Artículos de revistas: "Dawn redwood"

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Ahuja, M. R. "Strategies for conservation of germplasm in endemic redwoods in the face of climate change: a review". Plant Genetic Resources 9, n.º 3 (4 de febrero de 2011): 411–22. http://dx.doi.org/10.1017/s1479262111000153.

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This study reviews the various conservation strategies applied to the four redwood species, namely coast redwood (Sequoia sempervirens), Sierra redwood or giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides) and South American redwood or alerce (Fitzroya cupressoides), which are endemic in the USA, China and South America, respectively. All four redwood genera belong to the family Cupressaceae; they are monospecific, share a number of common phenotypic traits, including red wood, and are threatened in their native ranges due to human activity and a changing climate. Therefore, the management objective should be to conserve representative populations of the native species with as much genetic diversity as possible for their future survival. Those representative populations exhibiting relatively high levels of genetic diversity should be selected for germplasm preservation and monitored during the conservation phase by using molecular markers. In situ and ex situ strategies for the preservation of germplasm of the redwoods are discussed in this study. A holistic in situ gene conservation strategy calls for the regeneration of a large number of diverse redwood genotypes that exhibit adequate levels of neutral and adaptive genetic variability, by generative and vegetative methods for their preservation and maintenance in their endemic locations. At the same time, it would be desirable to conserve the redwoods in new ex situ reserves, away from their endemic locations with similar as well as different environmental conditions for testing their growth and survival capacities. In addition, other ex situ strategies involving biotechnological approaches for preservation of seeds, tissues, pollen and DNA in genebanks should also be fully exploited in the face of global climate change.

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2

Gressitt, J. Linsley. "The California Academy-Lingnan Dawn-Redwood Expedition". Arnoldia 58, n.º 4 (1998): 35–39. http://dx.doi.org/10.5962/p.251362.

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Glogov, Plamen y Gergana Zaemdzhikova. "CHARACTERISTICS OF METASEQUOIA GLYPTOSTROBOIDES ARTIFICIAL COMMUNITY КОKАLУАNЕ VILLAGE, SOFIA REGION". Ecological Engineering and Environment Protection 2022, n.º 1/2022 (30 de abril de 2022): 56–61. http://dx.doi.org/10.32006/eeep.2022.1.5661.

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The aim of the present study is phytocoenological characteristics and preliminary assessment of the health status of the first Dawn redwood (Metasequoia glyptostroboides) artificial plantation in Bulgaria established in 1969. The plantation of metasequoia is located in the land of the Kokalyane village (Sofia region) on an area of about 2500 m2. The study was conducted in the period April-July, 2021. The results show that the artificial stand was created on the locality of indigenous communities of Alnus glutinosa, which occupy the main part of the Iskar river banks between Plana and Lozenska mountains. The health status of the Dawn redwood plantation was assessed as “good”. From the distance of the 50-year period, the artificial afforestation with this exotic relic in the area of the village of Kokalyane can be considered successful.

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Chung, Yeong-Jin y Eui Jin. "Assessment of the Fire Risk Index and Fire Risk Rating of Five Wood Species According to Chung’s Equation-XII". Fire Science and Engineering 37, n.º 6 (31 de diciembre de 2023): 116–25. http://dx.doi.org/10.7731/kifse.2f976c20.

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Chung's equations-X, -XII, and -XII were applied to evaluate the fire risk index (FRI) and fire risk rating (FRR) of five wood species. The test specimens used were ginkgo tree, dawn redwood tree, toona tree, lime tree, and walnut tree. A cone calorimeter (ISO 5660-1) was selected and used to test the combustion characteristics of the specimens. The fire performance index-X (FPI-X) and fire growth index-X (FGI-X) calculated using Chung’s equations ranged from 560.59 to 2689.89 s<sup>2</sup>/kW and from 0.0005 to 0.0016 kW/s<sup>2</sup>, respectively. Furthermore, the FPI-XI and FGI-XI varied from 0.49 to 2.35 and from 1.67 to 5.33, respectively. FRI-XII, a FRR, showed that the fire risks of dawn redwood tree and ginkgo tree, at 10.88 (FRR: F) and 10.25 (FRR: F), respectively, were very high. In conclusion, a high FRI-XII value indicates that FPI-X and FPI-XI are low whereas FGI-X and FGI-XI are high.

