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1
Sellin, Arne. "Sapwood–heartwood proportion related to tree diameter, age, and growth rate in Piceaabies." Canadian Journal of Forest Research 24, no. 5 (May 1, 1994): 1022–28. http://dx.doi.org/10.1139/x94-133.
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The relationships of sapwood radial width and transverse area to tree diameter, age, and growth rate were investigated in Piceaabies (L.) Karst. A total of 125 trees growing with (suppressed trees) and without (dominant trees) competition for light were sampled. Both sapwood and heartwood amounts showed an increase with diameter at the stem base, with the heartwood portion increasing more rapidly. In young trees sapwood prevails both in terms of diameter and transverse area. After trees have reached a certain age, the width of the sapwood band remains more or less constant (on average 7.8 cm for dominant and 2.0 cm for suppressed trees), and the heartwood amount exceeds that of sapwood. The percentage of heartwood in suppressed trees is substantially greater than in dominant trees of the same age. Sapwood amount is closely correlated with the tree diameter, but not with age. Tree age controls the number of rings in sapwood, while the sapwood width depends on the tree's radial growth rate as well.
2
Medhurst, J. L., C. L. Beadle, and W. A. Neilsen. "Early-age and later-age thinning affects growth, dominance, and intraspecific competition in Eucalyptus nitens plantations." Canadian Journal of Forest Research 31, no. 2 (February 1, 2001): 187–97. http://dx.doi.org/10.1139/x00-163.
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High-intensity thinning treatments were applied to young Eucalyptus nitens (Deane and Maiden) Maiden plantations aged 6 (early-age thinning), 8, and 9 years (later-age thinning). Thinning treatments were an unthinned control plus final density levels that ranged from 100 to 600 trees/ha, representing between 14 and 72% of pretreatment stand basal area. Initial planting densities were between 1143 and 1430 trees/ha. Cumulative basal area increment was significantly reduced after both early- and later-age thinning if more than 50% of the standing basal area was removed. When select groups of trees in the thinning treatments were compared with the equivalent groups of trees in the unthinned control, there was a significant response to early-age thinning in the best 100-400 trees/ha and to later-age thinning for the best 100-600 trees/ha. Height increment was not affected by thinning. However, mean live crown ratio increased with time in thinned treatments. Dominant and codominant trees showed the greatest growth response to thinning. From the data presented in this study, a final density in the range of 200-300 trees/ha is recommended. This density would improve the growth of individual trees during a rotation length of 20 to 25 years without seriously under utilizing site resources.
3
Zaffou, Madiha, and Benjamin Campbell. "Willingness to Pay for Retail Location and Product Origin of Christmas Trees." Agricultural and Resource Economics Review 46, no. 3 (July 31, 2017): 464–78. http://dx.doi.org/10.1017/age.2017.5.
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Christmas tree sales are considerable throughout the United States. Understanding the drivers of purchase for Christmas trees is critical for producers and stakeholders within states with tree production. Using data from a choice experiment in combination with latent class modeling, we find that tree height is important, but tree species is less important. Further, we show that local labeling does not influence all consumers. With respect to retail location, we show that nursery/greenhouse and choose-and-cut retail outlets are preferred by a majority of consumers but not by all consumers. Recommendations for the varying retail outlets are provided.
4
Lyon, Merritt R., and Hosam M. Mahmoud. "Trees grown under young-age preferential attachment." Journal of Applied Probability 57, no. 3 (September 2020): 911–27. http://dx.doi.org/10.1017/jpr.2020.49.
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AbstractWe introduce a class of non-uniform random recursive trees grown with an attachment preference for young age. Via the Chen–Stein method of Poisson approximation, we find that the outdegree of a node is characterized in the limit by ‘perturbed’ Poisson laws, and the perturbation diminishes as the node index increases. As the perturbation is attenuated, a pure Poisson limit ultimately emerges in later phases. Moreover, we derive asymptotics for the proportion of leaves and show that the limiting fraction is less than one half. Finally, we study the insertion depth in a random tree in this class. For the insertion depth, we find the exact probability distribution, involving Stirling numbers, and consequently we find the exact and asymptotic mean and variance. Under appropriate normalization, we derive a concentration law and a limiting normal distribution. Some of these results contrast with their counterparts in the uniform attachment model, and some are similar.
5
Vichrová, G., H. Vavrčík, V. Gryc, and L. Menšík. "Preliminary study on phloemogenesis in Norway spruce: influence of age and selected environmental factors." Journal of Forest Science 57, No. 5 (May 16, 2011): 226–32. http://dx.doi.org/10.17221/1836-jfs.
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The process of phloem formation in Norway spruce (Picea abies [L.] Karst.) was analysed during the growing season 2009 in Rájec-Němčice locality (Czech Republic). The research series consisted of research plots with 34 and 105 years old spruce monocultures. The formation of phloem cells was determined by the examination of small increment cores taken once a week. Cross-sections of tissues were studied under a light microscope. Cambium activation was observed on 9 April both in young and old trees. On the same date the first newly formed cells of early phloem were observed in old trees but in young trees one week later. Although the time of early phloem formation was 14 days longer in old trees, there were no large differences in the numbers of formed cells. The beginning of the longitudinal axial parenchyma formation was determined in young trees on May 14. In old trees this activity was seen a week later. The influence of air temperature and soil moisture was also analysed in relation to phloemogenesis.
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Alekseychenko, N. А., and M. А. Podolhova. "Age-old Trees of Ukrainian Polissya's Dendrological Parks." Scientific Bulletin of UNFU 26, no. 4 (June 30, 2016): 22–27. http://dx.doi.org/10.15421/40260403.
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Kärenlampi, Petri P. "Age distribution of trees in stationary forest system." Journal of Theoretical Biology 270, no. 1 (February 2011): 13–18. http://dx.doi.org/10.1016/j.jtbi.2010.11.019.
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Quinn, Eadaoin M., and Sean C. Thomas. "Age-related Crown Thinning in Tropical Forest Trees." Biotropica 47, no. 3 (April 8, 2015): 320–29. http://dx.doi.org/10.1111/btp.12218.
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Rumyantsev, Denis Evgenyevich, and Andrey Vasilyevich Cherakshev. "Methodological approaches for determining the age of trees." Principles of the Ecology 38, no. 4 (December 2020): 104–17. http://dx.doi.org/10.15393/j1.art.2020.10142.
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10
Yu, Zhongdong, Hongru Ding, Kuocheng Shen, Fangfang Bu, George Newcombe, and Huixiang Liu. "Foliar endophytes in trees varying greatly in age." European Journal of Plant Pathology 160, no. 2 (March 4, 2021): 375–84. http://dx.doi.org/10.1007/s10658-021-02250-7.
