Elementi rasta i struktura veštački podignute sastojine smrče u starosti 37 i 62 godine na staništu balkanskog kitnjaka na Goču

Abstract

Na jednoj trajnoj oglednoj površini u veštački podignutoj sastojini smrče na staništu balkanskog kitnjaka na Goču prikazani su elementi rasta i sastojinska struktura u starosti 37 i 62 godine i analizirana je njihova promena. Sastojina je podignuta sa 4500 sadnica po hektaru. U starosti 37 godina na trajnoj oglednoj površini utvrđeno je 2600 stabala po hektaru, sa temeljnicom 43,52 m2·ha−1 i zapreminom 319,97 m3·ha−1, a u starosti 62 godine utvrđeno je 878 stabala po hektaru sa temeljnicom 42,61 m2·ha−1 i zapreminom 454,48 m3·ha−1. Prva selektivna proreda, sprovedene pri srednjoj visini aspiranata (500 po hektaru) 17,6 m u starosti 37 godina je bila niska (qd = 0,88) i umerene jačine po broju stabala (28,3%) i zapremini (23,5%). Od preostalog broja stabala (1823 po hektaru) u periodu od 38. do 62. godine iz sastojine je pretežno sanitarnom sečom izlučeno 956 stabala (52,4%), sa pokazateljem niske prorede (qd = 0,68). Od početno izdvojenih aspiranata u 37. godini do 62. godine, pod uticajem biološkog diferenciranja stabala i pod uticajem nepovoljnih egzogenih faktora, a u postupku nege koji karakteriše niska proreda, u sastojini je izdvojeno 220 stabala budućnosti po hektaru. U 62. godini u sastojini su prisutni elementi nepovoljne izgrađenosti i statičke nestabilnosti jer je stepen vitkosti povećan u odnosu na stanje u 37. godini, pa se može zaključiti da je povećan i rizik za ostvarivanje njene potencijalne proizvodne i meliorativne uloge, a što je primarno posledica izostanka adekvatne nege u periodu od 38. do 62. godine.

Growth elements and stand structure of an artificially established Norway spruce stand were presented at age 37 and 62-yr on the basis of a single permanent sample plot and their changes analyzed. The stand was established with 4500 seedlings per hectare. At age 37-yr on the permanent sample plot, 2600 trees per hectare were recorded with basal area of 43.52 m2•ha−1 and standing volume of 319,97 m3•ha−1. At stand age 62-yr, 878 trees per hectare were recorded with basal area of 42.61 m2•ha−1 and standing volume of 454,48 m3•ha−1. First selective thinning, conducted at mean aspirant’s height of 17.6 m (500 trees per hectare) at age 37-yr was characterized as a moderate (28.3% trees per hectare and 23.5% volume thinned) thinning from below (qd = 0.88). Out of the remaining number of trees (1823 per hectare), in the following period between 38-62-yr, 956 trees per hectare (52.4%) were removed, mostly through sanitary cutting that can be characterized as thinning from below (qd = 0.68). Out of the initially selected aspirants at age 37-yr, 220 elite trees were selected at age 62-yr due to the effects of self-thinning in the stand and unfavorable exogenous factors as well as the thinning from below regime. At age 62-yr, the stand structure is unfavorable and statically unstable as the slenderness coefficient is increased compared to the condition at 37-yr. Thus, it can be concluded that the risk for achieving the productive and meliorative potentials of the stand is increased, primarily due to absence of adequate maintenance of the stand between age 38 and 62-yr.