Growth-rate indices and coefficients of the types of growth in height of coniferous forest stands

Based on data about the growth in height of different coniferous tree species, namely Scots and Austrian pines (Pinus sylvestris L. and Pinus nigra Arnold), Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.), have their growth rates within the same age range been investigated. New coefficients have been suggested for estimating their types of growth and the suitability of using these coefficients has been proved, as they have been compared with the Douhovnicov’s zero natural indicators for the particular curves, and a high level of correlation has been found. The important parametric (qualitative) growth-rate curves, the curves of the normal numbers for the height growth of the four coniferous tree species are presented and analyzed, as well as the index curves. Further on, while applying the new growth-type coefficients, the values and ranges of the growth-rate indices have been found for the tree species investigated. It has been concluded that the growth-type coefficients, as well as the growth-rate indices, are tools quite comfortable and rather suitable for finding differences and similarities between the rates and types of the growth of forest stands.