Isoenzyme analysis of mouse-like rodents (Rodentia, Cricetidae)

Vytauto Didžiojo universiteta

Trend in Ambient Ozone and an Attempt to Detect Its Effect on Biota in Forest Ecosystem. Step I of Lithuanian Studies

The presented study aimed to explore the relationships between ambient ozone (O3) and tree defoliation, specific diversity, and abundance of soil microarthropods, stream macroinvertebrates, and small mammals (mainly rodents) in order to test the hypothesis that changes in the considered objects of the forest ecosystem could be related to changes in ambient O3, concentration of which is below critical level. The observations were carried out from 1994 at three integrated monitoring stations. The obtained data revealed that only peak O3 concentrations (from 125-215 ig.m-3) had significant effect on changes in the considered components of forest biotaVytauto Didžiojo universitetasŽemės ūkio akademij

N deposition, balance and benefit in the forest ecosystem of main landscape types of Lithuania

Sulphur emissions have declined in Europe by 67% since the early 1980s due to enactment of strict pollution control strategies, whereas nitrogen emissions have remained fairly constant. Consequently, the effect and benefits of nitrogen deposition remain among the most relevant ecological issues. The presented data reveal the trends of nitrate and ammonium concentrations in the air, their wet deposition and concentrations in soil water, ground and runoff water as well as the trends of different components of forest biota in areas where integrated monitoring stations have been operating since 1994. Data on nitrogen concentrations in the soil, ground and surface waters were analysed in relation to air nitrogen concentrations and their deposition. Changes in tree crown defoliation, and abundance, and diversity of the soil micro-arthropods, stream macro-invertebrates and small mammals were analysed in relation to concentrations of N compounds in studied substances in an effort to estimate N deposition benefits in forest ecosystems. N balance in areas studied revealed that the amount of nitrogen inflow into the system was very high in comparison with its elimination from the catchments. Approximately 1000 N kg/km(2) in LT01 and 600 N kg/km(2) in LT03 are accumulated in the investigated ecosystems per year. But, the relationship between condition of the conifers and air N compounds and their deposition was more significant than between N concentrations in soil and groundwater. N concentration in the studied substances resulted in more significant changes in abundance of soil micro-arthropods, stream macro-invertebrates and small mammals than in their diversityVytauto Didžiojo universitetasŽemės ūkio akademij