We used RAPDs (Random Amplified Polymorphic DNAs) to investigate genetic diversity and its partition within and between three populations of Iris aphylla in Poland. Analysis of Molecular Variance (AMOVA) of 84 distinct RAPD multiband genotypes revealed higher variation within populations (77.2%) than genetic differentiation between them (22.8%, P < 0.002). Values of genetic diversity indices (H) were similar in all three sites (0.21–0.24). The differentiation of the populations corresponded to low average gene flow (Nm = 0.81). Our results indicated that genetic diversity was independent of population size. We concluded that although sexual reproduction and gene flow between populations of I. aphylla were very limited, they preserved high levels of genetic diversity. Relatively large number of seeds, which migrated in the past to populations, as well as patterns of reproduction and life history of I. aphylla may explain this situation. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142, 65–72.

The study aimed to determine the long-term changes of the Senecio macrophyllus M.BIEB. population traits: the abundance, reproduction mode, individual fecundity, seed rain and recruitment of new genets in the course of xerothermic grassland overgrowing. The study had also the applied goal: to estimate the chances of special care species to survive in the changing environment without management regime for the maintenance of grassland. The model object was the island population of large-leaved ragwort on Bia³a Góra (the White Mountain) near Tomaszów Lubelski, South-East Poland. To achieve these aims I used the following sets of data: phytosociological relevés made in plant communities in an interval of 16-18 years; repeated elaboration of the numbers and life-stage structure of the population, both by non-surface and surface method; observation of plants life cycle in 50 labelled genets; population reproduction and seed rain amounts. The area of an open xerothermic grassland decreased due to the process of overgrowing by bushes which was accompanied by the increasing coverage of forest and meadow herbs as well as monocotyledons, mainly Brachypodium pinnatum and Calamagrostis epigejos. The abundance of the S. macrophyllus population noticable diminished. The flowering mode has been changing during years from an oscillation to a chaotic type which caused the significant decreasing of the individual fecundity, population reproduction and seed rain. In last years it was reflected in the interruption of juveniles recruitment.

Knowledge of the flowering phase and plant pollination ecology is very important for understanding the life history of long-lived perennials. In the case of rare species, the information may have implications for conservation practices. Our studies on flower morphology and blooming biology of the vulnerable plant Senecio macrophyllus M. BIEB. were conducted in situ (flowering, activity of insect visitors) in the largest population in SE Poland and in laboratory (light and scanning electron microscopy). The disc florets open diurnally with most intensive anthesis in the early afternoon and attract insect visitors with nectar and pollen. In highly protandrous disc florets, pollen viability decreases in time, whereas stigma receptivity increases. The upper part of the pistil forms a brush-like pollen presenter, covered with unicellular trichomes with chromoplasts. Pollen presentation lasts 4-11 hours per floret, and 8 days in a single head, the main function of which is to extend the availability of male gamets for reproduction. The number of florets per head, the head size, and the number of pollen grains produced per anther, and the pollen grain viability differed significantly between microsites. The finding indicates that, apart from the biotic factors, abiotic conditions may considerably influence generative reproduction of the species. In the study area, the principal visitors of S. macrophyllus flowers were Hymenoptera, with predominance of Apis mellifera (53.4% of visits). The remarkable share of butterflies (13.9%) recognized as the long-distance moving insects may improve the genetic variability of individuals within a fragmented population. A more detailed study is necessary to explain the role of insect visitors in effective pollination and in gene transfer between patches. The assessment of optimal conditions for the generative reproduction is fundamental for the in situ conservation of this rare species.

