Statystyczna małopowierzchniowa metoda oceny zdrowotności drzew. Cześć I. Opis metody

摘要

The increasing importance of forest health inventory, particularly a small-scale inventory stems from the introduction of new, ecology-based management and protection methods into small fragments of managed forests or into partially protected landscapes in national parks. The aim of this paper is to describe a small-scale statistical method, to assess the health condition of trees and to discuss the survey sampling design selected for this purpose. A four-scale classification was used to assess the degree of crown defoliation (non-defoliated trees, trees with weak, moderate and severe defoliation). The level of defoliation was expressed in the SINUS (System of Information on Natural Environment) surface sub-blocks. A survey sampling was used to assess the degree of tree defoliation by applying an simple random sampling design on P_3 plots of the SINUS system. The relationship between the binominal distribution and Snedecor' F distribution was used to calculate the confidence interval limits for tree fraction in a given defoliation class. The use of simple random sampling design in the method proposed in this paper would be the optimal solution when there is small likelihood of occurrence of spatial ordering in the general population, the change in the sampling number during future studies cannot be precluded and the general population size is small.