Brojnost drvenastih vrsta kao elemenat strukture i diverziteta mešovitih sastojina

Abstract

U našoj šumarskoj nauci i operativi brojnost i raznovrsnost drvenastih vrsta u šumskim sastojinama ocenjivane su najčešće preko ukupnog broja vrsta drveća, što je metodološki delimično neadekvatan pristup. Stoga je u ovom radu kvantifikacija brojnosti i ocena raznovrsnosti drvenastih vrsta u mešovitim šumama bukve sa plemenitim lišćarima na području Nacionalnog parka 'Đerdap' analizirana pomoću pet različitih indeksa brojnosti vrsta: broja vrsta (S indeks), dva indeksa brojnosti vrsta (R1 i R2), očekivanog broja vrsta pri uzorku sa jednakim brojem stabala (E(S84)) i očekivanog broja pri uzorku jednake površine (E(S0,25ha)). Rezultati su pokazali da ocena nivoa raznovrsnosti drvenastih vrsta u šumskim sastojinama zavisi od primenjenog indeksa kojim se karakteriše brojnost vrsta drveća. Zaključeno je da su brojnost i raznovrsnost drvenastih vrsta najveće u sastojinama ekološke jedinice B (E(S84)=8,6 vrsta) i ekološke jedinice G (E(S0,25ha)=9,4 vrsta), a najmanje u sastojinama ekološke jedinice V (E(S84)=5,8 vrsta, E(S0,25ha)=5,5 vrsta).

In our forest science and forest operations, the tree species richness and diversity of woody species in forest stands are most often evaluated based on the total number of tree species, which is a methodologically partly inadequate approach. For this reason, the quantification and the evaluation of diversity of woody species in mixed forests of beech with valuable broadleaves in the area of the National Park 'Đerdap' were analyzed by five different indices of tree species richness: number of species (S index), two indices of the species richness (R1 and R2), expected number of species in the sample with equal numbers of trees (E(S84)), and expected number of species in the sample with equal areas (E(S0,25ha)). The results showed that the level of woody species diversity in forest stands depended on the applied index characterizing the tree species richness. It was concluded that the tree species richness and diversity were the highest in the stands of ecological unit B (E(S84)=8.6 species) and in the stands of ecological unit G (E(S0,25ha)=9.4 species), and they were the lowest in the stands of ecological unit V (E(S84)=5.8 species, E(S0,25ha)=5.5 species).