GIS-baserad habitatmodell för mindre hackspett : ett verktyg för att bevara skyddsvärda lövskogar inom Umeälvlandskapet

Abstract: Deciduous forests are, according to the National Environmental Quality Objectives, a priority area. Deciduous forests are rich in species and the occurrence of dead wood is an important factor for biodiversity. In order to identify valuable deciduous forests for bio-diversity, conservation needs good analyses and planning tools. Habitat models combined with geographic information systems can be used to study the spatial structure of suitable habitat. The Lesser spotted woodpecker (Dendrocopos minor) has been proposed as an indicator species for deciduous forests, since this species is highly specialized on insect larvae in dead wood and requires large areas of deciduous-rich environments. Many riparian forest with high species richness and high nature conservation values are found along the Ume river in Umeå municipality. The Lesser spotted woodpecker occurs frequently in alder-dominated forests along the coast and rivers in this area. This study examined tools and methods to highlight valuable deciduous forests in the landscape along the Ume river. Two models were tested, one which assembled habitat quality and one that looked at the spatial distribution of suitable habitats for the Lesser spotted woodpecker. When compared with an inventory of the Lesser spotted woodpecker in the same area, there was a good match between the models and inventory results. This study shows that the use of GIS models and an indicator species works well at the landscape level and for nature conservation planning. For a synoptic planning, the results of this work provide a good foundation for conservation assessments and help to set clear and monitorable targets for the landscape. The Lesser spotted woodpecker may be used as a symbol for riparian gray alder forests in Umeå municipality.