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Fekry, R., W. Yao, A. Sani-Mohammed y D. Amr. "INDIVIDUAL TREE SEGMENTATION FROM BLS DATA BASED ON GRAPH AUTOENCODER". ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences X-1/W1-2023 (5 de diciembre de 2023): 547–53. http://dx.doi.org/10.5194/isprs-annals-x-1-w1-2023-547-2023.

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Abstract. In the last two decades, Light detection and ranging (LiDAR) has been widely employed in forestry applications. Individual tree segmentation is essential to forest management because it is a prerequisite to tree reconstruction and biomass estimation. This paper introduces a general framework to extract individual trees from the LiDAR point cloud based on a graph link prediction problem. First, an undirected graph is generated from the point cloud based on K-nearest neighbors (KNN). Then, this graph is used to train a convolutional autoencoder that extracts the node embeddings to reconstruct the graph. Finally, the individual trees are defined by the separate sets of connected nodes of the reconstructed graph. A key advantage of the proposed method is that no further knowledge about tree or forest structure is required. Seven sample plots from a plantation forest with poplar and dawn redwood species have been employed in the experiments. Though the precision of the experimental results is up to 95 % for poplar species and 92 % for dawn redwood trees, the method still requires more investigations on natural forest types with mixed tree species.

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6

Gao, Sha, Zhengnan Zhang y Lin Cao. "Individual Tree Structural Parameter Extraction and Volume Table Creation Based on Near-Field LiDAR Data: A Case Study in a Subtropical Planted Forest". Sensors 21, n.º 23 (6 de diciembre de 2021): 8162. http://dx.doi.org/10.3390/s21238162.

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Individual tree structural parameters are vital for precision silviculture in planted forests. This study used near-field LiDAR (light detection and ranging) data (i.e., unmanned aerial vehicle laser scanning (ULS) and ground backpack laser scanning (BLS)) to extract individual tree structural parameters and fit volume models in subtropical planted forests in southeastern China. To do this, firstly, the tree height was acquired from ULS data and the diameter at breast height (DBH) was acquired from BLS data by using individual tree segmentation algorithms. Secondly, point clouds of the complete forest canopy were obtained through the combination of ULS and BLS data. Finally, five tree taper models were fitted using the LiDAR-extracted structural parameters of each tree, and then the optimal taper model was selected. Moreover, standard volume models were used to calculate the stand volume; then, standing timber volume tables were created for dawn redwood and poplar. The extraction of individual tree structural parameters exhibited good performance. The volume model had a good performance in calculating the standing volume for dawn redwood and poplar. Our results demonstrate that near-field LiDAR has a strong capability of extracting tree structural parameters and creating volume tables for subtropical planted forests.

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7

Cao, Lin, Hao Liu, Xiaoyao Fu, Zhengnan Zhang, Xin Shen y Honghua Ruan. "Comparison of UAV LiDAR and Digital Aerial Photogrammetry Point Clouds for Estimating Forest Structural Attributes in Subtropical Planted Forests". Forests 10, n.º 2 (10 de febrero de 2019): 145. http://dx.doi.org/10.3390/f10020145.

