FOREST SURVEY PARAMETERS OF PINE TREE STANDS ACCORDINGTO LONG-TERM OBSERVATION DATA

When considering not only raw materials, but ecosystem functions of forests, the dynamics of forest stand indicators at all stages of growth is important. To regulate a high degree of fulfillment of ecosystem functions, the priority tasks are to increase the stability of stands and their productivity. The aim of the research is to study dynamics of growth and productivity of pine tree stands according to long-term observations data. The materials for the study were data of long-term observations due to the pine forest stands and plantations on permanent plots of the Forest Experimental Station of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy. Four main characteristics of the stock dynamics of pine stands have been identified, which requires the development of new approaches to its modeling. At the same time, the life cycle of a stand is not a monotonous process, as is customary, but a wave-like process of the dynamics of all main stand indicators, due to the different dependence of the influence of both internal (manifestations of self-regulation in stands and feedback loops) and external factors. The presence of several stages of dynamics can be reflected by empirical models, which include the sum of simple growth functions or nonmonotonic functions with one detection of the maximum or multiplicative-additive models of growth and correction functions. Generalized models of the dynamics of the stand basal areas and stocks of measurements that in late ages overcrowded stands have an advantage over rare ones. The nonmonotonic dynamics of stand yield and productivity indicators needs to be taken into account when substantiating the age of maturity and when designing thinning.