Distribution of deadwood and other forest structural indicators relevant for bird conservation in Natura 2000 special protection areas in Poland.

Numerous bird species, often rare or endangered, rely on the presence of standing and downed deadwood for shelter, nesting, and foraging. Habitat quality was evaluated on the basis of deadwood volume, the density of large standing deadwood, and the space filling index (SFI). The SFI reflects the degree of space filling of the bottom layers taking into account tree trunks, seedlings, saplings, ground vegetation, stumps, and downed deadwood.

Measurement data from sample plots characterizing three development stages of a subalpine spruce forest and describing the bird assemblages associated with them.

The paper presents data on tree stands located in a subalpine spruce forest in the Gorce National Park (Western Carpathians, Poland) as well as on the birds inhabiting them in the breeding and nonbreeding seasons. The authors conducted stand measurements on a total of twenty-four sample plots, with eight plots established in each of the three studied forest development stages (mature, break-up, and growing-up) representing successive phases of subalpine forest development. The study area designated for each stage was 30 ha.