The results of the formation of overstocked 15year pine stands (with initial density of trees 35.6 thousand per ha) in the Krasnoyarsk foreststeppe the thinning aimed at reducing their density with ...keeping only the trees of a certain cenotic position (dominant, codominant and suppressed) in order to obtain information about the possible equalization of their forest inventory indicators in the process of their growth are presented. It was found that after thinning the dominant trees stand had density of 4.3 thousand per ha, had the best growth characteristics (mean height and mean diameter) and upheld that tendency through the whole observation period. After 7 years mean diameter of dominant trees increased from 4.8 ± 0.1 to 9.4 ± 0.2 cm, mean height increased from 4.8 ± 0.1 до 8.1 ± 0.1 m. Stem timber volume increased 5.0 times to the value of 141.63 m3 per ha, relative density – from 0.51 to 1.27. Stand density for codominant trees decreased to 6.6 thousand per ha after the thinning. The mean diameter of codominant trees increased 2.6 times and amounted 6.1 ± 0.1 cm, the mean height increased from 3.4 ± 0.1 to 5.7 ± 0.1 m. Stem timber volume increased from 7.92 to 60.06 m3/ha, relative density increased 3.7 times (1.00). After the thinning the suppressed trees underwent a long (1–2 years) adaptation period, had disproportional growth in height and decreased growth in diameter (relative height 244). Stand density for suppressed trees pine Pinus sylvestris L. decreased to 6.3 thousand per ha after the thinning. The mean diameter of the suppressed trees after 7 years after the thinning changed from 0.9 ± 0.1 to 4.2 ± 0.1 cm, the mean height – from 2.3 ± 0.1 to 3.8 ± 0.1 m. Timber volume increased from 1.09 to 17.23 m3 per ha, relative density increased from 0.07 to 0.69.
Carbon storage and sequestration in tropical mountain forests and their dependence on elevation and temperature are not well understood. In an altitudinal transect study in the South Ecuadorian ...Andes, we tested the hypotheses that (i) aboveground net primary production (ANPP) decreases continuously with elevation due to decreasing temperatures, whereas (ii) belowground productivity (BNPP) remains constant or even increases with elevation due to a shift from light to nutrient limitation of tree growth. In five tropical mountain forests between 1050 and 3060 m a.s.l., we investigated all major above- and belowground biomass and productivity components, and the stocks of soil organic carbon (SOC). Leaf biomass, stemwood mass and total aboveground biomass (AGB) decreased by 50% to 70%, ANPP by about 70% between 1050 and 3060 m, while stem wood production decreased 20-fold. Coarse and large root biomass increased slightly, fine root biomass fourfold, while fine root production (minirhizotron study) roughly doubled between 1050 and 3060 m. The total tree biomass (above- and belowground) decreased from about 320 to 175 Mg dry mass ha⁻¹, total NPP from ca. 13.0 to 8.2 Mg ha⁻¹ yr⁻¹. The belowground/aboveground ratio of biomass and productivity increased with elevation indicating a shift from light to nutrient limitation of tree growth. We propose that, with increasing elevation, an increasing nitrogen limitation combined with decreasing temperatures causes a large reduction in stand leaf area resulting in a substantial reduction of canopy carbon gain toward the alpine tree line. We conclude that the marked decrease in tree height, AGB and ANPP with elevation in these mountain forests is caused by both a belowground shift of C allocation and a reduction in C source strength, while a temperature-induced reduction in C sink strength (lowered meristematic activity) seems to be of secondary importance.
