Seabird colony effects on soil properties and vegetation zonation patterns on King George Island, Maritime Antarctic

Seabirds are among the most important vectors transferring biogenic compounds from the sea onto land in the polar regions and, consequently, influencing the properties of soil and vegetation. We studied the influence of bird colonies (Adélie penguin Pygoscelis adeliae, gentoo penguin P. papua and giant petrels Macronectes giganteus) on soil properties and plant communities on King George Island, Maritime Antarctic. We designated seven transects, each starting from the colony edge and running to a natural boundary feature, which were divided into contiguous sample plots where we identified specific plant taxa (Prasiola crispa, Deschampsia antarctica, Colobanthus quitensis, Usnea sp.), as well as hydrophilous and xerophilous ecological groups of mosses. Based on percentage contributions of each of these taxa, we distinguished six distinct vegetation zones along the transects, in which we measured physical (moisture, conductivity and pH) and chemical (NO3 −, NO2 −, NH4 +, K+ and PO4 3− content) soil parameters. Our study confirmed that, with increasing distance from bird colonies, the concentration of nutrients and soil conductivity decreased, while pH increased. The vegetation zones were clearly related to this gradient of seabird colony influence and occurred in the same sequence for all three bird species examined, although the largest colony of Adélie penguins had the strongest effect on vegetation. Similarly, the physical and chemical soil properties did not differ significantly between the colonie

Changes in floristic richness and diversity of phytocoenoses on riparian habitats affected by diverse land-use forms

In many ecological studies the theory prevails that the increased human economic activity can lead to simplification of species composition of phytocoenoses and a decline of their species diversity. However, there are also other views on this issue. Therefore, an attempt was undertaken to verify these contradictory opinions. The research was conducted at three sites characterised by a diversified and intensified land use form (the nature reserve, 50 year-old poplar plantation and a grassland). The results from the nature reserve were compared with the data for 1963-1965 when other plant communities dominated in the reserve. The results of field observations collected in the form of relevés were used to assess the number of species, α-species diversity of phytocoenoses and ß-diversity.The largest number of species was found in the meadow, a fewer species were recorded in the reserve and the fewest in the poplar plantation; whereas the average number of species per relevé and the differences between the sites were minor. The species heterogeneity index varied within the range of 3.11–3.36, whereas the extreme differences were recorded in the reserve between the current results and the results from the 1960s. The studied phytocoenoses differed mostly in ß-diversity. The average index for the poplar plantation was lower than mean values of indices recorded in communities of the riparian forest and meadows. The obtained results support the opinion about non linear correlation between the increased disturbances and the decline of species richness and species diversity in phytocoenoses

Property taxes as proposed tool to stabilize economy

W artykule autor przedstawia propozycję zastosowania podatków majątkowych jako narzędzia stabilizacji wymiany gospodarczej poprzez wpływ na rynek finansowy. Po omówieniu podstawowych instrumentów podatkowych wykorzystywanych do opodatkowania rynku finansowego autor opisuje kryteria, które powinny być wzięte pod uwagę przy konstruowaniu instrumentu podatkowego oddziałującego korzystnie na stabilność gospodarczą. Następnie autor wskazuje, z jakich powodów kryteria te mogą być spełnione w pełniejszej formie dzięki zastosowaniu instytucji podatków majątkowych.The paper discusses a proposition of using property taxes as a tool for stabilizing the economy, through influencing financial market. After discussing basic tax instruments used to tax financial markets, the author draws criteria that should be taken into account when constructing a tax instrument that may have a positive influence on economic stability. Next, the author presents reasons for which property taxes would be better suitable for meeting this criteria