Klimato sąlygų poveikis paprastosios pušies metiniam prieaugiui Aukštaitijos nacionaliniame parke (Lietuva)

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First records of Phytophthora spp. based on DNA analysis in Lithuania

The assessment of alien invasive species of Phytophthora genus causing serious forest tree species diseases was carried out in Lithuania. The presence of Phytophthora DNA was recorded for the first time using real-time PCR analysis on 23 DNA samples. The sampling includes wood from diseased trees, leaves from shrubs, leaves baited in water, and soil samples taken around diseased plants. Extracted DNA from soil and plant tissues was tested for the presence of Phytophthora. All analysed samples were positively recognized by Phytophthora-specific probe during real-time PCR which proves the presence of pathogens in environmental samples.Przemysław Szmi

Dendrochronological Analysis Of Subfossil Fraxinus From The Middle And Late Holocene Period In Lithuania

Dendrochronological investigations on subfossil European ash (Fraxinus excelsior L.) wood found in two bogs of Western Lithuania are presented. Radiocarbon dating has revealed that Fraxinus grew in the Middle and Late Holocene, from approximately 4700 BC to 1500 BC. It is proposed that the growth of Fraxinus at these bogs was limited by differing hydrological regimes. Rising soil water levels induced a long decline in radial growth followed by a sharp reduction (up to 51%) in ring widths before the trees died. Until now, forest history in Lithuania was mostly based on results from palynological studies. This research demonstrates the potential of using dendrochronology to extend the distribution record of Fraxinus in the Baltic region during different periods of the Holocene.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]

Dendroklimatologinis paprastosios pušies (Pinus sylvestris L.) tyrimas Lietuvos pajūryje

Aplinkos tyrimų centrasVytauto Didžiojo universiteta

Dendroclimatological study on the radial growth of European larch (Larix decidua Mill.) in Lithuania

Larch trees were planted in Lithuania at the beginning of the 19th century. European larch is one of the most beautiful planted trees in Lithuanian parks and forests. The influence of climatic factors on treeͲring formation of larch in Lithuania is not adequately studied. Earlier results based usually on several trees or few experimental plots and applying different methodology have provided controversial results. It was known that the radial growth of larch in Lithuania is tolerant to winter colds as well as the significant role of climatic conditions in previous season. This study was aimed at investigating the climate/radial growth relationships of larch using response function and pointer year analysis in a network of experimental plots in Lithuania. Moreover, we have investigated the interͲrelationships between negative pointer years and light rings of larch. 26 research plots (357 mature larches) were selected in larch stands in Lithuania. TreeͲring widths were measured using an image analysis technique. Then, the crossͲdating and standardization were carried out and local chronologies were compiled. The response function analysis was carried out in 17 plots from 1950– 2003. The stability of relationships was tested in three longest larch chronologies using moving intervals from 1895–2006. Response function has demonstrated that the radial growth of larch is inversely related to air temperature in previous June – September, while the relationships in previous July are statistically significant in all regions and stable from 1895–2006. The influence of air temperature in April and May is positive and increasing. The relationships in January are higher in Eastern Lithuania. However, coefficients are decreasing. The relationships with precipitation are usually positive across Lithuania, but more variable than the relationships with air temperature.[...]Aplinkos tyrimų centrasVytauto Didžiojo universiteta

1992 m. sausra Lietuvoje ir pasekmės paprastajai eglei

Vytauto Didžiojo universiteta

Dendrochronological analysis of subfossil fraxinus and quercus wood excavated from the Kegai mire in Lithuania

Dendrochronological investigations on subfossil Fraxinus and Quercus wood found in the Kegai mire in Western Lithuania are discussed. Radiocarbon dating has revealed that the trees grew in the Middle and Late Holocene (Fraxinus approximately from 4700 BC to 1500 BC and Quercus from 3400 to 2300 BC). These trees were slow-growing (on average less than 1 mm per year) and usually with a less pronounced age trend in comparison to living trees. The subfossil Fraxinus lived longer (131 years) than modern ash trees (76 years). It is supposed that their growth was limited by humid periods. The raise of soil water induced a long downward trend in ring width of ash and oak. This was followed by an abrupt reduction (up to 51%) in ring width before the die-off of ash trees. Up to now, forest history in Lithuania relied mostly on palynological studies, thus our results extend the current knowledge on the distribution of deciduous trees in the Baltic region in different periods of the HoloceneAplinkos tyrimų centrasVytauto Didžiojo universiteta

Seasonal growth variations of pine, spruce, and birch recorded by band dendrometers in NE Lithuania

We present the 1976-2010 results of a study on seasonal circumference growth carried out in NE Lithuania. The growth variations were recorded every three days using manual band dendrometers installed on 29 trees: 23 Scots pines (Pinus sylvestris L.), 3 Norway spruces (Picea abies (L.) Karsten) and 3 silver birches (Betula pendula Roth). The average onset of the growth was observed between May 6-10 and the cessation between August 28-30; growth on average lasted for 111-117 days. The growth onset and cessation time were highly variable among individual trees. A tendency for an earlier onset and cessation, and for an increase in growth duration from 1976 to 2010 was observed. Pine and spruce reach their maximum growth in June, while the birch culminated in July. Birch demonstrated much slower growth in April and May in comparison to pine and spruce. Our study has revealed a tendency of an increasing growth rate during April-June and an inverse trend in July and AugustAplinkos tyrimų centrasVytauto Didžiojo universiteta