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AbstractTemple trees, including the gymnosperm Platycladus orientalis and the angiosperm Styphnolobium japonicum, have been planted in China for thousands of years. Tree age thus varies widely from young to ancient trees. Foliar endophytes of P. orientalis and S. japonicum were surveyed in this exploratory study that was based on isolation into culture and sequencing of fungi from trees varying in age from 10 to 5000 years (P. orientalis) and from 10 to 1700 years (S. japonicum). Sequenced endophytes of P. orientalis and S. japonicum belonged to 24 and 16 fungal genera, respectively. Principal components analysis showed that 14 components were necessary to explain 90% of the variance in endophyte community structure in P. orientalis. In S. japonicum eight components were needed for 90%. It is against that backdrop of complex etiology in community structuring, that the relative frequencies (abundances) of 17 of the 24 endophytes from P. orientalis and 9 of the 16 from S. japonicum were significantly correlated with tree age. There were two major trends. Abundant fungal genera [Fusarium + Alternaria = 74.57% (P. orientalis) and 81.24% (S. japonicum)] tended to decline linearly with tree age. Most of the rare fungal genera, in contrast, increased in relative abundance linearly with tree age. Diversity (H′) and richness (Margalef) of endophyte communities in foliage thus increased as the trees aged. Relative abundances of pathogenic endophytes, or latent pathogens, (Pestalotiopsis funerea and Amyloporia subxantha in P. orientalis; Collectotrichum gloeosporioides and Botryosphaeria dothidea in S. japonicum) also increased linearly as the trees aged.Since leaf age does not vary with tree age in the deciduous S. japonicum, nor in the evergreen P. orientalis, ‘tree age’ currently lacks a mechanistic explanation for its apparent importance among common foliar endophytes.
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Rizeei, Hossein Mojaddadi, Helmi Z. M. Shafri, Mohamed Ali Mohamoud, Biswajeet Pradhan, and Bahareh Kalantar. "Oil Palm Counting and Age Estimation from WorldView-3 Imagery and LiDAR Data Using an Integrated OBIA Height Model and Regression Analysis." Journal of Sensors 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/2536327.
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The current study proposes a new method for oil palm age estimation and counting from Worldview-3 satellite image and light detection and range (LiDAR) airborne imagery. A support vector machine algorithm (SVM) of object-based image analysis (OBIA) was implemented for oil palm counting. The sensitivity analysis was conducted on four SVM kernel types with associated segmentation parameters to obtain the optimal crown coverage delineation. Extracting tree’s crown was integrated with height model and multiregression methods to accurately estimate the age of trees. The multiregression model with multikernel sizes was examined to achieve the most optimized model for age estimation. Applied models were trained and examined over five different oil palm plantations. The results of oil palm counting had an overall accuracy of 98.80%, while the overall accuracy of age estimation showed 84.91%, over all blocks. The relationship between tree’s height and age was significant which supports the polynomial regression function (PRF) model with a 3×3 kernel size for under 10–12-year-old oil palm trees, while exponential regression function (ERF) is more fitted for older trees (i.e., 22 years old). Overall, recent remote sensing dataset and machine learning techniques are useful in monitoring and detecting oil palm plantation to maximize productivity.
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Zhou, Qi, and Juan Carlos Melgar. "Tree Age Influences Nutrient Partitioning among Annually Removed Aboveground Organs of Peach." HortScience 55, no. 4 (April 2020): 560–64. http://dx.doi.org/10.21273/hortsci14731-19.
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The aim of this research was to assess how fruit tree age influences nutrient partitioning patterns in aboveground organs. We selected 6-year-old (mature) and 20-year-old (old) ‘Cresthaven’ peach trees and measured the macronutrient concentrations in organs removed during pruning, thinning, harvesting, and leaf fall for 3 years. Then, we calculated the total amount of nutrients removed at each event and studied the partitioning patterns between mature and old peach trees. The results showed that mature peach trees had higher phosphorus (P) and potassium (K) concentrations in fruit mesocarp and fallen leaves than old trees. When we estimated the total nutrient content, mature peach trees allocated more nitrogen (N), P, K, and calcium (Ca) to pruned wood and harvested fruit but had less N and Ca in senescing leaves compared with old peach trees. The results of this study suggest that the different proportion of organs removed through orchard management practices from trees of different ages as well as the concentration of nutrients in these organs must be considered when estimating nutrient restitution needs and tree nutritional requirements.
13
Attis Beltrán, H., G. Martínez Pastur, H. Ivancich, M. V. Lencinas, and L. M. Chauchard. "Tree health influences diameter growth along site quality, crown class and age gradients in Nothofagus forests of southern Patagonia." Journal of Forest Science 59, No. 8 (September 24, 2013): 328–36. http://dx.doi.org/10.17221/30/2013-jfs.
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We examined the influence of tree health on annual diameter increment of trees along gradients in stand site quality, crown classes and tree age in Nothofagus pumilio forests of Southern Patagonia. Healthy trees had higher annual diameter increment than unhealthy trees along all gradients (site quality, crown class, tree age). We argue that tree health could be employed as a qualitative variable in models of tree growth to estimate aboveground biomass and carbon stocks in this forest system.
14
Lai, Po Ying, C. Y. Jim, and Hao Zhang. "Heritage Trees in Macau: Relationships Among Biomass Structure, Age, and Ecosystem Services." Arboriculture & Urban Forestry 46, no. 2 (March 1, 2020): 109–34. http://dx.doi.org/10.48044/jauf.2020.009.
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Older trees in good health are expected to provide more ecosystem services and equivalent economic values due to their large size. The relationship of tree dimensions, respective tree height, crown area, diameter at breast height (dbh), and total leaf area vis-a-vis age were studied for 790 heritage trees ≥ 100 years old in Macau; 50 genera and 63 species were represented. Seven out of ten common genera showed no significant increase for all tested parameters except increase of dbh with age. Other factors, such as condition and geometry of growing spaces, controlled the performance of heritage trees, as well as the realization of their biological potential size, with implications on the provision of ecosystem services. The effects of these heritage trees on air-quality improvement and gross carbon sequestration were quantified by the i-Tree Eco model. Overall, 806.8 kg of air pollutants were removed annually, with benefits valued at US $8,091. The heritage trees stored 3,041 t carbon in total and sequestered 842 kg carbon/yr, equivalent to US $601 in annual benefits. The values were much higher than ordinary urban forest trees. Ten common heritage tree genera were ranked by their capacities for air quality improvement, carbon storage, and sequestration. The findings can serve as a decision tool for heritage tree management and conservation and to estimate potential ecosystem services of established trees
15
Chen, Y., L. Chen, Y. Xu, J. Luo, X. Wang, and S. Peng. "Estimating the age of old oil-tea camellia trees." Acta Horticulturae, no. 1185 (November 2017): 287–96. http://dx.doi.org/10.17660/actahortic.2017.1185.36.
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16
Stephens, Matthew. "Times on Trees, and the Age of an Allele." Theoretical Population Biology 57, no. 2 (March 2000): 109–19. http://dx.doi.org/10.1006/tpbi.1999.1442.
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17
Volney, W. J. A., and K. I. Mallett. "Light rings and the age of jack pine trees." Canadian Journal of Forest Research 22, no. 12 (December 1, 1992): 2011–13. http://dx.doi.org/10.1139/x92-264.
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In a routine determination of jack pine (Pinusbanksiana Lamb.) tree ages, several rings were overlooked or were difficult to count. Sections of the wood, when examined at higher magnification, revealed an unusually high proportion of "light rings." Light rings are characterized by having a small number of latewood cells whose walls are not as thick as those of latewood cells found in normal rings. Under low magnification, bands of these light rings may be interpreted as a single annual ring. Light rings may thus be a source of error in determining tree ages for forest productivity studies, particularly in older stands that have been affected by defoliators and root disease.
