@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}
}
@article{RudolphVossMoradietal.2013,
  author    = {Rudolph, Nicole and Voss, Sebastian and Moradi, Ahmad B. and Nagl, Stefan and Oswald, Sascha Eric},
  title     = {Spatio-temporal mapping of local soil pH changes induced by roots of lupin and soft-rush},
  series = {Plant and soil},
  volume    = {369},
  journal   = {Plant and soil},
  number    = {1-2},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0032-079X},
  doi       = {10.1007/s11104-013-1775-0},
  pages     = {669 -- 680},
  year      = {2013},
  abstract  = {The rhizosphere is a dynamic system strongly influenced by root activity. Roots modify the pH of their surrounding soil causing the soil pH to vary as a function of distance from root surface, location along root axes, and root maturity. Non-invasive imaging techniques provide the possibility to capture pH patterns around the roots as they develop. We developed a novel fluorescence imaging set up and applied to the root system of two lupin (Lupinus albus L., Lupinus angustifolius L.) and one soft-rush (Juncus effusus L.) species. We grew plants in glass containers filled with soil and equipped with fluorescence sensor foils on the container side walls. We gained highly-resolved data on the spatial distribution of H+ around the roots by taking time-lapse images of the samples over the course of several days. We showed how the soil pH in the vicinity of roots developed over time to different values from that of the original bulk soil. The soil pH in the immediate vicinity of the root surface varied greatly along the root length, with the most acidic point being at 0.56-3.36 mm behind the root tip. Indications were also found for temporal soil pH changes due to root maturity. In conclusion, this study shows that this novel optical fluorescence imaging set up is a powerful tool for studying pH developments around roots in situ.},
  language  = {en}
}