Magistro darbe tiriama pušynų atvejinių kirtimų įtaka medynų žemutinių ardų augalijos formavimuisi. Darbo objektas: Tyrimo objektas – pomiškis, žolinė augmenija ir samanos neplynose pušynų kirtavietėse. Darbo tikslas: Ištirti pomiškio, žolinės ir samanų dangos formavimosi ypatumus pušynų atvejinių kirtimų kirtavietėse. Darbo metodai: Pušynuose, kuriuose buvo atlikti atvejiniai kirtimai buvo parinkti 4 pastovūs bareliai. Trijuose bareliuose atvejiniai kirtimai buvo vykdyti 2007 metais, o viename tyrimų barelyje – 2005 metais. Visuose bareliuose augavietės tipas buvo Nbl. Pomiškis, žolinė ir samanų danga buvo įvertinta 20 m ilgio ir 1 m pločio transektose. Pomiškis skaičiuotas nurodant rūšį ir skaičių. Samanų, žolinės augmenijos projekcinis padengimas įvertintas procentais. Darbo rezultatai: Vidutinis paprastosios pušies daigų kiekis 1 m2 antrais metais po atvejinių kirtimų sumažėjo, o karpotojo beržo daigų kiekis 1 m2 iš esmės nepasikeitė. Kai kuriose kirtavietėse antrais metais po kirtimų atsirado paprastosios eglės daigų. Kirtavietėse rastos 29 skirtingos žolių rūšys. Daugeliu atvejų antrais metais po atvejinių kirtimų kirtavietėse žolių rūšių skaičius padidėjo. Žolinės dangos vidutinis projekcinis padengimas antrais metais po atliktų atvejinių kirtimų ženkliai padidėjo. Daugiausiai vidutinis projekcinis padengimas praėjus metams po atvejinių kirtimų padidėjo kirtaviečių augalų – miškinio ir smiltyninio lendrūnų. Viso rastos 4 samanų rūšys. Vidutinis projekcinis samanų... [toliau žr. visą tekstą] / The object of the study: Undergrowth, herbs and moss in pinewoods after shelterwood cuttings. The aim of the study: The main goal of this research was to find out influence of shelterwood cuttings on herbs, moss and seedlings in pinewoods. Methods: The research areas were established in 2007 year shelterwood cutting and in 2005 year shelterwood cutting of pinewood. Saplings, herbs and moss were counted in transect which was 20 meters length and 1 meter width. There were indicated saplings species and number. Average cover projection of herbs and moss was evaluated by percent. The results: The average the number of pine’s saplings decreased in one square meter in shelter wood cuttings of second year. The average the number of birch saplings didn’t change in one square meter in essence on the following year after shelterwood cuttings. In some shelterwood cuttings were found spruce’s saplings on second year. There were 29 different species of herbs in shelterwood cuttings. In most cases the number of herbs species increased on following year. Average cover projection of herbs signally increased on the following year after shelterwood cuttings. There were founded 4 species of moss. Moss average cover projection didn’t change in essence on the following year after shelterwood cuttings.

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]

There is research of regularity of free tree mortality in various age pine stands, growing in Nbl places in master work. Presented this process’s characteristics- amounts of mortality by the number and volume of the tree. We used absolute and relational parameters of free tree mortality. An object of work- 20-140 years old pine stands, which is pure, conditionally average growing in Nbl places. Long-time investigation involved pine of the Jonava district and Berezina reserve (Belarus). Information involved free mortality from various literary sources. Aim- fined a regularity of free tree mortality. A method of work- Barrel method of forestry research was used in outdoor work’s. Inventory of barrel research was repeated 2-3 times in 4-7 years. Without our got information analyze from barrel research we used a method of met analyze, when various authors information of free tree mortality is united in one based object by the source of literature. Results of work- Tree mortality research involved 20-140 years old pine, growing in Nbl places. Our investigation and results analysis shows 2-5% trees mortality (per year) registered in pine samplings; 0,3-6% - in mide-aged pine stands; 1-5% - in premature stands; 5-6% trees mortality in mature stands. Average of size of trees mortality equal: in pine samplings- 4,2 m3/ha per year, in mide-aged stands - 2,7 m3/ha per year, in premature forests - 2,6 m3/ha per year, in mature stands - 2,7 m3/ha per year. Our appointed average and... [to full text]

