@article{SocherPratiBochetal.2012,
  author    = {Socher, Stephanie A. and Prati, Daniel and Boch, Steffen and M{\"u}ller, J{\"o}rg and Klaus, Valentin H. and H{\"o}lzel, Norbert and Fischer, Markus},
  title     = {Direct and productivity-mediated indirect effects of fertilization, mowing and grazing on grassland species richness},
  series = {The journal of ecology},
  volume    = {100},
  journal   = {The journal of ecology},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0022-0477},
  doi       = {10.1111/j.1365-2745.2012.02020.x},
  pages     = {1391 -- 1399},
  year      = {2012},
  abstract  = {Recent declines in biodiversity have given new urgency to questions about the relationship between land-use change, biodiversity and ecosystem processes. Despite the existence of a large body of research on the effects of land use on species richness, it is unclear whether the effects of land use on species richness are principally direct or indirect, mediated by concomitant changes in ecosystem processes. Therefore, we compared the direct effects of land use (fertilization, mowing and grazing) on species richness with indirect ones (mediated via grassland productivity) for grasslands in central Europe. We measured the richness and above-ground biomass in 150 grassland plots in 3 regions of Germany (the so-called Biodiversity Exploratories). We used univariate and structural equation models to examine direct and indirect land-use effects. The direct effects of mowing (-0.37, effect size) and grazing (0.04) intensity on species richness were stronger compared with the indirect effects of mowing (-0.04) and grazing (-0.01). However, the strong negative effect of fertilization (-0.23) on species richness was mainly indirect, mediated by increased productivity compared with the weak direct negative effect (-0.07). Differences between regions in land-use effects showed five times weaker negative effects of mowing (-0.13) in the region with organic soils (Schorfheide-Chorin), strong overall negative effects of grazing (-0.29) for the region with organic soils opposed to a similar strong positive effect (0.30) in the Hainich-Dun region, whereas the Schwabische Alb region displayed a five times weaker positive effect (0.06) only. Further, fertilization effects on species richness were positive (0.03) for the region with organic soils compared to up to 25 times stronger negative effects in the other two regions. Synthesis. Our results clearly show the importance of studying both direct and indirect effects of land-use intensity. They demonstrate the indirect nature, via productivity, of the negative effect of fertilization intensity on plant species richness in the real-world context of management-induced gradients of intensity of fertilization, mowing and grazing. Finally, they highlight that careful consideration of regional environments is necessary before attempting to generalize land-use effects on species diversity.},
  language  = {en}
}
@article{SoliveresMaestreUlrichetal.2015,
  author    = {Soliveres, Santiago and Maestre, Fernando T. and Ulrich, Werner and Manning, Peter and Boch, Steffen and Bowker, Matthew A. and Prati, Daniel and Delgado-Baquerizo, Manuel and Quero, Jose L. and Sch{\"o}ning, Ingo and Gallardo, Antonio and Weisser, Wolfgang W. and M{\"u}ller, J{\"o}rg and Socher, Stephanie A. and Garcia-Gomez, Miguel and Ochoa, Victoria and Schulze, Ernst-Detlef and Fischer, Markus and Allan, Eric},
  title     = {Intransitive competition is widespread in plant communities and maintains their species richness},
  series = {Ecology letters},
  volume    = {18},
  journal   = {Ecology letters},
  number    = {8},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1461-023X},
  doi       = {10.1111/ele.12456},
  pages     = {790 -- 798},
  year      = {2015},
  abstract  = {Intransitive competition networks, those in which there is no single best competitor, may ensure species coexistence. However, their frequency and importance in maintaining diversity in real-world ecosystems remain unclear. We used two large data sets from drylands and agricultural grasslands to assess: (1) the generality of intransitive competition, (2) intransitivity-richness relationships and (3) effects of two major drivers of biodiversity loss (aridity and land-use intensification) on intransitivity and species richness. Intransitive competition occurred in >65\% of sites and was associated with higher species richness. Intransitivity increased with aridity, partly buffering its negative effects on diversity, but was decreased by intensive land use, enhancing its negative effects on diversity. These contrasting responses likely arise because intransitivity is promoted by temporal heterogeneity, which is enhanced by aridity but may decline with land-use intensity. We show that intransitivity is widespread in nature and increases diversity, but it can be lost with environmental homogenisation.},
  language  = {en}
}