18
Sillett, Stephen C., Robert Van Pelt, George W. Koch, Anthony R. Ambrose, Allyson L. Carroll, Marie E. Antoine, and Brett M. Mifsud. "Increasing wood production through old age in tall trees." Forest Ecology and Management 259, no. 5 (February 2010): 976–94. http://dx.doi.org/10.1016/j.foreco.2009.12.003.
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19
Steenkamp, C. J., J. C. Vogel, A. Fuls, N. van Rooyen, and M. W. van Rooyen. "Age determination of Acacia erioloba trees in the Kalahari." Journal of Arid Environments 72, no. 4 (April 2008): 302–13. http://dx.doi.org/10.1016/j.jaridenv.2007.07.015.
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20
Turfan, Nezahat, Sezgin Ayan, Esra Nurten Yer Çelik, Halil Baris Ozel, and Saadettin Murat Onat. "Age-related changes of some chemical components in the leaves of sweet chestnut (Castanea sativa Mill.)." BioResources 15, no. 2 (April 22, 2020): 4337–52. http://dx.doi.org/10.15376/biores.15.2.4337.4352.
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The aim of this study was to investigate the developmental physiology of sweet chestnut trees (Castanea sativa Mill.) of different age groups (≥ 25, ≥ 50, ≥ 100, ≥ 200, and ≥ 400) in the Catalzeytin district of Kastamonu, Turkey. For this purpose, photosynthetic pigments, proline, total soluble protein, glucose, sucrose, total soluble carbohydrate and starch values, malondialdehyde (MDA) and hydrogen peroxide (H2O2) concentration, and also ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD) activities were measured in leaf samples. Hence, significant differences were found in the amounts and concentrations of all types of chlorophyll, carotenoid, proline, total soluble protein, glucose, sucrose, total soluble carbohydrate, starches, MDA, H2O2, APX, CAT, and SOD among the trees of different age groups. While the chlorophyll a value was low in young trees, the chlorophyll b value was low in older trees. It was determined that the MDA content was high in old trees, whereas it was low in young trees. While the amounts of glucose, sucrose, total soluble carbohydrate, and starch were highest in ≥ 400-year-old trees, they were lowest in the young trees. Both APX and CAT activities were high in young trees, whereas SOD activity was lowest in ≥ 400-year-old trees.
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Turfan, Nezahat, Sezgin Ayan, Esra Nurten Yer Celik, Halil Baris Ozel, and Saadettin Murat Onat. "Age-related changes of some chemical components in the leaves of sweet chestnut (Castanea sativa Mill.)." BioResources 15, no. 2 (April 22, 2020): 4337–52. http://dx.doi.org/10.15376/biores.15.2.4337-4352.
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The aim of this study was to investigate the developmental physiology of sweet chestnut trees (Castanea sativa Mill.) of different age groups (≥ 25, ≥ 50, ≥ 100, ≥ 200, and ≥ 400) in the Catalzeytin district of Kastamonu, Turkey. For this purpose, photosynthetic pigments, proline, total soluble protein, glucose, sucrose, total soluble carbohydrate and starch values, malondialdehyde (MDA) and hydrogen peroxide (H2O2) concentration, and also ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD) activities were measured in leaf samples. Hence, significant differences were found in the amounts and concentrations of all types of chlorophyll, carotenoid, proline, total soluble protein, glucose, sucrose, total soluble carbohydrate, starches, MDA, H2O2, APX, CAT, and SOD among the trees of different age groups. While the chlorophyll a value was low in young trees, the chlorophyll b value was low in older trees. It was determined that the MDA content was high in old trees, whereas it was low in young trees. While the amounts of glucose, sucrose, total soluble carbohydrate, and starch were highest in ≥ 400-year-old trees, they were lowest in the young trees. Both APX and CAT activities were high in young trees, whereas SOD activity was lowest in ≥ 400-year-old trees.
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Hannrup, Björn, and Inger Ekberg. "Age-age correlations for tracheid length and wood density in Pinus sylvestris." Canadian Journal of Forest Research 28, no. 9 (September 1, 1998): 1373–79. http://dx.doi.org/10.1139/x98-124.
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The existence of strong genetic correlations between traits at an early age and at an adult age should shorten the generation turnover of tree breeding populations and render forest tree breeding more effective. Genetic age-age correlations for tracheid length and wood density were estimated in Scots pine (Pinus sylvestris L.) and the efficiency of early selection for these traits was evaluated. Increment cores of 10-mm diameter were collected from trees of 106 full-sib families in a progeny trial located in southeastern Sweden and consisting of controlled matings between 30 parent trees. The additive genetic age-age correlations were consistently close to unity for all traits and ages studied. The additive genetic variance differed significantly from zero for all traits. The dominance variance was zero for tracheid length and small and insignificant for wood density. The heritabilities varied between 0.3 and 0.5. The genetic gain per year for both tracheid length and wood density was largest if selection was carried out at tree age 11, the lowest age studied, indicating that early tests for these traits will be efficient.
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Sillett, Stephen C., and Matthew N. Goslin. "Distribution of epiphytic macrolichens in relation to remnant trees in a multiple-age Douglas-fir forest." Canadian Journal of Forest Research 29, no. 8 (September 1, 1999): 1204–15. http://dx.doi.org/10.1139/x99-081.
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Alternatives to clear-cutting are being implemented to increase biodiversity of managed forests in the Pacific Northwest. Lichens are an integral component of old growth, but lichen biomass develops slowly in forests. We evaluated the long-term potential of live tree retention for lichen conservation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. We sampled lichen litterfall in a 2-ha stand that contained 200- to 600-year-old remnant trees scattered in a forest composed mostly of 100-year-old trees that established following fire. We used association, principal components, and regression analyses to relate lichen litterfall biomass to the proximity of remnant trees. Two epiphytic lichens were strongly associated with remnant trees: the foliose cyanolichen Lobaria oregana (Tuck.) Müll. Arg. and the fruticose green algal lichen Sphaerophorus globosus (Hudson) Vainio. Biomass of both species was highest near remnant trees, and biomass was slightly higher within groves of remnant trees than it was at the edges of these groves or near isolated trees. Lichens appear to have persisted on remnant trees through the last fire and are slowly recolonizing younger trees from this source of propagules. Retention of live trees, maintenance of hardwoods, and longer rotation periods have great potential to maintain old-growth-associated lichens in at least some managed forests.
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Duncan, Richard P., and Glenn H. Stewart. "The temporal and spatial analysis of tree age distributions." Canadian Journal of Forest Research 21, no. 12 (December 1, 1991): 1703–10. http://dx.doi.org/10.1139/x91-236.
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The temporal and spatial patterns of tree establishment and stand disturbance history are often based on the interpretation of age-class frequency distributions. In particular, the presence of even-aged groups of trees is often used as compelling evidence of past disturbance. However, even-aged groups of trees may be indistinguishable in an age distribution if several different-aged patches occur, especially if their ages overlap. For two different types of forest we used spatial autocorrelation analysis to statistically test for the presence of even-aged patches in tree age data. Ordination and cluster analysis were subsequently applied to a matrix of association measures that reflected both spatial proximity and age similarity to identify even-aged groups of trees. Although the method worked well for our forests, which contained light-demanding tree species, it is likely to be less applicable to forests dominated by shade-tolerant species, because trees may be of many different ages if they were present as suppressed individuals prior to disturbance. However, in these instances the method could be usefully applied in other types of analysis, such as the distribution of growth release dates, tree-fall or fire-scar dates, and growth rates.
