Direct and indirect effects on ant communities in a land use gradient in grasslands

Picture: The photo shows an open-air ground from which grass with wide stalks is growing. Numerous ants are crawling on the stalks and on the ground.

Hypotheses

Land use intensification in grasslands results in a decrease in ant abundance and diversity.
Different types of land use may affect composition of ant communities and overall ant abundance either by altering available food sources (indirect effects) or by disturbance of nesting sites (direct effects).

Picture: The photo shows a microscope image of ten orange-brown ant bodies.

Goals

The aims of the proposed project are to measure the impact of different land use intensities in grassland experimental plots on

ant species richness and abundance
trophobiont (mostly aphid) species richness and abundance (above- and below-ground) as a potential food source with regard to honeydew production or as prey items
niche trait diversity of ants and aphids (morphometric traits, nest structure, life-history traits of aphids, host-plant use of aphids, ant-visitation, secondary endosymbionts that may mediate host use)
intraspecific variation in trophic niche of ants and strophic structure of ant communities (characterized by feeding experiments, stable isotopes and ecological stoichiometry)
specificity of ant-aphid interactions (analyzed in interaction networks)
phenotypic (niche trait) and phylogenetic community structure of ants and aphids to uncover mechanisms of community assembly.

Picture: The diagram shows questions and information on three thematic fields of the AntAphid project. The three fields are firstly environment and land use gradient, secondly species level and thirdly community level.

Picture: The photo shows three small white bowls photographed from above in a meadow. one of the bowls is lying with the bottom facing upwards. the bottom is labelled with the number 4. the other two bowls lying next to each other contain bait for ants. the bait consists of artificial food, has an elongated lumpy shape and a light colour in a mixture of beige and yellow. two ants are sitting on the bait in the left bowl. the upper edge of the bowls is labelled with the identification A E 67, the left edge of the bowls is labelled with the number 1. on the lower edge of the left bowl is the ratio 1 to 3. on the right bowl the ratio is indicated as 3 to 1.

Picture: The photograph shows a young smiling scientist in a workroom at a row of tables, turned around to face the camera. In front of the scientist is a microscope. To the left of it are a pair of scissors, a pencil and a pair of tweezers. To the right of it are seven small containers, presumably with examination material in them. Behind the row of tables on the wall is a large long shelf filled with work materials. To the right of the picture in the background are a window, an active computer monitor and two office chairs.

Publications

Direct and indirect effects of land-use intensification on ant communities in temperate grasslands

Heuss L., Grevé M. E., Schäfer D. Busch V., Feldhaar H. (2019): Direct and indirect effects of land-use intensification on ant communities in temperate grasslands. Ecology and Evolution 9 (7), 4013-4024. doi: 10.1002/ece3.5030

Temperate ant communities under anthropogenic impact

Grevé M. E. (2019): Temperate ant communities under anthropogenic impact. Dissertation, University Bayreuth

Effect of forest management on temperate ant communities

Grevé M. E., Hager J., Weisser W. W., Schall P., Gossner M. M., Feldhaar H. (2018): Effect of forest management on temperate ant communities. Ecosphere 9 (6), e02303. doi: 10.1002/ecs2.2303

Links to other projects within the Biodiversity Exploratories

The abundance and diversity of ants within grassland plots will be linked to that of other arthropod groups (Arthropods I; W. Weisser, TU München and M. Gossner, Swiss Federal Research Institute WSL).

As a baseline for the characterization of the trophic niche using stable isotope analysis we will make use of the data on pplant stable isotope signatures in grassland plots of the project BioComp (N. Hölzel, T. Kleinebecker, Universität Münster).

Scientific assistants

Alumni

Prof. Dr. Heike Feldhaar

Alumni

Michael Grevé

Alumni

Lisa Heuss