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What diameter?What height?Influence of measures of average tree size on area-based allometric volume relationships
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作者 Yilin Wang John A.Kershaw +2 位作者 Mark J.Ducey Yuan Sun James B.McCarter 《Forest Ecosystems》 SCIE CSCD 2024年第1期100-109,共10页
Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and he... Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume equation.When density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height measure.When density was not included(Volume=f(Diameter,Height)),the opposite was true.For models with density included,moment-based estimators of stand diameter and height performed better than all other measures.For models without density,largest tree estimators of stand diameter and height performed better than other measures.The overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses. 展开更多
关键词 allometric relationships Stand structure Volume estimation Stand-level attributes
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Ecological Networks of Allometric Growth,Feeding Behavior and Gut Microbiota in Chinese Alligator Hatchlings
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作者 Ke SUN Wengang LI +10 位作者 Guangwei FAN Liuyang YANG Huabin ZHANG Yilin SHU Yongkang ZHOU Genjun TU Song ZHANG Pingsi YI Maliha AYUB Xiaobing WU Tao PAN 《Asian Herpetological Research》 SCIE CSCD 2024年第2期104-114,共11页
Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study a... Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study analyzed the intrinsic factors influencing the allometric growth of Chinese alligator hatchlings based on their body mass gain,feeding behavior,and gut microbiota.This information would enhance the health management of Chinese alligator hatchlings.There was a significant correlation between the total distance moved,the average number of conspecifics nearby,and body mass gain.Chinese alligator hatchlings with a greater growth rate showed greater activity and more independent behavior during feeding than those with a lower growth rate.Moreover,after feeding started,some functions of the gut microbiota showed significant relationships with growth rate and feeding activity.Chinese alligator hatchlings with a greater growth rate showed greater levels of heme biosynthesis than those with a lower growth rate,and feeding activity was inhibited by long-chain fatty acid biosynthesis.These results elucidate the relationships between health,feeding behavior,and the gut microbiota of Chinese alligator hatchlings.Understanding the intrinsic factors of their health and feeding behavior can improve the health management of Chinese alligator hatchlings in captivity for conservation. 展开更多
关键词 allometric growth BEHAVIOR Chinese alligator hatchlings gut microbiota
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Geographic Differences in Allometric Patterns of Males of the Japanese Firefly Luciola parvula
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作者 Yutaka Iguchi 《Advances in Entomology》 2024年第1期18-23,共6页
It has been well known for many years that males of Luciola parvula (Coleoptera, Lampyridae) have two morphs, namely small and large morphs in Japan. This article performed a statistical reanalysis of their morphologi... It has been well known for many years that males of Luciola parvula (Coleoptera, Lampyridae) have two morphs, namely small and large morphs in Japan. This article performed a statistical reanalysis of their morphological measurements based on previously published data and compared them. As a result, the two morphs were found to have different allometric patterns in the Hakone and Nagano areas, Japan. In Hakone, the relationships between their pronotum width and length were expressed by a common allometric line and a shift in location along the line. However, in Nagano, the relationships between their pronotum width and body length were expressed by two parallel allometric lines (a common slope and different intercepts). The allometric pattern of males of this species may vary among different parts of the body or among different areas. Therefore, this article recommends future studies to measure the same parts of the body as previous studies to clarify geographic variation in allometric relationships. 展开更多
关键词 Body Size Male Dimorphism allometric Pattern Hakone Nagano
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Filling the“vertical gap”between canopy tree species and understory shrub species:biomass allometric equations for subcanopy tree species 被引量:2
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作者 Xue Sun Xingchang Wang +2 位作者 Chuankuan Wang Quanzhi Zhang Qingxi Guo 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期903-913,共11页
