Archiv der Kategorie: BIBS

Two faunistic papers on grassland invertebrates

Recently, Märkische Entomologische Nachrichten has published two faunistic papers. The first one in on Carabid beetles (Coleoptera: Carabidae) of dry grasslands in Berlin (and Brandenburg). At 52 dry grassland sites in Berlin and Brandenburg we sampled 106 species including a new record for Berlin and numerous endangered species. The second one,
Wild bees of dry grasslands in Berlin, summarises bee data from 49 dry grasslands in Berlin. Both papers highlight the importance of urban sites as secondary habitats for rare and endangered invertebrates.

New paper on urban bats

Tree cover mediates the effect of ALAN on urban bats has been published in Frontiers in Ecology and Evolution. For Download, please go to the Frontiers Webpage.

Abstract: With urban areas growing worldwide, so does artificial light at night (ALAN) which negatively affects many nocturnal animals, including bats. The response of bats to ALAN ranges from some opportunistic species taking advantage of insect aggregations around street lamps, particularly those emitting ultraviolet (UV) light, to others avoiding lit areas at all. Tree cover has been suggested to mitigate the negative effects of ALAN on bats by shielding areas against light scatter. Here, we investigated the effect of tree cover on the relationship between ALAN and bats in Berlin, Germany. In particular, we asked if this interaction varies with the UV light spectrum of street lamps and also across urban bat species. We expected trees next to street lamps to block ALAN, making the adjacent habitat more suitable for all species, irrespective of the wavelength spectrum of the light source. Additionally, we expected UV emitting lights next to trees to attract insects and thus, opportunistic bats. In summer 2017, we recorded bat activity at 22 green open spaces in Berlin using automated ultrasonic detectors. We analyzed bat activity patterns and landscape variables (number of street lamps with and without UV light emission, an estimate of light pollution, and tree cover density around each recording site within different spatial scales) using generalized linear mixed-effects models with a negative binomial distribution. We found a species-specific response of bats to street lamps with and without UV light, providing a more detailed picture of ALAN impacts than simply total light radiance. Moreover, we found that dense tree cover dampened the negative effect of street lamps without UV for open-space foraging bats of the genera Nyctalus, Eptesicus, and Vespertilio, yet it amplified the already existing negative or positive effect of street lamps with or without UV on Pipistrellus pipistrellus, P. pygmaeus, and Myotis spp. Our study underpins the importance of minimizing artificial light at night close to vegetation, particularly for bats adapted to spatial complexity in the environment (i.e., clutter-adapted species), and to increase dense vegetation in urban landscape to provide, besides roosting opportunities, protection against ALAN for open-space foraging bats in city landscapes.

Field work news – Chapter 2

Biodiversity assessments at full blast

My last post belongs to the past by now – anyway, that means that I moved to my outdoor workplace. We are mapping sand lizard populations and sampling pollinators, moths (and recording bats at the same time) and still ground-dwelling arthropods. We also running an experiments to measure seed predation along urban gradients. Hopefully we are able to start another experiment on pollinator visitation rates soon – so long as the weather is co-operating.

Field work news – Chapter 1

Plants, plant traits and ground-dwelling arthropods

Unfortunately, spring was very cold and rainy but however, we ‚bravely‘ started our field work for the BIBS project some weeks ago. Currently, our team is doing the plant diversity assessments and also pitfall traps are exposed. Moreover, we are measuring plant traits to analyse intraspecific trait variations along the urbanisation gradient – we are going to run these analyses for invertebrate taxa and hopefully sand lizard populations as well – wait and see. In addition, some students are observing phenology of plant species at 30 sites – very labour-intensive. Today I emptied our pitfall traps for the first time and I can’t wait to study our samples in the lab.

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.