O presente trabalho apresenta resultados sobre a análise do crescimento de Araucaria angustifolia (Bertol.) O.Kuntze (Araucariaceae) no planalto norte de Santa Catarina, relativos à estimativa da ...idade, incremento do lenho, cronologias e correlações com temperatura e precipitação. Foram coletadas amostras de madeira de 74 árvores de duas áreas, uma em São Bento do Sul (SB) e outra em Campo Alegre (CA), com auxílio de trado de incremento de 5 mm de diâmetro, que foram secas ao ar livre e polidas. As camadas de crescimento foram contadas e mensuradas no Image ProPlus, codatados com o auxílio do software COFECHA e as séries temporais foram utilizadas para produzir cronologias no software ARSTAN. A idade das árvores variou de (19) 38 (65) anos em SB e de (34) 62 (123) anos, em CA. O incremento médio foi de (0,03) 3,86 (16,46) mm com desvio padrão de ±2,16 mm em SB e de (0,08) 2,56 (12,79) mm e desvio padrão de ±1,67 mm em CA. A correlação com variáveis meteorológicas indicou que o incremento do lenho de A. angustifolia no planalto norte de Santa Catarina é inversamente proporcional à temperatura média no inverno e primavera do ano corrente, antes e durante a fase de crescimento, e diretamente proporcional à precipitação média no verão anterior à fase de crescimento.
Relationships between climatic variables and tree-ring width (TRW) of dominant European larch ( Mill.) and European beech ( L.) trees growing outside of their natural distribution area in western ...Latvia were studied. Chronologies of TRW, which covered the periods 1949â2012 and 1911â2012, were produced for beech and larch, respectively. Common signatures in TRW between both species were observed, but their amplitude differed. Correlation analysis showed that variation of TRW of both species was affected by drought related climatic variables. Tree-ring width of beech was affected by temperature in the previous July and August and the effect of spring and autumn temperature was observed. Since the 1980s, the effect of July precipitation has become significant. Summer precipitation was significant for larch in the mid-part of the previous century; however, temperature in the previous September has become a limiting factor since 1970s. The limiting effect of winter and spring temperature apparently lost its significance around the 1950s.
Larix decidua
Fagus sylvatica
Abstract This work aims to analyze the age structure of forests in Krasnodar Krai in order to estimate their carbon sequestration potential. The research was conducted during 2015–2020 in 14 forested ...districts of Krasnodar Krai in the Russian Federation. A database of 96,000 sample plots was used. Aspen occupied the maximum area (20% of trees), while much smaller areas were occupied by linden, birch, pine, and oak (p≥0.05 with aspen). Spruce occupied three times smaller areas compared to aspen (p≤0.05), while maple, elm, ash, and alder had ten times smaller areas (p≤0.01). Among deciduous species by age, mature and overmature stands predominate, while in conifers a young growth prevails (44% – for pines). All pine forests belong to the 1st quality class (91%), for birch and aspen, it is 75–80% of trees (p≤0.05 with the frequency for pine), for spruce – 52% (p≤0.05), and for oak – 10% (p≤0.01). Different tree species make different contributions to carbon sequestration – from 0.3 tons per 1 ha ( Alnus glutinosa ) to 1.7 tons per ha ( Fraxinus excelsior ). Taking into account the areas occupied in the forest by different tree species, their contribution will also be different – from 0.5 thousand tons/1 year ( F. excelsior ) to 290 thousand tons per 1 year ( Populus tremula ). The total increase in wood stocks and carbon sequestration is mainly due to six forest tree species. The results obtained can be used to assess the potential for carbon sequestration in temperate forests, taking into account their different age structure and tree species composition.
Within the framework of the International Cooperative Programme on Integrated Monitoring (ICP IM), nitrogen pools and fluxes and their balance were determined for the German Integrated Monitoring ...(IM) site, Neuglobsow, characterized by very low soil nitrogen. From 1998 to 2013, total nitrogen (N) deposition in form of ammonium and nitrate was 6.80 ± 1.36 and 6.46 ± 1.09 kg N ha
−1
year
−1
, respectively (in total 13.26 ± 2.01 kg N ha
−1
year
−1
). Meanwhile, the average gaseous loss was 0.7 kg N ha
−1
year
−1
and the leaching loss was 2.38 kg N ha
−1
year
−1
. Since the remaining atmospheric net N-inputs (10.18 kg N ha
−1
year
−1
) exceeds plant uptake (8.36 kg N ha
−1
year
−1
), there is a nitrogen surplus of 1.82 kg N ha
−1
year
−1
. This surplus and the accelerated mineralization of the soil organic matter which was stored during the decades before the study began when temperatures were slightly cooler, combined with low leaching rates, explain the high nitrogen supply found in the leaves and needles. However, with decreasing nitrogen deposition, biomass export and with air temperatures rises expected the ecosystem N-supply will likely decline in the long run.