Subcanopy tree species are an important component of temperate secondary forests.However,their biomass equations are rarely reported,which forms a“vertical gap”between canopy tree species and understory shrub specie... Subcanopy tree species are an important component of temperate secondary forests.However,their biomass equations are rarely reported,which forms a“vertical gap”between canopy tree species and understory shrub species.In this study,we destructively sampled six common subcanopy species(Syringa reticulate var.amurensis(Rupr.)Pringle,Padus racemosa(Lam.)Gilib.,Acer ginnala Maxim.,Malus baccata(Linn.)Borkh.,Rhamnus davurica Pall.,and Maackia amurensis Rupr.et Maxim.)to establish biomass equations in a temperate forest of Northeast China.The mixed-species and species-specifi c biomass allometric equations were well fi tted against diameter at breast height(DBH).Adding tree height(H)as the second predictor increased the R^(2)of the models compared with the DBH-only models by–1%to+3%.The R^(2)of DBH-only and DBH-H equations for the total biomass of mixed-species were 0.985 and 0.986,respectively.On average,the biomass allocation proportions for the six species were in the order of stem(45.5%)>branch(30.1%)>belowground(19.5%)>foliage(4.9%),with a mean root:shoot ratio of 0.24.Biomass allocation to each specifi c component diff ered among species,which aff ected the performance of the mixed-species model for particular biomass component.When estimating the biomass of subcanopy species using the equations for canopy species(e.g.,Betula platyphylla Suk.,Ulmus davidiana var.japonica(Rehd.)Nakai,and Acer mono Maxim.),the errors in individual biomass estimation increased with tree size(up to 68.8%at 30 cm DBH),and the errors in stand biomass estimation(up to 19.2%)increased with increasing percentage of basal area shared by subcanopy species.The errors caused by selecting such inappropriate models could be removed by multiplying adjustment factors,which were usually power functions of DBH for biomass components.These results provide methodological support for accurate biomass estimation in temperate China and useful guidelines for biomass estimation for subcanopy species in other regions,which can help to improve estimates of forest biomass and carbon stocks. 展开更多
关键词 Subcanopy tree species BIOMASS allometric equations Temperate forests Biomass allocation
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Are allometric model parameters of aboveground biomass for trees phylogenetically constrained? 被引量:2
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作者 Xing-Zhao Huang Fang-Bing Li +2 位作者 Zi-Xuan Wang Yi Jin Hong Qian 《Plant Diversity》 SCIE CAS CSCD 2023年第2期229-233,共5页
Knowledge of which biological and functional traits have,or lack,phylogenetic signal in a particular group of organisms is important to understanding the formation and functioning of biological communities.Allometric ... Knowledge of which biological and functional traits have,or lack,phylogenetic signal in a particular group of organisms is important to understanding the formation and functioning of biological communities.Allometric biomass models reflecting tree growth characteristics are commonly used to predict forest biomass.However,few studies have examined whether model parameters are constrained by phylogeny.Here,we use a comprehensive database(including 276 tree species) compiled from 894 allometric biomass models published in 302 articles to examine whether parameters a and b of the model W=aD~b(where W stands for aboveground biomass,D is diameter at breast height) exhibit phylogenetic signal for all tree species as a whole and for different groups of tree species.For either model parameter,we relate difference in model parameter between different tree species to phylogenetic distance and to environmental distance between pairwise sites.Our study shows that neither model parameter exhibits phylogenetic signals(Pagel's λ and Blomberg's K both approach zero).This is the case regardless of whether all tree species in our data set were analyzed as a whole or tree species in different taxonomic groups(gymnosperm and angiosperm),leaf duration groups(evergreen and deciduous),or ecological groups(tropical,temperate and boreal) were analyzed separately.Our study also shows that difference in each parameter of the allometric biomass model is not significantly related to phylogenetic and environmental distances between tree species in different sites. 展开更多
关键词 allometric biomass model Pagel'sλ Blomberg's K Phylogenetic constraint
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The worldwide allometric relationship in anatomical structures for plant roots 被引量:1
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作者 Yue Zhang Jing-Jing Cao +3 位作者 Qing-Pei Yang Ming-Zuo Wu Yong Zhao De-Liang Kong 《Plant Diversity》 SCIE CAS CSCD 2023年第6期621-629,共9页