Lietuvoje iki 90% energijos gamybai naudojamos biomasės sudaro mediena. Iš miško išvežant visas miško kirtimo atliekas, o ne paliekant natūraliam suirimui, maisto medžiagų nuostoliai miško ekosistemoje padidėja iki 5 kartų. Kompensuojamasis miškų tręšimas medienos kuro pelenais – tai vienas iš būdų grąžinti maisto medžiagas į miško ekosistemą. Darbe įvertintas kompensuojamojo tręšimo medienos kuro pelenais diferencijuotas ir kompleksinis (kartu su azotu) poveikis brukninių pušynų gyvosios dirvožemio dangos struktūrai bei biomasės cheminei sudėčiai. Pirmą kartą Lietuvoje tiriamas ilgalaikio tręšimo azotu bei didelių azoto dozių poveikis brukninių pušynų, augančių nederlinguose smėlžemiuose, gyvosios dirvožemio dangos rūšių sudėčiai bei gausumui. Nustatytas foninių azoto iškritų sąlygotas nitrofilinių augalų rūšių išplitimas brukninių pušynų (Vaccinio-Pinetum) gyvojoje dirvožemio dangoje. Ištirtas miško ekosistemos edifikatorių konkurencinis poveikis rizosferoje: dirvožemio drėgniui, pH bei cheminei sudėčiai, žolių/krūmokšnių padengimui bei biomasei, gyvosios dirvožemio dangos dominanto bruknės (Vaccinium vitis-idea L.) biomasei bei biomasės cheminei sudėčiai. Atlikti tyrimai leidžia daryti išvadas, kad samanų rūšims tiek medienos kuro pelenų, tiek azoto poveikis yra neigiamas, tuo tarpu žolių/krūmokšnių rūšims – teigiamas. Visgi, azoto poveikis žolių/krūmokšnių rūšims priklauso ne tik nuo dozės, bet ir nuo patekimo į miško ekosistemą dažnio. Brukniniuose pušynuose... [toliau žr. visą tekstą] / In Lithuania the energy production from the forest wood comprises up to 90% of the total biomass derived energy. Increasing use of wood fuel increases the removal of the plant essential nutrients from the ecosystem because the branches, tops and needles/leaves contain relatively higher amount of the nutrients than stems. If to compare with the removal of the stems-only, the nutrient losses from the forest ecosystem increase up to 5 times. One way to return nutrients to the ecosystem is to apply forest fuel waste – wood ash - as fertilizers. In this study the effects of the differential wood ash fertilization and ash fertilization in complex with nitrogen on the ground vegetation structure (species composition, abundance), biomass and chemical composition in Pinus sylvestris stands (forest type – Vaccinio-Pinetum) was estimated. For the first time, the long-term impact of nitrogen as well the influence of the high nitrogen doses on ground vegetation structure and abundance in Scots pine stands growing on infertile sandy soils (Haplic Arenosols) were studied in Lithuania. The spreading of the nitrophylous plant species in the ground vegetation in pine stands during 20 years period were detected. The role of the trees competition in the soil rhizosphere zone on ground vegetation was analysed. The following soil and ground vegetation parameters were estimated: soil moisture, pH and chemical composition, also the biomass of vascular plants, coverage, biomass and chemical... [to full text]

The distribution of Heterobasidion annosum in Scots pine stands in Nemenčinė Forest Enterprise, Mera and Magūnai forest districts were examined in this Master thesis. The object of the study: Scots pine stands that were established on formerly used agricultural land, former tank range areas and the stands growing in the cut areas of mature stands. Also, the Scots pine stands where after partly clear sanitation cuttings the birch groups were planted, in purpose to avoid the disturbances of Heterobasidion annosum. The aim of the study: to summaries the information about the distribution of Heterobasidion annosum in Lithuanian forests; to study the distribution of Heterobasidion annosum in Scots pine plantations established in agricultural lands and the cut areas of mature stands. The evaluation of the effectiveness of earlier used partly clear sanitation cuttings against Heterobasidion annosum in disturbed stands was also done. Methods: the distribution of Heterobasidion annosum in the forests of Nemenčinė Forest Enterprise, Mera forest district was evaluated visually. Each studied plot was evaluated according 4 grades. 6 assessment plots in Magūnai forest district were evaluated for the effectiveness of partly clear sanitation cuttings. The stand characteristics of the remained healthy pine and birch trees were measured using standard silvicultural mensuration methods, taking the measurements of each tree at breast height, in 2 cm precision. The results: The distribution of... [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]