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The influence of the edge effect on the meadow vegetation pattern was studied in the forest glades in the central part of the Middle Sudety Mts. (SW Poland). The spectacular edge effect is seen in the range of 4 m from the forest border towards the center of the glades. Within that belt we observed decrease in tree and bush species number, increase in share of graminoids and Fabaceae species, as well as increase in share of species generally related to grassland communities. A significant increase in species number and values of Shannon−Wiener diversity index was noticed within the distance of eight meters from the edges of glades.
Due to social and economic changes which have occurred in the last decades, many meadows located in mountain regions have ceased to be used. Abandonment of meadows leads to the degradation of their species composition. An example of degradation may be seen in the development of patches dominated by Calamagrostis epigejos. The aim of this research was to determine the influence of C. epigejos in its consecutive expansion stages on qualitative properties of meadow sward and on selected physico-chemical properties of soils. The study revealed strong degradation of mountain meadows due to the expansion of C. epigejos. The degradation manifested in a decrease in species diversity, a decline of species typical for mesic meadows, and an increased proportion of synanthropic species. The increase in aboveground biomass of C. epigejos strongly reduced the biomass of other species, while underground biomass had no effect on accompanying species. However, only a small impact of C. epigejos expansion on soil degradation was detected. The cumulating plant necromass dominated by this species caused a decrease in diversity indices and, at the same time, an increase in exchangeable forms of potassium and phosphorus in the soil.
Along a 4.8 km long stretch of the ecological corridor of the lêza river, 175 patches dominated by Helianthus tuberosus s.l. were found. Among them, about two-thirds are not bigger than 4 m2, but many of the other patches cover areas of several hundred square meters to about 1300 m2. The effect of the H. tuberosus stands on the vegetation of anthropogenic habitats was studied at two sites: one post-agricultural and one post-industrial. At both sites, a system of transects with study plots was laid out. The transects began outside of the H. tuberosus stands (stage A) and penetrated their inside comprising three distinguished stages (B to D) of increasingly higher and denser thickets of sunflower. No significant differences between habitats were found. At both sites, there was a strong decrease in the number and biomass of co-occurring species only in the older stages (C and D) of thicket development, but not at the edges (B), where short H. tuberosus individuals strongly compete with other species.
The influence that different sampling methods have on the results and the interpretation of vegetation analysis has been much debated, but little is yet known about how the spatial arrangement of samples affect patterns of species composition and environment–vegetation relationships within the same vegetation type. We compared three data sets of the same sample size obtained by three standard sampling methods: preferential, random, and systematic. These different sampling methods were applied to a study area comprising of 36 ha of intermittently wet Molinia meadows. We compared the performance of the three methods under two management categories: managed (extensively mown) and unmanaged (abandoned for 10 years). A total of 285 vegetation-plots were sampled, with 95 plots recorded per sampling method. In preferential sampling, we sampled only patches of vegetation with an abundance of indicator species of the habitat type, while random and systematic plots were positioned independently from the researcher by using GIS. The effect of each sampling method on the patterns of species composition and species–environment relationships was explored by redundancy analysis and the significance of effects was tested by the randomization test. Preferential sampling revealed different patterns of species composition than random and systematic sampling methods. Random and systematic sampling methods have resulted in broader vegetation variability than with preferential sampling method. Preferential sampling revealed different relationship between soil parameters and species composition in contrast to random and systematic sampling methods. Although we have not found significant differences in vegetation–environment relationships between random and systematic sampling methods, random sampling revealed a more robust correlation of species data to soil factors than preferential and systematic sampling methods. Intentional restriction of vegetation variation sampled preferentially may be detrimental to statistical inference in studies of species composition patterns and vegetation–environment relationships.
This work presents a list of localities for the following species: Anomodon attenuatus, A. viticulosus, Dicranum viride, Gymnomitrion alpinum, Hedwigia ciliata, Homalia trichomanoides, Lophoziopsis longidens, Obtusifolium obtusum, Odontoschisma elongatum, Orthodicranum tauricum, Porella platyphylla, and Syntrichia papillosa.
This work presents a list of localities for the following species: Bucklandiella heterosticha, Conocephalum salebrosum, Fuscocephaloziopsis lunulifolia, Hamatocaulis vernicosus, Harpanthus scutatus, Hedwigia ciliata, Leskea polycarpa, Lophoziopsis excisa, Odontoschisma denudatum, Schljakovia kunzeana, Sciuro-hypnum reflexum, Sphagnum riparium and Tomentypnum nitens.
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