The Dependence of the Productivity of Pine Forests of Moscow Experimental Forestry on Soil Conditions

We have studied the effect of soil conditions on the productivity (site index) of pine forests in the zone of coniferous–broad-leaved forests. The research object is natural pine forests of different productivities related to the effect of soil and ground factors. The research is performed in northeastern Moscow oblast at the Sverdlovsk branch of the Moscow educational–experimental forestry. It is revealed that it is the main soil properties that determine the site index of the studied pine forests, include groundwater level, the thickness of the ungleyed mineral part of soil profile, and humus reserves in the mineral part of soil. Gleying rate, the depth of the gley horizon, the thickness of the organic horizon, and the occurrence of ortsteins and iron-manganese concretions are the most important soil indicators of the water regime, which is closely related to forest productivity (site index). The cluster analysis has enabled us to assign the soil varieties to five groups with respect to their productivity and taxonomic position. These informative soil properties should be included into forest GIS and taken into account when planning forestry measures. The diagnostic model may be used in assessing the potential productivity of forest soils and elaborating measures for the rational use of forest lands.