The goal of the present research was to find correlations between the topographic attributes of a river valley and local ground-floor vegetation and its habitat requirements expressed by ecological indicator values (EIV), using the geographical information systems (GIS), digital elevation model (DEM), and multivariate statistical analysis. We paid special attention to the river course, which determines the differentiation in slope aspects and the amount of solar radiation reaching the ground surface. The model object was an almost latitudinal, ca. 4-km-long break section of the Sopot river, crossing the escarpment zone of the Central Roztocze Highlands, southeastern Poland. The main material comprised species lists (with estimated abundance) for each ca. 200-m-long section, according to the river valley course, separately for the left and right riverbanks, 40 sections altogether, ca. 15 000 vegetation records, and physical and chemical soil measurements. A 3-meter resolution DEM was derived from a 1:10 000 topographic map. We calculated the correlations between the topographic attributes of the valley, species richness, and the EIVs for all the species recognized in each section of the valley. We found 241 herb plant species in the ground-floor vegetation of the study area. We did not find significant differences between the two riversides (61 ±13 species per one section for the left and 63 ±17 for the right side). Thus, the parallel course of the river valley does not change the species richness on a more "sunny" and more "shiny" riverbank. However, this factor "cooperating" with other topographic attributes of the valley significantly differentiates the shape of species showing various requirements for basic habitat resources: light, moisture, soil trophy, reaction, dispersion, and organic-matter content.

Abstract:Ellenberg indicator values (EIV) have been widely used to estimate habitat variables from floristic data and to predict vegetation compositionbasedonhabitatproperties.GeographicalInformationSystems(GIS)andDigitalElevationModels(DEM)arevaluable toolsforstudyingtherelationshipsbetweentopographicandecologicalcharactersofriversystems.A3-meterresolutionDEMwas derived for a.3-km-longbreaksectionoftheSzumRiver(SEPoland)froma1:10,000topographicmap.Dataonthediversityand ecological requirements of the local vascular flora were obtained while making floristic charts for 32 sections of the river valley (each200 mlong)andphysicalandchemicalsoilmeasurements;next,thedataweretranslatedintoEIV.Thecorrelationsofthe primaryandsecondarytopographicattributesofthevalley,speciesrichness,andEIV(adaptedforthePolishvascularflora)were assessedforallspeciesrecognizedineachvalleysection.Thetotalareaandproportionofaflatarea,meanslope,slopecurvature, solar radiation (SRAD), and topographic wetness index (TWI) are the most important factors influencing local flora richness and diversity.Thehighestcorrelationswerefoundforthreeecologicalindicators,namelylight,soilmoisture,andsoilorganiccontent. TheDEMseemstobeusefulindeterminationofcorrelationsbetweentopographicandecologicalattributesalongaminorrivervalley.©VersitaSp.zo.o.

The break section of the Szum river and the mouth part of its left tributary, Miedzianka (Roztocze, SE Poland) were the object of the research conducted in the years [1999][2000][2001]. The aim of the study was to establish the abiotic conditions of the diversity of vegetation and the richness of vascular flora in a small lowland river valley. A real vegetation map was drawn in the scale 1:5000. The syntaxonomic classification of plant communities and habitat trophism were established on the basis of 120 phytosociological relevés and 160 soil samples, respectively. On the area of barely 35.4 ha identified were 48 plant associations and communities representing 11 phytosociological classes, among them habitats protected in Poland (16 types) and important at the EU scale (3). There were found 378 species of 72 families, including: 21 species under strict protection, 9 under partial protection, 25 plants threatened on the regional scale, and 2 included into the Polish Red Data Book. Most of interesting species and non-forest communities occur in the parts of the valley above and below a landscape reserve Szum, established in 1958, covering presently 18.17 ha. The greatest floral richness was found in the peatbog-meadow complexes (Phragmitetea, Molinio-Arrhenatheretea, Scheuchzerio-Caricetea), in bog-alder forests and willow bushes (Alnetea glutinosae), and streamline ash-alder carrs (Querco-Fagetea, Alno-Ulmion), while the smallest in the pine and poorer upland mixed fir forests (Vaccinio-Piceetea). Vascular flora appears to be the richest in the sections of the valley where the bottom is overgrown by non-forest communities. The results of the study indicate that it is necessary to enlarge the area of the existing nature reserve.KEY WORDS: small lowland river valley, plant communities, ecological conditions, vascular flora, protected and threatened species, nature conservation, geobotanical cartography.NE sites or biotopes of Europaen importance, and then recognized as potential elements of NATURA 2000 network (Dyduch-Falniowska, Zaj¹c 1996;Dyduch-Falniowska et al. 1999;Zaj¹c 2003). MATERIAL AND METHODS Study areaThe Szum river valley, together with the mouth section of its left tributary, Miedzianka (Fig. 1A), both crossing the escarpment zone of Roztocze, were chosen as a model object of the study on plant cover diversity in a valley of a small, lowland river. The examined area lies in the mesoregion of Central Roztocze belonging to the Roztocze macroregion (Kondracki 2000). A characteristic climatic feature of the region is a considerable termic diversity visible in the monthly, seasonal and annual average air temperatures. The value of the mean annual temperature in the years 1951-1990 was 6.7-6.9°C, i.e. 0.3-0.8°C less than in the neighbouring areas, and this difference can be attributed to the influence of hypsometry (Kaszewski et al. 1995). On the other hand, the average precipitation is ca. 100 mm higher than the Polish mean, exceeding 700 mm, out of which 400-450 mm falls on the summer season (the ...