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Connor, Kristina F., and Ronald M. Lanner. "Age-related changes in shoot growth components of Great Basin bristlecone pine." Canadian Journal of Forest Research 19, no. 7 (July 1, 1989): 933–35. http://dx.doi.org/10.1139/x89-142.
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Shoots were collected from various-aged Great Basin bristlecone pine trees (Pinuslongaeva D.K. Bailey) at three locations to determine whether shoot growth, stem unit production, and stem unit length decreased with increasing tree age. Trees from a southern Utah site were 14–2052 years old, whereas those from two White Mountains, California, locations were 824–4712 years old. Variation in shoot length, stem unit production, and stem unit length were not significant when regressed on tree age (r2 = 0.010–0.237). The fact that shoots from older trees showed no sign of reduced growth when compared with those from younger trees suggests that diminishment of annual shoot increment is not a definitive sign of aging in Great Basin bristlecone pine.
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M, Kayalvizhy. "Trees in Pathuppattu." Indian Journal of Tamil 1, no. 1 (February 25, 2020): 27–39. http://dx.doi.org/10.34256/ijot2013.
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Nature took inevitable part and parcel in our world. It plays a vital role in the life of human beings. The soil and nature are binded with Human being. Trees are the prominint part in our natural vegetation. In the Sangam age number of trees were used by Tamil people. So, our great anciestors recorded the trees in their literary works. The Sangam literature Pathuppattu Provides many informations about the trees. Those peoples lived with the trees praised it and recorded their uses for the future generations. Trees from Sangam period played an important role in the life of peope.
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Lucas-Borja, Manuel Esteban, Arun K. Bose, Enrique Andivia, David Candel-Pérez, Pedro A. Plaza-Álvarez, and Juan C. Linares. "Assessing Tree Drought Resistance and Climate-Growth Relationships under Different Tree Age Classes in a Pinus nigra Arn. ssp. salzmannii Forest." Forests 12, no. 9 (August 27, 2021): 1161. http://dx.doi.org/10.3390/f12091161.
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The magnitude of drought impact in forest ecosystems depends on which group of trees are more severely affected; greater mortality of smaller trees can modulate the trajectories of succession, while the mortality of larger trees can disproportionately offset the ecosystem’s carbon balance. Several studies have documented a greater vulnerability of large trees to extreme droughts while some other studies reported a greater growth reduction in smaller trees during droughts. We tested these hypotheses by comparing tree basal area increment (BAI), drought resistance (i.e., magnitude of growth decline during drought), and resilience (i.e., magnitude of growth recovery after drought) across five different age-classes in black pine (Pinus nigra Arn. ssp. salzmannii) forests in Spain. Our results showed that the BAI patterns, drought resistance, and resilience were strongly influenced by tree age-classes. In addition, the effect of climatic water balance (precipitation minus potential evapotranspiration) on BAI significantly varied among age-classes. The effect of water balance on BAI was lower for younger age-classes (1–39 years of age) compared to older age-classes. We observed a greater growth reduction (i.e., lower resistance) in older trees (>40 years of age) during droughts compared to younger trees (<40 years of age). However, all trees, irrespective of their ages, were able to recover the growth rates after the drought. In general, younger trees showed a greater capacity in recovering the growth rate (i.e., more resilient) than older trees. We detected no significant effects of stand basal area and stand density on BAI, drought resistance, and resilience. Overall, our results indicated that growth of older trees was more negatively affected during drought. Therefore, these older/larger trees can be selected for commercial thinning, or can be released from competition, which can minimize the potential impacts of future droughts in black pine forests in Spain.
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Clark, Stacy L., and Stephen W. Hallgren. "Age estimation of Quercus marilandica and Quercus stellata: applications for interpreting stand dynamics." Canadian Journal of Forest Research 34, no. 6 (June 1, 2004): 1353–58. http://dx.doi.org/10.1139/x04-020.
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We compared methods to correct age of cores that failed to intercept the tree's pith for two oak species, blackjack oak (Quercus marilandica Muenchh.) and post oak (Quercus stellata Wangenh.), and determined the difference in age at tree base (010 cm from ground level) versus breast height (1.4 m from ground level). Methods to correct age of off-center cores were relatively similar in error for both species (2.98.1 years). Ocular estimation of number of rings to pith required the least amount of data collection and manipulation to apply. A regression technique using tree diameter provided the lowest absolute error (913 years) for age estimation of rotten cores, compared with methods that used mean ring widths to extrapolate tree age. Age difference due to coring height averaged 9 years for both species and was highly variable, indicating that trees should be cored as close to ground level as possible. Age structure of this forest could be accurately reconstructed to within 5-year age-classes using recommended methods, with the exclusion of large, rotten, and putatively old trees.
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Matthes, Uta, Peter E. Kelly, and Douglas W. Larson. "Predicting the age of ancient Thuja occidentalis on cliffs." Canadian Journal of Forest Research 38, no. 12 (December 2008): 2923–31. http://dx.doi.org/10.1139/x08-131.
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In rocky, heterogeneous environments that support old-growth forests, the relationship between tree size and age is weaker than it is for trees growing in productive and homogeneous habitats. To assist in the management and conservation of ancient forests on rocky land of low productivity, it would be useful if the relationships among age, environmental heterogeneity, and morphological variability could be understood and used to develop predictive models of longevity so that extensive core sampling of trees would not be required. Here we sampled 296 mature Thuja occidentalis L. growing on limestone cliffs along the Niagara Escarpment, southern Ontario, Canada. We measured a variety of site conditions and morphological traits, including age, which varied from 51 to 1316 years. We then used redundancy analysis and multiple regression to model the relationships among age, morphology, growth rate, and environment, resulting in quantitative models predicting tree age from four subsets of variables. We subsequently tested the models on 60 additional trees not used to build the models and found that they predicted up to 78% of the variation in actual tree age. This approach could be adopted for use in other forest types to predict the age of trees without using tree-ring analysis.
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BOLAND, JOHN, and RUSSELL SINCLAIR. "DEVELOPING AGE-SIZE RELATIONSHIPS FOR LONG LIVED TREE SPECIES." Journal of Biological Systems 22, no. 02 (June 2014): 309–26. http://dx.doi.org/10.1142/s0218339014400087.
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Calculating the age of trees is often desirable in vegetation studies, but is sometimes difficult. In arid areas in particular, tree rings may not be annual, and growth may be related more to rainfall than annual cycles. A relationship between age and trunk circumference was developed for two species, Acacia aneura and Myoporum platycarpum, based on measurements of trees of known age (<80 years) growing on permanent quadrats on the Koonamore Reserve, in semi-arid South Australia. Extrapolation beyond the known ages was made by finding the maximum girth of mature trees in a larger population and using this to estimate an asymptote to which the curve is constrained to approach. We envisage that the techniques developed here could be applied to other species of a similar nature, those for which there is no relationship between number of tree rings and age.
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Prokopuk, Yu S., and Ya I. Krylov. "Condition, protection and maintenance of age-old pedunculate oak trees in Feofania forest." Ecology and Noospherology 29, no. 1 (June 12, 2018): 36–41. http://dx.doi.org/10.15421/031806.
