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Height growth of Korean pine plantation sapling in Benxi, Liaoning Province, China
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作者 LIU Qiang WANG Jun 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第1期141-143,共3页
The height growth of Korean pine plantation was investigated for different ages of saplings in Benxi city of the eastern Liaoning, China. The sapling and seedling age were determined by branch annuals. Results show th... The height growth of Korean pine plantation was investigated for different ages of saplings in Benxi city of the eastern Liaoning, China. The sapling and seedling age were determined by branch annuals. Results show that the mean height of third- to eight-year Korean pines ranges from 13.31 cm to 111.73 cm and only 19.4% of the saplings reached the height above 130 cm. The height (Y) of eight-year-old Korean pine increases linearly with the increment of ground stem (x) (Y=3.1x+35.15). The relation between height and age can be described by an exponential equation. The second year after planting of the Korean pine is considered as the key period of Korean pine growth really adapting to the local environment; plantation management should be strengthened in this year. The Korean pine seedlings need two years to adapt to the local environment, thus early care and management should be taken in the second year. 展开更多
关键词 Benxi city korean pine sapling PLANTATION sapling height SECTION
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Habitat associations of saplings and adults in an old-growth temperate forest in the Changbai mountains, northeastern China 被引量:6
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作者 YE Ji HAO Zhan-qing +1 位作者 XIE Peng LI Jing-gong 《Forestry Studies in China》 CAS 2011年第1期13-22,共10页
Species-habitat association analysis is useful to detect spatial arrangement of individual plants, to discover rules about the distribution of species and to generate hypotheses about the possible underlying process c... Species-habitat association analysis is useful to detect spatial arrangement of individual plants, to discover rules about the distribution of species and to generate hypotheses about the possible underlying process controlling observed structures. Quantifying methods were used to classify habitats in terms of topographical variables in a mixed temperate broad-leaved Korean pine forest of the Changbai mountains in northeastern China. All of the 625 20 m × 20 m quadrats of the plot could be unambiguously assigned to one of three habitat categories (low-plateau, high-plateau and slope). Torus-translation tests were used to estimate species-habitat associations. Many species are clearly distributed in a biased fashion with respect to habitats. Fifteen (55.6%) out of 27 species showed strong positive or negative association with specific habitats. We compared species-habitat associations at the sapling and adult stages. Adjusted density values indicated few species exhibit extremely strong habitat associations. Only 9 out of 26 species had adjusted densities 〉 3 in the habitat for which they had strong positive affinity. Few species show the same associations at the small tree and large tree stages. Only 3 out of 22 occurring associations with a specific habitat appeared to have a consistent habitat association at the two stages. These results suggest that species-habitat associations exist in the 25-ha plot of the temperate forest of the Chang- bai mountains. Owing to limitations in our statistical methodology, we partly underestimated associations by ignoring rare species. Regeneration niches can contribute to co-existence, but regeneration niches due to habitat associations play a limited role in species co-existence, since most species show a similar trend in habitat associations at the sapling and adult stages. We should pay more attention to shifts in habitat associations, i.e. niche shifts at different stages of existence. 展开更多
关键词 niche differentiation habitat association environmental heterogeneity saplings and adults life stages
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Effect of nitrogen levels on photosynthetic parameters,morphological and chemical characters of saplings and trees in a temperate forest 被引量:3
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作者 Jinwei Sun Fuqi Yao +2 位作者 Jiabing Wu Pingcang Zhang Wensheng Xu 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第6期1481-1488,共8页
Exploring the response differences of leaf physiology parameters to enhanced nitrogen deposition between saplings and trees is vital for predicting the variations of terrestrial ecosystem structure and function under ... Exploring the response differences of leaf physiology parameters to enhanced nitrogen deposition between saplings and trees is vital for predicting the variations of terrestrial ecosystem structure and function under future global climate change. In this study, the ecophysiological parameters of saplings and trees of Fraxinus mandshurica Rupr. were measured at different levels of nitrogen addition in a temperate forest. The results show that ecophysiological parameters maximum net photosynthetic rate(Pmax), apparent quantum efficiency(a), dark respiration(Rd), light saturation point(Lsp), photosynthetic nitrogen use efficiency(PNUE),specific leaf area(SLA)and stomatal conductance under saturated light intensity(Gsmax) were higher in saplings than in trees. These physiological parameters and not Nleaf(leaf nitrogen content)led to relatively lower Pmaxand Rdin trees. For both saplings and trees, low and median nitrogen addition(23 and 46 kg ha-1a-1) resulted in significant increases in Pmax, Rd, Lsp, Chl, PNUE, SLA and Gsmax. These parameters tended to decline under high additions of nitrogen(69 kg ha-1a-1),whereas Nleaf was always enhanced with increasing nitrogen. Variations in Pmax and Rd with increasing nitrogen were attributed to variations in the strongly related parameters of, Lsp, Chl, PNUE, SLA and Gsmax. Overall, the response sensitivity of physiological parameters to enhanced nitrogen levels was lower in trees compared with saplings. 展开更多
