Maria Zając

Extinct and endangered archaeophytes and the dynamics of their diversity in Poland

Extinct and endangered archaeophytes and the dynamics of their diversity in Poland

Survival problems of archaeophytes in the Polish flora

Abstract These considerations have been based on the updated list of archaeophytes appearing in Poland. The extent of endangerment has been assessed for particular species according to the updated IUCN classification. Non-threatened and invasive species have also been taken into consideration. A number of quite fundamental changes have been made to the classification, as compared to the publication of Zając et al. of 2009.

Directional northern element in the flora of vascular plants of Poland

Directional northern element in the flora of vascular plants of Poland The directional element is a local determinant of spatial diversity of flora of a given country, within widely understood geographical elements. In Poland, a country situated in the middle of Europe, most species belong to the transitional element (with no range limit in our country). Besides the transitional element, the directional northern element (with its southern limit in Poland) is present. It can be divided into two distinct groups: species that have their absolute southern range limit in Poland and those that have both southern and northern limits with a significant disjunction in Central Poland. Although they are two different groups, they will be discussed within the combined study. The first one constitutes 1.9% of the directional element, the second one 1.3%. As far as general ranges are concerned, Circumboreal and Eurosiberian species prevail in the first group, with a significant share of the taxa of geographical connective element. European-temperate taxa are the most numerous in the second group. The two above-mentioned groups will also be distinguished by their species belonging to the higher syntaxonomical units. Such a small share of the northern element in the flora of Poland confirms that our country belongs to the Central European Province, where the North-European element is, to a large extent, a relict of the earlier periods of the Holocene.

Biodiversity of Poland: An Exemplary New Series@@@Flowering Plants and Pteridophytes of Poland: A Checklist = Krytyczna lista roślin naczyniowych Polski@@@Census Catalogue of Polish Mosses@@@Ecological Indicator Values of Vascular Plants of Poland = Ekologiczne liczby wskaźnikowe roślin naczyniowych Polski@@@Flowering Plants and Pteridophytes of Poland: A Checklist = Krytyczna lista roslin naczyniowych Polski@@@Ecological Indicator Values of Vascular Plants of Poland = Ekologiczne liczby wskaznikowe roslin naczyniowych Polski

Polyploidy is frequent among the grasses. This study indicates that it has a high frequency in the subfamily Chloridoideae, where more than 90% of the studied specimens are polyploids. These levels range from diploid (2n = 20 for x = 10 and 2n = 18 for x = 9) to 16-ploid (2n = 160) for x = 10 in Ctenium concinnum Nees and 20-ploid (2n = 180) for x = 9 in Hilaria mutica Benth. This polyploid trend is seen in southern Africa, as well as worldwide. Analysis indicates that many polyploids are alloploids, suggesting extensive hybridization within this group. This is supported by the presence of apomixis in many members of the subfamily. Both polyploidy and apomixis are thought to be important evolutionary mechanisms in Chloridoideae as well as closely related Panicoideae, and have a high frequency in southern Africa. Due to the stable ecological, geographical and climatological history of Africa, the continent is ideally suited for the stabilization of hybrid complexes by means of apomixis and polyploidization.

Effect of anthropogenic factors, landscape structure, land relief, soil and climate on risk of alien plant invasion at regional scale

We compared the effectiveness of explanatory variables representing different environmental spheres on the risk of alien plant invasion. Using boosted regression trees (BRT), we assessed the effect of anthropogenic factors, soil variables, land relief, climate and landscape structure on neophyte richness (NR) (alien plant species introduced after the 15th century). Data on NR were derived from a 2 × 2 km grid covering a total area of 31,200 km2 of the Carpathian massif and its foreground, Central Europe. Each of the examined environmental spheres explained NR, but their explanatory ability varied more than two-folds. Climatic variables explained the highest fraction of deviation, followed by anthropogenic factors, soil type, land relief and landscape structure. The global model, which incorporated crucial variables from all studied environmental spheres, had the best explanatory ability. However, the explained deviation was far smaller than the sum of the deviations explained by the single-sphere models. The global model showed that the deviation that could be explained by variables representing particular spheres, overlapped. The variables representing landscape structure were not included in the global model as they were found to be redundant. Finally, the climatic variables explained a smaller fraction of the deviation than the anthropogenic factors. The partial dependency plots allowed the assessment of the course of dependencies between NR and particular explanatory variables after eliminating the average effect of all other variables. The relationships were usually curvilinear and revealed some values of environmental variables beyond which NR changed considerably.

Some regularities in the distribution of kenophytes in the Polish Carpathians and their foreland.

Abstract The Polish Carpathians and their northern foreland are a rewarding object for the kenophyte distribution research. The study, using the cartogram method, showed that the number of kenophyte species decreases with increasing altitude. Only few kenophytes were found in the lower forest zone. This regularity concerns also the species that reach higher altitudes in the mountains of their native lands. A number of species migrated into the Carpathians through rivers and streams. River valleys generate many open habitats, which are easily colonized by kenophytes due to the lack of competition. In the Carpathians, towns used to be founded in the mountain valleys and this was also a favouring factor of kenophyte propagation. The arrangement of mountain ranges in the Polish Carpathians, including their foreland, hindered the migration of some species and allowed to discover the possible migration routes into the area covered by research. Tracing these migration routes was possible only for those species that have not occupied the whole available area yet. Additionally, the study indicated the most dangerous invasive species in the Polish Carpathians and their foreland.