The cortex(i.e.,absorptive tissue)and stele(transportive vascular tissue)are fundamental to the function of plant roots.Unraveling how these anatomical structures are assembled in absorptive roots is essential for our... The cortex(i.e.,absorptive tissue)and stele(transportive vascular tissue)are fundamental to the function of plant roots.Unraveling how these anatomical structures are assembled in absorptive roots is essential for our understanding of plant ecology,physiology,and plant responses to global environmental changes.In this review,we first compile a large data set on anatomical traits in absorptive roots,including cortex thickness and stele radius,across 698 observations and 512 species.Using this data set,we reveal a common root allometry in absorptive root structures,i.e.,cortex thickness increases much faster than stele radius with increasing root diameter(hereafter,root allometry).Root allometry is further validated within and across plant growth forms(woody,grass,and liana species),mycorrhiza types(arbuscular mycorrhiza,ectomycorrhiza,and orchid mycorrhizas),phylogenetic gradients(from ferns to Orchidaceae),and environmental change scenarios(e.g.,elevation of atmospheric CO_(2)concentration and nitrogen fertilization).These findings indicate that root allometry is common in plants.Importantly,root allometry varies greatly across species.We then summarize recent research on the mechanisms of root allometry and potential issues regarding these mechanisms.We further discuss ecological and evolutionary implications of root allometry.Finally,we propose several important research directions that should be pursued regarding root allometry. 展开更多
关键词 allometric relationship Root dimeter Cortex thickness Stele radius
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Developing allometric equations to estimate forest biomass for tree species categories based on phylogenetic relationships
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作者 Mingxia Yang Xiaolu Zhou +7 位作者 Changhui Peng Tong Li Kexin Chen Zelin Liu Peng Li Cicheng Zhang Jiayi Tang Ziying Zou 《Forest Ecosystems》 SCIE CSCD 2023年第4期494-503,共10页
The development of allometric biomass models is important process in biomass estimation because the reliability of forest biomass and carbon estimations largely depends on the accuracy and precision of such models.Nat... The development of allometric biomass models is important process in biomass estimation because the reliability of forest biomass and carbon estimations largely depends on the accuracy and precision of such models.National Forest Inventories(NFI)are detailed assessments of forest resources at national and regional levels that provide valuable data for forest biomass estimation.However,the lack of biomass allometric equations for each tree species in the NFI currently hampers the estimation of national-scale forest biomass.The main objective of this study was to develop allometric biomass regression equations for each tree species in the NFI of China based on limited biomass observations.These equations optimally grouped NFI and biomass observation species according to their phylogenetic relationships.Significant phylogenetic signals demonstrated phylogenetic conservation of the crown-to-stem biomass ratio.Based on phylogenetic relationships,we grouped and matched NFI and biomass observation species into 22 categories.Allometric biomass regression models were developed for each of these 22 species categories,and the models performed successfully(R^(2)=0.97,root mean square error(RMSE)=12.9​t·ha^(–1),relative RMSE=11.5%).Furthermore,we found that phylogeny-based models performed more effectively than wood density-based models.The results suggest that grouping species based on their phylogenetic relationships is a reliable approach for the development and selection of accurate allometric equations. 展开更多
关键词 allometric equation Forest biomass National Forest Inventory Species grouping Tree architecture Wood density
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Effects of Pruning Types on Tree Vigor of Bamboo-Leaf Oak Inferred from Allometric Analysis
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作者 Hideyasu Shimada 《American Journal of Plant Sciences》 2023年第12期1430-1438,共9页
There are two well-known types of tree pruning, crown raising and crown reduction. In Japan, the former has been rarely used, whereas the latter has been widely used. However, it remains unclear which type is more eff... There are two well-known types of tree pruning, crown raising and crown reduction. In Japan, the former has been rarely used, whereas the latter has been widely used. However, it remains unclear which type is more effective to maintain tree vigor and health. Bamboo-leaf oak (Quercus myrsinifolia) trees were experimentally planted and pruned with the two pruning types compared with the no-pruning type. In the crown raising, the lower part of each tree was pruned, and its dominant leader was maintained from the aspect of structural pruning, whereas in the crown reduction, the upper part of each tree was pruned, and the tree height was reduced. The oak trees were observed and recorded in terms of leaf area, leaf weight, branch weight, and tree shape for about one year. The morphological data were statistically analyzed in terms of their allometric relationships. The crown raising type shared the same allometric patterns with the no-pruning types, but the crown reduction type did not. The trees of the crown reduction type were more likely to suffer from pests and disease. The allometric differences between the two pruning types may be considered the result of a decline in whole-tree vigor and health in crown reduction. The crown raising seemed more likely to control tree vigor and health than the crown reduction. The present results would help arborists determine which method to use for pruning. 展开更多
