Tirti Utenos miškų urėdijos pušynai, kuriuose 2003 ir 2006 m. buvo užfiksuoti pažeminiai miško gaisrai. Tyrimo tikslas nustatyti gaisrų padarytą poveikį metinio radialiojo prieaugo augimui. Duomenų surinkimui naudota dendrochronologinių tyrimų duomenų rinkimo metodika. Surinti duomenys išanalizuoti CHRONOL programa. Tyrimais įrodyta, kad gaisrai daro neigiamą įtaką pušynų radialiojo prieaugio augimui. / The research material for dendrochronological analysis was collected in forest area located in Utena Forest Enterprise. The objects of study were as follows: 40 year-old Vaccinium Pinetum one-layer stands, quality class – II. In two objects forest fires were in 2003 and in other two – 2006. Also, one object was selected as control where fire has not been observed. To estimate the influence made by fire to tree (Pinus sylvestris L.) radial increment, samples were taken ussing Pressler age borer in accordance with the methods for collecting experimental material of dendrochronological research work (Stravinskiene, 1994). To measure annual radial increment and estimate tree ring structure, the samples were examined by LINTAB tree-ring measurement system and TSAP computer programme. The COFECHA programm was used for analyzing obtained primary data. Using the COFECHA programme we performed cross-dating quality control. Annual tree-ring width series of asynchronous growth or lagged correlation were rechecked, corrected or eliminated from the next stages of the research with the master chronology approach. To determine impact of fire to stand growth conditions upon Pinus Sylvestris L. radial increment dendrochronological research work, dendrochronological scales of the stands with former observed fires and control stand was carried out. Well-defined decrease of radial increment was ascertained. Fire presence makes significant impact of annual radial increment dynamic after it’s... [to full text]

The main goal of this study was to investigate space structure of pure pine stands, to assess optimal parameters of trees crown depending on stand age. The study was carried out in seven trials of 2 – 8 age classes pine stand. Trees crown horizontal projection area, the overlapping of crown, tree DBH, 5 years increment of diameter, tree developing class was measured of 200 trees in every trial. It was investigated that maximally possible crown projection area makes up from 12,0 thousand m2/ha to 6,5 thousand m2/ha while the age of stands changes from 2 to 8 age class. Depending upon the age of pine stand, maximally possible crown cover area makes up from 8,5 thousand m2/ha to 6,2 thousand m2/ha and decreases with increasing of stand age. The area of inevitable openings comprises 15-38 % of a forest area and increases with increasing of stand age. The overlapping comprises 43-6 % and decreases with increasing of stand age. The area of pine crown increases from 1,2 to 8,8 m2 while the age of stands changes from 2 to 8 age class. In the same age class the area of tree crown depends on tree developing class. The crown area of well-developed trees (class A) is 1.7-1.9 times bigger then crown area of poor-developed trees (class B) and 2.7-4.6 times bigger then crown area of trees being developed in a depressed state (class C). The crown area of vigorously-developed trees (class A’) is 1.8-3.5 times bigger than crown area of well-developed trees (class A). 1 m2 of the crown area... [to full text]