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Estimating forest structural attributes of planted forests plays a key role in managing forest resources, monitoring carbon stocks, and mitigating climate change. High-resolution and low-cost remote-sensing data are increasingly available to measure three-dimensional (3D) canopy structure and model forest structural attributes. In this study, we compared two suites of point cloud metrics and the accuracies of predictive models of forest structural attributes using unmanned aerial vehicle (UAV) light detection and ranging (LiDAR) and digital aerial photogrammetry (DAP) data, in a subtropical coastal planted forest of East China. A comparison between UAV-LiDAR and UAV-DAP metrics was performed across plots among different tree species, heights, and stem densities. The results showed that a higher similarity between the UAV-LiDAR and UAV-DAP metrics appeared in the dawn redwood plots with greater height and lower stem density. The comparison between the UAV-LiDAR and DAP metrics showed that the metrics of the upper percentiles (r for dawn redwood = 0.95–0.96, poplar = 0.94–0.95) showed a stronger correlation than the lower percentiles (r = 0.92–0.93, 0.90–0.92), whereas the metrics of upper canopy return density (r = 0.21–0.24, 0.14–0.15) showed a weaker correlation than those of lower canopy return density (r = 0.32–0.68, 0.31–0.52). The Weibull α parameter indicated a higher correlation (r = 0.70–0.72) than that of the Weibull β parameter (r = 0.07–0.60) for both dawn redwood and poplar plots. The accuracies of UAV-LiDAR (adjusted (Adj)R2 = 0.58–0.91, relative root-mean-square error (rRMSE) = 9.03%–24.29%) predicted forest structural attributes were higher than UAV-DAP (Adj-R2 = 0.52–0.83, rRMSE = 12.20%–25.84%). In addition, by comparing the forest structural attributes between UAV-LiDAR and UAV-DAP predictive models, the greatest difference was found for volume (△Adj-R2 = 0.09, △rRMSE = 4.20%), whereas the lowest difference was for basal area (△Adj-R2 = 0.03, △rRMSE = 0.86%). This study proved that the UAV-DAP data are useful and comparable to LiDAR for forest inventory and sustainable forest management in planted forests, by providing accurate estimations of forest structural attributes.

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8

Payton, Greg. "Conserving the Dawn Redwood: The Ex Situ Collection at the Dawes Arboretum". Arnoldia 68, n.º 1 (2010): 26–33. http://dx.doi.org/10.5962/p.251543.

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9

Ahuja, M. Raj. "Origin and genetic nature of polyploidy in paleoendemic coast redwood (Sequoia sempervirens (D. Don) Endl.)". Silvae Genetica 71, n.º 1 (1 de enero de 2022): 54–65. http://dx.doi.org/10.2478/sg-2022-0007.

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Abstract It is not known when the polyploid coast redwood (Sequoia sempervirens) evolved from its diploid ancestors, and what is its type of polyploidy. Whether close relatives of Sequoia, giant sequoia (Sequoiadendron giganteum) and dawn redwood (Metasequoia glyptostroboides), have possibly contributed to the ancestry of hexaploid of Sequoia remains an open question. The nature of hexaploidy in Sequoia has baffled biologists for more than a century. Based on the chromosome configurations in Sequoia, G. Ledyard Stebbins was the first geneticists who postulated in 1948 that Sequoia is an autoallohexaploid (AAAABB), and an ancient species of Metasequoia might have been one of the putative ancestors of Sequoia. After its chromosome number (2n=6x=66) was confirmed in hexaploid Sequoia, the type of polyploidy in Sequoia has been further investigated for the past 70 years by a number of investigators, using cytogenetic and genetic data. Although an autoallohexaploid (AAAABB) origin of Sequoia has remained one of the dominant hypotheses until recently, an alternative hypothesis, amongst other possible origins, was also put forth by Ahuja and Neale (2002), that Sequoia may be partially diploidized autohexaploid (AAAAAA), derived from some ancestral species of Sequoia, thus carrying a single ancestral genome. Cytogenetic, molecular genetics, and genome sequence data now support the hypothesis that Sequoia originated as an autohexaploid.

