There are several stages in litter decomposition, its rate being the highest in the initial stage. Early in the decomposition process, readily extractable compounds are primarily released, contributing to the annual nutrient cycle. The aim of this study was to determine the characteristics of early-stage needle litter decomposition depending on hydrothermal, phytocoenotic, and soil conditions. The study showed that the greatest effect on the rate of needle decomposition was produced by the hydrothermal parameters closely associated with forest floor temperature and moisture. Needle litter degradation in a middle-taiga cowberry-type pine stand amounted to 31.5 ± 3.5% over a growing season (110 days), 44.0 ± 1.4% over an annual cycle, and 55.8 ± 5.1% over a period of two years. The effect of the ground vegetation structure on needle litter decomposition was minor in the first year, but after two years of the experiment the greatest needle mass loss was found in the cowberry-dominated microgroup. The rate of needle litter decomposition in the bilberry-dominated microgroup was lower on coarse-sandy soil (32%) than on fine-sandy soil (38%), but only in one, warmer year, with no such differences observed in the cowberry-dominated microgroup.

A multidisciplinary survey of three small rivers emptying to Lake Onego was carried out; information was collected regarding the aquatic biota, the species and age structure of riparian forests, their floristic diversity, and soils. The integral indicator chosen to assess the ecological condition of the watercourses was the characteristics of the rivers’ fish fauna, in particular fish of the Salmonidae family. Surveys of the rivers and riparian forest communities yielded records of 181 vascular plant species (11 of them macrophytes), 11 moss species, 2 lichen species; the fish fauna was made up of 9 species. Overall, the riparian forests featured a relatively wide range of typological diversity. The tree stands varied from the poor Ledum types (site class V) to the most productive Oxalis types (site classes III–I). Analysis of the tree species and age structure of forests in the riparian buffers revealed a prevalence of stable coniferous tree stands in good condition. Statistically reliable correlations were detected between the fish fauna and the tree species composition and inventory characteristics of the riparian forest stands, soil morphological characteristics, and the species diversity of the living ground cover and macrophytes. The species diversity of the riparian and the aquatic biotas were found to correlate positively with each other. Fish numbers were seen to negatively correlate with some characteristics of riparian forest soils (forest floor thickness, podzolic horizon), while the correlation with the humus horizon thickness was positive. Significant positive correlations were identified between aquatic organisms (fish, zoobenthos) and a majority of the stream’s hydrological parameters. The resultant up-to-date information about water-forest system components is important for understanding the role of small streams, which, alongside the scant officially recognized “spawning” rivers, are an ecological niche in the life cycle of salmonid fishes in Northwest Russia.

Plant litter decomposes via several stages, the most intensive one being the early stage, when it is mostly readily extractable compounds that are released, contributing to annualnutrient cycling. The aim of this study was to find patterns in the rate of initial decomposition of needle litter depending on the ambient hydrothermal conditions in a cowberry pine stand both in general and in different ground vegetation microgroups. The measured parameters were air temperature and relative humidity, temperature of the forest floor and underlying soil horizons, amount and pH of precipitation and percolating water.The effect of mean monthly values of these parameters on the rate of needle litter decomposition in specific months during the first growing season was estimated both for the entire stand and under different ground vegetation microgroups. Studies have shown that the rate of needle decay is influenced the most significantly by hydrothermal parameters associated with forest floor temperature and moisture. The effect of the communitymicrogroup structure becomes visible only late in the growing season in the lichen-dominated ground vegetation microgroup, probably owing to the seasonal excess of moisturein its forest floor. Differences in needle decomposition rates between ground vegetation microgroups vanish during the winter season under the effect of abiotic factors. The degreeof needle fall decay in the cowberry pine stand in the middle taiga subzone was 31.36 ± 3.32 % after the first growing season (110 days), and 42.16 ± 0.02 % over most of the annual cycle (335 days).

A multi-sided study of the interactions between forest and soil requires choosing sample plots in such a way when their soil characteristics are as similar as possible but the types of biocoenoses are different. This study employed materials from the database “Soils of Karelia”, which has pooled together long-term data on soils of the Republic of Karelia. The aim of the analysis was to identify the soil traits that are the most sensitive to the type of biocoenosis. The biocoenoses chosen for the analysis were automorphic pine, spruce and birch communities, collectively accounting for 99 % of forest stands in Karelia, growing on podzolic-type Al-Fe-humus soils with sandy texture over sandy or loamy-sand till, which represent the most widespread type of soils in the study area. The analysis was performed for the following soil horizons: forest floor (O), eluvial (E) and illuvial (B). In order to characterize the soil horizons the physico-chemical parameters were used: рН (KCl), total С and N content, labile P205 and K20 compounds content, and gross content of SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, P2O5. Discriminant analysis was employed to determine the traits contributing the most to the differentiation of biocoenosis types. The contribution of the traits to differentiation between groups was measured by Wilks’ lambda. Overall, the analysis has shown that N and C content the most significantly reflect the changes happening under the effect of the forest, both in the organic and in the mineral parts of the soil, as corroborated by the findings of numerous Russian and foreign researchers.

