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.