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Large old trees are significant elements of forests, arboretums, botanical gardens and parks and perform a number of unique functions contributing to ecosystem integrity and biodiversity. At the same time human activities such as compaction of topsoil layers, deterioration of soil permeability and soil aeration drive the decline of large old trees. The human impact is also exacerbated by plants inevitable physiological age-specific changes. The presence of such old trees in urban environments brings great scientific promises enhancing a social, cultural and historical forest value, although these benefits increase responsibility for trees maintaining. Regarding old-growth trees historical, cultural, and environmental significance and their overall vulnerability, the individual-by-individual tree protection measures are required. Pedunculate oak (Quercus robur L.) is among the most widespread long-lived species in Europe, in particular in Ukraine. In Feofania (or Theophania) forest, that is an oak-hornbeam forest located in southern part in Kyiv, the age of the oldest oak trees reaches about 300 years. In this article, we aim to estimate vitality, overall condition, and recreational digression stages of pedunculate oak trees and to develop the recommendations to maintain and extend trees longevity in Feofania forest. We estimate the stages of recreational digression and vitality using an approach of Hensiruk et al. (1987) and Sanitary Regulations in forests of Ukraine (1995) respectively. The dendrochronological analysis is performed on core samples from sixteen age-old pedunculate oaks in order to determine their exact cambial age and to evaluate their growth rates. We use at least two cores per tree extracted at a height from 0.5 m to 1.3 m above ground level with an increment borer. The tree-ring widths are measured using AxioVision (Carl Zeiss) software to the nearest 0.01 mm. To identify false rings we employ stereomicroscope MBS-1. The individual tree-ring series are cross-dated, standardized and checked using the COFECHA program. Then we determine exact cambial age of oak trees as number of tree-rings in individual series. To estimate the age of trees with cores without pith we use a graphical method. The analyze is performed on 42 increment cores containing 7335 annual rings formed in the period from 1746 to 2016. Measured diameter of the age-old oaks ranges from 57.6 cm to 165.2 cm. The longest chronological series contains 271 years. The age of studied trees varies from 202 to 275 years averaging 175 years and radial growth ranges from 1.07±0.400 mm to 2.85±1.487 mm averaging 1.95±0.792 mm. In recent years the reduction of radial growth isn’t observed, although in a long time interval in five studied trees the rings width not exceeds the individual series average value. However, the growth rate reducing could not be regarded as critical for trees vitality because it is above 10 % of the average value yet. The evaluated mean increment coefficient is 5.13±1.482 years in cm that allows to estimate the age of dominant and codominant oaks in the association of Galeobdoloni luteae-Carpinetum in other forests. The estimated vitality is mostly of 6–7 points. Five oaks are in «satisfactory condition», nine oaks are «weakened», one oak is «very weakened» and one tree is «dying». «Weakened» trees are with mechanically damaged stem and are often suffered from leaves defoliation caused by Acrocercops brongniardella and Microsphaera alphitoides. Regarding wood samples maintenance, the «dying» oak stem is found rotted in its center. The recreational digression is at the stage 1–4. For eight oaks it is at the first stage, for four oaks at the second stage, for two oaks at the third stage and for two oaks at the fourth stage with 60 % destruction of the understorey. The number of age-old Q. robur trees is limited, thus measures to care could consider individual tree-specific features. Given trees vitality and stages of recreational digression, we develop the guidelines to preserve and extend trees longevity. We also propose to include four old-growth oaks in the list of monumental plants.
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Netsvetov, M. V., and Yu S. Prokopuk. "Age and radial growth of age-old trees of Quercus robur in Feofania Park." Ukrainian Botanical Journal 73, no. 2 (April 30, 2016): 126–33. http://dx.doi.org/10.15407/ukrbotj73.02.126.
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Bobinac, Martin, Sinisa Andrasev, Andrijana Bauer-Zivkovic, and Nikola Susic. "Effects of heavy thinnings on the increment and selection of trees for tending in Norway spruce monoculture in natural hazard conditions." Bulletin of the Faculty of Forestry, no. 115 (2017): 31–54. http://dx.doi.org/10.2298/gsf1715031b.
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The paper studies the effects of two heavy selection thinnings on the increment of Norway spruce trees exposed to ice and snow breaks in eastern Serbia. In a thinning that was carried out at 32 years of age, 556 candidates per hectare were selected for tending, and at the age of 40, of the initial candidates, 311 trees per hectare (55.9%) were selected as future trees. In all trees at 41-50 age period, diameter increment was higher by 31%, basal area increment by 64% and volume increment by 67% compared to 32-40 age period. The collective of indifferent trees is significantly falling behind compared to future trees in terms of increment values in both observed periods. However, the value of diameter, basal area and volume increments, of the collective of "comparable" indifferent trees are lower in comparison to the values of increments of future trees by 10-15% in the 32-40 age period, and by 15-21% in the 41-50 age period and there are no significant differences. The results show that heavy selective thinnings, initially directed at a larger number of candidates for tending at stand age that does not differ much from the period of carrying out first "commercial" thinnings, improve the growth potential of future and indifferent trees, where it is rational to do the tree replacement for the final crop in "susceptible" growth stage to snow and ice breaks.
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Jones, Robert H., and Dudley J. Raynal. "Root sprouting in American beech: production, survival, and the effect of parent tree vigor." Canadian Journal of Forest Research 17, no. 6 (June 1, 1987): 539–44. http://dx.doi.org/10.1139/x87-090.
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Root sprout age-class distributions around American beech trees were measured to characterize production of sprouts under closed canopies. Annual mortality of root sprouts was estimated by static and cohort life table analyses. Sprouts around parent trees with and without beech bark disease were compared to test for effects of lowered parent vigor on sprout production and vigor. Age-class distributions were highly variable, indicating episodic production of sprouts. Trends in the data suggested that (i) for individual parent beech trees, the number of sprouts per age-class decreased exponentially as sprout age increased; and (ii) parent trees with larger diameters had more sprouts, more sprout age-classes, but greater variability in age-class distribution. Life table analyses indicated uniform per capita mortality rates for clumps of sprouts but decreasing mortality with age for individual sprouts within clumps. Low parent vigor, due in part to beech bark disease, was weakly correlated with reduced sprout production, but diseased trees maintained populations of older sprouts that differed little from sprouts associated with nondiseased trees.
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Wall, R. E. "Deterioration of severely defoliated balsam fir in relation to stand age, spacing, and foliar protection." Canadian Journal of Forest Research 18, no. 5 (May 1, 1988): 490–97. http://dx.doi.org/10.1139/x88-072.
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Balsam fir (Abiesbalsamea (L.) Mill.) trees that had been heavily defoliated by the spruce budworm (Choristoneurafumiferana (Clem.) were felled and examined for decays and secondary insect activity during the declining phase of the budworm outbreak. Trees were sampled in (i) a 25- to 30-year-old stand that had been spaced a decade earlier to about 2.4 × 2.4 m and allowed to become defoliated, (ii) adjacent unspaced controls, (iii) a nearby mature (60- to 80-year-old) stand that had been defoliated, and (iv) and (v) spaced and unspaced plots that had been protected from defoliation by annual sprays of trichlorfon. Sampling was done annually over a 4-year period from preselected defoliated trees, and after the budworm population had collapsed from trees that had been intensively studied with respect to defoliation and mortality. Where defoliation was allowed to proceed unchecked (i) one-half of the spaced, (ii) one-third of the unspaced, and (iii) all of the mature trees died. The trees were attacked by wood wasps (Siricidae) and the sapwood-staining fungus, Amylostereumchailletii (Pers. ex Fr.) Boidin, followed by various stem-invading insects (Pissodesdubius Rand., Pityokteinessparsus Lee, Trypodendronlineatum (Oliv.), and Monochamusscutellatus Say) and by the sap-rot fungus Hirschioporusabietinus (Pers. ex Fr.) Donk. In surviving defoliated trees (i and ii) and in trees that had been protected by trichlorfon sprays (iv and v), numerous siricid injuries with associated pockets of stain caused by A. chailletii were found in the lower bole.
