@article{Heinze2020,
  author    = {Heinze, Johannes},
  title     = {Herbivory by aboveground insects impacts plant root morphological traits},
  series = {Plant ecology : an international journal},
  volume    = {221},
  journal   = {Plant ecology : an international journal},
  number    = {8},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1385-0237},
  doi       = {10.1007/s11258-020-01045-w},
  pages     = {725 -- 732},
  year      = {2020},
  abstract  = {Aboveground herbivory induces physiological responses, like the release of belowground chemical defense and storage of secondary metabolites, as well as physical responses in plants, like increased root biomass production. However, studies on effects of aboveground herbivory on root morphology are scarce and until now no study tested herbivory effects under natural conditions for a large set of plant species. Therefore, in a field experiment on plant-soil interactions, I investigated the effect of aboveground insect herbivory on root morphological traits of 20 grassland plant species. For 9 of the 20 species, all individuals showed shoot damage in the presence of insect herbivores, but no damage in insect herbivore exclusions. In these 9 species root biomass increased and root morphological traits changed under herbivory towards thinner roots with increased specific root surface. In contrast, the remaining species did not differ in the number of individuals damaged, root biomass nor morphological traits with herbivores present vs. absent. The fact that aboveground herbivory resulted in thinner roots with increased specific root surface area for all species in which the herbivore exclusion manipulation altered shoot damage might indicate that plants increase nutrient uptake in response to herbivory. However, more importantly, results provide empirical evidence that aboveground herbivory impacts root morphological traits of plants. As these traits are important for the occupation of soil space, uptake processes, decomposition and interactions with soil biota, results suggest that herbivory-induced changes in root morphology might be of importance for plant-soil feedbacks and plant-plant competition.},
  language  = {en}
}
@article{RaatzPirhoferWalzlMuelleretal.2021,
  author    = {Raatz, Larissa and Pirhofer-Walzl, Karin and M{\"u}ller, Marina E.H. and Scherber, Christoph and Joshi, Jasmin Radha},
  title     = {Who is the culprit: Is pest infestation responsible for crop yield losses close to semi-natural habitats?},
  series = {Ecology and Evolution},
  volume    = {11},
  journal   = {Ecology and Evolution},
  edition   = {19},
  publisher = {Wiley-Blackwell},
  address   = {Oxford},
  issn      = {1467-6435},
  doi       = {10.1002/ece3.8046},
  pages     = {13232 -- 13246},
  year      = {2021},
  abstract  = {Semi-natural habitats (SNHs) are becoming increasingly scarce in modern agricultural landscapes. This may reduce natural ecosystem services such as pest control with its putatively positive effect on crop production. In agreement with other studies, we recently reported wheat yield reductions at field borders which were linked to the type of SNH and the distance to the border. In this experimental landscape-wide study, we asked whether these yield losses have a biotic origin while analyzing fungal seed and fungal leaf pathogens, herbivory of cereal leaf beetles, and weed cover as hypothesized mediators between SNHs and yield. We established experimental winter wheat plots of a single variety within conventionally managed wheat fields at fixed distances either to a hedgerow or to an in-field kettle hole. For each plot, we recorded the fungal infection rate on seeds, fungal infection and herbivory rates on leaves, and weed cover. Using several generalized linear mixed-effects models as well as a structural equation model, we tested the effects of SNHs at a field scale (SNH type and distance to SNH) and at a landscape scale (percentage and diversity of SNHs within a 1000-m radius). In the dry year of 2016, we detected one putative biotic culprit: Weed cover was negatively associated with yield values at a 1-m and 5-m distance from the field border with a SNH. None of the fungal and insect pests, however, significantly affected yield, neither solely nor depending on type of or distance to a SNH. However, the pest groups themselves responded differently to SNH at the field scale and at the landscape scale. Our findings highlight that crop losses at field borders may be caused by biotic culprits; however, their negative impact seems weak and is putatively reduced by conventional farming practices.},
  language  = {en}
}
@article{RaatzPirhoferWalzlMuelleretal.2021,
  author    = {Raatz, Larissa and Pirhofer-Walzl, Karin and M{\"u}ller, Marina E.H. and Scherber, Christoph and Joshi, Jasmin Radha},
  title     = {Who is the culprit: Is pest infestation responsible for crop yield losses close to semi-natural habitats?},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-54962},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-549622},
  pages     = {13232 -- 13246},
  year      = {2021},
