Professor Lutz Eckstein is co-author in a new paper in the journal Applied Vegetation Science led by Yves Klinger (Justus-Liebig-University Giessen, Germany). The authors assessed the role of mowing machinery and endozoochory by migratory sheep as dispersal vectors in semi-natural grasslands by comparing the species compositions and traits of species found in the vectors to the regional above-ground vegetation and soil seed bank. Plant material from mowers (n = 12 from one date) and dung samples from migratory sheep (n = 39 from 13 dates) were collected and the dispersed plant species were determined using the emergence method. We compared the species compositions to the regional above-ground vegetation and seed bank using non-metric multidimensional scaling (NMDS) and indicator species analysis. Furthermore, we compared functional traits of the dispersed species to traits of non-dispersed species of the regional species pools by calculating log-response ratios and performing metaregressions.

Sheep in the Rhön Mountains. Photo by Yves Klinger.

We found that mower samples were more similar to the above-ground vegetation whereas dung samples were more similar to the seed bank. Mowers and sheep endozoochory favored the dispersal of species with different traits and phenologies. Species with small seed sizes were prevalent in both vectors. Mowers were less selective concerning most traits, but favored high-growing grasses such as Alopecurus pratensis and Trisetum flavescens. Sheep dung samples contained less grasses and more palatable species, such as Urtica dioica.

Log-response ratios dispersal vectors vs species pools of sheep vs above-ground. LDMC = Leaf Dry Mass Content, EIV N = Ellenberg Indicator Value for Nutrients. Zero indicates the mean value of the non-dispersed species from the respective species pool, bars show mean log-response ratios ± confidence intervals. Figure is part of Figure 3 in the paper.

Sheep endozoochory and mowing machinery are complementary dispersal vectors favoring species with differing functional traits. Sheep endozoochory enables dispersal of species that have unfavorable traits (e.g. low releasing heights) or phenologies for dispersal by mowing machinery. To ensure the dispersal of a high number of plant species in semi-natural grasslands, the interplay of different vectors should be considered.

Read more about the paper here: https://doi.org/10.1111/avsc.12579.

Yves P. Klinger, Sarah Harvolk-Schöning, Lutz Eckstein, Wiebke Hansen, Annette Otte and Kristin Ludewig recently published the paper ”Applying landscape structure analysis to assess the spatio-temporal distribution of an invasive legume in the Rhön UNESCO Biosphere Reserve” in the journal Biological Invasions.

Lutz Eckstein, Professor in Biology at Karlstad University, writes about their work:

The legume Lupinus polyphyllus. Photo by Lutz Eckstein

“We applied a combination of aerial mapping and GIS-based landscape analysis to study the invasion of the legume, Lupinus polyphyllus, in the Rhön UNESCO Biosphere Region as a case. We assessed the changes in lupine distribution between 1998 and 2016 in a strictly protected part of the Biosphere Region by means of landscape structure analysis. The area invaded by L. polyphyllus doubled from 1998 to 2016. The number of lupine stands decreased by 25%, but average stand size increased by 300%. In 2016, large and well-connected mesic grasslands that were situated close to roads were more heavily invaded than small and remote wet grasslands. Our results show that landscape composition plays an important role for the spread of invasive plants. Specifically, invasive stand characteristics, such as stand size, form, and connectivity, are crucial for driving the invasion process. Therefore, in addition to landscape composition, invasive stand characteristics should be included in the planning of conservation measures. Overall, aerial mapping combined with landscape analysis provides a cost-effective and practical tool for landscape managers to prioritize invasive control measures.”

Access the paper here, or contact any of the authors.