@article{PlueDeFrenneAcharyaetal.2017,
  author    = {Plue, Jan and De Frenne, Pieter and Acharya, Kamal and Brunet, J{\"o}rg and Chabrerie, Olivier and Decocq, Guillaume and Diekmann, Martin and Graae, Bente J. and Heinken, Thilo and Hermy, Martin and Kolb, Annette and Lemke, Isgard and Liira, Jaan and Naaf, Tobias and Verheyen, Kris and Wulf, Monika and Cousins, Sara A. O.},
  title     = {Where does the community start, and where does it end?},
  series = {Journal of vegetation science},
  volume    = {28},
  journal   = {Journal of vegetation science},
  number    = {2},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1100-9233},
  doi       = {10.1111/jvs.12493},
  pages     = {424 -- 435},
  year      = {2017},
  abstract  = {QuestionBelow-ground processes are key determinants of above-ground plant population and community dynamics. Still, our understanding of how environmental drivers shape plant communities is mostly based on above-ground diversity patterns, bypassing below-ground plant diversity stored in seed banks. As seed banks may shape above-ground plant communities, we question whether concurrently analysing the above- and below-ground species assemblages may potentially enhance our understanding of community responses to environmental variation. LocationTemperate deciduous forests along a 2000km latitudinal gradient in NW Europe. MethodsHerb layer, seed bank and local environmental data including soil pH, canopy cover, forest cover continuity and time since last canopy disturbance were collected in 129 temperate deciduous forest plots. We quantified herb layer and seed bank diversity per plot and evaluated how environmental variation structured community diversity in the herb layer, seed bank and the combined herb layer-seed bank community. ResultsSeed banks consistently held more plant species than the herb layer. How local plot diversity was partitioned across the herb layer and seed bank was mediated by environmental variation in drivers serving as proxies of light availability. The herb layer and seed bank contained an ever smaller and ever larger share of local diversity, respectively, as both canopy cover and time since last canopy disturbance decreased. Species richness and -diversity of the combined herb layer-seed bank community responded distinctly differently compared to the separate assemblages in response to environmental variation in, e.g. forest cover continuity and canopy cover. ConclusionsThe seed bank is a below-ground diversity reservoir of the herbaceous forest community, which interacts with the herb layer, although constrained by environmental variation in e.g. light availability. The herb layer and seed bank co-exist as a single community by means of the so-called storage effect, resulting in distinct responses to environmental variation not necessarily recorded in the individual herb layer or seed bank assemblages. Thus, concurrently analysing above- and below-ground diversity will improve our ecological understanding of how understorey plant communities respond to environmental variation.},
  language  = {en}
}
@article{NaafWulf2011,
  author    = {Naaf, Tobias and Wulf, Monika},
  title     = {Traits of winner and loser species indicate drivers of herb layer changes over two decades in forests of NW Germany},
  series = {Journal of vegetation science},
  volume    = {22},
  journal   = {Journal of vegetation science},
  number    = {3},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {1100-9233},
  doi       = {10.1111/j.1654-1103.2011.01267.x},
  pages     = {516 -- 527},
  year      = {2011},
  abstract  = {Questions What are the most likely environmental drivers for compositional herb layer changes as indicated by trait differences between winner and loser species? Location Weser-Elbe region (NW Germany). Methods We resurveyed the herb layer communities of ancient forest patches on base-rich sites of 175 semi-permanent plots. Species traits were tested for their ability to discriminate between winner and loser species using logistic regression analyses and deviance partitioning. Results Of 115 species tested, 31 were identified as winner species and 30 as loser species. Winner species had higher seed longevity, flowered later in the season and more often had an oceanic distribution compared to loser species. Loser species tended to have a higher specific leaf area, were more susceptible to deer browsing and had a performance optimum at higher soil pH compared to winner species. The loser species also represented several ancient forest and threatened species. Deviance partitioning indicated that local drivers (i.e. disturbance due to forest management) were primarily responsible for the species shifts, while regional drivers (i.e. browsing pressure and acidification from atmospheric deposition) and global drivers (i.e. climate warming) had moderate effects. There was no evidence that canopy closure, drainage or eutrophication contributed to herb layer changes. Conclusions The relative importance of the different drivers as indicated by the winner and loser species differs from that found in previous long-term studies. Relating species traits to species performance is a valuable tool that provides insight into the environmental drivers that are most likely responsible for herb layer changes.},
  language  = {en}
}