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Publicação
Floristic composition patterns of Mediterranean annual non-nitrophilous grasslands in Eastern Portugal
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Orientador(es)
Resumo(s)
Helianthemetea guttati communities are pioneer spring and early summer ephemeral grasslands, dominated by nonnitrophilous
therophytes. In Continental Portugal, these communities have not yet been fully investigated, and thus the
objectives of the present study are: (1) to identify community types in therophytic grasslands; (2) to recognize those
communities that configure the European priority habitat 6220* (pseudo-steppe with grasses and annuals); (3) to establish
environmental gradients underlying their spatial variation; (4) to assess how floristic composition is affected by land use
factors. Vegetation sampling using phytosociological methodology was carried out on 80 grasslands. Modified Twinspan
classification and canonical correspondence analysis (CCA) was applied for the classification and ordination of releve´s
whereas partial CCA (pCCA) and variation partitioning were used to assess the relative influence of individual land use
factors. Some 270 species were identified across 11 community types whose floristic patterns were mainly explained by
environmental gradients related to altitude and soil type while land use variables could only explain a small part of the
floristic variation. Based on biogeography and the determination of diagnostic species, four phytosociological new
associations and a new subassociation are proposed: Holco-Brachypodietum distachyi, Holco-Micropyretum tenellae, Micropyro-
Anthoxanthetum aristati and Leontodonto-Vulpietum bromoidis vulpietosum membranaceae
Descrição
Palavras-chave
community types environmental factors land use factors therophytic grasslands variation partitioning
Contexto Educativo
Citação
"Plant Biosystems". ISSN 1724-5575. (2012) 1-16