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Publicação
Os efeitos da intensificação agrícola na comunidade de aves das estepes cerealíferas
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Resumo(s)
This study evaluates the agricultural intensification effects on steppe bird populations of
cereal fields and fallows. Through the analysis of landscape dynamics between 2002–2011, a
gradient of agricultural intensification was identified in selected areas of Baixo Alentejo.
In cereal fields, total bird abundance of steppe and resident birds decreased along
the intensification gradient. During the breeding season, this trend should be related to
an increase in height and density of vegetation structure in intensive areas. Food availability is
not influenced by intensification. In extensive areas, the bird abundance is influenced by
differences associated to the type of cereal and vegetation structure. In fallows, the abundance
of steppe and resident birds is affected by intensification. Wintering and breeding species are
influenced by fallow age and livestock presence. The multi-scale analysis of local
management and landscape composition effects on steppe bird community in cereal
fields showed that local component is more important in winter. In fallows, both components
are equally important for steppe bird community. Between-year variations (2002-2008) in
Tetrax tetrax population densities were shown to be influenced by agricultural intensification
and rainfall
Descrição
Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia
Palavras-chave
steppe bird population agricultural intensification landscape dynamics cereal steppes Tetrax tetrax fallows cereal fields vegetation structure food availability inter-anual variations
Contexto Educativo
Citação
Delgado, A.M.S. - Os efeitos da intensificação agrícola na comunidade de aves das estepes cerealíferas. Lisboa: ISA, 2013, 271 p.