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Aura
|
2004
|
nr 04
11-12
Polish agriculture differs from the agriculture in most EU countries as regards the break-up of arable land into small plots and moderately intensive agricultural management. Due to this, agricultural land in a number of Polish regions features a relatively high diversity. However, in lowlands of western, south-western and central Poland the agriculture has been intensified for a long time which has resulted in stronger human pressures on species populations and natural impoverishment. The author discusses these issues using Dezydery Chłapowski Landscape Park located in Turwia area (Wielkopolska region).
The population density and brood results of the White Stork were studied between 1984 and 1991 in Legnica voivodeship (4037 km²), where a large copper industry centre has been developed for over 30 years. A total of 2217 data items, concerning nest occupation and brood results, were collected in relation to ca. 350 nests in the study area. The density of breeding pairs was 6.7/100 km². The copper industry was not found to have any direct negative impact on population dynamics and breeding parameters. In the 640 km² former administrative district ("powiat") of Legnica, where a metalworks has been operating since 1959, the density of die White Stork population has been increasing since 1922. In Legnica voivodeship as a whole, the population density increased by about 35% between the years 1974 and 1984 or by more then in the majority of the adjacent voivodeships. The mean numbers of young per breeding pair (JZa) -1.98 and per successful pair (JZm) - 2.54 as well as the proportion of unsuccessful pairs (%HPo) -19.4% were similar to the values recorded in the other regions of Poland. Brood results around the metalworks - the most heavily polluted areas - revealed no negative impacts on JZa, JZm or %HPo, in relation to distance from the metalworks or wind direction.
The aim of the study was to determine the relation between landscape structure, point counts number and the number of breeding bird species occuring in different types of farmland. Species number was evaluated using point counts on six plots localised in Polish and German farmland (from 30-52 points/plot, 10 min/point, radius — 100 or 150 m). The equation: S = cAz, where S — species number, A — sample size (number of points), c, z — parameters, was used to test the relation between point counts number and species numbers. The coefficients of determination amounted to 0.95-0.99. Among the parameters of equation, c was more strongly correlated with landscape parameters (e.g. wood cover). The analysis revealed, that unified farmland requires bigger representative sample size compared to other, more diversified types of farmland. At least 50 points are needed for proper comparing bird species number between farmlands or periods.
Acta Ornithologica
|
1995
|
tom 29
|
nr 3
145-154
Studies carried out in an agricultural landscape between 1989 and 1992 revealed 32 wintering species of birds along 13.6 km of transects passing through three biotopes: woodland interior, woodland edge and belts of trees. 42 species were noted in the area as a whole. The variability in the densities and biomass of plant-eating species was found to be greater than that for insect-eaters, but no trends were noted for changes in density in the course of the winter. The variability in the density of plant-eating species was less differentiated in the different biotopes and greater than that observed for insect-eating species. 27 species fed in belts of trees (7.3 ind. /ha), 24 at the woodland edge (2 ind. / ha) and 22 in the woodland interior (3.9 ind./ha). Plant-eating species showed a significant preference for belts of trees over the other biotopes, while insect-eating species favoured belts of trees or the woodland interior where population density was concerned, and the woodland interior when it came to biomass. The proportion of insect-eating species was lowest in belts of trees (35% by population density and 10% by biomass) and highest in the woodland interior (86% and 71% respectively). Population density and biomass were correlated positively with the age of tree stand for insect-eating species but not for plant-eating species. The distribution of birds in woodbelts was modified by adjoining woods: population density (total or within trophic guilds) was higher near woodlands than in central parts of the belt of trees.
Acta Ornithologica
|
1997
|
tom 32
|
nr 2
175-184
Work done in the years 1991-1994 involved an assessment of breeding bird density and numbers of species in relation to habitat structure in 74 plots located in mid-field woods in an agricultural landscape 50 km south of Poznań (W Poland). A total of 68 breeding species were recorded, with a density of 14.6 pairs/ha. The dominants in the community were: Fringilla coelebs (15.7%), Emberiza citrinella (12.8%), Passer montanus (7.4%), Miliaria calandra (5.1%). In the avenue-shaped woods the density (9.8 p/ha) and mean number of species (10) were lower than in wood belts (where the respective figures were 18.3 p/ha and 16 species) or clumps (14.9 and 21). The densities of birds expressed per unit of length were 13.8 p/km in avenues compared with 33.6 p/km in belts. It was found that 74-91% of differences in the numbers of species and densities in the different types of woods could be related to just several habitat parameters, above all the age of tree stand, the percentage cover of tree stand and shrub layers and the area of the given wood.
Protection of high biodiversity in an intensively farmed areas is strongly related to managing the diverse structure of a landscape, for example by planting shelterbelts. The study was aimed at recognition of avifauna dynamics in young (with the age of 1–4 years at the beginning of the study) shelterbelts (N=9) and at estimation of their importance for farmland birds. Bird density was estimated by mapping method in successive years 1996–2001 and the data were combined and analysed in respect to age of shelterbelts. Eighteen breeding species were found (5–8 pairs km⁻¹), among them most abundant were Corn Bunting (Miliaria calandra) (with dominance of 33%), Yellow Wagtail (Motacilla flava) (19%) and Whitethroat (Sylvia communis) (12%). No trend in the changes of species richness and total density was recorded. The density of species preferring building nests and/or feeding in herb layer (like Yellow Wagtail, Skylark Alauda arvensis and Whinchat Saxicola rubetra) decreased during study period while the density of species associated to higher layers of vegetation like Yellowhammer (Emberiza citrinella), Red-backed Shrike (Lanius collurio) increased. According to earlier study, bird species richness and abundance in studied young shelterbelts were lower than in several dozens years old ones. However, in relation to species colonization both classes of shelterbelts (species building their nests on the ground or in low shrubs), young shelterbelts were as important as old ones.
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