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The investigation of Ambrosia pollen counts in the air of Sosnowiec was carried out from 1998 to 2010 by means of the volumetric method. The pollen season which was determined by means of the 98% method started at the end of July and the beginning of August and lasted until the end of October. The highest Ambrosia pollen count was recorded in 1999 (222 grains x m-3) and the lowest in 2001 (18 grains x m-3). It was stated that the daily count of pollen grains depended on the wind direction and maximum air temperature. The strongest correlations were found with maximum temperature and with a wind direction from the south east. A high negative correlation coefficient was found between the frequency of inflows of air masses from the west and the annual total of pollen grains and the value of the maximum daily count. The closest sites of Ambrosia L. are at a distance of 25–40 kilometres from the sampling point. Significant correlations with the frequency of inflow of air masses can support the conclusion that Ambrosia pollen grains recorded in Sosnowiec were most probably carried not only from local sources but also, at least in part, from distant places.
Gentiana asclepiadea L. is a montane flowering plant species that has a very limited lowland distribution in Poland. The only existing lowland station that is known occurs in the Katowice-Muchowiec (Silesian Upland). In this paper a second station from the Silesian Upland in the Mikołów-Jamna area is described. A single cluster of rare albiflora form was observed within the newly discovered population. Information about the status and distribution of the Willow Gentian in Poland is also given.
One hundred and one stands of non-native red oak Quercus rubra L. were examined across various forest types with the objective to relate the influence of environmental variables on the abundance of this species and to characterise its impact on the species richness and proportion of functional groups of native plant species. Amongst randomly selected stands more than 50% were self-regenerating ones, i.e. seedlings were present. The cover of Q. rubra seedlings was positively correlated with light intensity (rs = 0.38, P <0.05) and negatively with the content of nitrogen (rs = –0.20, P <0.05) and loss on ignition (rs = 0.20, P <0.05) in soil. The cover of mature trees was positively correlated with the value of pH (rs = 0.22, P <0.05). Separate correlations with DCA scores of phytosociological relevés and the cover of red oak in each layer showed that the species influenced the floristic composition of forest vegetation. The cover of mature trees of red oak negatively affected both the number of understorey species (rs = –0.39, P <0.01) and the cover of shrubs (rs = –0.21, P <0.05) and herbaceous species (rs = –0.22, P <0.05). Q. rubra in the form of a mature tree had a negative influence on the cover of barochores, endozoochores and species of Grime’s CSR strategy. The cover of red oak’s seedlings was negatively correlated with the cover of annual species (rs = –0.21, P <0.05). Saplings of Q. rubra had a negative influence on the cover of dyszoochores (rs = –0.21, P <0.05) and was positively correlated with competitors (rs = 0.31, P <0.01), megaphanerophytes (rs = 0.27, P <0.05) and therophytes (rs = 0.25, P <0.05). The study showed that Q. rubra is a competitive species both as a mature tree and in the form of seedlings or small saplings and thus it can contribute to the reduction of biodiversity in forest communities.
The descent of some mountain species into the lowlands is an interesting phenomenon in plant geography and ecology. The main purpose of the present study is to update the list of mountain species for the Silesian Uplands and to provide a synthesis of the knowledge accumulated to date on the habitats for their occurrence, a possible origin and their distribution patterns. In the present study, both the authors’ own records and those obtained by other researchers have been used: published, unpublished and herbarium records, and assembled in a form compatible with the Atlas of distribution of vascular plants in Poland (ATPOL) in the ATPOL– Silesia database). A list of mountain species present in the study region (approximately 4000 km2) is provided in relation to their altitudinal groups. For each species, information about its affiliation to geographical elements and the type of habitats in which it has occurred is recorded. The distribution of mountain species in the Silesian Uplands has been investigated by mapping the species onto a grid of 2 × 2 km squares (1040 in total). For ATPOL squares, containing at least one mountain species (N = 647), CORINE land cover data were obtained and used in explaining the distribution of mountain species composition and richness. In the vascular flora of the Silesian Uplands 76 mountain taxa have been noted, including 2 submontane, 41 montane, 1 subalpine and 32 multizonal species. The list of mountain species has been supplemented with Lonicera nigra and Cirsium erisithales. Many mountain species occurring in the Silesian Uplands have localities distributed throughout the whole region and thus they do not represent any particular type of range. Some species show certain patterns of distribution associated with local habitat conditions. Stands of the montane species are concentrated mainly in the western part of the Silesian Uplands, while the multizonal species are concentrated in the eastern and central part of the study area. Most of the mountain species occur in natural habitats, in particular in broadleaved woodlands, even when they have been degraded. However, some of the species prefer strongly degraded habitats, in particular sand- and clay-pits, quarries and industrial spoils which has been confirmed by multivariate (RDA) analysis. Discussing the possible origin of the mountain species in the Silesian Uplands one can consider migration routes from two directions: from the Sudety Mts. or from the Carpathian Mts. (located approximately 400 km south-west from a study area and 50–100 km south, respectively). Another possible explanation is that the species had a wider range during the glaciations and survived here in refugia.
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