Lesna biomasa v neurjih poškodovane in s podlubniki napadene navadne smreke (Picea abies (L.) Karst) kot surovinski vir ekstraktivov

Štolcer, Vanja (author), Oven, Primož (mentor), Vek, Viljem (comentor)

Naravne ujme, ki jih spremljajo napadi podlubnikov in razvoj bolezni, povzročajo obsežne poškodbe gozdnega drevja ter zmanjšujejo kakovost in uporabnost lesa. Ostanki odmrle lesne biomase v gozdu in drevesa, napadena s podlubniki, predstavljajo pomemben, vendar premalo izkoriščen vir ekstraktivnih snovi. Namen doktorske disertacije je bil raziskati vsebnost esktraktivov v tkivih dreves navadne smreke (Picea abies (L.) Karst.), napadenih s smrekovim lubadarjem (Ips spp.), in tkivih dreves navadne smreke, ki so bila podrta v vetrolomu v letu 2017 v primerjavi z referenčnimi zdravimi drevesi. Vzorčenje je potekalo na območju Plešivške kope in Plešivca v letih 2021 in 2022. Po poseku smo vzdolž debel odvzeli 3-5 kolutov, iz katerih smo izolirali vzorce beljave, jedrovine, grč in skorje. Vzorce smo ekstrahirali s sistemom za pospešeno ekstrakcijo ASE. Vsebnost lipofilnih in hidrofilnih ekstraktivov smo določili gravimetrično, vsebnost celokupnih fenolov in proantocianidinov z UV-Vis spektrofotometrijo, fenolne spojine smo identificirali s HPLC, lipofilne ekstraktive pa z GC-MSD. Vsebnost hidrofilnih ekstraktivov je bila pri vseh proučevanih skupinah najvišja v grčah, sledila je skorja, nato beljava, najnižje vsebnosti pa so bile v jedrovini. Lipofilnih ekstraktivov je bilo največ v skorji, nato v grčah, ki jim je sledila beljava, njihova najnižja vsebnost pa je bila v jedrovini. Grče so vsebovale najvišje vsebnosti celokupnih fenolov (87,53 mg/g, 71,67 mg/g, 71,43 mg/g). Med fenolnimi spojinami so v tkivih prevladovali lignani, predvsem izolaricirezinol, ki jih je bilo največ v grčah proučevanih skupin, razen v skorji zdravih dreves, kjer so prevladovale fenolne kisline. Skorja je bogat vir proantocianidinov, taksifolin pa je bil prevladujoč flavonoid z najvišjimi vsebnostmi v grčah in skorji. Med smolnimi kislinami je v proučevanih tkivih prevladovala dehidroabietinska kislina, ki je je bilo največ v grčah odmrle lesne biomase. V skorji dreves, napadenih s smrekovim lubadarjem, so bile povišane tudi vsebnosti abietinske in izopimarne kisline. Ugotovitve te študije so pokazale, da je ta premalo cenjena in neizkoriščena lesna biomasa dragocen surovinski vir za pridobivanje ekstraktivov. Možnost biorafineracije tovrstne lesne biomase bistveno prispeva k trajnostnemu povečanju izrabe gozdov in k celotni izrabi lesa slabše kakovosti.

• Language: Slovenian
• Keywords: Picea abies (L.) Karst, navadna smreka, naravne ujme, smrekov lubadar, odmrla lesna biomasa, ekstraktivi, les, skorja, biorafinerija, krožno biogospodarstvo
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: BF - Biotechnical Faculty
• Publisher: [V. Štolcer]
• Year: 2026
• PID: 20.500.12556/RUL-182373
• UDC: 630*537:42+453:866(043.3)
• COBISS.SI-ID: 277575683
• Publication date in RUL: 08.05.2026

Secondary language

• Language: English
• Title: Woody biomass of Norway spruce (Picea abies (L.) Karst.) damaged in storms and attacked with bark beetles as a raw material of extractives

Abstract

In recent years, the natural disturbances, accompanied by bark beetle infestations and disease outbreaks, cause extensive damage to forests, reducing wood quality and usability. Dead woody biomass and bark beetle-attacked trees represent an important but underutilized source of extractives. The aim of this doctoral dissertation was to investigate the content of extractives in the tissues of Norway spruce (Picea abies (L.) Karst.) trees attacked by the spruce bark beetle (Ips spp.) and in trees damaged in a windstorm in 2017, compared to healthy reference trees. Sampling was carried out in the Plešivška kopa and Plešivec areas in 2021 and 2022. After harvesting, 3-5 discs were dissected along the trunks, from which sapwood, heartwood, knotwood, and bark samples were isolated. The samples were extracted using the accelerated solvent extraction (ASE). Lipophilic and hydrophilic extractives were determined gravimetrically, total phenols and proanthocyanidins by UV-Vis spectrophotometry, phenolic compounds were identified by HPLC, and the lipophilic extractives by GC-MSD. The content of hydrophilic extractives in all investigated groups was the highest in the knots, followed by bark and sapwood, and lowest in heartwood, while lipophilic extractives were the highest in the bark, followed by knots and sapwood, and lowest in heartwood. Total phenols were the highest in the knots (87,53 mg/g, 71,67 mg/g, 71,43 mg/g). The bark was rich with proanthocyanidins. Lignans were predominant phenolic compounds, especially in knots, particularly isolariciresinol, while taxifolin was the most abundant flavonoid in knots and bark. Dehydroabietic acid was the most abundant resin acid, especially in knots of dead woody biomass, while increased contents of abietic and isopimaric acid were also found in the bark of bark beetle-attacked trees. The study showed that this underappreciated and underutilized woody biomass is a valuable source for of extractives, and its possibility of biorefining can significantly increase the sustainable utilization of forests and improve the use of low-quality wood.

• Keywords: Picea abies (L.) Karst, Norway spruce, natural disturbances, bark beetle, dead woody biomass, extractives, wood, bark, biorefinery, circular bioeconomy