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10

Zhang, Yuheng. "‘The Panda of Plants’: The Discovery of Dawn Redwood and National Identity Construction in Modern China". International Journal for History, Culture and Modernity 7, n.º 1 (2 de noviembre de 2019): 271–300. http://dx.doi.org/10.18352/hcm.557.

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This article analyzes the role played by the 1940s discovery of dawn redwood (Shuishan , Metasequoia glyptostroboides) in the construction of a modern Chinese national identity, as manifested in Chinese intellectual and popular discourse from the second half of the twentieth century to the present day. As the shuishan was transformed from a distinct biological species into an iconic national species, modern China as an ‘imagined community’ was forged in three dimensions. Spatially, the emerging national space was anchored in the world of nations; the temporal scale was redefined, and Chinese history projected back into deep time; and through the attribution of moral qualities to the tree, the ressentiment arising from the late development of nationalism was reaffirmed but also countered.

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11

Nelson, E. Charles. "Metasequoia glyptostroboides, the dawn redwood: Some Irish glosses on its discovery and introduction into cultivation". Curtis's Botanical Magazine 15, n.º 1 (febrero de 1998): 77–80. http://dx.doi.org/10.1111/1467-8748.00135.

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12

HAO, DE-JUN, BIN-QI FAN, PENG SU, QUN LIU y YAN WANG. "The flat mite Brevipalpus lewisi (Acari: Tenuipalpidae) infesting the Dawn Redwood Metasequoia glyptostroboides". Systematic and Applied Acarology 18, n.º 2 (30 de junio de 2013): 197. http://dx.doi.org/10.11158/saa.18.2.12.

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13

Yin, Shan, Xianxian Zhang, Jukka Pumpanen, Guangrong Shen, Feng Xiong y Chunjiang Liu. "Seasonal Variation in Soil Greenhouse Gas Emissions at Three Age-Stages of Dawn Redwood (Metasequoia glyptostroboides) Stands in an Alluvial Island, Eastern China". Forests 7, n.º 12 (4 de noviembre de 2016): 256. http://dx.doi.org/10.3390/f7110256.

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14

Vargo, Lauren J., Gregory Wiles, Nicholas Wiesenberg, Christopher J. Williams y Ken Cochran. "Climate Response of Metasequoia glyptostroboides Inferred from Tree Rings, Secrest Arboretum, Wooster, Ohio, USA". Ohio Journal of Science 120, n.º 2 (2 de junio de 2020): 22. http://dx.doi.org/10.18061/ojs.v120i2.7073.

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Metasequoia glyptostroboides, a deciduous gymnosperm, also known as dawn redwood, was thought to be extinct until living members of the species were found in China in 1943. Analyzing the climate response of a transplanted stand of the trees can give insights into their physiological plasticity, into their use in restoration and reforestation, as well as into interpreting the environmental conditions of the geologic past from fossil Metasequoia. An annual ring-width chronology—spanning 1955 to 2010 and based on a stand of 19 M. glyptostroboides trees planted in Secrest Arboretum in northeast Ohio, USA—shows negative correlations with maximum monthly temperatures: with the strongest relationship with February and the warm months of June and July, all significant at the 99% confidence levels. A positive May to June precipitation correlation is the strongest moisture signal (p < 0.05) and the narrowest rings in the chronology occurred during the drought of 1987 to 1988, consistent with one of the warmest and driest Junes on record. These results have implications for the future as climate change affects the native and transplanted range of this species. Future response of this species to a changing climate will depend on the relative rates of warming maximum temperatures in the winter and summer, as well as changing moisture conditions during the summer months.

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15

Wu, Yafeng, Tingou Sha, Zijian Zhao, Zhengbin He y Songlin Yi. "Influence of Different Pretreatments on the Acoustic Properties of Dawn Redwood (Metasequoia glyptostroboides Hu et Cheng)". BioResources 11, n.º 1 (1 de febrero de 2016). http://dx.doi.org/10.15376/biores.11.1.2734-2743.