Tree-ring analyses and dendrometer measurements were carried out on 37 tree species in a semi-deciduous forest of the Reserva Forestal de Caparo, Venezuela, where the mean annual rainfall is about ...1700mm and there is a dry season from December to March. The main purposes of the investigation were to show the seasonality of cambial growth, and the connection between precipitation patterns and tree-ring curves. Long-term rates of wood increment were also estimated. Cambial markings in consecutive years showed that annual rings were formed by many species. The distinctiveness of growth zones was usually greater in deciduous species than in evergreen species, although not all deciduous species had distinct rings. Dendrometer measurements showed that the annual growth rhythm was related to precipitation patterns. Evergreen species tended to show only a short interruption of wood growth (during the later part of the dry season), whereas deciduous species stopped growth completely at the end of the rainy season. For deciduous species, regression analyses showed close relations between tree-ring width and the sum of precipitation outside the rainy seasons (i.e. November to April). Evergreen species reacted to the total annual amount of precipitation. Variation in longest available ring chronology (for Terminalia quianensis) showed little correlation with the El Nino-Southern Oscillation effect. On average trees from natural forests showed relatively constant growth over the entire life span. Plantation trees grew fast up to an age of 15-20 years, but annual increments then decreased to values seen in natural forest trees.
For the last 200 years for territory of the Zilair plateau (Southern Ural Mountains) on the basis of the analysis of an increment of late wood of common oak (Quercus robur L.) reconstruction of ...strong damages of leaves of an oak by gypsy moth (Limantria dispar L.) was made. It is shown that during gypsy moth outbreaks, as a rule, in the first year of outbreak the oak forests located in a southern part of a plateau were damaged. For the second and third years of outbreak strong damages of an oak were displaced in northern direction.
Рассмотрены количественные данные о радиальном приросте стволовой древесины дуба черешчатого (Quercus robur L.) в условиях нефтехимического загрязнения в Башкирском Предуралье. Показано, что на ...границе ареала распространения дуб черешчатый становится более чувствительным к техногенному воздействию и климатическим изменениям, а при усилении степени загрязнения радиальный прирост достоверно снижается. В условиях техногенного загрязнения в онтогенезе дуба значительно сокращается виргинильный период, тогда как остальные онтогенетические периоды практически не изменяются. Радиальный прирост поздней древесины дуба полностью отражает динамику изменения общего радиального прироста; радиальный прирост ранней древесины для дуба является малоинформативным параметром. Поскольку дуб в Предуралье произрастает на границе ареала своего распространения, в динамичных условиях окружающей среды с критическими для него природно-климатическими и техногенными характеристиками, при лесовосстановлении и озеленении промышленных зон следует отказаться от широкого использования дуба черешчатого в пользу других древесных растений.
Quantitative data on oak stem wood radial increment were obtained in the Urals foothills area of Bashkiria impacted by petrochemical pollution. It has been shown that oak is most sensitive to anthropogenic and climatic influences at the periphery of its areal and that its radial increment significantly decreases with increasing pollution. The virginal period significantly shortens under anthropogenic pollution, whereas other ontogenetic periods remain virtually unaffected. Oak late stem wood radial increment is fully responsible for changes in the total stem wood increment, whereas changes in the early stem wood increment are of low informative value. Because oak in Urals foothills is confined to the periphery of its natural areal, its wide use for reforestation and gardening in industrial zones impacted by anthropogenic pollution and drastic climatic changes is unreasonable, and preference should be given to other woody plants.
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