A b s t r a c tPopulations of two rhizomatous species, Asarum europaeum (asarabacca) and Maianthemum bifolium (May lily), were examined in two, and four forest habitats respectively, in the Roztocze National Park (south-eastern Poland). May lily populations were studied in habitats: the Carpathian beechwood, upland mixed fir forest, subboreal moist mixed coniferous forest and bog-alder forest. Asarabacca was studied in two habitats: beechwood and Scots pine community (an 80-year-old plantation). In both the species studied intra-and inter-populational differences of the size of genets in terms of above-and below-ground parts of individuals as well as the biomass and area occupied were observed. In May lily populations the greatest mean number of shoots per genet was found in the fir forest (11.62 + 3.29), a value almost twice as great as that in the moist coniferous forest and nearly three times greater than in the bog-alder forest. Total rhizome length was also the greatest in the fir forest (351.9 + 98.7 cm) followed by moist coniferous forest, beechwood and alder forest habitats. In all populations of May lily a greater part of total dry weight biomass is in below-ground organs. The greatest biomass value of a genet was found in the fir forest (4.275 g), the smallest in the bog-alder forest (0.1 t0 g). All populations differed significantly in terms of leaf area, leaf length (with the exception of fir forest and beechwood habitats where the values were the greatest), and leaf width (excluding moist coniferous and bog-alder forests which had the smallest values). In the case of asarabacca, both the mean number of ramets per genet (3.36 ± 0.45 vs. 2.49 ± 0.20) and total rhizome length (40.3 + 6.4 cm vs. 21.1 ± 1.8 cm) were greater in the beechwood habitat than in the pine community. In the first population genets had 3-5 times greater the total biomass of those from the pine community. Only genets of the latter had proportionately more dry weight biomass in above-ground parts. It seems to be correlated with greater rhizome dieback and disintegration of genets into smaller units. Both populations were significantly different in terms of all examined parameters of leaves. Genets of both the species studied were found to have their own structure of developmental phases that often differed for shoots and rhizomes.

Various forms of human activity in large cities contribute to the creation of a specific climate and new environmental conditions for plants. One of the most important results is the so-called atmospheric urban heat island (UHI). The aim of this study was to compare the thermal conditions in the Lublin City center with those of suburban areas, and so confirm the existence of the UHI and then analyze the influence of thermal conditions on features of the flora. The analysis of the air temperatures was based on data from 2000 to 2014 provided by meteorological stations in the Lublin City center and its nearest surroundings. Floristic data were collected during field studies between 2012–2014 and included species richness and frequency, life forms, and synecological groups of the flora and its elements. The thermal requirements of species were defined on the basis of ecological indicator values (EIVs). Our research confirmed the presence of the UHI in the Lublin City center. Over the study period, the mean temperature in the city center was by 0.87°C higher than that in the suburban areas. The largest differences in mean annual air temperature between the city center and the suburbs were recorded in 2007 and 2011–2013. In total, 552 species were recorded, including six life-form and synecological groups, 246 thermophilous and 436 heliophilous species. The species richness, proportion of therophytes, alien, thermo- and heliophilous species decreased with distance from the city center. The thermal conditions expressed by the EIV L and T ranged from L = 4.5, T = 3.8 in the city center, to L = 3.1, T = 3.4 in the suburbs. An ordination analysis facilitated determination of the relationships between characteristics of the flora, the EIV values, and land use classes. An increasing level of anthropopressure was found to be positively correlated with thermal conditions and the flora traits.