Landscape context plays an important role for the occurrence of the white-backed woodpecker Dendrocopos leucotos
摘要
Habitat models typically relate the occurrence of a species to environmental predictors measured within study sites or home ranges (“local habitat”). However, sites with high local habitat quality might be unoccupied when the composition and configuration of the surrounding landscape hamper their colonization.
ObjectivesWe examined the occurrence of the white-backed woodpecker, an umbrella species of European conservation concern, in relation to local habitat and landscape context (habitat amount, habitat fragmentation, and matrix quality).
MethodsThe study was conducted in Western Austria, Eastern Switzerland, and the Principality of Liechtenstein. Variables describing local habitat and landscape context were compared between 30 sites with and 30 sites without white-backed woodpecker presence.
ResultsLandscape context explained 2.5 times more of the variance in occurrence probability than local habitat. Occurrence probability increased with the volume of lying deadwood and abundance of trees with dead branches at the local scale. It also increased with the proportion and fragmentation of old deciduous forests (representing habitat amount and habitat fragmentation, respectively) and increasing proportion of coniferous and young deciduous forest (representing matrix quality) at spatial scales ranging from 20 to 64 km2 (i.e., 6 to 20 times the annual home range size).
ConclusionsConservation measures for the white-backed woodpecker might be ineffective in landscapes with low forest cover, even if high-quality habitat at the local scale is abundant. Conservation of and habitat improvements in areas with a high proportion of old deciduous forest and of coniferous and young deciduous forests are thus key.