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Turfan, Nezahat, Sezgin Ayan, Esra Nurten Yer, and Halil Barış Özel. "Age-Related Changes of Some Chemical Components in the Leaves of Oriental Beech (Fagus orientalis Lipsky.)." South-east European forestry 10, no. 2 (November 4, 2019): 117–24. http://dx.doi.org/10.15177/seefor.19-15.
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Background and Purpose: This study presents the analysis of photosynthetic pigments, proline, total soluble protein, total amino acids, glucose, sucrose, total soluble sugars, total amount of phenolic compounds and flavonoids, malondialdehyde (MDA) and hydrogen peroxide (H2O2) concentration in the leaf samples collected from oriental beech trees, which are naturally spread in Kastamonu Province, Turkey, with differing ages, enzyme activities of ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD). Material and Methods: The research was carried out on oriental beech trees (Fagus orientalis L.) of different ages located at 1300 m high elevation in Ahlat Village of Kastamonu Province, Turkey. Oriental beech trees of different ages (≥25, ≥50, ≥100, ≥200 and ≥600 years-old) constituted the material of this study. In leaf samples taken from trees of different ages, photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoid), proline, total soluble protein, total amino acid, glucose, sucrose, total soluble sugars, the amount of total phenolic compounds and flavonoids, MDA, H2O2 concentration, enzyme activities of APX, CAT and SOD, as well as the relationship between the total content of C, N and H elements and the tree ages were studied. Results: As a result of the research conducted, significant differences were determined in terms of chlorophyll, total phenolic compound, flavonoid, glucose, amounts of sucrose, nitrogenous compounds, proline, total soluble protein, MDA, H 2O2 concentrations, and the activities of APX, CAT and SOD in the leaves of oriental beech trees with differing ages. The highest content of chlorophyll a was found to be in the youngest age group of ≥25 years. Total chlorophyll is low in young trees and high in middle-aged, old and very old trees. According to the results obtained, it was concluded that the MDA and H2O2 concentrations in the trees did not vary depending on the age of trees only, but also on the genotype, environmental conditions and metabolic activities. It was concluded that the fact that the total chlorophyll, phenolic compounds and sucrose content in oriental beech trees are high and that MDA content is low could have an influence on the long life of ≥600 years-old oriental beech trees. Conclusions: The activity of photosynthesis is related to leaf characteristics more than the age of trees.
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Hart, Patrick J. "Tree growth and age in an ancient Hawaiian wet forest: vegetation dynamics at two spatial scales." Journal of Tropical Ecology 26, no. 1 (December 8, 2009): 1–11. http://dx.doi.org/10.1017/s0266467409990320.
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Abstract:In this study I document the growth rate and age of trees in an old-growth montane Hawaiian wet forest and use these results to evaluate the cyclic succession model for forest dynamics. I used two methods to estimate the age of trees – the crown-class model and radiocarbon dating. Over 6000 trees belonging to eight species were tagged and measured over 7 y on Hawaii Island. Growth rates for the dominant tree (Metrosideros polymorpha) were relatively low (mean = 1.3 mm y−1) and varied with tree size and crown class. 14C-based age estimates for 27 M. polymorpha trees loosely corroborated estimates based on the crown-class method. The oldest tree dated by 14C had a median age of 647 y BP, placing it among the oldest documented angiosperm trees in the northern hemisphere. 14C dating revealed that the upper canopy may be comprised of three distinct age groups of M. polymorpha trees of similar size, with the median age of each group separated by 200–250 y. The high density of large, very old trees in multiple groups is unusual for a tropical forest and indicates that forest development may occur through gap-phase regeneration at a fine scale and stand-level mortality at a coarser scale.
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Zawieja, Bogna, and Katarzyna Kaźmierczak. "Longitudinal analysis of annual height increment differentiation in Scots pine (Pinus sylvestris L.) stands of different age classes." Folia Forestalia Polonica 56, no. 4 (December 1, 2014): 179–84. http://dx.doi.org/10.2478/ffp-2014-0020.
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Abstract In the study, the measurements of Scots pine height increments were used to compare the increments of pine trees of different age classes. All of the analyzed trees were growing in stands located on fresh mixed coniferous forest sites. The study concerned a 10-year period of growth of 8 tree age classes. Due to variation in climate conditions, all trees were studied over the same calendar period. Longitudinal analysis was used to compare different age classes of trees with reference to the increments in height. This procedure had not been previously used for such purpose. The results obtained did not confirm the hypothesis of parallel profiles implying that there existed differences in the growth of trees in various age groups.
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Pickering, Catherine Marina, and Kristy Barry. "Size/age distribution and vegetative recovery of Eucalyptus niphophila (snowgum, Myrtaceae) one year after fire in Kosciuszko National Park." Australian Journal of Botany 53, no. 6 (2005): 517. http://dx.doi.org/10.1071/bt04117.
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Size/age distribution and vegetative regeneration were examined for 50 Eucalyptus niphophila Maiden & Blakely trees in each of eight subalpine sites in Kosciuszko National Park 1 year after the January–February 2003 bushfires. Trees sampled were generally large and mature, with an average of 2.5 trunks, lignotuber diameter of 54 cm and largest trunk diameter of 18 cm, with a few larger trees at all sites. Converting the girth of largest trunk into rough age estimates by using an existing regression formula gave an approximate minimum (~29 years), maximum (~186 years), median (~58 years) and average age of ~64 years (error of ~15 years). For trees with trunks after fire, 96.5% had lost all existing leaves. Nearly all trees (95%) had shoots from the lignotuber, but only 4.25% of trees had also epicormic shoots on trunks and stems. Size/age were related to some but not all measures of regeneration. In the future, existing trunks could senesce, with nearly all regrowth from the lignotubers. This could result in a change from open woodlands with large/old trees with a few trunks to closed woodlands of lower-growing trees with a mallee form.
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Vetter, Roland E., and Paulo C. Botosso. "Remarks on Age and Growth Rate Determination of Amazonian Trees." IAWA Journal 10, no. 2 (1989): 133–45. http://dx.doi.org/10.1163/22941932-90000481.
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Specific data and comments are given on age and growth rate determination in trees of the Brazilian Amazon basin, based on longterm observation and research of diameter increment, radiocarbon dating, microscopic wood structure, and gamma- and X-ray densitometry; special attention is given to species of the unflooded Terra Firrne forest. Annual dry seasons in eastern Amazonia provoke periodical cambial activity which may be measured as variation in girth increment and is recorded in the wood anatomy as well as its density. Gamma radiation densitometry is discouraged because of poor results. X-ray densitometry and the radiocarbon method are promising but must be refined. Irregular specific climatic events should be considered to be possible natural marks.
