Title: Express-indication of organic matter deposition in urban stands

Abstract

The growth of urban areas makes it relevant to study the characteristics of urban ecosystems, including their role in the storage of atmospheric carbon. The availability of studying forest litter and the simplicity of estimating parameters makes it possible to obtain information on the state of urban objects in an express mode for the purposes of environmental monitoring and assessment of the deposition of organic matter. Coniferous, in particular spruce plantations are the most preferred objects of monitoring. The recreational impact on coniferous plantations causes some increase in the intensity of the biological cycle, the indicators of which are the properties of forest litters, such as thickness, reserves, the proportion of detritus and easily decomposable components in the upper horizon of the litter, as well as the ratio of different horizons of the litter in terms of thickness and reserves. In addition, recreation somewhat levels the differentiating influence of the spruce crown. The increase in the intensity of the cycle is apparently associated with both the direct destructive effect on the litter during trampling and the change in the composition of the living ground cover. The recreational load leads to a significant decrease in the reserves of organic matter in the litter and carbon reserves due to its decomposition, and, accordingly, additional carbon ingress into the atmosphere from urban areas. The carbon loss of terrestrial detritus during recreation is about 20-60 kg/100 m2 compared to undisturbed plantations. Thus, when improving urban landscaping, it is necessary to plan the diversion of transit flows of visitors from the locations of coniferous plantations in order to reduce the recreational load on these ecosystems. For the rapid assessment of anthropogenic disturbance of the ecosystem, such indicators as the thickness and type of litter, as well as the ratio of the thickness of the upper horizons of the litter and the sum of the thicknesses of the underlying horizons are proposed.