Ecological Systems and Devices Annotation << Back Optimality Statistical Justifi cation of Fiveyear Increment Norm of Linear Dendrochronologies for Forest Ecosystems Ecological Monitoring Maksimova O.V., Koukhta A.E. The dimensions of internodes (linear increments) are a convenient object for operational monitoring of forest biogeocenoses. However, for linear chronologies, the types of habitats with the most sensitive chronologies have not yet been identifi ed, as well as the increment norm required for indexing the series of internode sizes is not justifi ed. For the Scots pine Pinus sylvestris L. of protected areas ecosystems in the direction from south to north, the dendrochronology’s informativeness of two previous years in relation to the observed year was studied. The increment norm was statistical justifi ed by identifying signifi cant autocorrelation coeffi cients for each sample at different lags. It has been shown that over a two year period, the effects of climatic factors on pine populations congregate, as a result of which it is advisable to consider the analysis of the impact of climatic factors on the growth series cumulatively. The most informative are the increments series of the northern border of the areal in all types of biotopes, as well as the chronologies of all types of habitats in the south of the range of Pinus sylvestris. The obtained results served as a basis for the 5 years increment norm, which represents the most adequate refl ection of the forest stands response to climatic parameters and allows us to assess the accumulated impact of climatic factors on forest stands over the previous 2 growing seasons. Keywords. Scots pine, linear increment, increment norm, autocorrelation, biotope type. Pp. 10-21.