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1
Content available remote Diversity and abundance of bird communities in three mountain forest stands : effect of the habitat heterogeneity
Balaz M., Balazova M.
Polish Journal of Ecology
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2012
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Vol. 60, nr 3
629-634
EN
The structural composition of the forest habitats is considered to be one of the most important factors affecting the breeding bird community composition. Structurally more homogenous forests are usually characterized by lower number of bird species and their densities. This study presents results of a comparison of the breeding bird communities in three Carpathian mountain forests, and the effect of the forest composition on breeding bird species richness and density. There are the bird communities occurring in semi-natural forests: natural mixed forest (NMF) - spruce-beech forest situated ca. 1000 m a.s.l. and UFZ-spruce forest in the upper forest zone (UFZ) up to 1510 m a.s.l., and the managed spruce forest (MSF) at altitude which is similar to NMF. The territory mapping method was used to estimate the number of breeding species and their densities during years 2004-2006. The species richness as well as the density of breeding bird communities were found to be higher in the semi-natural habitats (33 breeding species; 64.6 breeding pairs 10[^-1] ha in NMF and 28 breeding species; 57.6 breeding pairs 10[^-1] ha in UFZ) than in the managed habitat (21 breeding species; 53.6 breeding pairs 10[^-1] ha). This was true even for the high-elevated study plot despite the fact that the altitude is usually negatively correlated with both the species richness and density.
2
Content available remote Factors affecting bird species diversity on a local scale : a case study of a mosaic landscape in southern Poland
Tworek S.
Polish Journal of Ecology
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2007
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Vol. 55, nr 4
771-782
EN
The main objective of this paper was to investigate factors that affect bird species diversity at local spatial scales including the role of habitat heterogeneity. The studies were carried out in a mosaic landscape of southern Poland, in habitat fragments, each described by variables which characterised the size of the plot and its spatial structure, including vegetation. A species diversity index was then calculated for each plot using Shannon-Wiener index, based on count of nesting birds obtained through territory mapping method. Correspondence analysis (CA) was then used to illustrate relationships between groups of plots of different scopes of species diversity and the measured characteristics of the plots. The high diversity among birds was found to be primarily connected with an increase in the proportion of old forest, whereas the diversity decreased with an increase in the proportion of 'farmland' (including meadows and pastures). Other significant effects on the changes in species diversity were exerted by the degree of density in the herb layer and the tree canopy layer, as well as by the presence of wetlands. The local-scale inertia in the heterogeneous-type habitats results primarily from the differences in quality and structure of the plot, which reflect their position between the 'forest' - 'non-forest' gradient. In the studied range of sizes (0.2-40 ha), the size of a given plot is of lesser significance than that of the vegetation structure. All the variables which represent potential effects upon the local-scale diversity of birds, and the suitability of CA are discussed against the background of the results of this study and available literature data.
3
Content available remote Populations of the bank vole in an industrial environment : demography and population numbers consequences
Luk'janova L., Luk'janov O., Bol'sakov V.
Polish Journal of Ecology
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2000
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Vol. 48, Suppl.
133-139
EN
Industrial factors exert considerably influence on the level of bank vole abundance and dynamics in numbers of the bank vole by decreasing habitat quality and disturbing the balance of reproduction, mortality and migration. As a result of industrial degradation and fragmentation of habitats, accompanied by the reduction of their ecological capacity and area, the level of the bank vole abundance is considerably reduced. The dynamics in numbers of the bank vole in impact populations is characterized by a lower leveland an increased amplitude of dynamics. At significant industrial loads, dynamics in numbers lose periodicity and are characterized by a longer phase of depression
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