TY  - JOUR
A1  - Vikuk, Veronika
A1  - Fuchs, Benjamin
A1  - Krischke, Markus
A1  - Mueller, Martin J.
A1  - Rueb, Selina
A1  - Krauss, Jochen
T1  - Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods—A Re-Evaluation of Intoxication Risk in Germany?
JF  - Journal of Fungi
N2  - Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable.
KW  - Epichloë
KW  - Lolium perenne
KW  - toxicity
KW  - grasslands
KW  - HPLC/UPLC methods
KW  - endophyte
KW  - plant fresh/dry weight
KW  - alkaloid detection methods
KW  - mycotoxins
KW  - phenology
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213171
SN  - 2309-608X
VL  - 6
IS  - 3
ER  - 
TY  - JOUR
A1  - Hopfenmueller, Sebastian
A1  - Steffan-Dewenter, Ingolf
A1  - Holzschuh, Andrea
T1  - Trait-Specific Responses of Wild Bee Communities to Landscape Composition, Configuration and Local Factors
N2  - Land-use intensification and loss of semi-natural habitats have induced a severe decline of bee diversity in agricultural landscapes. Semi-natural habitats like calcareous grasslands are among the most important bee habitats in central Europe, but they are threatened by decreasing habitat area and quality, and by homogenization of the surrounding landscape affecting both landscape composition and configuration. In this study we tested the importance of habitat area, quality and connectivity as well as landscape composition and configuration on wild bees in calcareous grasslands. We made detailed trait-specific analyses as bees with different traits might differ in their response to the tested factors. Species richness and abundance of wild bees were surveyed on 23 calcareous grassland patches in Southern Germany with independent gradients in local and landscape factors. Total wild bee richness was positively affected by complex landscape configuration, large habitat area and high habitat quality (i.e. steep slopes). Cuckoo bee richness was positively affected by complex landscape configuration and large habitat area whereas habitat specialists were only affected by the local factors habitat area and habitat quality. Small social generalists were positively influenced by habitat area whereas large social generalists (bumblebees) were positively affected by landscape composition (high percentage of semi-natural habitats). Our results emphasize a strong dependence of habitat specialists on local habitat characteristics, whereas cuckoo bees and bumblebees are more likely affected by the surrounding landscape. We conclude that a combination of large high-quality patches and heterogeneous landscapes maintains high bee species richness and communities with diverse trait composition. Such diverse communities might stabilize pollination services provided to crops and wild plants on local and landscape scales.
KW  - habitats
KW  - bees
KW  - grasslands
KW  - species diversity
KW  - biodiversity
KW  - pollination
KW  - flowers
KW  - foraging
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-112872
ER  -