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Lennon, Ben. "ESTIMATING THE AGE OF GROUPS OF TREES IN HISTORIC LANDSCAPES." Arboricultural Journal 32, no. 3 (September 2009): 167–88. http://dx.doi.org/10.1080/03071375.2009.9747572.
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Kurt, Yusuf. "Age-age correlations and prediction of early selection age for diameter growth in a 35-years old Pinus brutia Ten. Genetic experiment." Forest Systems 30, no. 3 (December 2021): e010-e010. http://dx.doi.org/10.5424/fs/2021303-17745.
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Aim of study: Forest geneticists developed various methods to predict an early selection age for forest tree species in order to shorten the breeding cycles. This study aims to estimate age-age correlations among diameter growth of trees at different ages and predict early selection age for Pinus brutia Ten. Area of study: P. brutia populations in the study were sampled from the most productive distribution range of the species, which is an important forest tree in the eastern Mediterranean Basin. To understand genetic variation and determine early selection age for the species, a common garden experiment was established in two test sites near Antalya city, Turkey, in 1979. Material and methods: Wood increment cores at breast height were collected at age 30 years, and diameters (dbh) were measured for the ages 13, 15, 19, 21, 23, 25, and 27 years on the cores. Diameters at ground level (dgl) and dbh were also measured on live trees at age 35. Variance components, age-age correlations, heritability and selection efficiency were estimated for the diameters. Main results: Age-age genetic correlations for diameters were high (mostly > 0.90). Genetic correlations between dgl (at age 35) and dbh (at all measurement ages) ranged from 0.84 to 0.99. Regressions of genetic correlation on natural log of age ratio (LAR) of juvenile age to older age were significant (P < 0.0001). Selection efficiencies estimated by employing the prediction equation indicated that for rotation age 40, the optimum selection age would be between 3 to 5 years, and for rotation age 100 it would be between 5 to 9 years. Research highlights: The results of this study provide information that can be used to find early selection ages in P. brutia. On relatively poor test sites most trees may not attain enough height growth to have measurable dbh trait. In such cases, dgl and/or tree height traits (both of which are highly correlated with dbh traits of all ages) can be measured and used instead of dbh trait for evaluations.
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Tkaczyk, Miłosz, and Robert Tomusiak. "Determining the age of young birch (Betula pendula Roth) trees growing on former agricultural." Forest Research Papers 74, no. 4 (December 1, 2013): 357–63. http://dx.doi.org/10.2478/frp-2013-0034.
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Abstract In Poland, according to the law (amendment of the act of 21st May 2010) – on the provision of information on the environment and its protection, public participation in environmental protection and environmental impact assessments etc. (Official Law Journal article 08.199.1227, as amended) – the owner can cut down trees without permission, if they do not exceed the age of 10 years old. However, if an owner happens to cuts down a tree on his property without knowing the age of the tree, he is liable to prosecution under this act. The aim of this study is to verify whether there is a possibility to calculate the actual age of silver birch trees growing on farmer agricultural lands using features that enable age of standing trees to be identified. Using these criteria, owners would be able to calculate the age of trees on their own. The research used 183 sample trees located on three research plots. For each tree, the dbh, height and prepared samples of wood from the trees base were used to give the age of the tree. The relationship between age and dbh, as well as between the age and the height was examined. The strength of correlation was compared and the strongest was used in the proposed model. Using these correlations two types of charts were constructed to estimate the age of young birches on the basis of dbh and height.
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Angélico, Talita dos Santos, Carmen Regina Marcati, Sergio Rossi, Magali Ribeiro da Silva, and Júlia Sonsin-Oliveira. "Soil Effects on Stem Growth and Wood Anatomy of Tamboril Are Mediated by Tree Age." Forests 12, no. 8 (August 9, 2021): 1058. http://dx.doi.org/10.3390/f12081058.
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Soil influences the growth of trees and the characteristics of the wood; but could this influence change during the ontogeny of trees? To answer this question, we analyzed the wood anatomy of 9-year-old trees and 2-year-old saplings of Enterolobium contortisiliquum, known as “tamboril”, growing in eutrophic and oligotrophic soil in the Brazilian Cerrado, and assessed the effect of age on plant–soil relationship. Sapwood samples were collected from the main stem, anatomical sections were prepared in the lab, and 12 anatomical wood traits were measured. Individuals in eutrophic soil had greater stem diameter and height than those in oligotrophic soil. Trees in eutrophic soil had vessel-associated parenchyma cells with abundant storage compounds. Fibers walls were 47% thicker and intervessel pits diameter were 14% larger in trees of eutrophic soil. A greater proportion of solitary vessels (74%) was observed in trees rather than in saplings (50%). The secondary xylem of trees was mainly formed by fibers (63%) whereas in saplings it was mainly formed by storage tissue (64%). Our study provides evidence that the influence of soil conditions on tree growth reflects variations in wood anatomical features. No significant response to soil type was observed in saplings, thus demonstrating that the relationship between soil type and wood growth is mediated by tree age. These findings help to develop reliable reforestation strategies in tropical ecosystems characterized by different levels of soil fertility.
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Voitiuk, Vasyl, Valentyna Andreieva, Oleksandr Kychyliuk, Anatolii Hetmanchuk, Marcin Klisz, and Vasyl Mohytych. "Application of growth traits and qualitative indices for selection of Scots pine (Pinus sylvestris l.) elite trees. A case study from Volyn region, western ukraine." Folia Forestalia Polonica 62, no. 3 (September 1, 2020): 199–209. http://dx.doi.org/10.2478/ffp-2020-0019.
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AbstractSince the plus trees are selected based on phenotype, it is necessary to evaluate them in progeny test. The aim of this study is an indication of selecting elite mother trees based on the results from half-sib progeny test trials. As study sites, two Scots pine half-sib progeny tests were selected. During evaluation, the progenies had reached the age of 38 and 40 years, respectively. In both progeny trials, quantitative parameters and qualitative traits of Scots pine half-sib progenies were investigated. Based on these data, complex evaluation of half-sib families was carried out. We concluded that, Scots pine progenies at the age of 38 and 40 years in fresh and moist mixed forests are characterised by acceptable quality, with the survival being 25%–33% per progeny test trial. Based on a complex evaluation of 38- and 40-year-old half-sib progenies of plus trees, we proposed to select 31% of tested plus/mother trees as candidates for elite trees. Further, the list of candidates for elite trees was created with five plus trees from the Volyn region (26% of the total tested from the region) and four plus trees from the Lviv region (40% of the total tested from the region). With age, the share of the best and undesirable trees decreases, while the proportion of intermediate trees increases in both control trees and half-sib progenies. At the age of 38 and 40 years, the proportion of fast-growing offspring was from 0% to 36%, while the declining trend that was observed in previous years was being continued. Thus, due to the declining trend in the proportion of fast-growing offspring observed at the age of 38 and 40 years, we propose to select candidate trees for an elite group not early than after 40 years of test their progenies.
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Chalupa, V. "In vitro propagation of mature trees of Sorbus aucuparia L. and field performance of micropropagated trees." Journal of Forest Science 48, No. 12 (May 22, 2019): 529–35. http://dx.doi.org/10.17221/11923-jfs.
