@article{WoltersBittmannKummer2005,
  author    = {Wolters, Steffen and Bittmann, Felix and Kummer, Volker},
  title     = {The first subfossil records of Urtica kioviensis Rogow. and their consequences for palaeoecological interpretations},
  year      = {2005},
  abstract  = {Among plant remains from Mesolithic layers dating from 9249 to 7779 B.C. at the excavation site of Friesack IV in north-eastern Germany, nutlets of Urtica kioviensis were identified. Morphological studies have shown that they clearly differed from all other European Urtica species investigated. In contrast, pollen morphological investigations revealed only slight differences between the central European Urtica species, which could hardly have been noticed during routine or normal pollen analyses. The records of U. kioviensis nutlets are the first subfossil finds reported and prove the indigenous status of this taxon in north-eastern Germany. The records are discussed in the context of the overall species spectrum of the Mesolithic layers and consequences for the interpretation of pollen analytical studies concerning human impact are pointed out},
  language  = {en}
}
@article{ThinesKummer2013,
  author    = {Thines, Marco and Kummer, Volker},
  title     = {Diversity and species boundaries in floricolous downy mildews},
  series = {Mycological progress : international journal of the German Mycological Society},
  volume    = {12},
  journal   = {Mycological progress : international journal of the German Mycological Society},
  number    = {2},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1617-416X},
  doi       = {10.1007/s11557-012-0837-7},
  pages     = {321 -- 329},
  year      = {2013},
  abstract  = {Floricolous downy mildews are a monophyletic group of members of the genus Peronospora (Oomycota, Peronosporales). These downy mildews can be found on a variety of families of the Asteridae, including Asteraceae, Campanulaceae, Dipsacaceae, Lamiaceae, and Orobanchaceae. With the exception of Peronospora radii, which can also cause economically relevant losses, sporulation usually takes place only on floral parts of their hosts. However, only very few specimens of these mostly inconspicuous downy mildews have so far been included in molecular phylogenies. Focusing on Lamiaceae, we have investigated multiple specimens of floricolous downy mildews for elucidating species boundaries and host specificity in this group. Based on both mitochondrial and nuclear loci, it became apparent that phylogenetic lineages in the Lamiaceae seem to be host genus specific and significant sequence diversity could be found between lineages. Based on distinctiveness in both phylogenetic reconstructions and morphology, the downy mildew on flowers of Stachys palustris is introduced as a new species, Peronospora jagei sp. nov., which can be morphologically distinguished from Peronospora stigmaticola by broader and shorter conidiospores. The diversity of the floricolous down mildews might be higher than previously assumed, although specimens from a much broader set of samples will be needed to confirm this view.},
  language  = {en}
}
@article{ScherberEisenhauerWeisseretal.2010,
  author    = {Scherber, Christoph and Eisenhauer, Nico and Weisser, Wolfgang W. and Schmid, Bernhard and Voigt, Winfried and Fischer, Markus and Schukze, Ernst-Detlef and Roscher, Christiane and Weigelt, Alexandra and Allan, Eric and Beßler, Holger and Bonkowski, Michael and Buchmann, Nina and Buscot, Fran{\c{c}}ois and Clement, Lars W. and Ebeling, Anne and Engels, Christof and Halle, Stefan and Kertscher, Ilona and Klein, Alexandra Maria and Koller, Robert and K{\"o}nig, Stephan and Kowalski, Esther and Kummer, Volker and Kuu, Annely and Lange, Markus and Lauterbach, Dirk},
  title     = {Bottom-up effects of plant diversity on multitrophic interactions in a biodiversity experiment},
  issn      = {0028-0836},
  year      = {2010},
  language  = {en}
}
@article{RaetzelKummerOtteetal.2002,
  author    = {R{\"a}tzel, Stefan and Kummer, Volker and Otte, Volker and Sipman, Harri J. M},
  title     = {Bemerkenswerte Flechtenfunde aus Brandenburg VII},
  year      = {2002},
  language  = {de}
}
@article{RottstockKummerFischeretal.2017,
  author    = {Rottstock, Tanja and Kummer, Volker and Fischer, Markus and Joshi, Jasmin Radha},
  title     = {Rapid transgenerational effects in Knautia arvensis in response to plant community diversity},
  series = {The journal of ecology},
  volume    = {105},
  journal   = {The journal of ecology},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0022-0477},
  doi       = {10.1111/1365-2745.12689},
  pages     = {714 -- 725},
  year      = {2017},
