee species belonging to more than 20 % of the taxa known for Berlin. Urbanization significantly affected species composition of bees; 18 species were affiliated to different levels of urbanization. Most bee species were not affected by any of the environmental variables tested, and urbanization had a negative effect only for one bee species. Further, we determined that restoration of diverse grasslands positively affected bee species richnesss in urban environments. We conclude that differently structured and managed greenspaces in large-scale housing areas can provide additional foraging habitats and refuges for pollinators. This supports approaches towards a biodiversity friendly management within urban regions and may be of particular importance given that anthropogenic pressure is increasing in many rural landscapes.

Biological traits and functional diversity in arachnology

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.

Grasshopper sampling

First field work within the BIBS project finished

We finished the grasshopper sampling last week! More than 60 urban dry grasslands had been sampled during summer and we are now happy to have a first extensive dataset for the BIBS project. In all, we acoustically and visually assessed more than 4000 grasshopper individuals with 22 species – including some very interesting species such as Calliptamus italicus. We are looking forward to first functional diversity analyses in the next few weeks.

Birding in Berlin

Urban birds of prey

Several raptor species become more and more urban dwellers and they thrive very well in many different urban habitats now. In Berlin, four species are very common – even in heavily urbanised areas. While the common buzzard (Buteo buteo) mostly inhabits parks and urban woodlands, aeries of the peregrine falcon (Falco peregrinus) and the common kestrel (Falco tinnunculus) can be found in higher buildings all over the city. The latter can be regularly seen at the Tempelhofer Feld (see photo) and a good place to observe the peregrine falcon is the Alexanderplatz and the television tower which is used as raised hide, even during the night. kestrel

In the last years, we conducted research on the northern goshawk (Accipiter gentilis). Interestingly, this species spreads more and more into the heavily urbanised areas and while it was breeding in urban parks and large gardens at the beginning, aeries can be found in backyards in isolated tree by now. Sometimes northern goshawks are even hunting in busy roads like the Schlesische Straße in Kreuzberg. Watch out for more findings …

New paper on urban biodiversity

Biodiversity functions of urban cemeteries: evidence from one of the largest Jewish cemeteries in Europe has been accepted for publication in Urban Forestry & Urban Greening.

Authors Kowarik I, Buchholz S, von der Lippe M & Seitz B

Abstract As the world becomes more urbanized, urban cemeteries may become increasingly valuable for biodiversity conservation as cemeteries are ubiquitous elements of the green infrastructure in cities worldwide. By implementing a multi-taxon approach at different spatial extents, we analyzed habitat functions of a large urban cemetery in Berlin (Weißensee Jewish Cemetery) and explored related environmental variables. This cemetery is an outstanding cultural heritage site but it also stands for old urban cemeteries that have progressed to urban woodland, an ecosystem type that exists in many regional and religious contexts. The cemetery provided a habitat for 604 species; species of conservation concern comprised 1.6–100% of total species among different groups of taxa (in decreasing order: bats, birds, lichens, bryophytes, carabids, vascular plants, spiders). Species richness and species composition at the plot level were significantly related to differences in management intensity and resulting vegetation structures but differed among taxonomic groups. In vascular plants, carabids and spiders, the species composition varied significantly with habitat age, and there was a set of characteristic species for different age classes in each species group. Our results thus support the use of differentiated management approaches to maintain habitat heterogeneity by allowing wilderness development in some parts of a cemetery while keeping others more open. Since these aims can be combined with efforts to preserve outstanding grave architectures and allow access to visitors, our study indicates ways of reconciling conflicting aims of heritage preservation and biodiversity conservation, a promising perspective for biodiversity conservation in culturally shaped urban landscapes. We conclude that cemeteries provide important cultural ecosystem services within the urban green infrastructure.

Bridging in Biodiversity Science

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

Working in the invertebrate lab

Insects and spiders of Galápagos

Together with my colleagues from the invertebrate lab of the Charles Darwin Research Station I recently finished the identifications of the spider, beetle and bug samples from the Los Gemelos project. We found a number of very interesting endemic species such as the spiders Darwinneon crypticus, Galaporella thaleri or Olios galapagoensis as well as endemic beetles such as Anchonus galapagoensis, Ataenius aequatorialis or Mordellistena galapagoensis. It was a great experience for me to see all this new species – and of course to work with the awesome team. Many thanks! Back in Berlin again, I am going to run the statistical analyses – look out for coming publications. If you are already interested in some basic results from the Los Gemelos project please make a note of the following paper which will published in the Galápagos Report soon:

Restoration of the blackberry-invaded Scalesia forest: impacts on the vegetation, invertebrates and birds (by Jäger H, Cimadom A, Buchholz S, Tebbich S, Rodriguez J, Barrera D, Breuer M, Walentowitz A, Carrión A, Sevilla C & Causton C)