@article{PfestorfKoernerSonnemannetal.2016,
  author    = {Pfestorf, Hans and K{\"o}rner, Katrin and Sonnemann, Ilja and Wurst, Susanne and Jeltsch, Florian},
  title     = {Coupling experimental data with individual-based modelling reveals differential effects of root herbivory on grassland plant co-existence along a resource gradient},
  series = {Journal of vegetation science},
  volume    = {27},
  journal   = {Journal of vegetation science},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1100-9233},
  doi       = {10.1111/jvs.12357},
  pages     = {269 -- 282},
  year      = {2016},
  abstract  = {QuestionThe empirical evidence of root herbivory effects on plant community composition and co-existence is contradictory. This originates from difficulties connected to below-ground research and confinement of experimental studies to a small range of environmental conditions. Here we suggest coupling experimental data with an individual-based model to overcome the limitations inherent in either approach. To demonstrate this, we investigated the consequences of root herbivory, as experimentally observed on individual plants, on plant competition and co-existence in a population and community context under different root herbivory intensities (RHI), fluctuating and constant root herbivore activity and grazing along a resource gradient. LocationBerlin, Germany, glasshouse; Potsdam, Germany, high performance cluster computer. MethodsThe well-established community model IBC-Grass was adapted to allow for a flexible species parameterization and to include annual species. Experimentally observed root herbivory effects on performance of eight common grassland plant species were incorporated into the model by altering plant growth rates. We then determined root herbivore effects on plant populations, competitive hierarchy and consequences for co-existence and community diversity. ResultsRoot herbivory reduced individual biomass, but temporal fluctuation allowed for compensation of herbivore effects. Reducing resource availability strongly shifted competitive hierarchies, with, however, more similar hierarchies along the gradient under root herbivory, pointing to reduced ecological species differences. Consequently, negative effects on co-existence and diversity prevailed, with the exception of a few positive effects on co-existence of selected species pairs. Temporal fluctuation alleviated but did not remove negative root herbivore effects, despite of the stronger influence of intra- compared to interspecific competition. Grazing in general augmented co-existence. Most interestingly, grazing interacted with RHI and resource availability by promoting positive effects of root herbivory. ConclusionsThrough integrating experimental data on the scale of individual plants with a simulation model we verified that root herbivory could affect plant competition with consequences for species co-existence. Our approach demonstrates the benefit that accrues when empirical and modelling approaches are brought more closely together, and that gathering data on distinct processes and under specific conditions, combined with appropriate models, can be used to answer challenging research questions in a more general way.},
  language  = {en}
}
@article{HeinzeSitteSchindhelmetal.2016,
  author    = {Heinze, Johannes and Sitte, Mario and Schindhelm, Anne and Wright, J. and Joshi, Jasmin Radha},
  title     = {Plant-soil feedbacks: a comparative study on the relative importance of soil feedbacks in the greenhouse versus the field},
  series = {Oecologia},
  volume    = {181},
  journal   = {Oecologia},
  publisher = {Springer},
  address   = {New York},
  issn      = {0029-8549},
  doi       = {10.1007/s00442-016-3591-8},
  pages     = {559 -- 569},
  year      = {2016},
  abstract  = {Interactions between plants and soil microorganisms influence individual plant performance and thus plant-community composition. Most studies on such plant-soil feedbacks (PSFs) have been performed under controlled greenhouse conditions, whereas no study has directly compared PSFs under greenhouse and natural field conditions. We grew three grass species that differ in local abundance in grassland communities simultaneously in the greenhouse and field on field-collected soils either previously conditioned by these species or by the general grassland community. As soils in grasslands are typically conditioned by mixes of species through the patchy and heterogeneous plant species' distributions, we additionally compared the effects of species-specific versus non-specific species conditioning on PSFs in natural and greenhouse conditions. In almost all comparisons PSFs differed between the greenhouse and field. In the greenhouse, plant growth in species-specific and non-specific soils resulted in similar effects with neutral PSFs for the most abundant species and positive PSFs for the less abundant species. In contrast, in the field all grass species tested performed best in non-specific plots, whereas species-specific PSFs were neutral for the most abundant and varied for the less abundant species. This indicates a general beneficial effect of plant diversity on PSFs in the field. Controlled greenhouse conditions might provide valuable insights on the nominal effects of soils on plants. However, the PSFs observed in greenhouse conditions may not be the determining drivers in natural plant communities where their effects may be overwhelmed by the diversity of abiotic and biotic above- and belowground interactions in the field.},
  language  = {en}
}