Investigations were carried out in the regions of the Hornsund Station, Spitsbergen at summer 1979. The aim of the studies was to determine the effect of the Station on the natural environment around the Station. After taking an inventory of the sources of pollution and in result of the determination of the range of the pressure of anthropogenic factors the whole area under degradation was divided into three parts: an area without possibilities of recultivation, a devastated area and an area of normal natural environment. It was found thąt the main source of the contamination of tundra are fuels derived from mineral oil. The distribution of fuel concentrations in the soil corresponds to the direction of the slope of the ground and the flow of the surface waters. Mechanical transformation of the surface of the tundra is also an outcome of the degradation.
We talk to Dr. Katarzyna Błachowiak-Samołyk, professor at the Department of Marine Ecology at the PAS Institute of Oceanology in Sopot, about the impact of human activity on life in the oceans.
Although the Antarctic has avoided the worst effects of alien species, its future seems endangered due to increasing natural and man-made pressures. Rapid changes in three major environmental variables have occurred in the Antarctic region during the last decades. In the short term terrestrial biota are likely to benefit from reduced environmental stresses, but in the long run the colonization of the region by lower latitude species with greater competitive ability will become increasingly important and can lead to large-scale changes in biological composition and trophic complexity in some existing Antarctic terrestrial ecosystems. Moreover, the recent dynamic climate changes combined with human activities in the Antarctic region might modify the status of several alien species which have hitherto been considered transient or persistent and could, therefore, become naturalized and threaten the native communities on a larger scale than today, or influence the status of naturalized species.
The article presents the results of analyses of changes in the number of ponds in the Wys-koć catchment basin carried out in the years 1980–2003 and the characteristics of ponds excavated in that period. Only water reservoirs of an area less than 2 ha were considered. Analyses were based on topographic maps in the scale of 1:10 000 and aerial photographs taken in 1996. The results indicated that the number of filled ponds increased, especially those located in fields and grasslands. However, forest and wetland ponds were the most resistant to the processes of quantitative degradation because not even a single pond was filled during the analysed period. Over 70% newly excavated water bod-ies were made as an effect of exploitation of mineral and peat resources. However, nowadays ponds are more often created as a result of intentional human activities and are used for fish farming, recrea-tion and as water retention reservoirs used in irrigation of small agricultural and gardening areas.
The freshwater dinoflagellate represent microfossils which are very rarely noted in lake deposits. In Late Holocene sediments of the Lake Młynek, the Iława Lakeland, northern Poland, we identified intense blooms of algae of the genus Palatinus. They occurred primarily in the period of strong human impact during expansion of the Monastic State of the Teutonic Order. The most amazing thing is that samples in which conventional palynological maceration has been used dinoflagellate are represented by armored vegetative forms instead of cysts. During this laboratory processes, especially acetolysis, cellulosic thecae of armored forms should be destructed. This is the second known example of acetolysis resistant thecae of modern dinoflagellate, built by substance other than cellulose. Palatinus blooms were associated probably with the hydrotechnical works made by Teutonic Knights in the catchment, which caused supply and discharge of micronutrients e.g. selenium in the basin.
During thirty three expeditions to the Polish Arctowski Antarctic Station signifi− cant influences of human activity upon the environment have been recorded. Introductions of alien species, shifts of bird and seal breeding areas and decreases in both bird and seal populations, are the most obvious effects of human pressure. Though numbers of visits by tourists have increased during this period, impacts from expeditioners appear to be the main cause of changes. In particular, increasing numbers and mobility of summer groups at the station are the likely most influential factors.
Vegetation changes in the Lower San Valley near Jaroslaw are reconstructed from the Younger Dryas to the present time on the basis of palynological analysis of the peat core. The pollen profile came from a an old riverbed and was supplemented by radiocarbon datings. The Younger Dryas and early Preboreal vegetation was characterised by a high proportion of forest communities with pine (Pinus sylvestris and P. cembra) and birch (Betula), while patches of open area were dominated by the steppe with Artemisia. Climatic amelioration during the Preboreal chronozone led to the rapid spread of elm (Ulmus), which was probably a dominant taxon on the lowest terraces of the valley. Terrestrialization of the water body existing in the palaeomeaner and the subsequent beginning of peat accumulation caused a deterioration in pollen preservation. Hence, the interpretation of the profile section spanning the period between the Boreal and Subatlantic chronozones was seriously disturbed due to selective corrosion and the overrepresentation of Pinus sylvestris type and Filicales monolete sporomorphs. Between ca. 336 and 1152 AD fluctuations in woodland cover were recorded. Important components in those forests, despite the domination of Pinus sylvestris, were Quercus, Carpinus betulus, Fagus sylvatica and Abies alba. The first pollen grains of cereals (Cerealia type) were found before ca. 1605-1414 BC and may be attributed to the agricultural activity of the Neolithic and/or early Bronze tribes. Periods of strong deforestation caused by humans were probably related to the time when the Tarnobrzeska Group of the Lusatian Culture and the Przeworska Culture were active. The first groups of Slavs did not significantly influence the environment, but the subsequent development of those groups led to more visible deforestation, which was triggered after the establishment of Jaroslaw in the 11 th century AD.