The Area of Forest Stand Identification and Required Quantity of Surveys in Tree Stands of Forest Elements
R. A. Ziganshin
V. N. Sukachev Institute of Forest, Russian Academy of Sciences, Siberian Branch, Akademgorodok, 50/28, Krasnoyarsk, 660036 Russian Federation
Keywords: tree stand, forest stand, biogeocenosis, elementary association and terrain (tract), variation of forest inventory indices, norms for a quantity of surveys
Abstract
Often the authors of scientific papers, both young and older generations, do not indicate in their articles and books the accuracy and reliability of their investigation. Sometimes they naively believe that in forestry enough once-accepted standard for the required quantity of surveys, forgetting that mathematical statistics, as in all of mathematics, should be guided by the so-called «domain of existence» of this or that regularity of certain numerical ratios. In particular, in forest inventory, as well as in forest science it is required to identify the full area of tree stand or forest stands, biogeocoenoses, or forest type compartment (sub-compartment), because at different ages and with different stand density to achieve the same accuracy and a confidence interval will require a completely different area of identifying and unequal number of measurements of a tree inventory indices. «Complete» we consider the stand, where the whole range of a tree diameter distribution is represented and statistically reliable. Academician V. N. Sukachev recommended studying forest types following the necessary area of their identification. It is not correct, based on the part of tree stand or forest stand, to accurately identify and evaluate quantitative and qualitative indicators of the biogeocoenoses. The author, based on his wide and long-term forest survey experience of different tree stands and tree species, of different age and density, tried to bring together the results of the research to develop regulatory requirements dictated by different inventory signs’ variability in different cases. The greater the variability (variation) feature, the higher its entropy (uncertainty, disorder), and the greater the quantity of surveys (measurements) have to perform, to achieve the practical necessity of accuracy and reliability of the inventory work. The beginning of the article provides a rigorous and complete interpretation of «tree stand» and «forest stand». Then the article compares the variation of forest inventory indices in sub-compartments for III category of forest planning and in landscape tracts, showing that the survey on natural base is much preferable by the achievable accuracy. In this article all of the standard indicators are summarized in 4 tables for convenient and practical use.
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