Alien vascular plants in the Silesian Upland of Poland: distribution, patterns, impacts and threats: Symptoms of anthropogenic changes in the flora include processes of extinction in some species and spread in others. These tendencies have increased in magnitude in recent centuries, adversely affecting natural biodiversity on a regional, national and continental scale. The main idea behind the project presented here was to investigate the diversity of the alien vascular flora at the regional scale and to update the list of invasive alien species for the Silesian Upland. The aim of this study is also to provide a synthesis of the knowledge accumulated to date on the conditions for their occurrence, their distribution patterns and the possible threat they might pose. The distribution of particular species at the regional scale was investigated by mapping the species on a 2 km x 2 km grid. The study showed that the list of alien plant species for the Silesian Upland encompasses 338 species, including 125 archaeophytes, 195 kenophytes (=neophytes) and 18 species of an uncertain status in the Polish flora. A threat evaluation was performed for particular species on the basis of the number of localities, the diversity of preferred habitats recorded, and their current (over the last decade) tendency to colonise new localities. As a result, a final list of 101 invasive species has been selected. Among the alien plant species considered to be invasive in the area of the Silesian Upland, 20 species are identified as ‘weeds’ (13 archaeophytes and 7 kenophytes), another 25 (exclusively kenophytes), penetrating into natural habitats, are defined as ‘transformers’

Abandoned railway areas are places for the spontaneous spread of plants and the formation of specific plant communities. However, only limited information on this subject is available in the literature. The study aimed to determine the direction and the rate of forest formation, taking into account selected environmental factors. A floristic, phytosociological, and soil survey was carried out on a set of abandoned railway lines in the Silesia Province (southern Poland). For this purpose, 30 plots of vegetation were selected: 15 located in the vicinity of forests (F) and 15 surrounded by ruderal or segetal communities (NF). As a result, a total of 132 species (121 vascular plants and 11 mosses) were recorded, including 83 species at F plots and 78 species at NF plots. During the research, 13 syntaxa were distinguished. It was found that silt content, nitrate nitrogen (N-NO₃), pH, and phosphorous have a significant impact upon which species dominated in the surveyed areas. It was found that the proximity of the forest was a crucial factor in determining the development of forest communities on abandoned railway areas. These results can be helpful for understanding how environmental conditions shape the forest structure on these types of habitats.

The Province of Silesia, in Poland, is an area where many railway connections, of mostly local importance, have been closed recently. In some cities, they have been eliminated altogether and passenger rail transport has been replaced by bus transport. For this research, a sociological study was conducted using the diagnostic survey method and the questionnaire technique. A transversal testing strategy was also used. The aims of the study were to illustrate the function of abandoned railway areas in the landscape and to present possible recommendations for their development from the point of view of the needs of society. The research population included 1,685 people who were students at the University of the Third Age and adult residents. The surveys focused on the possibility of exploiting the natural potential of railway areas. The respondents’ answers provided suggestions for the development of unused railway areas, which included creating bicycle lanes, alleys with a high biodiversity of both flora and fauna, and walking tracks. The analysis of the study’s results can be useful to both local authorities and the Management of the Polish State Railways (PKP S.A.) in their decision-making processes concerning the revitalization of unused railway areas. Similar revitalization efforts have already been undertaken by various cities and communities.

Lathyrus aphaca, which is in Poland considered to be an ephemerophyte recorded mainly in the north-west and the south-west, has lately been observed in arable fields in the south of the country. Recent and historical data on the distribution of the taxon in Poland are presented. Original relevés conducted in arable fields in Poland are analysed and compared to those from the Czech Republic, Germany and Slovenia. The current status of L. aphaca in the Polish flora is discussed.

The study sums up the data gathered to-date on the distribution in Poland of an interesting synanthropic species - Polygonum polystachyum. The distribution of this species in Poland was described and the numbers of existing populations were estimated. The habitats were described in detail and the status of the species in the Polish flora was discussed.

The main goal of this study is to present a diversity of invasive plants occurring in the south-western part of the Silesian Upland and to estimate their impact on transformation of the native plant cover. Among 101 species considered to be invasive, three groups were distinguished: “not harmful” (46 species), “weeds” (32) and “transformers” (23). Subsequently, their characteristics is given (origin, geographical-historical groups, life forms, frequency of occurrence) and they are briefly compared. Special attention is paid to the species included in the “transformers” group which enter natural and semi-natural habitats and transform the native plant cover to the largest extent. It has been determined that these are usually large perennial plants or trees, of predominantly North American origin, with numerous localities in which they often form compact patches occupying large areas.