@article{VillagomezNuernbergerRequieretal.2021,
  author    = {Villagomez, Gemma N. and N{\"u}rnberger, Fabian and Requier, Fabrice and Schiele, Susanne and Steffan-Dewenter, Ingo},
  title     = {Effects of temperature and photoperiod on the seasonal timing of Western honey bee colonies and an early spring flowering plant},
  series = {Ecology and Evolution},
  volume    = {11},
  journal   = {Ecology and Evolution},
  number    = {12},
  doi       = {10.1002/ece3.7616},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258770},
  pages     = {7834-7849},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{RequierPailletLarocheetal.2019,
  author    = {Requier, Fabrice and Paillet, Yoan and Laroche, Fabienne and Rutschmann, Benjamin and Zhang, Jie and Lombardi, Fabio and Svoboda, Miroslav and Steffan-Dewenter, Ingolf},
  title     = {Contribution of European forests to safeguard wild honeybee populations},
  series = {Conservation Letters},
  volume    = {13},
  journal   = {Conservation Letters},
  number    = {2},
  doi       = {10.1111/conl.12693},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204407},
  pages     = {e12693},
  year      = {2019},
  abstract  = {Abstract Recent studies reveal the use of tree cavities by wild honeybee colonies in European forests. This highlights the conservation potential of forests for a highly threatened component of the native entomofauna in Europe, but currently no estimate of potential wild honeybee population sizes exists. Here, we analyzed the tree cavity densities of 106 forest areas across Europe and inferred an expected population size of wild honeybees. Both forest and management types affected the density of tree cavities. Accordingly, we estimated that more than 80,000 wild honeybee colonies could be sustained in European forests. As expected, potential conservation hotspots were identified in unmanaged forests, and, surprisingly, also in other large forest areas across Europe. Our results contribute to the EU policy strategy to halt pollinator declines and reveal the potential of forest areas for the conservation of so far neglected wild honeybee populations in Europe.},
  language  = {en}
}