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Wysokość dwunastoletnich odnowień dębu szypułkowego na różnej wielkości gniazdach o wydłużonym kształcie w kierunku wschód-zachód

100%

Drozdowski S., Andrzejczyk T., Buraczyk W., Turkot S.

Sylwan

2013

tom 157

nr 06

The study presents spatial variation in the height of a 12−year−old oak regeneration in the north−south and east−west gradients in the cut patches with a similar width (28 m) but differing in length (33−70 m), with the longer side facing east−west direction. A comparison of the cut patches with an area of 7, 11 and 16 ares showed that oaks in large patches were on average 25% higher than in small patches and the diversity of trees in the WE and NS gradients depended on the size of the patch. In each case, the lowest trees occurred in the zone of strong root competition of shelterwood, whose influence decreased with the enlargement of the cut patches. The results of the study show that the establishment of large (15−20 ares) elliptical or rectangular patches whose area can be expanded by lengthening the axis in the east−west direction is the recommended method of pedunculate oak renewal in forest practice.

An East-West gradient in the breeding distribution and species richness of the European woodland avifauna

80%

Tomialojc L.

Acta Ornithologica

2000

tom 35

nr 1

3-17

In spite of environmental uniformity of the European Plains, a conspicuous east-west gradient in the woodland avifauna and breeding bird community composition has been revealed. The species richness in the western woodland avifauna is lower by 32-36% than in the respective eastern samples (n = 120-127 species). Apart from being poorer in species, western communities tend to contain a higher proportion of species which develop dense populations. These features may result from past — mostly postglacial — natural events, from a secondary gradient in the intensity of human impact or from both of them. The data at hand provide evidence for a strong prevalence of the second factor. In view of the mostly anthropogenic character of the differences described, many west-European data can hardly be used as models of the natural patterns in studies of breeding bird ecology. New continent-wide comparative research is necessary to better control for anthropogenic bias in field data. For valid future pan-continental comparisons of bird communities a few large patches of near-pristine woodland should be preserved in the East, as well as restored in the West. Bird ecology studies need also a better co-operation with the archaeozoological and historical research to take into consideration past conditions which could also have influenced the present-day life patterns of European birds.

Ograniczanie wyników

1 Acta Ornithologica

1 Sylwan

1 Andrzejczyk T.

1 Buraczyk W.

1 Drozdowski S.

1 Tomialojc L.

1 Turkot S.

1 2013

1 2000

Wyniki wyszukiwania

Wysokość dwunastoletnich odnowień dębu szypułkowego na różnej wielkości gniazdach o wydłużonym kształcie w kierunku wschód-zachód

An East-West gradient in the breeding distribution and species richness of the European woodland avifauna