No abstract

Snow cover is one of the crucial factors influencing the plant distribution in harsh Arctic regions. In tundra environments, wind redistribution of snow leads to a very heterogeneous spatial distribution which influences growth conditions for plants. Therefore, relationships between snow cover and vegetation should be analyzed spatially. In this study, we correlate spatial data sets on tundra vegetation types with snow cover information obtained from orthorectification and classification of images collected from a time-lapse camera installed on a mountain summit. The spatial analysis was performed over an area of 0.72 km 2 , representing a coastal tundra environment in southern Svalbard. The three-year monitoring is supplemented by manual measurements of snow depth, which show a statistically significant relationship between snow abundance and the occurrence of some of the analyzed land cover types. The longest snow cover duration was found on "rock debris" type and the shortest on "lichen-herb-heath tundra", resulting in melt-out time-lag of almost two weeks between this two land cover types. The snow distribution proved to be consistent over the different years with a similar melt-out pattern occurring in every analyzed season, despite changing melt-out dates related to different weather conditions. The data set of 203 high resolution processed images used in this work is available for download in the supplementary materials.

Main aim of the work assumed recognition of physicochemical changes in snowpack occurring during the melting period. Properties of snow cover had been identified at two sites in Western Sudetes mountains (860 and 1228 m asl) in SW Poland since the end of January, and monitored until the disappearance of snow in late Spring. Snow pit measurements and sample collection at both sites were made followed by chemical analyses with the use of ionic chromatography. The results were compared for subsequent stages of snowpack evolution. Thermometers installed above the ground during summer in one site (860 m asl) helped to identify the thermal gradient existing inside snow during winter. During studies, special attention was paid to the pollutant elution with determination the different release rates of individual ions from the snow cover. Results of chemical analysis showed that during the thaw, the first portions of meltwater were responsible for drainage into the ground a substantial part of the impurities. During the first two weeks of thaw at higher elevated site, pollutants released from the snow cover load amounted to 123.5 mMol·m−2. In those days, there was a release to the ground of approximately 74, 74, and 57 %, respectively of H+, NO3−, and SO42− ions contained in the snow cover, while only 14 % of snow mass in the form of meltwater was released.