  abstract  = {Semi-natural habitats (SNHs) are becoming increasingly scarce in modern agricultural landscapes. This may reduce natural ecosystem services such as pest control with its putatively positive effect on crop production. In agreement with other studies, we recently reported wheat yield reductions at field borders which were linked to the type of SNH and the distance to the border. In this experimental landscape-wide study, we asked whether these yield losses have a biotic origin while analyzing fungal seed and fungal leaf pathogens, herbivory of cereal leaf beetles, and weed cover as hypothesized mediators between SNHs and yield. We established experimental winter wheat plots of a single variety within conventionally managed wheat fields at fixed distances either to a hedgerow or to an in-field kettle hole. For each plot, we recorded the fungal infection rate on seeds, fungal infection and herbivory rates on leaves, and weed cover. Using several generalized linear mixed-effects models as well as a structural equation model, we tested the effects of SNHs at a field scale (SNH type and distance to SNH) and at a landscape scale (percentage and diversity of SNHs within a 1000-m radius). In the dry year of 2016, we detected one putative biotic culprit: Weed cover was negatively associated with yield values at a 1-m and 5-m distance from the field border with a SNH. None of the fungal and insect pests, however, significantly affected yield, neither solely nor depending on type of or distance to a SNH. However, the pest groups themselves responded differently to SNH at the field scale and at the landscape scale. Our findings highlight that crop losses at field borders may be caused by biotic culprits; however, their negative impact seems weak and is putatively reduced by conventional farming practices.},
  language  = {en}
}
@article{ReinhardGeisslerBlaum2019,
  author    = {Reinhard, Johanna E. and Geissler, Katja and Blaum, Niels},
  title     = {Short-term responses of darkling beetles (Coleoptera:Tenebrionidae) to the effects of fire and grazing in savannah rangeland},
  series = {Insect Conservation and Diversity},
  volume    = {12},
  journal   = {Insect Conservation and Diversity},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1752-458X},
  doi       = {10.1111/icad.12324},
  pages     = {39 -- 48},
  year      = {2019},
  abstract  = {Fire and grazing shape biodiversity in savannah landscapes. In land use management, knowing the effects of fire and grazing on biodiversity are important in order to ensure environmental sustainability. Beetles specifically are indicators of the biodiversity response to fire and grazing. A grazing exclusion and burning experiment in a split-plot design was used in order to investigate the interacting effects of fire and wildlife grazing on biomass, diversity, and species composition of darkling beetles (Coleoptera, Tenebrionidae) over time after fire. Darkling beetle species richness and diversity were responding in a three-way-interaction to fire, grazing, and time after fire, whereby biomass of darkling beetles remained unaffected and species compositional changes were attributed to seasonal changes of time only. Fire on ungrazed plots had a negative effect on species diversity and richness 2 weeks and 6 months post fire, whereas fire on grazed plots had no impact on species diversity and richness. Grazing only lowered species diversity and richness 6 months after fire treatments. Results suggest that grazing overrides the effects of fire and that the similar effects caused by fire and grazing are due to niche and assemblage simplification of the habitat.},
  language  = {en}
}
@article{WeithoffTaubeBolius2017,
  author    = {Weithoff, Guntram and Taube, Anne and Bolius, Sarah},
  title     = {The invasion success of the cyanobacterium Cylindrospermopsis raciborskii in experimental mesocosms},
  series = {Aquatic Invasions},
  volume    = {12},
  journal   = {Aquatic Invasions},
  publisher = {Regional Euro-Asian Biological Invasions centre-reabic},
  address   = {Helsinki},
  issn      = {1798-6540},
  doi       = {10.3391/ai.2017.12.3.07},
  pages     = {333 -- 341},
  year      = {2017},
  abstract  = {The potentially toxic, invasive cyanobacterium Cylindrospermopsis raciborskii, originating from sub-tropical regions, has spread into temperate climate zones in almost all continents. Potential factors in its success are temperature, light and nutrient levels. Grazing losses through zooplankton have been measured in the laboratory but are typically not regarded as a factor in (failed) invasion success. In some potentially suitable lakes, C. raciborskii has never been found, although it is present in water bodies close by. Therefore, we tested the invasive potential of three different isolates introduced into natural plankton communities using laboratory mesocosm experiments under three grazing levels: ambient zooplankton densities, removal of large species using 100 mu m mesh and a ca. doubling of large species. Three C. raciborskii isolates originating from the same geographic region (North-East Germany) were added separately to the four replicates of each treatment and kept in semi-continuous cultures for 21 days. Two isolates disappeared from the mesocosms and were also not viable in filtered lake water indicating that the lake water itself or the switch from culture medium to lake water led to the decay of the inoculated C. raciborskii. Only one out of the three isolates persisted in the plankton communities at a rather low level and only in the treatment without larger zooplankton. This result demonstrates that under potentially suitable environmental conditions, top-down control from zooplankton might hamper the establishment of C. raciborskii. Non-metric multidimensional scaling showed distinct variation in resident phytoplankton communities between the different grazing levels, thus differential grazing impact shaped the resident community in different ways allowing C. raciborskii only to invade under competitive (= low grazing pressure) conditions. Furthermore, even after invasion failure, the temporary presence of C. raciborskii influenced the phytoplankton community.},
  language  = {en}
}