@article{RostasBollmannSavilleetal.2018,
  author    = {Rost{\´a}s, Michael and Bollmann, Felix and Saville, David and Riedel, Michael},
  title     = {Ants contribute to pollination but not to reproduction in a rare calcareous grassland forb},
  series = {PeerJ},
  volume    = {6},
  journal   = {PeerJ},
  doi       = {10.7717/peerj.4369},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227053},
  pages     = {e4369, 1-16},
  year      = {2018},
  abstract  = {The number of plants pollinated by ants is surprisingly low given the abundance of ants and the fact that they are common visitors of angiosperms. Generally ants are considered as nectar robbers that do not provide pollination service. We studied the pollination system of the endangered dry grassland forb Euphorbia seguieriana and found two ant species to be the most frequent visitors of its flowers. Workers of Formica cunicularia carried five times more pollen than smaller Tapinoma erraticum individuals, but significantly more viable pollen was recovered from the latter. Overall, the viability of pollen on ant cuticles was significantly lower (p < 0.001)-presumably an antibiotic effect of the metapleural gland secretion. A marking experiment suggested that ants were unlikely to facilitate outcrossing as workers repeatedly returned to the same individual plant. In open pollinated plants and when access was given exclusively to flying insects, fruit set was nearly 100\%. In plants visited by ants only, roughly one third of flowers set fruit, and almost none set fruit when all insects were excluded. The germination rate of seeds from flowers pollinated by flying insects was 31 +/- 7\% in contrast to 1 +/- 1\% resulting from ant pollination. We conclude that inbreeding depression may be responsible for the very low germination rate in ant pollinated flowers and that ants, although the most frequent visitors, play a negligible or even deleterious role in the reproduction of E. seguieriana. Our study reiterates the need to investigate plant fitness effects beyond seed set in order to confirm ant-plant mutualisms.},
  language  = {en}
}
@article{AlbrechtClassenVollstaedtetal.2018,
  author    = {Albrecht, J{\"o}rg and Classen, Alice and Vollst{\"a}dt, Maximilian G.R. and Mayr, Antonia and Mollel, Neduvoto P. and Schellenberger Costa, David and Dulle, Hamadi I. and Fischer, Markus and Hemp, Andreas and Howell, Kim M. and Kleyer, Michael and Nauss, Thomas and Peters, Marcell K. and Tschapka, Marco and Steffan-Dewenter, Ingolf and B{\"o}hning-Gaese, Katrin and Schleuning, Matthias},
  title     = {Plant and animal functional diversity drive mutualistic network assembly across an elevational gradient},
  series = {Nature Communications},
  volume    = {9},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-018-05610-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221056},
  pages     = {1-10},
  year      = {2018},
  abstract  = {Species' functional traits set the blueprint for pair-wise interactions in ecological networks. Yet, it is unknown to what extent the functional diversity of plant and animal communities controls network assembly along environmental gradients in real-world ecosystems. Here we address this question with a unique dataset of mutualistic bird-fruit, bird-flower and insect-flower interaction networks and associated functional traits of 200 plant and 282 animal species sampled along broad climate and land-use gradients on Mt. Kilimanjaro. We show that plant functional diversity is mainly limited by precipitation, while animal functional diversity is primarily limited by temperature. Furthermore, shifts in plant and animal functional diversity along the elevational gradient control the niche breadth and partitioning of the respective other trophic level. These findings reveal that climatic constraints on the functional diversity of either plants or animals determine the relative importance of bottom-up and top-down control in plant-animal interaction networks.},
  language  = {en}
}
@article{DuquePoelmanSteffanDewenter2019,
  author    = {Duque, Laura and Poelman, Erik H. and Steffan-Dewenter, Ingolf},
  title     = {Plant-mediated effects of ozone on herbivores depend on exposure duration and temperature},
  series = {Scientific Reports},
  volume    = {9},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-019-56234-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202805},
  pages     = {19891},
  year      = {2019},
  abstract  = {Abiotic stress by elevated tropospheric ozone and temperature can alter plants' metabolism, growth, and nutritional value and modify the life cycle of their herbivores. We investigated how the duration of exposure of Sinapis arvensis plants to high ozone and temperature levels affect the life cycle of the large cabbage white, Pieris brassicae. Plants were exposed to ozone-clean (control) or ozone-enriched conditions (120 ppb) for either 1 or 5 days and were afterwards kept in a greenhouse with variable temperature conditions. When given the choice, P. brassicae butterflies laid 49\% fewer eggs on ozone-exposed than on control plants when the exposure lasted for 5 days, but showed no preference when exposure lasted for 1 day. The caterpillars took longer to hatch on ozone-exposed plants and at lower ambient temperatures. The ozone treatment had a positive effect on the survival of the eggs. Ozone decreased the growth of caterpillars reared at higher temperatures on plants exposed for 5 days, but not on plants exposed for 1 day. Overall, longer exposure of the plants to ozone and higher temperatures affected the life cycle of the herbivore more strongly. With global warming, the indirect impacts of ozone on herbivores are likely to become more common.},
  language  = {en}
}