TY  - JOUR
A1  - Villagomez, Gemma N.
A1  - Nürnberger, Fabian
A1  - Requier, Fabrice
A1  - Schiele, Susanne
A1  - Steffan-Dewenter, Ingo
T1  - Effects of temperature and photoperiod on the seasonal timing of Western honey bee colonies and an early spring flowering plant
JF  - Ecology and Evolution
N2  - Temperature and photoperiod are important Zeitgebers for plants and pollinators to synchronize growth and reproduction with suitable environmental conditions and their mutualistic interaction partners. Global warming can disturb this temporal synchronization since interacting species may respond differently to new combinations of photoperiod and temperature under future climates, but experimental studies on the potential phenological responses of plants and pollinators are lacking. We simulated current and future combinations of temperature and photoperiod to assess effects on the overwintering and spring phenology of an early flowering plant species (Crocus sieberi) and the Western honey bee (Apis mellifera). We could show that increased mean temperatures in winter and early spring advanced the flowering phenology of C. sieberi and intensified brood rearing activity of A. mellifera but did not advance their brood rearing activity. Flowering phenology of C. sieberi also relied on photoperiod, while brood rearing activity of A. mellifera did not. The results confirm that increases in temperature can induce changes in phenological responses and suggest that photoperiod can also play a critical role in these responses, with currently unknown consequences for real-world ecosystems in a warming climate.
KW  - Apis mellifera
KW  - climate change
KW  - rocus sieberi
KW  - phenology
KW  - plant–pollinator interaction
KW  - temporal mismatch
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258770
VL  - 11
IS  - 12
ER  - 
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  -