Archiv des Autors: s.buchholz

Urban pollinator project: First field works completed

One of the main objectives of our project is to analyse interactions between honey bees and wild bees (and other wild pollinators) in urban habitats. Of particular interest is the question of whether there is food competition between honey and wild bees and which role environmental conditions – such as amount of flowering plants – play. We are currently conducting experiments to answer this question.

New research project: Wild boar effects on biodiversity in urban habitats

We are launching a new research project to analyse wild boar effects on habitats, plant and insect biodiversity and sand lizard populations. This project is funded by Stiftung Naturschutz Berlin and will start in September 2019.

New research project on urban pollinators

Implementing the Berlin Bee Strategy for conservation of bees and other pollinators in Berlin by optimising the protection of wild bees (funded bei Senatsverwaltung für Umwelt, Verkehr und Klimaschutz Berlin) – more info coming soon.

New paper on urban pollinators

Urbanisation modulates plant-pollinator interactions in invasive vs. native plant species“ has been published in Scientific Reports. The article is open access.

In this article, we show that invasive black locust (Robinia pseudoacacia) is a “pollinator-friendly” tree and attracts not only honey bees but also wild bees and other wild pollinators. However, we also found that attractiveness of black locust decreases with increasing urbanisation.

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.

New methodological paper

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.