关键词 allometric Difference Crown Raising Crown Reduction OAK Tree Growth
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Allometric response of perennial Pennisetum centrasiaticum Tzvel to nutrient and water limitation in the Horqin Sand Land of China 被引量:4
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作者 Wei MAO TongHui ZHANG +2 位作者 YuLin LI XueYong ZHAO YingXin HUANG 《Journal of Arid Land》 SCIE 2012年第2期161-170,共10页
Optimal partitioning theory (OPT) suggests that plants should allocate relatively more biomass to the organs that acquire the most limited resources. The assumption of this theory is that plants trade off the biomas... Optimal partitioning theory (OPT) suggests that plants should allocate relatively more biomass to the organs that acquire the most limited resources. The assumption of this theory is that plants trade off the biomass allocation between leaves, stems and roots. However, variations in biomass allocation among plant parts can also occur as a plant grows in size. As an alternative approach, allometric biomass partitioning theory (APT) asserts that plants should trade off their biomass between roots, stems and leaves. This approach can minimize bias when comparing biomass allocation patterns by accounting for plant size in the analysis. We analyzed the biomass allo- cation strategy of perennial Pennisetum centrasiaticum Tzvel in the Horqin Sand Land of northern China by treating samples with different availabilities of soil nutrients and water, adding snow in winter and water in summer. We hypothesized that P. centrasiaticum alters its pattern of biomass allocation strategy in response to different levels of soil water content and soil nitrogen content. We used standardized major axis (SMA) to analyze the allometric rela- tionship (slope) and intercept between biomass traits (root, stem, leaf and total biomass) of nitrogen/water treat- ments. Taking plant size into consideration, no allometric relationships between different organs were significantly affected by differing soil water and soil nitrogen levels, while the biomass allocation strategy of P. centrasiaticum was affected by soil water levels, but not by soil nitrogen levels. The plasticity of roots, leaves and root/shoot ratios was 'true' in response to fluctuations in soil water content, but the plasticity of stems was consistent for trade-offs between the effects of water and plant size. Plants allocated relatively more biomass to roots and less to leaves when snow was added in winter. A similar trend was observed when water was added in summer. The plasticity of roots, stems and leaves was a function of plant size, and remained unchanged in response to different soil nitrogen levels. 展开更多
关键词 optimal partitioning allometric biomass partitioning limited resources biomass allocation allometric relationships
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Morphological changes and allometric growth in hatcheryreared Chinese loach Paramisgurnus dabryanus(Dabry de Thiersant, 1872) 被引量:11
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作者 张云龙 吴巧婉 +7 位作者 胡伟华 汪帆 邵韦涵 张诚明 赵忠波 何辉 樊启学 顾泽茂 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第4期757-762,共6页
The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power ... The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities. 展开更多
关键词 Paramisgurnus dabryanus early life stages length-weight relationship allometric growth
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Allometric models to estimate biomass organic carbon stock in forest vegetation 被引量:6
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作者 Mohammed Alamgir M.Al-Amin 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第2期101-106,共6页
A study was conducted in the forest area of Chittagong (South) Forest Division, Chittagong, Bangladesh for developing al- lometric models to estimate biomass organic carbon stock in the forest vegetation. Allometric... A study was conducted in the forest area of Chittagong (South) Forest Division, Chittagong, Bangladesh for developing al- lometric models to estimate biomass organic carbon stock in the forest vegetation. Allometric models were tested separately for trees (divided into two DBH classes), shrubs, herbs and grasses. Model using basal area alone was found to be the best predictor of biomass organic carbon stock in trees because of high coefficient of determination (r^2 is 0.73697 and 0.87703 for 〉 5 cm to ≤ 15 cm and 〉 15 cm DBH (diameter at breast height) rang, respectively) and