Mechanism of the Accumulation Function Changing for Carbon and Nitrogen in the Litter–Mineral Soil System of Urban Larch Plantations under Recreational Load
摘要
The influence of recreation on carbon (C) and nitrogen (N) reserves in the litter and upper mineral horizons of soils under larch stands in Izmaylovsky Park, Moscow, has been studied. The objects of study are a recreationally disturbed and a control (undisturbed) larch urban forest (third and first stages of digression, respectively). Carbon and nitrogen reserves in all litter subhorizons and in different fractions of subhorizon L as well as reserves of total and labile C and N in the 0–10 cm layer of the mineral part of the soil profile have been determined. Under recreational load, the accumulative role of litter decreases compared to the control and the difference in the C and N reserves in the litter by the tessera components is leveled out. The decrease in the C and N reserves in the litter is determined by a decrease in the total reserves of the litter itself. Significant decline of the C and N reserves in the humified and fermentative litter subhorizons associated with the recreation have been detected. Maximum C and N losses from the litter have been determined in the near-trunk spaces. Within the L–F–H litter profile, maximum losses are observed in the humified subhorizon of the sub- and inter-crown spaces. No changes in C and N accumulation in the upper mineral soil horizon have been detected under recreational load corresponding to the third stage of soil degradation.