Search results for " ecological gradients"

showing 3 items of 3 documents

Formalized classification of European fen vegetation at the alliance level

2017

AimsPhytosociological classification of fen vegetation (Scheuchzerio palustris-Caricetea fuscae class) differs among European countries. Here we propose a unified vegetation classification of European fens at the alliance level, provide unequivocal assignment rules for individual vegetation plots, identify diagnostic species of fen alliances, and map their distribution.LocationEurope, western Siberia and SE Greenland.Methods29 049 vegetation-plot records of fens were selected from databases using a list of specialist fen species. Formal definitions of alliances were created using the presence, absence and abundance of Cocktail-based species groups and indicator species. DCA visualized the s…

0106 biological sciencesVegetation classificationBos- en LandschapsecologieWetlandManagement Monitoring Policy and Law010603 evolutionary biology01 natural sciencesSupervised vegetation classificationVegetation plotsForest and Landscape EcologyVegetatieNature and Landscape Conservationgeographygeography.geographical_feature_categoryVegetationBiogeography ; Ecological gradients ; Endangered habitats ; Mires ; Releves ; Supervised vegetation classification ; Unsupervised vegetation classification ; Vegetation plots ; WetlandsEcologyChemistryEcologyMiresRelevésSpecies diversityUnsupervised vegetation classificationVegetation15. Life on landPE&RCEndangered habitatsBorealBiogeographyIndicator speciesWetlandsEcological gradientsOrdinationVegetatie Bos- en LandschapsecologieSpecies richnessVegetation Forest and Landscape Ecology010606 plant biology & botany
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Phytoplankton distribution along trophic gradients within and among reservoirs in Catalonia (Spain)

2008

SUMMARY 1. Longitudinal gradients in the epilimnetic waters of stratified reservoirs provide a useful database to study changing environmental conditions. The spatial distribution, assemblage structure and specific adaptations of phytoplankton assemblages can be analysed along these gradients over short time scales. 2. Four reservoirs with a similar typology, located along an altitudinal gradient in the same eco-region, were sampled along their longitudinal axes. In total, 19 sampling stations provided a trophic spectrum, ranging from oligo-mesotrophy to hypertrophy, which was quantified by calculating the trophic state index of each sampling station in the four reservoirs. 3. Several patte…

Biomass (ecology)EcologyAbundance (ecology)PhytoplanktonSettore BIO/03 - Botanica Ambientale E ApplicataTrophic state indexAquatic ScienceBiologycanyon-shaped reservoirs ecological gradients eutrophication phytoplankton structure trophic state indexEutrophicationSpatial distributionHydrobiologyTrophic level
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Downy-oak woods of Italy: phytogeographical remarks on a controversial taxonomic and ecologic issue

2014

The importance of downy oak as an integral component of the "submediterranean" woods has been underscored by many studies. Nevertheless, terms like "submediterranean" and "downy oak" are some of the most poorly understood concepts in European phytogeographic and taxonomic research. Downy oak is well known to be a problematic taxon. The name "Quercus pubescens" (= Q. humilis) combines populations characterized by increasing phenotypic and genomic polymorphisms along north-south gradients, which is explained as the result of a "founder effect" produced by a relatively fast post-glacial re-colonization of the northern areas through rare long-distance dispersal events. On the other hand, polymo…

GeographyTaxonbiologyEcologyeducationBotanyBiological dispersalQuercus pubescensdowny oak ecological gradients syntaxonomy phytogeography coenologic variability distribution patterns human impactPhytogeographybiology.organism_classificationDowny oak Ecological gradients Syntaxonomy Phytogeography Coenologic variability Distribution patterns Human impactFounder effect
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