significance of regression (P is 0.000 for each DBH range) coefficients for both DBH range. The other models using height alone; DBH alone; height and DBH together; height, DBH and wood density; with liner and logarithmic relations produced relatively poor coefficient of determination. The allometric models for dominant 20 tree species were also developed separately and equation using basal area produced higher value of determination of coefficient. Allometric model using total biomass alone for shrubs, herbs and grasses produced higher value of determination of coefficient and significance of regression coefficient (r^2 is 0.87948 and 0.87325 for shrubs, herbs and grasses, respectively and P is 0.000 for each). The estimation of biomass organic carbon is a complicated and time consuming research. The allometric models developed in the present study can be utilized for future estimation of organic carbon stock in forest vegetation in Bangladesh as well as other tropical countries of the world. 展开更多
关键词 allometric models organic carbon stock tree HERBS SHRUBS grasses
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Species-specific allometric equations for improving aboveground biomass estimates of dry deciduous woodland ecosystems 被引量:3
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作者 Amsalu Abich Tadesse Mucheye +2 位作者 Mequanent Tebikew Yohanns Gebremariam Asmamaw Alemu 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第5期1619-1632,共14页
Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of E... Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of Ethiopia have not as yet been developed.This study attempts to develop and evaluate species-specific allometric equations for predicting aboveground biomass(AGB)of dominant woody species based on data from destructive sampling for Combretum collinum,Combretum molle,Combretum harotomannianum,Terminalia laxiflora and mixed-species.Diameter at breast height ranged from 5 to 30 cm.Two empirical equations were developed using DBH(Eq.1)and height(Eq.2).Equation 2 gave better AGB estimations than Eq.1.The inclusion of both DBH and H were the best estimate biometric variables for AGB.Further,the equations were evaluated and compared with common generic allometric equations.The result showed that our allometric equations are appropriate for estimating AGB.The development and application of empirical species-specific allometric equations is crucial to improve biomass and carbon stock estimation for dry woodland ecosystems. 展开更多
关键词 WOODLAND allometric equations ABOVEGROUND biomass Destructive sampling
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Quantification by allometric equations of carbon sequestered by Tectona grandis in different agroforestry systems 被引量:2
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作者 Avinash Jain S.A.Ansari 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第4期699-702,共4页
Non destructive methods for quantification of carbon seques- tration in tropical trees are inadequately developed. We described a stan- dardized method for estimating carbon stock in teak (Tectona grandis Linn. F.).... Non destructive methods for quantification of carbon seques- tration in tropical trees are inadequately developed. We described a stan- dardized method for estimating carbon stock in teak (Tectona grandis Linn. F.). We developed linear allometric equations using girth at breast height (GBH), height and age to quantify above ground biomass (AGB). We used AGB to estimate carbon stock for teak trees of different age groups (1.5, 3.5, 7.5, 13.5, 18.5 and 23.5 years). The regression equation with GBH, y = 3.174x - 21.27, r2=0.898 (p 〈0.01), was found precise and convenient due to the difficulty in determination of height and age in dense natural forests of teak. The equation was evaluated in teak agroforestry systems that included Triticum aestivum (wheat), Cicer arietinum (gram), Withania somnifera (ashwagandha), 展开更多
关键词 Tectona grandis agroforestry system allometric equation carbon sequestration above ground biomass
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Allometric models for aboveground biomass of six common subtropical shrubs and small trees 被引量:2
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作者 Cheng Huang Chun Feng +6 位作者 Yuhua Ma Hua Liu Zhaocheng Wang Shaobo Yang Wenjing Wang Songling Fu Han Y.H.Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第4期1317-1328,共12页
