Growth Reactions of Sub-Alpine Norway Spruce (Picea Abies (L.) Karst) Following One-Sided Light Exposure (Case Study at Davos "Lusiwald")

In 1982, several rectangular openings were cut in a 100 year old sub-alpine Norway spruce forest stand to initiate regeneration at the Lusiwald site at Davos, Switzerland. The openings on the steep, north-facing slope created rapid changes to the environment of the border trees. Growth reactions of these border trees were compared and analysed with reference trees from the adjacent closed canopy stand in 1997. The radial growth pattern of the two data sets differed within the 14-year period since the openings were cut; the border trees showed growth releases. The growth reaction at the stem base was larger than at breast height. Changes in wind exposure may have influenced border trees to adapt their root systems. Sub-alpine Norway spruce stands aged around 100 years, which are usually considered slow-growing on a north aspect, still seem capable of reacting to greater resource availability such as sudden light changes.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. It was digitized from a physical copy provided by the Laboratory of Tree-Ring Research at The University of Arizona. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]

The X-Ray Technique as Applied to Dendroclimatology

Measurements of maximum and minimum density as well as earlywood and latewood thickness are measured on Swiss alpine trees using the x-ray densitometry facilities at the Eidgenössische Anstalt für das forstliche Versuchswesen, Birmensdorf, Switzerland. Methods for assuring accurate estimates of absolute density are described. The characteristics of each type of ring measurement are discussed, and their relationships to monthly temperature and precipitation data are analysed by means of Gleichläufigkeit percentages and response function techniques. The temperature during the growing season is directly correlated with the various parameters, especially with maximum density, but temperature at other times during the year and precipitation also have some influence. Four transfer functions were obtained between the treering data and temperature at four meteorological stations from July through September. Maximum density was the single tree-ring characteristic most highly related to climatic data, but a calibration using all four tree-ring variables for the growth year concurrent with climate and for the year following the occurrence of climate gave the most reliable result. In the latter case, 70.6% of the temperature variance was calibrated, and 62.4% of the variance was verified using independent climatic data from the same climatic stations. Excellent climatic reconstructions are obtained using the four tree-ring parameters derived from the densitometric measurements.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. It was digitized from a physical copy provided by the Laboratory of Tree-Ring research at The University of Arizona. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]

Investigation and evaluation of copper and zinc concentration tendencies in Pinus sylvestris L. tree-rings / Vario ir cinko koncentracijos kaupimosi tendencijos Pinus sylvestris L. metinėse rievėse tyrimai ir vertinimas /

Free trace metals are one of the most relevant environmental problems of today; consequently, it is becoming important to evaluate their spatial distribution and accumulation rates in the natural environment. For this analysis, Scots pine (Pinus sylvestris L.) was chosen as suitable for indication of environmental stress because of its simple wood structure and of well distinct tree-rings for evaluation of temporal trace metals concentration changes. For the primary study, we chose the most evenly forested territory – the south-eastern part of Lithuania. The study results revealed that the background Zn concentration in Scots pines is 7.2 mg·kg−1 and that of Cu amounts to 2.5 mg·kg−1 The anomaly concentration of both trace metals in Scots pine defined to be higher than 21.3 for Zn and 9.0 mg·kg−1 of d.w. for Cu. The Cu and Zn concentration in Scots pine stem distributed gradually with slightly increased values towards the bark. However, a lower concentration rate was noticed in the wood formed in 1930–1950, which agrees with the most extreme climatic period in Lithuania. Santrauka Viena iš aktualių nūdienos aplinkosaugos problemų yra sunkieji metalai, tad tampa vis svarbiau kuo išsamiau įvertinti jų sklaidą ir kaupimąsi gamtinėse sistemose. Šiems tyrimams pasirinkta paprastoji pušis (Pinus sylvestris L.). Dėl paprastos medienos sandaros, aiškiai matomų metinių rievių, tinkamumo metalų koncentracijų kitimui įvertinti laikui bėgant tai yra paranki medžių rūšis aplinkai sukeliamam stresui nustatyti. Pirminiam vertinimui atlikti pasirinkta viena iš miškingiausių Lietuvos vietovių – Pietryčių Lietuva. Iš gautų rezultatų galima teigti, kad Pietryčių Lietuvoje paprastosiose pušyse Zn foninis kiekis yra 7,2 mg·kg−1, o Cu – 2,5 mg·kg−1. Taip pat buvo apskaičiuotos šių metalų minimalios anomalios koncentracijos: Zn – 21,3 mg·kg−1, o Cu – 9,0 mg·kg−1. Zn ir Cu metinėse pušies rievėse buvo pasiskirstęs tolygiai, šiek tiek koncentracijos didėjo žievės link. Taip pat pastebėta, kad metinėse rievėse, susiformavusiose 1930–1950 m., abiejų metalų koncentracija, palyginti su kitų rievių, yra šiek tiek mažesnė. Tai gali būti siejama su 1930–1960 m. vyravusių itin ekstremalių orų laikotarpiu. Резюме Одной из актуальных современных экологических проблем являются тяжелые металлы, поэтому представляетсявсё более важным исследовать их рассеяние и аккумуляцию в природных системах. Для исследования фоновогонакопления тяжелых металлов древесиной сосны обыкновенной (Pinus sylvestris L.) были выбраны деревья, произрастающие на техногенно ненарушенных территориях. Для первичной оценки была выбрана одна из наиболеелесистых местностей Литвы – юго-восточная Литва. На основании полученных результатов можно утверждать,что в юго-восточной Литве в древесине сосны обыкновенной фоновая концентрация Zn составляет 7.2 мг/кг, Cu – 2.5 мг/кг. Концентрации цинка и меди в годичных кольцах сосны разделились поровну со слегка выраженным ееувеличением в направлении коры. Было также отмечено, что в годовых кольцах, сформировавшихся в 1930–1950годах, концентрации обоих металлов по сравнению с другими годовыми кольцами роста несколько меньше, чтоможет быть связано с господствовавшими в 1930–1960 годах экстремальными погодными условиями. Reikšminiai žodžiai: cinkas, varis, Pietryčių Lietuva, paprastoji pušis (pinus sylvestris L.), metinės rievės, foninės koncentracijos Ключевые слова: цинк, медь, юго-восточная Литва, сосна обыкновенная, годовые кольца, фоновые уровн