@article{KernerKraussMaihoffetal.2023,
  author    = {Kerner, Janika M. and Krauss, Jochen and Maihoff, Fabienne and Bofinger, Lukas and Classen, Alice},
  title     = {Alpine butterflies want to fly high: Species and communities shift upwards faster than their host plants},
  series = {Ecology},
  volume    = {104},
  journal   = {Ecology},
  number    = {1},
  doi       = {10.1002/ecy.3848},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312015},
  year      = {2023},
  abstract  = {Despite sometimes strong codependencies of insect herbivores and plants, the responses of individual taxa to accelerating climate change are typically studied in isolation. For this reason, biotic interactions that potentially limit species in tracking their preferred climatic niches are ignored. Here, we chose butterflies as a prominent representative of herbivorous insects to investigate the impacts of temperature changes and their larval host plant distributions along a 1.4-km elevational gradient in the German Alps. Following a sampling protocol of 2009, we revisited 33 grassland plots in 2019 over an entire growing season. We quantified changes in butterfly abundance and richness by repeated transect walks on each plot and disentangled the direct and indirect effects of locally assessed temperature, site management, and larval and adult food resource availability on these patterns. Additionally, we determined elevational range shifts of butterflies and host plants at both the community and species level. Comparing the two sampled years (2009 and 2019), we found a severe decline in butterfly abundance and a clear upward shift of butterflies along the elevational gradient. We detected shifts in the peak of species richness, community composition, and at the species level, whereby mountainous species shifted particularly strongly. In contrast, host plants showed barely any change, neither in connection with species richness nor individual species shifts. Further, temperature and host plant richness were the main drivers of butterfly richness, with change in temperature best explaining the change in richness over time. We concluded that host plants were not yet hindering butterfly species and communities from shifting upwards. However, the mismatch between butterfly and host plant shifts might become a problem for this very close plant-herbivore relationship, especially toward higher elevations, if butterflies fail to adapt to new host plants. Further, our results support the value of conserving traditional extensive pasture use as a promoter of host plant and, hence, butterfly richness.},
  language  = {en}
}
@article{KlimmBraeuKoenigetal.2024,
  author    = {Klimm, Fabian S. and Br{\"a}u, Markus and K{\"o}nig, Sebastian and Mandery, Klaus and Sommer, Carolin and Zhang, Jie and Krauss, Jochen},
  title     = {Importance of habitat area, quality and landscape context for heteropteran diversity in shrub ecotones},
  series = {Landscape Ecology},
  volume    = {39},
  journal   = {Landscape Ecology},
  issn      = {0921-2973},
  doi       = {10.1007/s10980-024-01798-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358106},
  year      = {2024},
  abstract  = {Context Habitat loss and degradation impose serious threats on biodiversity. However, not all habitats receive the attention commensurate with their ecological importance. Shrub ecotones (successional stages between grasslands and forests) can be highly species-diverse but are often restricted to small areas as prevalent management practices either promote open grassland or forest habitats, threatening the effective conservation of ecotone species. Objectives In this study, we assessed the importance of habitat and landscape features of shrub ecotones for the rarely studied true bugs (Heteroptera), a functionally diverse taxon that comprises highly specialized species and broad generalists. Methods True bugs were sampled with a beating tray in 118 spatially independent shrub ecotones in a region of 45,000 square kilometers in Germany. In addition to habitat area and landscape context, we used a hedge index to evaluate habitat quality. Results Shrub ecotones in open habitats harbored a greater species richness and abundance compared to shaded ones in later seral stages, and species composition differed. Richness and abundance were positively affected by increasing habitat area and quality, whereas an increase in the proportion of semi-natural habitats within 1 km only enhanced richness. While feeding and habitat specialists were more sensitive to habitat area reduction than generalists, this was not the case for weak dispersers and carnivores. Conclusions Our findings emphasize the importance of large and high-quality ecotones that form a patchy mosaic of shrubs and herbaceous plants. Such ecotones can benefit both grassland species and species depending on woody plants. Conservation authorities should balance between promoting shrubs and keeping such habitats open to maximize species diversity.},
  language  = {en}
}