The aboveground biomass(AGB)of shrubs and small trees is the main component for the productivity and carbon storage of understory vegetation in subtropical secondary forests.However,few allometric models exist to accu... The aboveground biomass(AGB)of shrubs and small trees is the main component for the productivity and carbon storage of understory vegetation in subtropical secondary forests.However,few allometric models exist to accurately evaluate understory biomass.To estimate the AGB of five common shrub(diameter at base<5 cm,<5 m high)and one small tree species(<8 m high,trees’s seedling),206 individuals were harvested and species-specific and multi-species allometric models developed based on four predictors,height(H),stem diameter(D),crown area(Ca),and wood density(ρ).As expected,the six species possessed greater biomass in their stems compared with branches,with the lowest biomass in the leaves.Species-specific allometric models that employed stem diameter and the combined variables of D~2H andρDH as predictors accurately estimated the components and total AGB,with R^(2) values from 0.602 and 0.971.A multi-species shrub allometric model revealed that wood density×diameter×height(ρDH)was the best predictor,with R^(2) values ranging from between 0.81 and 0.89 for the components and total AGB,respectively.These results indicated that height(H)and diameter(D)were effective predictors for the models to estimate the AGB of the six species,and the introduction of wood density(ρ)improved their accuracy.The optimal models selected in this study could be applied to estimate the biomass of shrubs and small trees in subtropical regions. 展开更多
关键词 Aboveground biomass allometric models SHRUBS Small trees Subtropical forests
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Modeling of the height–diameter relationship using an allometric equation model:a case study of stands of Phyllostachys edulis 被引量:1
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作者 Xuan Gao Zhandong Li +5 位作者 Hongmei Yu Zehui Jiang Chen Wang Yu Zhang Lianghua Qi Lei Shi 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第2期339-347,共9页
Understanding the relationship between tree height (H) and diameter at breast height (D) is vital to forest design, monitoring and biomass estimation. We developed an allometric equation model and tested its appli... Understanding the relationship between tree height (H) and diameter at breast height (D) is vital to forest design, monitoring and biomass estimation. We developed an allometric equation model and tested its applicability for unevenly aged stands of moso bamboo forest at a regional scale. Field data were collected for 21 plots. Based on these data, we identified two strong power relationships: a corre- lation between the mean bamboo height (Hm) and the upper mean H (Hu), and a correlation between the mean D (Din) and the upper mean D (Du). Simulation results derived from the aUometric equation model were in good agreement with observed culms derived from the field data for the 21 stands, with a root-mean-square error and relative root-mean-square error of 1.40 m and 13.41%, respectively. These results demonstrate that the allometric equation model had a strong predictive power in the unevenly aged stands at a regional scale. In addition, the estimated average height-diameter (H-D) model for South Anhui Province was used to predict H for the same type of bamboo in Hunan Province based on the measured D, and the results were highly similar. The allometric equation model has multiple uses at the regional scale, including the evaluation of the variation in the H- D relationship among regions. The model describes the average H-D relationship without considering the effects caused by variation in site conditions, tree density and other factors. 展开更多
关键词 allometric equation Bamboo Height-diameter relationship MODEL Phyllostachys edulis POACEAE STRATIFICATION
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Development of Allometric Models for Estimating the Biomass of <i>Sclerocarya birrea</i>(A.Rich) Hoscht and <i>Boscia senegalensis</i>(Pers.) Lam. ex Poir. 被引量:2
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作者 Ramata Talla Moustapha Bassimbé Sagna +4 位作者 Mariama Dalanda Diallo Aly Diallo Daouda Ndiaye Oumar Sarr Aliou Guisse 《Open Journal of Ecology》 2020年第8期571-584,共14页
The objective of this study was to develop allometric models for estimating the biomass of <em>Sclerocarya birrea</em> (A.Rich) Hoscht and <em>Boscia senegalensis</em> (Pers.) Lam. ex Poir. The... The objective of this study was to develop allometric models for estimating the biomass of <em>Sclerocarya birrea</em> (A.Rich) Hoscht and <em>Boscia senegalensis</em> (Pers.) Lam. ex Poir. The inventory of these ligneous was carried out at Widou Thiengoly (North of Senegal). The sample consists of 43 individuals of Boscia senegalensis and 15 individuals of <em>Sclerocarya birrea</em>. The selected individuals were dendrometrically characterized before being cut, compartmentalized (trunk, branches, and twigs) and weighed entirely. Simple regression tests were performed to examine the most explanatory dendrometric parameter (<em>x</em>) for biomass (<em>y</em>) according to two types of models: the linear model (<em>y</em> = <em>ax</em> + <em>b</em>) and the polynomial model of degrees 2 (<em>y </em>= <em>ax</em><sup>2</sup> + <em>bx</em> + <em>c</em>). The criteria for selection and validity of the models are based firstly on the tests of normality, nullity, heterogeneity and autocorrelation of the residues. The results showed that the