Volumen 40 (2015): Heft 1 (December 2015)

The aim of the study was to describe pollen morphology and its variability of four Linum species: L. perenne subsp. extraaxillare, L. hirsutum, L. flavum and L. austriacum, all derived from Poland, but occurring in few natural sites within the country. Light and scanning electron microscopy was used and statistical analyses of quantitative pollen traits were performed. All taxa shared pollen grains which were 3-zonocolpate, isopolar, radiosymmetric, spheroidal and medium to large in size. Grains were semitectate, with the sculptural elements of the exine as gemmae or clavae. Additionally, upper parts of gemmae and clavae had a microstriate pattern. Despite great similarity among the investigated Linum species in pollen morphology, distinguishing features were determined.

The paper presents results of the inventory of localities of Scandix pecten-veneris L. in the Małopolska Upland conducted after 2000. The existing population resources were estimated and current distribution of the species in the Małopolska Upland and Poland was showed. Some threats to this species as well as conservation prospects were discussed.

Algological investigations were focused on taxonomy, chorology and ecology of threatened filamentous green alga species in Poland. Studies on Oedogonium capillare Kützing ex Hirn growing in large quantities in association with Cladophora rivularis (Linnaeus) Hoek in pond were conducted. The aim of these studies was to describe the distribution, ecology and morphology of O. capillare as part of a more comprehensive study of this filamentous green alga. It is the eighth record in Poland for O. capillare. Filaments of O. capillare were grown over a wide pH range (7.3-9.6) and in high variability of nutrients. Vegetative cells, oogonia and antheridia were observed, which allowed taxonomic identification. O. capillare occurs in eutrophic waters which requires protection of its habitat.

The present paper discusses the wild roses of the National Nature Park ‘Podilskyi Tovtry’. The purpose of the work was to compile a full list of the wild Rosa taxa growing in the study area and present their distribution. Based on the field studies during the years 2009-2013 and published data, 20 taxa have been recorded, among them: 16 native species (including three hybrids with the rank of species), 2 anthropophytes and 2 hybrids. However, the taxonomical status of Rosa caryophyllacea Besser is not clear and species requires taxonomical revision. Three new rosa species for the Park were found during the studies. These are: Rosa micrantha, R. ×subcanina and R. ×subcollina. The list of the roses occurring in this area is still far away from being completed, therefore, further research is needed.

The paper presents the distribution of 10 selected invasive plant species in Ukraine. The studied taxa comprised 8 invasive and 2 potentially invasive species. All species were characterized in phytogeographical, biological and ecological terms. Their distribution was shown on grid maps.

The results of an investigation of alien species that change the character, condition, form or nature of ecosystems over large areas (transformer species) in the flora of the Starobilsk grass-meadow steppe are presented. The check-list of alien plants includes over 386 species of vascular plants, of which 28 are invasive and 6 are transformer species. In this study, the data on the first records of alien species, their distribution history, ecology, occurrence in different plant communities and degree of naturalization were compiled. The distribution maps of transformer species are provided.

The object of the study is the distribution and spatial pattern of black cherry Padus serotina Ehrh. population and the impact of landscape structure on the expansion of this alien species in the suburban zone of the city, where the land-use has rapidly been transforming recently. The population of black cherry expands centrifugally, spreading from fringes of the city to outer zones of the agglomeration with more agricultural character. Individuals of P. serotina are distributed in clusters in this area. The maximum observed population density reaches 371/ha (mean 11.3/ha for colonized plots). The main factor influencing the landscape invasibility is cessation of agriculture. Although the first sources of spread of P. serotina are localities in forests, where 46% of the total number of individuals are concentrated, nevertheless, the largest group of juveniles (48%) was found on abandoned farmlands. Over 90% of all youngest individuals were recorded at a distance of up to 100 m from older ones. Chances of isolated occurrence are small and the probability of the colonization is strongly dependent on the occupation of adjacent areas by the species. Black cherry disperses, primarily, according to a spatial pattern of phalanxes, by occupying areas immediately adjacent to places previously colonized and then filling the available habitats. Long-distance dispersal seems to play a minor role for its expansion. Autocorrelation and diffusion models of spread should be taken into account in preventing further expansion of black cherry and planning conservation measures in natural protected areas.

Asclepias syriaca L. is on the invasive species list in Poland. Its sites are scattered, with the exception of cultivation sites; they are also not well identified in the country and that is why they have not been presented in the ATPOL (Distribution Atlas of Vascular Plants in Poland) yet. In this study, spatial structure of A. syriaca population against phytocenotic and soil conditions in Widuchowa (West Pomerania)were examined. Number of specimens, their density per 1 m², and mean crowding were determined. In addition, the population spatial structure type was identified through observations and by calculation of the dispersion coefficient. On the basis of the conducted research, it was found that the investigated population comprised 1 500 specimens and occupied the area of 38 m². It exhibited regular spatial distribution type (dispersion coefficient<1) and was characterized by high value of mean shoot density, which amounted to 29 spec./1 m² (max. 35 spec./1 m²). On the basis of the conducted chemical analysis of the soil from the A. syriaca habitat, the substrate was classified as alkaline soil (pH=7.3-7.6), of low total nitrogen (0.07-0.15%), as well as low total carbon content (0.8-1.45%).

In this paper, changes of the non-forest xerothermic vegetation of the “Murawy Dobromierskie” steppe reserve which occurred in the period 1993-2012 are examined. The material comprises 50 relevés, of which 43 date from 2012 and the other 7 - from 1993. Reléves were arranged in 5 analytic tables. A synoptic table was also compiled, and for each syntaxonomical species group distinguished, values of the cover coefficient (C), the collective group share index (G), and the systematic group value (D) were estimated and compared. On the basis of the obtained results, a significant decline in abundancy and/or constancy was observed within the following groups: Ch. Artemisietea vulgaris, Ch. Cirsio-Brachypodion pinnati, Ch. Festuco-Brometea, Ch. Geranion sanguinei, Ch. Koelerio-Corynephoretea, and Ch. Origanetalia and Trifolio-Geranietea sanguinei, whereas for the taxa of the Rhamno-Prunetea, a notable increase in the share of the reserve vegetation was recorded. A sizeable expansion of the moss layer was also observed in this period. The results are discussed with special regard to differences in the methodical background of both field studies.