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Nutrient-poor grasslands on siliceous soil in the lower Aar valley (Middle Hesse, Germany) - neglected vegetation types in the intersection range of four classes

Becker, Thomas; Schmiege, Christine LU ; Bergmeier, Erwin; Dengler, Juergen and Nowak, Bernd (2012) In Tuexenia p.281-318
Abstract
In the lower siliceous uplands of Central Europe, various types of nutrient-poor grasslands are widespread and grow intermingled. These species-rich grasslands, often dominated by taxa of the Festuca ovina aggregate, comprise various phytosociological classes. They are remnants of a historic rural landscape and are of conservation importance. Few studies on such grasslands are available and there has been disagreement in assigning them to appropriate habitat types or syntaxa. We investigated such nutrient-poor grasslands in the lower Aar valley (Middle Hesse, Rhenish Massif). We surveyed 104 vegetation plots distributed throughout the valley and identified syntaxa to (sub)association level. We carried out supervised classification... (More)
In the lower siliceous uplands of Central Europe, various types of nutrient-poor grasslands are widespread and grow intermingled. These species-rich grasslands, often dominated by taxa of the Festuca ovina aggregate, comprise various phytosociological classes. They are remnants of a historic rural landscape and are of conservation importance. Few studies on such grasslands are available and there has been disagreement in assigning them to appropriate habitat types or syntaxa. We investigated such nutrient-poor grasslands in the lower Aar valley (Middle Hesse, Rhenish Massif). We surveyed 104 vegetation plots distributed throughout the valley and identified syntaxa to (sub)association level. We carried out supervised classification combining cluster analysis, a priori assignment to classes based on prevailing diagnostic species, and regional refinement based on phi-value maximisation of the units. As a result, we classified five associations within four classes: Polytricho piliferi-Festucetum tenuifoliae/Galio harcynici-Deschampsietum flexuosae and Festuco rubrae-Genistelletum sagittalis (Calluno-Ulicetea), Jasiono montanae-Festucetum ovinae (Koelerio-Corynephoretea), Gentiano-Koelerietum pyramidatae (Festuco-Brometea) and Arrhenatheretum elatioris (Molinio-Arrhenatheretea). Ecologically, soil acidity (resulting from Ca concentrations of the bedrock) was the main cause of floristic dissimilarity of the grasslands and thus community differentiation. Many stands grew on soils with intermediate pH and showed a peculiar mixture of basiphilous and acidophilous species. We conclude that (i) our approach of supervised classification yields convincing reproducible results when a syntaxonomic system is adapted top-down to a geographically restricted area, (ii) nutrient-poor siliceous grasslands dominated by taxa of the Festuca ovina aggregate can be well assigned to ecologically meaningful syntaxa, and (iii) the nutrient-poor siliceous grasslands of the Lahn-Dill Highlands are of high conservation relevance and in urgent need of protection. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Calluno-Ulicetea, classification, Festuco-Brometea, grassland, conservation, Koelerio-Corynephoretea, Lahn-Dill Highlands, Molinio-Arrhenatheretea, ordination, phi value, Rhenish Massif, soil, analysis, syntaxonomy
in
Tuexenia
issue
32
pages
281 - 318
publisher
Die floristisch-soziologische Arbeitsgemeinschaft
external identifiers
  • wos:000306680700015
  • scopus:84871878420
ISSN
0722-494X
language
English
LU publication?
yes
id
cdd9585c-65cf-4c02-b21a-d722c1698f25 (old id 3079768)
alternative location
http://tuexenia.de.ds0201.hostingschmie.de/fileadmin/website/downloads/Tuexenia32/14_Becker_281-318.pdf
date added to LUP
2012-09-25 11:08:37
date last changed
2017-01-01 06:35:34
@article{cdd9585c-65cf-4c02-b21a-d722c1698f25,
  abstract     = {In the lower siliceous uplands of Central Europe, various types of nutrient-poor grasslands are widespread and grow intermingled. These species-rich grasslands, often dominated by taxa of the Festuca ovina aggregate, comprise various phytosociological classes. They are remnants of a historic rural landscape and are of conservation importance. Few studies on such grasslands are available and there has been disagreement in assigning them to appropriate habitat types or syntaxa. We investigated such nutrient-poor grasslands in the lower Aar valley (Middle Hesse, Rhenish Massif). We surveyed 104 vegetation plots distributed throughout the valley and identified syntaxa to (sub)association level. We carried out supervised classification combining cluster analysis, a priori assignment to classes based on prevailing diagnostic species, and regional refinement based on phi-value maximisation of the units. As a result, we classified five associations within four classes: Polytricho piliferi-Festucetum tenuifoliae/Galio harcynici-Deschampsietum flexuosae and Festuco rubrae-Genistelletum sagittalis (Calluno-Ulicetea), Jasiono montanae-Festucetum ovinae (Koelerio-Corynephoretea), Gentiano-Koelerietum pyramidatae (Festuco-Brometea) and Arrhenatheretum elatioris (Molinio-Arrhenatheretea). Ecologically, soil acidity (resulting from Ca concentrations of the bedrock) was the main cause of floristic dissimilarity of the grasslands and thus community differentiation. Many stands grew on soils with intermediate pH and showed a peculiar mixture of basiphilous and acidophilous species. We conclude that (i) our approach of supervised classification yields convincing reproducible results when a syntaxonomic system is adapted top-down to a geographically restricted area, (ii) nutrient-poor siliceous grasslands dominated by taxa of the Festuca ovina aggregate can be well assigned to ecologically meaningful syntaxa, and (iii) the nutrient-poor siliceous grasslands of the Lahn-Dill Highlands are of high conservation relevance and in urgent need of protection.},
  author       = {Becker, Thomas and Schmiege, Christine and Bergmeier, Erwin and Dengler, Juergen and Nowak, Bernd},
  issn         = {0722-494X},
  keyword      = {Calluno-Ulicetea,classification,Festuco-Brometea,grassland,conservation,Koelerio-Corynephoretea,Lahn-Dill Highlands,Molinio-Arrhenatheretea,ordination,phi value,Rhenish Massif,soil,analysis,syntaxonomy},
  language     = {eng},
  number       = {32},
  pages        = {281--318},
  publisher    = {Die floristisch-soziologische Arbeitsgemeinschaft},
  series       = {Tuexenia},
  title        = {Nutrient-poor grasslands on siliceous soil in the lower Aar valley (Middle Hesse, Germany) - neglected vegetation types in the intersection range of four classes},
  year         = {2012},
}