most explanatory dendrometric parameter of the biomass was the crown surface for <em>Boscia senegalensis</em> and the 1.30 m diameter for <em>Sclerocarya birrea</em> of all the tests performed, the second-order Polynomial model is the best predictor of above ground biomass for these two species. Thus, the allometric models established to predict the biomass of these two species are: <em>y</em> = 0.0023<em>x</em><sup>2</sup> + 0.4851<em>x</em> - 0.0519 for <em>Boscia senegalensis</em> and y = 0.35<em>x</em><sup>2</sup> + 10.35<em>x</em> - 12.90 for <em>S. birrea</em>;with very significant correlation coefficients (R<sup>2</sup>) of 0.85 and 0.94 respectively. These results can be used for a sequestered carbon assessment study and will play a role in monitoring the carbon market in Africa. 展开更多
关键词 allometric Equation Boscia senegalensis Sclerocarya birrea Ferlo Senegal
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Allometric equations of select tree species of the Tibetan Plateau, China 被引量:2
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作者 RAN Fei CHANG Rui-ying +3 位作者 YANG Yang ZHU Wan-ze LUO Ji WANG Gen-xu 《Journal of Mountain Science》 SCIE CSCD 2017年第9期1889-1902,共14页
The Tibetan forest is one of the most important national forest zones in China. Despite the potentially important role that Tibetan forest will play in the Earth?s future carbon balance and climate regulation, few all... The Tibetan forest is one of the most important national forest zones in China. Despite the potentially important role that Tibetan forest will play in the Earth?s future carbon balance and climate regulation, few allometric equations exist for accurately estimating biomass and carbon budgets of this forest. In the present study, allometric equations,both species-specific and generic, were developed relating component biomass(DW) to diameter at breast height(DBH) and tree height(H) for six most common tree species in Tibetan forest. The 6 species were Abies georgei Orr., Picea spinulosa(Griff.)Henry, Pinus densata Mast., Pinus yunnanensis Franch., Cypresses funebris Endl. and Quercus semecarpifilia Smith.. The results showed that, both DBH-only and DBH2 H based species-specific equations showed a significant fit(P<0.05) for all tree species and biomass components. The DBH-only equations explained more than 80% variability of the component biomass and total biomass, adding H as a second independent variable increased the goodness of fit, while incorporating H into the term DBH2 H decreased the goodness of fit. However, not all DBH-H combined equations showed a significant fit(P<0.05) for all tree species and biomass components. Hence, the suggested species-specific allometric equations for the six most common tree species are of the form ln(DW) = c + αln(DBH). The generalized equations of mixed coniferous component biomass against DBH, DBH2 H and DBH-H also showed a significant fit(P<0.05) for all biomass components. However, due to significant species effect, the relative errors of the estimates were very high. Hence, generalized equations should only be used when there are too many different tree species, or there is no species-specific model of the same species or similar growth form in adjacent area. 展开更多
关键词 Tibetan forest allometric models Species-specific Mixed coniferous forest Model evaluation
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Allometric models for estimating aboveground biomass and carbon in Faidherbia albida and Prosopis africana under agroforestry parklands in drylands of Niger
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作者 Massaoudou Moussa Larwanou Mahamane 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第6期1703-1717,共15页
This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland ... This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland sites. Linear regression with log transformation was used to model aboveground biomass according to dendrometric parameters. Error analysis, including mean absolute percentage of error(MAPE) and root mean square of error(RMSE), was used to select and validate the models for both species. Model 1(biomass according to tree diameter) for P. africana and F. albida were considered more representative. The statistical parameters of these models were R2 = 0.99, MAPE 0.98% and RMSE1.75% for P. africana, and R2 = 0.99, MAPE 1.19%,RMSE 2.37% for F. albida. The average rate of carbon sequestered was significantly different for the two species(P ≤ 0.05). The total amount sequestered per tree averaged0.17 × 10-3 Mg for P. africana and 0.25 × 10-3 Mg for F. albida. These results could be used to develop policies that would lead to the sustainable management of these resources in the dry parklands of Niger. 展开更多
关键词 Aboveground biomass AGROFORESTRY allometric models CARBON NIGER Soudano-sahelian
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Allometric biomass equations of Larix sibirica in the Altay Mountains, Northwest China