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16

MA Peng, 马朋, 李昌晓 LI Changxiao, 任庆水 REN Qingshui, 杨予静 YANG Yujing y 马骏 MA Jun. "Effects of simulated submergence and drought on nutrient contents in soils growing Dawn Redwood (Metasequoia glyptostroboides) saplings". Acta Ecologica Sinica 35, n.º 23 (2015). http://dx.doi.org/10.5846/stxb201405110966.

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17

Brischke, Christian, Susanne Bollmus, Eckhard Melcher y Ina Stephan. "Biological durability and moisture dynamics of Dawn redwood (Metasequoia glyptostroboides) and Port Orford cedar (Chamaecyparis lawsoniana)". Wood Material Science & Engineering, 23 de julio de 2022, 1–11. http://dx.doi.org/10.1080/17480272.2022.2101941.

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18

Liu, Duanchong, Wenxia Zhao, Wen-Xia Huai, Jianping Xia, Sanshan Cai, Ru-bin Zhang y Bin Li. "First Report of Root Rot Caused by Phytophthora acerina on Metasequoia glyptostroboides in China". Plant Disease, 8 de febrero de 2022. http://dx.doi.org/10.1094/pdis-12-21-2722-pdn.

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Metasequoia glyptostroboides Hu & W. C. Cheng (Taxodiaceae), commonly called the Chinese redwood or dawn redwood, is a well-known "living fossil" and rare relict plant species endemic to China, which has been successfully cultivated throughout the world (Ma 2007). In July to September 2020, trees of Chinese redwood which were more than thirty years-old, showed symptoms of decline and death associated with branch dieback, root and collar rot (Fig. 1) in Yangtze River shelter-forests of Jiangling County in Hubei Province, China (112°15′19″E, 30°11′56″N; 40m). Diseased roots and rhizosphere soils were collected in September 2020 and April 2021. Using the baiting method, a homothallic Phytophthora sp. was recovered consistently from diseased roots and soil samples of Chinese redwood. All the isolates of this Phytophthora sp. formed similar colonies on V8 agar and corn meal agar (Fig. 2), and then three representative isolates (L4-5-4, L4-5-5 and L4-5-6) were randomly selected for morphological and molecular identification. In distilled water, semipapillate persistent sporangia were borne in simple sympodial branched sporangiophores. Sporangia were predominantly ovoid (Fig. 3a, d and f), but other shapes were observed including subglobose (Fig. 3b), limoniform (Fig. 3c) or distorted shapes (Fig. 3e), averaging 44.1 ± 7.7 µm (n=102) in length and 32.8 ± 5.2 µm (n=102) in width, with narrow exit pores of 8.0 ± 1.4 µm (n=93) and a length/breadth ratio of 1.3 ± 0.10 (n=102). Chlamydospores were not observed. Oogonia were globose or subglobose, 20.51 to 40.15 µm (av. 33.1 ± 3.9 µm) (n=119) in diameter, with smooth walls and paragynous antheridium (Fig. 3g-i). Oospores were globose or subglobose in elongated oogonia with medium wall thickness of 1.9 ± 0.5 µm (n=36), aplerotic or plerotic and 16.9 to 32.6 µm in diameter (av. 26.6 ± 3.8 µm) (n=40). According to the above morphological characteristics, this Phytophthora sp. was placed in Waterhouse's (1963) group III. The sequences of the internal transcribed spacers (ITS) region of nuclear ribosomal DNA of each isolate (GenBank Accession No. OK087320, OK087321 and OK087322) was 760 bp and had identity of 99.84% with three P. acerina isolates (JX951285, JX951291 and JX951296), while the 800 bp β-tubulin (BTUB) sequences (OK140540, OK140541 and OK140542) showed 99.97% homology to the sequence of P. acerina (KC201283) (Ginetti, Moricca and Squires 2014) (Table 1). The ML phylogenetic trees were established by comparing ITS and BTUB sequences of three Phytophthora strains (L4-5-4, L4-5-5 and L4-5-6) with reference sequences of isolates of Phytophthora in ITS and BTUB in GenBank (Fig. 4-5). Based on the morphological and molecular characteristics, the strains were identified as namely P. acerina. In addition, pathogenicity assays were performed with one of the three strains (L4-5-4) on M. glyptostroboides using both one year old and three years old seedlings. Inoculum was prepared by subculturing agar plugs from edges of CMA cultures into V8 medium plates, incubating at 20 ℃ in darkness for 10 days. Six seedlings planted in pots filled with sterilized soil were inoculated by mycelium plug at root collar and stem wounded by a 8 mm diameter puncher. Six control seedlings were inoculated in the same manner as above, and sterile agar plugs were used. After 35 days, inoculated seedlings all had necrotic lesions at the inoculation sites, and some seedlings had the symptoms of foliage blight and dieback, whereas control seedlings remained healthy (Fig. 6). The number of fibrous roots after inoculation was significantly less than the control, and the roots of inoculated seedlings blackened or even rotted, while there were no obvious symptoms in the control (Fig. 7). Phytophthora isolates recovered from the symptomatic tissues of artificially inoculated plants were identical to isolate L4-5-4 in morphological characters and ITS sequencing. This is the first report of P. acerina causing root rot on the Chinese redwood in China. As only the seedlings were inoculated, further research is needed to address the epidemiology and pathogenicity of P. acerina to adult trees of Chinese red wood. References: Ginetti, B. et al. 2014. Plant Pathology, 63(4): 858-876. Ma, J. S. 2007. Bulletin of the Peabody Museum of Natural History, 48(2): 235-253. Waterhouse, G. M. 1963. Mycological Papers 92:1-22