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The influence of tree age, explant source and genotype on micropropagation of mature trees of Sorbus aucuparia has been investigated. Experiments demonstrated the feasibility to use juvenile parts of mature trees for in vitro propagation of selected genotypes. Explants from lower branches and from epicormic shoots of mature trees exhibited high multiplication coefficients of microshoots cultured on modified MS agar nutrient medium supplemented with cytokinin (BA, TDZ) and auxin (IBA). Microshoots produced from juvenile parts of mature trees exhibited good rooting response and produced plants were well adapted to grow in forest soils. The survival of micropropagated trees planted in experimental plots was high and losses during winter were low. Height and diameter increments of micropropagated trees originated from juvenile parts of mature trees were considerable and their dimensions after five years of growth were comparable with the dimensions of trees originated from seeds.
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Gea-Izquierdo, G., I. Cañellas, and G. Montero. "Site index in agroforestry systems: age-dependent and age-independent dynamic diameter growth models forQuercus ilexin Iberian open oak woodlands." Canadian Journal of Forest Research 38, no. 1 (January 2008): 101–13. http://dx.doi.org/10.1139/x07-142.
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Despite Quercus ilex L. being one of the most widespread tree species in the Mediterranean basin, there are no growth models in the literature for this species. In this study, we compare age-dependent and age-independent dynamic diameter growth models and discuss the concept of dominance in open stands. A posteriori dominance was determined to fit potential age-dependent growth models and a site index based on diameter growth was defined. Formulations derived from power decline base models (Korf and Hossfeld) best described diameter growth. The best approach for age-dependent models was a polymorphic and with variable asymptotes generalized algebraic difference approach formulation. Residual errors in trees between 20 and 55 cm ranged from ~7.0% in potential growth models to ~15% in age-independent models expanded by density. Using a unique age-dependent dynamic equation for all trees, regardless of dominance, did not increase the error very much. In age-independent models, the inclusion of the defined site index reduced the prediction error but requires that the age of trees is estimated to determine the site index. The difficulty of estimating Q. ilex age makes age-independent models very attractive for system modelling. Age-independent models could be useful in other ecosystems where age estimation is problematic.
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Wong, B. L., K. L. Baggett, and A. H. Rye. "Cold-season patterns of reserve and soluble carbohydrates in sugar maple and ice-damaged trees of two age classes following drought." Botany 87, no. 3 (March 2009): 293–305. http://dx.doi.org/10.1139/b08-123.
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This study examines the effects of summer drought on the composition and profiles of cold-season reserve and soluble carbohydrates in sugar maple ( Acer saccharum Marsh.) trees (50–100 years old or ∼200 years old) in which the crowns were nondamaged or damaged by the 1998 ice storm. The overall cold season reserve carbohydrate profiles in twig wood tissue of drought-stressed (DS) trees and non-drought-stressed (NDS) trees were generally similar, although differences were observed in the amount of reserve carbohydrates in DS and NDS trees. The cold-season level of starch stored in DS trees in early autumn in the wood tissue was about one-third to one-fifth that in NDS trees. The cold season sugar content in the DS trees was significantly greater than can be attributed to degradation of stored starch, only. The level of sucrose in DS trees remained high throughout the winter until termination of dormancy and dehardening. The concentrations of winter glucose and fructose in DS trees attained peak levels at the time of dormancy termination and declined during dehardening. The profiles of glucose and fructose in DS and damaged DS trees were generally different from that of sucrose throughout the leafless phase. In contrast, profiles of glucose and fructose in NDS trees closely paralleled that of sucrose. Elevated levels of sucrose, glucose, and fructose in DS sugar maple trees during the cold season may function as osmoregulators for freeze protection. Low sugar level or lack of increase in sugar level following dehardening in DS trees may suggest limited change in cellular constituents in adapting to low temperatures.
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Zhou, Qianyi, Zhaohong Jiang, Xin Zhang, Qing Lai, Yiming Li, Fei Zhao, and Zhong Zhao. "Tree age did not affect the leaf anatomical structure or ultrastructure of Platycladus orientalis L. (Cupressaceae)." PeerJ 7 (October 29, 2019): e7938. http://dx.doi.org/10.7717/peerj.7938.
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Tree aging is a new research area and has attracted research interest in recent years. Trees show extraordinary longevity; Platycladus orientalis L. (Cupressaceae) has a lifespan of thousands of years. Ancient trees are precious historical heritage and scientific research materials. However, tree aging and tree senescence have different definitions and are poorly understood. Since leaves are the most sensitive organ of a tree, we studied the structural response of leaves to tree age. Experiments investigating the leaf morphological structure, anatomical structure and ultrastructure were conducted in healthy P. orientalis at three different ages (ancient trees >2,000 years, 200 years < middle-aged trees <500 years, young trees <50 years) at the world’s largest planted pure forest in the Mausoleum of the Yellow Emperor, Shaanxi Province, China. Interestingly, tree age did not significantly impact leaf cellular structure. Ancient P. orientalis trees in forests older than 2,000 years still have very strong vitality, and their leaves still maintained a perfect anatomical structure and ultrastructure. Our observations provide new evidence for the unique pattern of tree aging, especially healthy aging. Understanding the relationships between leaf structure and tree age will enhance the understanding of tree aging.
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Gritsan, Y. I., V. M. Lovynska, and S. A. Sytnyk. "Radial increment dynamics in Pinus sylvestris stands within the Northern Steppe of Ukraine." Biosystems Diversity 26, no. 3 (August 7, 2018): 213–17. http://dx.doi.org/10.15421/011832.
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The parameters of periodic increment (5-years) and peculiarities of its change depending on age, diameter, height and volume of trunk of Scots pine are determined. The influence of climate conditions (air temperature and precipitation) on the dynamics of radial increment change of Scots pine trees are established. The results of experimental studies, obtained from 20 temporary sample plots of pine stands within the Northern Steppe of Ukraine are presented. We conducted an estimate of radial increment of Scots pine trunks as a basis for development of normative and information support for assessment of biotic productivity of this category of forest. All selected sample trees had different age and biometric parameters. The age of sample trees ranged from 9 to 90 years; diameter at breast height – from 4.0 to 41.7 cm; height – from 4.2 to 30.0 m, trunk volume – from 0.002 to 1.748 m3. It is found that the radial increment of pine stem was significantly dependent on tree age. The highest values of radial increment of Scots pine trees were observed for trees aged up to 20 years. With increasing age, radial increment had a decreasing trend, including 90-year old trees. Regression models of the dependence of radial increment of pine trees on the age and diameter are presented. In the article, the dependence of the values of radial increment of sample trees from types of forest are demonstrated. The highest values of Scots pine radial increment was observed in sugruds and gruds, which were presented in tree samples of 20 years. Comparative analysis of radial increment change in the trees of one age category, which grew in different conditions, was conducted. The older trees had the maximum increment in the conditions of dry sugrud, and the minimum increment in conditions of fresh subor. Also in this article we used generalized chronology of Scots pine radial increment reflecting regional variability of growth in pine trees. The results supplemented the research obtained earlier with new data on the dependence of the pine radial growth rate on forest-biometric parameters. These experimental data, their graph-analytical evaluation yielded an information basis for modeling the radial increment of pine trees, created on the basis of dependence of this parameter on biometric indexes – age and diameter at breast height.