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作者 LI Yuanyuan LIU Qijing +1 位作者 MENG Shengwang ZHOU Guang 《Journal of Arid Land》 SCIE CSCD 2019年第4期608-622,共15页
Boreal forests are important carbon sinks and have tremendous potential to mitigate climate change. Aboveground biomass of Siberian larch(Larix sibirica Ledeb.) stands in the Altay Mountains, Northwest China was studi... Boreal forests are important carbon sinks and have tremendous potential to mitigate climate change. Aboveground biomass of Siberian larch(Larix sibirica Ledeb.) stands in the Altay Mountains, Northwest China was studied and allometric equations that are related to the biomass of aboveground components using diameter at breast height(DBH) or both DBH and height(H) as independent variables for L. sibirica trees were derived in this paper. A linear simultaneous equation system by using either DBH or both DBH and H(DBH&H) indices, was used to ensure additivity of the biomass of individual tree components, and was fitted for L. sibirica. Model performance was validated using the jackknifing test. Results indicate that the goodness-of-fit for the regressions was lowest for the needles(R^2 ranging from 0.696 to 0.756), and highest for the stem wood(R^2 ranging from 0.984 to 0.997) and the aggregated biomass components(R^2 ranging from 0.994 to 0.995). The coefficient of determination for each component was only marginally improved in terms of model fit and performance in the biomass equations that used DBH&H as the independent variables compared to that used DBH as the independent variable, and needles yielded an even worse fit. Stem biomass accounted for the largest proportion(87%) of the aboveground biomass. Based on the additive equations that used DBH as the single predicitor in this study, the mean aboveground carbon stock density and the carbon storage values of L. sibirica forests were 74.07 Mg C/hm^2 and 30.69 Tg C, respectively, in the Altay Mountains. Empirical comparisons of published equations for the same species growing in the Altay Mountains of Mongolia were also presented. The mean aboveground carbon stock density estimated for L. sibirica forests was higher in the Chinese Altay Mountains than in the Mongolian Altay Mountains(66.00 Mg C/hm^2). 展开更多
关键词 LARIX sibirica additive EQUATION allometric EQUATION nested regression method carbon storage
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Correction of Left Ventricular Doppler Echocardiographic Measurements for Physiological Variances Using a Novel Optimized Multivariable Allometric Model in Healthy Chinese Han Adults
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作者 Guihua Yao Xiangyun Chen +12 位作者 Wenjing Yang Qing Zhang Jing Liu Huan Liang Hui Sun Yao Xu Li Wang Jinfeng Xu Cheng Zhang Fengrong Sun Mei Zhang Xueying Zeng Yun Zhang 《Engineering》 SCIE EI CAS 2022年第9期115-122,共8页
Most left ventricular(LV)Doppler measurements vary significantly with age and gender,making it necessary to correct them for physiological variances.We aimed to verify the hypothesis that different Doppler measurement... Most left ventricular(LV)Doppler measurements vary significantly with age and gender,making it necessary to correct them for physiological variances.We aimed to verify the hypothesis that different Doppler measurements correlate nonlinearly with different biometric variables raised to different scaling factors and exponents.In this work,a total of 23 LV Doppler parameters were measured in 1224 healthy Chinese adults.An optimized multivariable allometric model(OMAM)and scaling equations were developed in 70%of the subjects(group A),and the reliability of the model and equations was verified using the remaining 30%of the subjects(group B)as well as 183 overweight subjects(group C).The single-variable isometric model(SVIM)with body surface area(BSA)as a scaling variable was used for comparison.Before correction,all 23 LV Doppler parameters correlated significantly with one or more of the biometric variables.In group B,gender differences were found in 47.8%(11/23)of the parameters and were eliminated in 81.8%(9/11)of the parameters after correction with OMAM.The successful correction rate with OMAM was 100%(23/23)in group B and 82.6%(19/23)in group C.New reference values for corrected Doppler measurements independent of biometric variables were established.The SVIM with BSA successfully corrected none of the 23 parameters.In conclusion,different LV Doppler parameters allometrically correlated with one or more of the biometric variables.The novel OMAM developed in this study successfully corrected the effects of the physiological variances of most biometric variables on Doppler measurements in healthy and overweight subjects,and was found to be far superior to the SVIM.However,whether the OMAM equations can be applied to other ethnicities,obese subjects,and pathological conditions requires further investigation. 展开更多
关键词 Doppler echocardiography Physiological variance allometric model Normal reference values
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