Ахметова Г.В. 1 , Бахмет О.Н. 2 , Новиков Г.С. 3 , Медведева М.В. 4 , Солодовников А.Н. 5 РАЗРАБОТКА ГЕОИНФОРМАЦИОННОЙ СИСТЕМЫ «ПОЧВЫ РЕСПУБЛИКИ КАРЕЛИЯ»: ФОРМИРОВАНИЕ КОНЦЕПЦИИ И СТРУКТУРЫ АННОТАЦИЯВ настоящее время на основе обширного, полученного более чем за 60 лет исследований материала о почвах и почвенном покрове Республики Карелия созданы многочисленные карты.Составлены базовые почвенные карты различного масштаба как на весь регион, так и на отдельные территории, построены тематические картосхемы физико-химических свойств почв и содержания в них макро-и микроэлементов.В связи с этим для наиболее эффективного использования в научных и практических целях собранная картографическая информация требует систематизации и представления под единой оболочкой.Наиболее перспективным является использование современных технологий и создание геоинформационной системы (ГИС) «Почвы Республики Карелия».Основой для формирования ГИС являются переведенные в векторный формат архивные карты: Почвенная карта Карелии (масштаб 1 : 500 000, 1955 г.) и листы Государственной Почвенной Карты на территорию Карелии (масштаб 1 : 1 000 000, 1962 г.).В представленной работе обсуждается концепция и обозначены этапы формирования ГИС «Почвы Республики Карелия».Разработана ее структура, которая состоит из разделов: «Карты природных условий», «Общие почвенные карты», «Тематические почвенные карты», «Материалы почвенных исследований».Таким образом, в состав формирующейся ГИС будут входить векторные, растровые материалы и исходные табличные данные.Предложенные принципы позволят организовать работу по наполнению ГИС как архивными материалами почвенного наследия, так и данными современных исследований.Данная ГИС предназначена для реализации научных и прикладных задач, обеспечивая базу для организации природно-экологического мониторинга, а также может быть использована различными органами власти, образовательными учреждениями.

The after-effect of long-term application of various doses and combinations of mineral fertilizers (NPK, N) to pine crops on sandy Al-Fe-humus podzolized podbur soils was studied in the middle taiga of Karelia, near Lake Rindozero. The pine crops established by seeding in 1962 were fertilized in 1970, 1975, 1979 and 1985. The setup was N, NPK, and control (not fertilized). By the time of the survey the sample plots were occupied by 53‑year-old pure pine stands. Thirty years after the last treatment, 10 replications of forest floor samples were taken from each 0.5 ha plot to determine the stock, and 3 soil pits were made in each plot to take samples from specific genetic horizons for chemical analysis. In the sample plots, the most significant changes compared to the control were observed in the forest floor and the underlying eluvial horizon. The productivity of the resultant pine stands was promoted considerably, especially by NPK fertilization. Statistical treatment of the data revealed a significant increase in the forest floor stock upon fertilization in all the treatments as compared to the control. Mean tree diameter and height, as well as the stands’ growing stock were enlarged.

Ecological properties distinctions of spruce, birch and aspen stand’s various origin soil are investigated in Middle-taiga zone of North-West Russia. Studies were done in Karelia Republic, in permanent sample plots in the Kondopoga district, in a grass-forbs birch stand with sandy-loam humo-ferric podzolic soils over loamy clays transitional to varved clays, and a grass-forbs aspen and blueberry spruce stand’s with an epigleyic clayey soil over varved clays; as well as in the Pryazha district in a bilberry-herbaceous birch stand with sandy podzolic soil over sandy-loam till and a grass-bilberry aspen stand with sandy-loam podzolic soil over sandy-loam till. Studies have demonstrated that the forest floor in deciduous forest is usually shallower than in spruce stands, but richer in nutrients. The more base-saturated deciduous litterfall reduces soil acidity. Obvious qualitative distinctions from spruce forests in the soil humus fractions ratio were identified. The features noted were the high content of Ca-bound humus fractions and the dominance of humic acids over fulvic acids in the soluble humus part of deciduous forest’s soils.

The condition of forest litters at various distances from the Kostomuksha ore-dressing mill was studied. The effects of air-borne pollutants on the soil acidity, ash content and heavy metal accumulation through the 27-year period of the mill operation were revealed. The condition of the litters in the area of 25 km around the mill were assessed.