article id 563,
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                            The effects of landscape structure and forestry on the abundance and  dynamics of boreal forest bird species have been studied widely, but  there are relatively few studies in which the spatial structure and  quality of the landscape have been related to the spatial ecology of  bird species. In this paper, we present methods to measure territory and  landscape quality for the three-toed woodpecker (Picoides tridactylus)  and similar territorial forest bird species based on data from the  Finnish multi-source national forest inventory and metapopulation  theory. The three-toed woodpecker was studied with territory mapping  within an area of 340 square km in southern Finland in 1987–2000.  Altogether 195 breeding territory sites were observed. The spatial  occurrence of the territories was aggregated, and the highest densities  were observed in spruce-dominated old-growth forest areas. Both  territory and landscape quality had significant consequences for the  occurrence of the three-toed woodpecker. The spatial patterning and  permanence of breeding and non-breeding territories were influenced by a  combination of spatial dynamics of the species and the quality of the  landscape, the latter being much influenced by forestry. The  landscape-level spatial occurrence of the three-toed woodpecker in the  study area may represent source-sink dynamics. The results of this paper  suggest the presence of threshold values at different spatial scales,  which may determine the occurrence of the three-toed woodpecker and  similar species in managed forest landscapes.
                        
                
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                            Pakkala,
                            Finnish Museum of Natural History, University of Helsinki, P.O. Box 17, FIN-00014 University of Helsinki, Finland
                                                        E-mail:
                                                            timo.pakkala@helsinki.fi
                                                                                          
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                            Hanski,
                            Department of Ecology and Systematics, University of Helsinki, P.O. Box 47, FIN-00014 University of Helsinki, Finland
                                                        E-mail:
                                                            ih@nn.fi
                                                                                
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                            Tomppo,
                            Finnish Forest Research Institute, Unioninkatu 40 A, FIN-00170 Helsinki, Finland
                                                        E-mail:
                                                            et@nn.fi