Variabilnost dimenzij in deležev trahej v datiranih branikah bukve z dveh rastišč : diplomsko delo - visokošolski strokovni študij

Petric, Matej (avtor), Čufar, Katarina (mentor), Gorišek, Željko (recenzent)

V lesu odraslih bukev (Fagus sylvatica L.) z 2 rastišč, Panške reke (PR) pri Ljubljani in Menine planine (MP), smo v branikah, nastalih v letih 2006, 2008 in 2009 raziskali variabilnost dimenzij trahej. Na slikah mikroskopskih preparatov prečnih prerezov smo branike od ranega proti kasnem lesu razdelili na pasove po metodi premikajočih se oken, braniko 2006 PR pa tudi po metodi tedenskih prirastkov, ki smo jih določili s pomočjo Gompertzove funkcije iz predhodne študije nastajanja lesa. S pomočjo programa za analizo slike smo v vsakem oknu izmerili minimalni premer, maksimalni premer, obseg in površino vseh trahej ter število trahej na enoto površine. Površina in minimalni premer trahej sta bila najbolj relevantna za izdelavo trahejogramov za ovrednotenje variabilnosti dimenzij trahej po braniki. V branikah 2006 in 2009 PR so površine trahej v prvih 70 % branike le počasi upadale, nato pa se je trend upadanja naglo povečal, v braniki 2008 PR pa je bilo zmanjševanje trahej vidno že na približno polovici branike. Braniki 2008 in 2009 MP sta imeli podobno širino in primerljivo zgradbo s postopnim zmanjševanjem površin trahej. Kasni les je večinoma predstavljalo zadnjih 20 % branike. Število trahej na enoto površine je bilo po branikah razmeroma konstantno, le v zaključnem delu večine branik smo opazili rahlo zmanjšanje števila trahej. Z metodo premikajočih se oken smo prikazali variiranje dimenzij trahej z oddaljenostjo od letnice. Z metodo tedenskih prirastkov smo ugotovili kakšne dimenzije so imele traheje, ki so nastale v določenem času. To metodo lahko uporabimo le v branikah, za katere poznamo dinamiko nastanka, ki jo pridobimo v zamudnih študijah nastajanja lesa.

• Jezik: Slovenski jezik
• Ključne besede: les, bukev, Fagus sylvatica L., traheje, analiza slike, histometrija, wood, beech, Fagus sylvatica L., vessels, image analysis, histometry
• Vrsta gradiva: Diplomsko delo
• Tipologija: 2.11 - Diplomsko delo
• Organizacija: BF - Biotehniška fakulteta
• Kraj izida: Ljubljana
• Založnik: M. Petric
• Leto izida: 2011
• Št. strani: VII, 44 f.
• PID: 20.500.12556/RUL-159189
• UDK: 630*811.4
• COBISS.SI-ID: 1875849
• Datum objave v RUL: 02.07.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Variability of dimensions and proportions of vessels in dated tree-rings of beech from two sites : graduation thesis - higher professional studies

Izvleček

Vessel dimensions were analysed in tree-rings formed in 2006, 2008 and 2009 in the wood of adult beech (Fagus sylvatica L.) trees from 2 sites, Panška reka (PR) near Ljubljana, and Menina planina (MP). Images of cross-sections of each tree-ring were divided into sections from early-wood to late-wood according to the moving window method. Weekly increment method was also used with the tree-ring 2006 PR, where weekly increment was determined by the Gompertz function from the previous study on wood formation. Maximum diameter, minimum diameter, circumference, and area of the vessels as well as their quantity per square unit were determined in every window with image analysis software. Area and minimum diameter were the most relevant features to produce graphs of vessel sizes from early- to late-wood. The area of vessels decreased slowly in the first 70 % of treerings 2006 and 2009 PR, after that it dropped rapidly. In 2008 PR we observed a fast decrease of vessel dimensions already in the first half of the tree-ring. Tree-rings 2008 and 2009 MP had similar widths and comparable structures where the area of vessels was decreasing gradually. Late-wood constituted the last 20 % of tree-rings. The number of vessels per square unit was rather stable from early- to late-wood. It was only slightly reduced in the final part of the tree-rings. By using the moving windows method a variation of vessel dimensions has been established in connection to its distance from the growth ring boundary. By using the weekly increment method, we established the dimensions of vessels that were created at a certain period of time. This method is only applicable with tree-rings with a known formation dynamics, which can only be acquired from time consuming studies on wood formation.