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Importance of Old Forest Stands for Diversity of Birds in Managed Pine Forests : A Case Study from Augustów Forest (NE Poland)

Zawadzka D., Drozdowski S., Zawadzki G., Zawadzki J., Mikitiuk A.

Polish Journal of Ecology

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2018

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Vol. 66, nr 2

162--181

EN

We assessed the assemblages of birds inhabiting pine-dominated managed forest, aged between 1-5 years and above 140 years. Birds were counted on study plots representing eight different phases to the forest's development, with nesting, foraging and migratory guild categories recognised. Numbers of bird species and population densities, both increased markedly with stand age (respectively r = 0.988 and r = 0.936, P < 0.001). While numbers of ground-nesting bird species failed to correlate with stand age, successively older stands did support ever-greater proportions of species in the assemblage that nested in tree crowns (r = 0.976, P < 0.005) or tree holes (r = 0.833, P < 0.005). Raptors were most abundant in forest at the oldest stages of growth, and there was an age-gradient-related increase in the shares of both plant-eating species (r = 0.952, P < 0.005) and raptors (r = 0.764, P < 0.005). Resident birds were most numerous in the oldest forest. PCA for ten selected variables (relating to guild type) showed that the two principal components explained almost 98% of the variation among groups of bird guilds in relation to forest age. On the basis of their suitability for birds it was possible to distinguish three categories of stand by age group, of which the first encompasses the initial stage, the second a broad interval involving middle-aged stands of between 16 and 140 years, and the third forest more than 140 years old. The presence of the oldest stands of all can thus be seen to play a very important role in maintaining high-diversity populations of birds in managed forest.

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The winter bird community of rural areas in the proximity of cities : low density and rapid decrease in diversity

Ciach M.

Polish Journal of Ecology

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2012

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Vol. 60, nr 1

193-199

EN

The current problem in farmland ecology is the change in the character of rural development in areas neighbouring cities and towns. Progressive urbanization and the predominance of housing estates over agricultural aims led to a change in the bird community. During 2005-2010, a survey of birds wintering within densely populated built-up rural areas was conducted by the line transect method (a total length of 8 km). A total number of 33 species was recorded and the most numerous dominant was the House Sparrow Passer domesticus, which constituted 32.58% of the bird community. The group of dominants and subdominants (which constituted up to 20% of the bird community) included the Yellowhammer Emberiza citrinella and the Rook Corvus frugilegus, and a group of forest and synanthropic species - the Great Tit Parus major, the Blue Tit Cyanistes caeruleus, the Blackbird Turdus merula, and the Collared Dove Streptopelia decaocto. The total density varied in subsequent study years from 57.4 to 87.5 ind. 10 ha[^-1] and was approximately twice lower than in other rural regions studied in Poland. A significant decrease in the wintering birds. diversity index was recorded through the study period. The explanations for this could be in the character of villages in the proximity of builtup city areas. This has rapidly changed in recent years, and nowadays agricultural management in the region is discarded. As a result, farmlands of the region almost entirely lost their agricultural character, notably becoming a residential and recreational backup for cities. The villages neighbouring cities and towns are developed into suburban-like areas, where housing estates predominate over agricultural aims. Future consequences of these changes are far-reaching for farmland biodiversity and ecology. The decrease in species diversity and evolution into urban-like bird communities is the most probable scenario.

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Effect of habitat diversity on breeding birds : comparison of farmland bird community in the region of Wielkopolska (w. Poland) with relevant data from other european studies

Tryjanowski P.

Polish Journal of Ecology

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1999

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Vol. 47, no 2

153-174

EN

The breeding bird community of a 315 ha intensively used farmland in western Poland, consisting of arable fields and small part (ca. 5%) of margin habitats, was censused yearly from 1987 through 1997 by territory mapping. Its size was on average 318+-65 (SD) territories, belonging to 47+-4 species. Of the 71 stationary species, only 23 have been yearly present. Alauda arvensis, Motacilla flava, Emberiza citrinella, Sylvia communis and Acrocephalus palustris were the most abundant species throughout the period of the study. To determine the effect of land-use change of agricultural landscape on the abundance and diversity of breeding bird communities, the results of studies carried out on 12 similar large plots (1-10 km^2) in Central Europe were compared. The percent of margin habitats (hadgerows, ditches, small meadows, fallows etc.), when controlling for the effect of study plot size, is significantly correlated with number of breeding species (r=0.697) and total community density (r=0.899).