ÍNDICES PARA LA CARACTERIZACIÓN DE LA ESTRUCTURA DEL ESTRATO ARBÓREO DE ECOSISTEMAS FORESTALES

Abstract

Characterization of tree structure must be based on quantitative indexes that allow accurate analysis of human influence or natural succession processes that occur in forest ecosystems. The objective of this paper is the compilation of diverse quantitative variables to describe structural attributes of the upper story in forest ecosystems, as well as different methods of forest inventory to obtain them. To assess tree species composition, the indexes of Shannon H', of evenness E, and the species A profile, as well as the segregation S of Pielou and the species mingling index M¡ are discussed. The aggregation index R of Clark and Evans, the tree-to-tree distance variable D; and the contagien index W; were included, in order to describe the horizontal structure of ecosystems, for the characterization of the dimensional structure, the homogeneity coefficient H and the indexes of diameter differentiation TO; and height differentiation TH; are reviewed. Diverse forest inventory methods are examined to obtain the former structural indexes. Finally, the possibilities of application and the advantages of the named structural group of four trees procedure, in particular, are discussed.