No abstract

15Seabirds are amongst the most important vectors transferring biogenic compounds from the 16 sea onto land in the polar regions and, consequently, influencing the properties of soil and 17 vegetation. We studied the influence of bird colonies (Adélie and gentoo penguins, giant 18 petrels), on soil properties and plant communities on King George Island, Maritime Antarctic. 19We designated seven transects, each starting from the colony edge and running to a natural 20 boundary feature, which were divided into contiguous sample plots where we identified

Solar radiation reflectance was analysed to characterize Arctic ornithogenic tun− dra developing in the vicinity of large breeding colony of Brunnich's guillemots Uria lomvia and kittiwakes Rissa tridactyla at the foot of Gnålberget cliff (Hornsund, SW Spitsbergen). Radiometric method was found to be a useful tool for studying structure and functioning of plant formations. We measured reflectance of four wavelengths: 554 nm (YG), 655 nm (RED), 870 nm (NIR) and 1650 nm (SWIR) at 10 plots situated along the transect running from the colony to the sea. Moreover, data of plant community character, species quantitative composition as well as total biomass were collected to relate these pa− rameters with the spectral values. The results showed that radiometric data characterized vegetation well enough to recognize the same plant communities on the basis of spectral reflectance as distinguished with traditional phytosociological methods.

In spite of general knowledge that guano deposited near seabird colonies enhances fertility of poor polar soils, improves primary production and influences the tundra plant community, there are very few quantitative studies concerning plant responses to ornithogenic fertilization on the population level. We studied density, size variability and proportions of generative to vegetative individuals of polar scurvygrass Cochlearia groenlandica along a seabird influence gradient in south-west Spitsbergen. We found the seabird colony effect to being a predominant factor determining local ascurvygrass population structure. Plant density was increasing starting from the foot of the cliff (820 ind/m 2 ) and reaching the highest value (7500 ind/m 2 ) about 30 m from the colony. This density peak was a result of the flowering plants occurring in the area above in the highest number which produced plenty of seeds germinating several metres below. The density of flowering plants was significantly correlated with the physical and chemical features of the soil but concerned only small individuals (1-4 cm), whose numbers were negatively correlated with the level of available nutrients, and large-sized (13-20 cm) plants, which were correlated positively. The only significant factor influencing flowering plant density along the bird colony gradient was the content of organic matter in the soil. In the control transect, total plant density was three orders of magnitude lower. No or weak correlations were found between plant density and soil characteristics along that transect. Our study supports the hypothesis that seabirds have fundamental importance not only for vegetation abundance in the nutrient-poor Arctic environment but also to determine plant population structure in the vicinity of large breeding colonies.

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.