Коваль І. М.

Dendroclimatology as the Part of Dendrochronology

As a the brench of dendrochronology, dendroclimatology assesses the climate in the past and uses tree rings and weather data, mainly precipitation and temperatures, to assess future climate change. The rate of publications on dendroclimatology was slow during the first half of the 20th century, but it has grown exponentially since the 1960s. More than 3,000 of the 12,000 scientific publications now listed in the dendrochronology's online bibliog-raphy contain the word "climate". The purpose of the paper is to review the history of dendro-climatology and its basic provisions. The American astronomer A.I. Douglas at the beginning of the 20th century developed the methods and principles that we use today. The basic principles of dendrochronology are borrowed from general ecology: the uniformitarian principle, the principle of limiting factors, the principle of aggregate tree growth, the principle of ecological emplitude, the principle of crossdating, the principle of cite celection. The basic methods in dendrochronology are: selection of research sites, selection of cores, cross-dating, in-dexation of tree-ring chronologies. Statistical methods for quantifying tree to climate ratios are briefly discussed, as well as correlation analysis and response function. Examples of dendroclimatological studies are given. F.G. Kolyshchuk proposed an original technique for the study of radial pine growth in the Carpathian Mountains. He found that during the last 200 - 230 years different species of pine (Pinus mughus Scop., Sembra L.) growing in the high mountains and inter-forested marshes (P. Silvestris L., P. Mughus Scop.) In the Ukrainian Carpathians it’s revealed a similar growth rate in tree rings, which may be evidence of climatic conditioning of the dynamics of growth and the same response of these pine species to climate change. An example study of the response of pine radial growth to climate variations in the forest-steppe zone shows an increase in the sensitivity of stands due to climate warming. Conclusions. Dendroclimatology is an interdisciplinary science that helps to determine how similar or not cli-mate is today to the past and continues to play an extremely important role in the study of the response of forest ecosystems to climate change.

Postpyrogenic Development of Young Pine Stand in Forest-Steppe

Purpose of the work is to study the response of the radial growth of pine in the young to the effects of fires. Methods. Comparative ecological methods, taxation, standard dendrochronological methods, statistical, correlation and regression analyzes were used. Results. The study was conducted in a clean, young pine stand, which was damaged by wildfire in 2011. The wildfire occurred in favorable weather conditions (the vegetation season was warm and humid), which led to mitigating the effects of fire on the plantings. It was revealed that the radial increment of damaged trees in the year of wildfire (2011) was less than the tree rings at the control by 20%. During 2012-2017 increase of the radial growth of damaged trees was revealed because about 30% of trees were drying and living trees got extra light and reveal. Radial growth of survived trees reached the level as before the wildfire. Late wood responded faster to fire damage. Conclusions. The wildfire led to the death of weakened trees, significantly speeding up the process of natural thinning of the stand. The recovery of the radial growth of surviving trees occurred in 2014. Restoration of the radial growth of trees, survivors, occurred in 2014. It is advisable to use the proportion of late wood to assess the state of plantations after a wildfire.

Dendroclimotological research of scots pine in stand of the Left-bank Forest-steppe of Ukraine

Purpose of this research was to detect influence of climatic change on pine radial increment in stand in the Left-bank Forest-steppe of Ukraine as example 100-years-old stand at State Enterprise 'Kharkiv forest scientific research station’. Methods. Dendrochronological. Method of correlation function and multiple regressions (re-sponse function) were used to analyze the influence of climatic factors on tree radial increment. For this purpose computer program RESPO was used. Results. Tree ring series were built and were used for correlation analysis between climatic factors and pine radial increment for two periods: 1960-1988 and 1988-2016.Years of mini-mum (1933, 1942, 1956, 1972, 1976, 1976, 1987, 1992, 2002, 2006 та 2012) and maximum (1933, 1942, 1956, 1972, 1975, 1976, 1979, 1979, 1979, 1987, 1992, 2002 та 2012) of radial increment were detected. Depressions of pine radial increment were as a result of negative weather conditions: low and high winter and early-spring temperature, droughts during vegetation period. Maximums of radial increments were depended on favorable weather conditions for pine radial growth. Correlation and Response analysis for two periods showed that increase of temperature and precipitation, excluding winter precipitation, changed response of forest ecosystems to climatic change: if in first period (1960-1988) radial increment limited by April temperature and together July temperature positively influenced on radial growth, in second period (1988-2016) June temperature negatively infuenced on radial increment. Slight increase precipitation during vegetation period could not soften impact if high temperature during vegetatation period on tree radial increment. Conclusions. At comparison 1960-1988 and 1988-2016 it was detected that during first period positive influence of summer temperature on radial growth was distinctive and for second period one started to limit increment (negative influence) were detected. Slight increase of precipitation for vegetation period in second period significantly didn’t influence on pine radial growth. In second period increase of winter temperature and number of thaws negatively influenced on soil moisture, decreased of tree ring widths.
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