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19

Lin, Jiayuan, Decao Chen, Shuai Yang y Xiaohan Liao. "Precise aboveground biomass estimation of plantation forest trees using the novel allometric model and UAV-borne LiDAR". Frontiers in Forests and Global Change 6 (6 de octubre de 2023). http://dx.doi.org/10.3389/ffgc.2023.1166349.

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IntroductionPlantation forest is an important component of global forest resources. The accurate estimation of tree aboveground biomass (AGB) in plantation forest is of great significance for evaluating the carbon sequestration capacity. In recent years, UAV-borne LiDAR has been increasingly applied to forest survey, but the traditional allometric model for AGB estimation cannot be directly used without the diameter at breast height (DBH) of individual trees. Therefore, it is practicable to construct a novel allometric model incorporating the crown structure parameters, which can be precisely extracted from UAV LiDAR data. Additionally, the reduction effect of adjacent trees on crown area (Ac) should be taken into account.MethodsIn this study, we proposed an allometric model depending on the predictor variables of Ac and trunk height (H). The UAV-borne LiDAR was utilized to scan the sample plot of dawn redwood (DR) trees in the test site. The raw point cloud was first normalized and segmented into individual trees, whose Acs and Hs were sequentially extracted. To mitigate the effects of adjacent trees, the initial Acs were corrected to refer to the potential maximum Acs under undisturbed growth conditions. Finally, the corrected Acs (Acc) and Hs were input into the constructed allometric model to achieve the AGBs of DR trees.Results and discussionAccording to accuracy assessment, coefficient of determination (R2) and root mean square error (RMSE) of extracted Hs were 0.9688 and 0.51 m; R2 and RMSE of calculated AGBs were 0.9432 and 10.91 kg. The unrestricted growth parts of the tree crowns at the edge of a plantation forest could be used to derive the potential maximum Ac. Compared with the allometric models for AGB estimation relying only on trunk H or on initial Ac and H, the novel allometric model demonstrated superior performance in estimating the AGBs of trees in a plantation forest.

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Artículos de revistas sobre el tema "Dawn redwood"

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