Complexity of stand structures in two mixed mountain old-growth forests and adjacent managed forests in Bosnia and Herzegovina : doctoral dissertation

Keren, Srdjan (author), Diaci, Jurij (mentor), Govedar, Zoran (comentor)

This study was conducted in Dinaric mixed mountain old-growth (OG) forests Janj and Lom and adjacent managed stands on the same site (Piceo-Abieti-Fagetum illyricum), which were managed with a selection (plenter) system for more than a century. The following attributes were examined: light climate, ground vegetation, regeneration, tree density, dbh distribution shapes, tree species composition, mean diameter, basal area (BA), growing stock (GS) and coarse woody debris (CWD). As expected, taller and larger trees, higher BA, higher share of senescent phase and more CWD were found in OG forests. Regeneration process in OG forests was characterized by lower levels and variability of light, lover ground vegetation coverage and vascular plant diversity, and the species composition was more dominated by beech. Beech seedling density indicated positive relation to beech BA, while all regeneration stages of fir showed negative relation with fir BA. Beech was significantly more represented in OG forests also in the middlestory. Dbh distributions in both managed and OG forests had shapes that indicate a demographic equilibrium, despite high values of GS. Most frequent species specific shapes indicated demographic stability or even progression of beech, and imbalance or regression of conifers. Despite significant shares of spruce and fir in the upperstory, their regeneration and small trees were given low chances to replace mature trees in OG forests in the near future. Similarly to the natural disturbance pattern in OG forests Janj and Lom, single tree selection in managed forests performed only slightly better regarding recruitment of spruce and maple into the stand middlestory. The long-term comparison of OG forest structure indicated decline of conifers (especially spruce). However, comparison of recent data in managed and OG forests indicated that silvicultural activities may hold back long-term conifer decline since managed forests exhibited greater compositional stability.

• Language: English
• Keywords: old-growth forests, managed forests, structural attributes, selection silviculture, climatic extremes, Piceo-Abieti-Fagetum Illyricum
• Work type: Dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [S. Keren]
• Year: 2015
• Number of pages: XI f., 147 str.
• PID: 20.500.12556/RUL-115390
• UDC: 630*23:630*22+630*18Piceo-Abieti-Fagetum Illyricum(497.6)(043.3)=111
• URN: URN:NBN:SI:doc-AMZZ2ETX
• COBISS.SI-ID: 4069798
• Publication date in RUL: 24.04.2020

Secondary language

• Language: Slovenian
• Title: Raznolikost sestojnih struktur v dveh mešanih gorskih pragozdovih in bližnjih gospodarskih gozdovih v Bosni in Hercegovini

Abstract

Raziskava je bila izpeljana v Dinarskih jelovo-bukovih pragozdovih Janj in Lom (OG) ter gospodarskih gozdovih v bližini (MF) na primerljivih rastiščih (Piceo-Abieti-Fagetum illyricum), kjer že več kot stoletje prebiralno gospodarijo. Proučevale so se naslednje značilnosti gozdov: svetlobne in zeliščne razmere, pomlajevanje, drevesna sestava, gostota, temeljnica in debelinska struktura sestojev ter veliki drevesni ostanki. Kot je bilo pričakovati, so značilnosti OG: višja in večja drevesa, višje temeljnice, večji deleži terminalne faze in več drevesnih ostankov. Za ekologijo pomlajevanja v OG je bila značilna manjša količina in variabilnost svetlobe, manjša pokrovnost in raznovrstnost vaskularnih rastlin, v zmesi mladja pa je bolj prevladovala bukev kot v MF. Gostota manjšega bukovega mladja je bila v pozitivni povezavi s temeljnico bukve, medtem ko so vse razvojne faze jelovega mladja nakazovale negativno povezavo s temeljnico jelke. Bukev je tudi značilno prevladovala v srednji drevesni plasti pragozdov v primerjavi z MF. Porazdelitve prsnih premerov OG in MF so, kljub visokim lesnim zalogam, nakazovale demografsko ravnotežje. Najpogostejše vrstno specifične oblike porazdelitev so nakazovale demografsko stabilnost ali napredovanje bukve in demografsko neravnovesje ali nazadovanje iglavcev. Kljub znatnim deležem smreke in jelke v zgornji plasti, so njuni čakalci v spodnji plasti nakazovali slabe možnosti za nadomestitev odraslih dreves v OG. Podobno kot pri naravnem vzorcu motenj v OG Janj in Lom, prebiralno gospodarjenje ni bistveno izboljšalo deleža smreke in javorja v srednji plasti. Dolgoročna primerjava strukture OG je nakazala nazadovanje iglavcev (predvsem smreke). Vendar pa primerjalna analiza zadnjih podatkov v OG in MF nakazuje, da lahko gojenje gozdov prispeva k zadrževanju dolgoročnega nazadovanja iglavcev, kajti gospodarski gozdovi izkazujejo večjo stabilnost zmesi.

• Keywords: pragozdovi, gospodarski gozdovi, strukturne značilnosti, prebiralno gojenje gozdov, klimatski ekstremi, Piceo-Abieti-Fagetum Illyricum