The faunistic and ecological composition of bird communities were studied (1963-1993) in seven types of anthropogenic landscapes of the Palearctic forest zone. The areas included an anthropogenic gradient ranging from slightly modified woods — forest parks and rural settlements — to urban built-up areas. Study method: bird censuses on permanent and temporary routes and on permanent plots. In the gradient from slightly modified forest habitats to fully urbanized areas the number of species in communities declined, while the total density grew due to the presence of a few synanthropic species. The proportion of insectivorous birds decreased while the proportion of polyphagous species (those using mixed plant and animal food as well as anthropogenic foods) increased. Also the number of tree-nesting and ground-nesting species decreased, while the number of hole-nesting birds increased. In urban settlements species nesting in human structures prevailed. Anthropogenic transformation led to changes in the avian community structure based mainly on simplification of the natural bird communities. Thus, urban settings developed specific bird communities that differed in many ways from those of nearby forested areas.
Meadows and pastures occupy some 4 million hectares in Poland and constitute 21 per cent of arable land. Since they are man managed or made, their vegetation is most at risk. In recent decades, the meadow and peat-bog vegetation have decreased as a direct result of environmental contamination and degradation. The disappearing of flora has numerous implications. It leads to further relentless upsetting of the environmental balance. A loss of any species means decreased stability of the whole ecosystem as it disturbs the whole network of environmental interconnections.