@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}
}
@article{HeinzeJoshi2017,
  author    = {Heinze, Johannes and Joshi, Jasmin Radha},
  title     = {Plant-soil feedback effects can be masked by aboveground herbivory under natural field conditions},
  series = {Oecologia},
  volume    = {186},
  journal   = {Oecologia},
  number    = {1},
  publisher = {Springer},
  address   = {New York},
  issn      = {0029-8549},
  doi       = {10.1007/s00442-017-3997-y},
  pages     = {235 -- 246},
  year      = {2017},
  abstract  = {For plants, herbivory and interactions with their surrounding soil ecosystem are crucial factors influencing individual performance and plant-community composition. Until now, research has mostly focused on individual effects of herbivory or plant-soil feedbacks (PSFs) on plant growth and community composition, but few studies have explicitly investigated herbivory in the context of PSFs. These few studies, however, were performed under greenhouse conditions even though PSFs and herbivory may differ between greenhouse and field conditions. Therefore, we performed a field experiment in a grassland, testing the growth responses of three grass species that consistently differ in local abundance, on soils previously conditioned by these species. We tested these PSF effects for the three species both in the presence and in the absence of aboveground herbivores. Without herbivores, the two subdominant species suffered from negative PSF effects. However, in the presence of herbivores and on heterospecific soils, the same two species experienced a significant loss of shoot biomass, whereas, in contrast, enhanced root growth was observed on conspecific soils, resulting in overall neutral PSF effects. The dominant species was not damaged by herbivores and showed overall neutral PSF effects in the field with and without herbivores. Our study provides empirical evidence that negative PSF effects that exist under natural field conditions in grasslands can be overwhelmed by aboveground herbivory. Hence, potential PSF effects might not be detected in the field, because other abiotic and biotic interactions such as aboveground herbivory have stronger effects on plant performance and might therefore mask or override these PSF effects.},
  language  = {en}
}
@article{EstherGroeneveldEnrightetal.2011,
  author    = {Esther, Alexandra and Groeneveld, J{\"u}rgen and Enright, Neal J. and Miller, Ben P. and Lamont, Byron B. and Perry, George L. W. and Tietjen, Britta and Jeltsch, Florian},
  title     = {Low-dimensional trade-offs fail to explain richness and structure in species-rich plant communities},
  series = {Theoretical ecology},
  volume    = {4},
  journal   = {Theoretical ecology},
  number    = {4},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1874-1738},
  doi       = {10.1007/s12080-010-0092-y},
  pages     = {495 -- 511},
  year      = {2011},
  abstract  = {Mathematical models and ecological theory suggest that low-dimensional life history trade-offs (i.e. negative correlation between two life history traits such as competition vs. colonisation) may potentially explain the maintenance of species diversity and community structure. In the absence of trade-offs, we would expect communities to be dominated by 'super-types' characterised by mainly positive trait expressions. However, it has proven difficult to find strong empirical evidence for such trade-offs in species-rich communities. We developed a spatially explicit, rule-based and individual-based stochastic model to explore the importance of low-dimensional trade-offs. This model simulates the community dynamics of 288 virtual plant functional types (PFTs), each of which is described by seven life history traits. We consider trait combinations that fit into the trade-off concept, as well as super-types with little or no energy constraints or resource limitations, and weak PFTs, which do not exploit resources efficiently. The model is parameterised using data from a fire-prone, species-rich Mediterranean-type shrubland in southwestern Australia. We performed an exclusion experiment, where we sequentially removed the strongest PFT in the simulation and studied the remaining communities. We analysed the impact of traits on performance of PFTs in the exclusion experiment with standard and boosted regression trees. Regression tree analysis of the simulation results showed that the trade-off concept is necessary for PFT viability in the case of weak trait expression combinations such as low seed production or small seeds. However, species richness and diversity can be high despite the presence of super-types. Furthermore, the exclusion of super-types does not necessarily lead to a large increase in PFT richness and diversity. We conclude that low-dimensional trade-offs do not provide explanations for multi-species co-existence contrary to the prediction of many conceptual models.},
  language  = {en}
}