Volume 73, Nº 2 (2018)

The peculiarities of the litter in three parkland lime plantations of Moscow oblast with different periods of mowing of the grass cover are studied. The forest litter is characterized as destructive low-power with a comparatively low margin. The most significant indicators of forest conditions are total litter stocks, the proportion of detritus, and the ratio of stocks of grass in the litter and biomass stocks of the grass layer, which indirectly indicates the intensity of the biological cycle. The maximum rate of the biological cycle is revealed for periodically extruded lime plantations.

Based on a case study of Moscow forest parks Losinyi Ostrov and Bitsevskii Les, the paper presents a quantitative assessment of changes in the physical, chemical, and biological properties of soils on trails in these parks and in linear trailside (pritropinochnye) zones depending on the recreation load level. It is shown that soil properties differ in their sensitivity to recreation. The widths of impact zones range from 20 to 100 cm from the edges of trails depending on the sensitivity of the soil property, recreation load, and type of biogeocenosis.

Long-term laboratory and microfield experiments have revealed the effective doses of humates for their use as detoxifiers of urban soils. The developed original technique allowed us to modify the commercial product Ekstra by fundamentally changing the ratio of amphiphilic fractions of humic substances. Field tests of new Ekstra growth showed its high efficacy as a plant growth stimulator and antistress preparation, which makes it possible to mitigate (or greatly reduce) the toxic effects of various pollutants on plants in contaminated areas.

Carbon dioxide (CO₂) emission from the soil surface in forest biogeocenoses of the Zvenigorod Biological Station of Moscow State University in summer varies on average from 120 to 350 mg C–CO₂/(m² h) and depends on the hydrothermal conditions (soil moisture and temperature) and the type of phytocenosis. The intensity of CO₂ emission in the biogeocenosis does not depend on its parcel structure and varies with respect to plant microgroups: it is maximum in oxalis pine–spruce and maple–lime forests and bracken spruce–birch forests and minimum in areas of forest fall without vegetation. The upper (from 0 to 20 cm thick) soil layer provides up to 50% of the total soil CO₂ emission. The role of microbial respiration in the total CO₂ emission from soils is determined by weather conditions and varies from 9–33% in a dry summer to 55–75% in a summer with favorable temperature and moisture.