  abstract  = {1. Plant species persistence in natural communities requires coping with biotic and abiotic challenges. These challenges also depend on plant community composition and diversity. Over time, biodiversity effects have been shown to be strengthened via increasing species complementarity in mixtures. Little is known, however, whether differences in community diversity and composition induce rapid transgenerational phenotypic adaptive differentiation during community assembly. We expect altered plant-plant and other biotic interactions (mutualists or antagonists) in high vs. low diverse communities to affect immediate within-and between-species trait differentiations due to competition for light and nutrients. 2. Three years after the initiation of a large-scale, long-term biodiversity experiment in Jena, Germany, we tested for effects of varying experimental plant community diversity (1-60 plant species; one to four plant functional groups) and composition (with or without legumes and/or grasses) on phenotypic differentiation and variation of the tall herb Knautia arvensis. We measured reproduction at different diversity levels in the Jena Experiment (residents hereafter) and, in an additional common garden experiment without competition, recorded subsequent offspring performance (i.e. growth, reproductive success and susceptibility to powdery mildew) to test for differentiation in phenotypic expression and variability. 3. We observed phenotypic differences among diversity levels with reduced fecundity of K. arvensis residents in more diverse communities. In the next generation grown under common garden conditions, offspring from high-diversity plots showed reduced growth (i.e. height) and lower reproduction (i.e. fewer infructescences), but increased phenotypic trait variability (e.g. in leaf width and powdery mildew presence) and also tended to be less susceptible to powdery mildew infection. 4. Community composition also affected Knautia parents and offspring. In the presence of legumes, resident plants produced more seeds (increased fecundity); however, germination rate of those seeds was reduced at an early seedling stage (reduced fertility). 5. Synthesis. We conclude that rapid transgenerational effects of community diversity and composition on both mean and variation of phenotypic traits among offspring exist. In addition to heritable variation, environmentally induced epigenetic and/or maternal processes matter for early plant community assembly and may also determine future species coexistence and community stability.},
  language  = {en}
}
@article{RottstockJoshiKummeretal.2014,
  author    = {Rottstock, Tanja and Joshi, Jasmin Radha and Kummer, Volker and Fischer, Markus},
  title     = {Higher plant diversity promotes higher diversity of fungal pathogens, while it decreases pathogen infection per plant},
  series = {Ecology : a publication of the Ecological Society of America},
  volume    = {95},
  journal   = {Ecology : a publication of the Ecological Society of America},
  number    = {7},
  publisher = {Wiley},
  address   = {Washington},
  issn      = {0012-9658},
  pages     = {1907 -- 1917},
  year      = {2014},
  abstract  = {Fungal plant pathogens are common in natural communities where they affect plant physiology, plant survival, and biomass production. Conversely, pathogen transmission and infection may be regulated by plant community characteristics such as plant species diversity and functional composition that favor pathogen diversity through increases in host diversity while simultaneously reducing pathogen infection via increased variability in host density and spatial heterogeneity. Therefore, a comprehensive understanding of multi-host multi-pathogen interactions is of high significance in the context of biodiversity-ecosystem functioning. We investigated the relationship between plant diversity and aboveground obligate parasitic fungal pathogen ("pathogens" hereafter) diversity and infection in grasslands of a long-term, large-scale, biodiversity experiment with varying plant species (1-60 species) and plant functional group diversity (1-4 groups). To estimate pathogen infection of the plant communities, we visually assessed pathogen-group presence (i.e., rusts, powdery mildews, downy mildews, smuts, and leaf-spot diseases) and overall infection levels (combining incidence and severity of each pathogen group) in 82 experimental plots on all aboveground organs of all plant species per plot during four surveys in 2006. Pathogen diversity, assessed as the cumulative number of pathogen groups on all plant species per plot, increased log-linearly with plant species diversity. However, pathogen incidence and severity, and hence overall infection, decreased with increasing plant species diversity. In addition, co-infection of plant individuals by two or more pathogen groups was less likely with increasing plant community diversity. We conclude that plant community diversity promotes pathogen-community diversity while at the same time reducing pathogen infection levels of plant individuals.},
  language  = {en}
}
@article{RistowHerrmannIlligetal.2006,
  author    = {Ristow, Michael and Herrmann, Andreas and Illig, Hubert and Klemm, Gunther and Kummer, Volker and Kl{\"a}ge, Hans-Christian and Machatzi, Bernd and Raetzel, Stefan and Schwarz, R. and Zimmermann, Friedrich},
  title     = {Liste und Rote Liste der etablierten Gef{\"a}ßpflanzen Brandenburgs},
  year      = {2006},
  language  = {de}
}
@article{RaetzelKummer2010,
  author    = {Raetzel, Stefan and Kummer, Volker},
  title     = {Die Erforschung der in Brandenburg vorkommenden Kryptogamen nach 1945 (Moose, Pilze)},
  year      = {2010},
  language  = {de}
}
@article{OtteRaetzelSipmanetal.2000,
  author    = {Otte, Volker and R{\"a}tzel, Stefan and Sipman, Harri J. M. and Kummer, Volker},
  title     = {Bemerkenswerte Flechtenfunde aus Brandenburg V},
  year      = {2000},
  language  = {de}
}
@article{OtteRaetzelKummeretal.2001,
  author    = {Otte, Volker and R{\"a}tzel, Stefan and Kummer, Volker and De Bruyn, Uwe},
  title     = {Bemerkenswerte Flechtenfunde aus Brandenburg VI},
  year      = {2001},
  language  = {de}
}