关键词 Physiology parameters Added nitrogen saplingS Trees Deciduous broadleaved species
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Does nitrogen fertilization impact nonstructural carbohydrate storage in evergreen Podocarpus macrophyllus saplings? 被引量:1
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作者 Renshan Li Jianming Han +5 位作者 Liqiong Zhu Lijun Zhao Xiangling Huang Mingyue Zhang Qingpeng Yang Weidong Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第4期1653-1661,共9页
Nonstructural carbon(NSC),which represents the relationship between the carbon source and carbon sink,is an important factor that reflects the functions and performance of a tree.However,little is known regarding the ... Nonstructural carbon(NSC),which represents the relationship between the carbon source and carbon sink,is an important factor that reflects the functions and performance of a tree.However,little is known regarding the timeseries responses of NSC storage in evergreen species to different nitrogen(N)fertilization regimes.This study,which was based on a pot experiment,examined the response of the NSC(soluble sugars and starch storage to different N addition intensities[light N addition(LN):6.5 g N m^(-2)a^(-1);moderate N addition(MN):13.0 g N m^(-2)a^(-1);and heavy N addition(HN):26.0 g N m^(-2)a^(-1))]in saplings of the evergreen species Podocarpus macrophyllus.Our results showed that the net photosynthetic rate(P_(n))under MN was significantly higher than that under LN,but was comparable to that under HN.Moreover,saplings subject to MN had a significant higher leaf biomass than that to LN and HN.These results indicated that the C supply via photosynthesis under MN was greater than that under LN and HN.The NSCs reserve under MN was considerable with that under LN,which suggested that saplings in MN group consumed higher and stored lower properties of NSCs than those in LN group.However,saplings under HN stored higher properties of NSCs than those under MN considering that no difference in NSCs pools was found between the two treatments.The leaf N concentrations were found in the increasing sequence of LN<MN<HN,whilst the leaf chlorophyll concentration under HN was obviously lower than that under MN.The growth rate under MN was higher than that under LN and HN.We concluded that the NSCs allocation between con-sumption and reserve in P.macrophyllus saplings depended on soil N availability,and an excessive N addition to soil favors the storage rather than the consumption of NSCs by plants. 展开更多
关键词 PHOTOSYNTHATE ALLOCATION Source-sink balance Plant nutrient supply Podocarpus macrophyllus saplings
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Environmental and biological factors affecting the abundance of Prosopis flexuosa saplings in the central-west Monte of Argentina
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作者 Cappa F.M. Campos V.E. +2 位作者 Barri F.R. Ramos L. Campos C.M. 《Forest Ecosystems》 SCIE CSCD 2022年第1期103-110,共8页
Background:Trees and forests in drylands help mitigate the challenges through provision of economic products and vital environmental services such as habitat for biodiversity,prevention of erosion and desertification,... Background:Trees and forests in drylands help mitigate the challenges through provision of economic products and vital environmental services such as habitat for biodiversity,prevention of erosion and desertification,regulation of water,microclimate,and soil fertility.The condition and changes in dry forests can be assessed by using ecological indicators able to quantify spatial and temporal changes in vegetation.One of the ways to determine the condition of the forest is to study the dominant tree species and its regeneration.Our study aimed to assess whether the abundance of Prosopis flexuosa saplings is affected by environmental and biological factors.Results:To evaluate the first variables we used data from remote sensing such as satellite images and Aster Global Digital Model(GDEM).The second set of variables was about exotic and native ungulates and we used feces of these animals and camera traps to take data.We found that sapling abundance related positively to sandy substrates and negatively to Wetness Index.On the other hand,in relation to biological variables,the abundance of saplings was positively affected by density of adult trees and by number of seeds dispersed by equines,but space use by Lama guanicoe had a negative relationship with saplings.This research shows that P.flexuosa saplings are benefited from sandy substrates and the conditions around adult trees.In addition to this,we found that exotic ungulates in low densities have neutral(i.e.cattle)or positive(i.e.equines)effects on sapling abundance.Conclusions:Based on these findings,we conclude that regeneration of the population of P.flexuosa in our study area has no major problems.In addition,we corroborated that the presence of exotic and domestic ungulates in low densities does not have deleterious consequences for saplings of the dominant tree,P.flexuosa. 展开更多
关键词 Bos primigenius taurus Dry forests EQUINES Exotic and domestic ungulates Lama guanicoe Prosopis flexuosa Remote sensing saplingS Seed dispersal
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Indexes of Tree Structure of Cylindrical Pear Orchards at the Sapling Stage
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作者 Shuwei WEI Shaomin WANG +1 位作者 Ran DONG Xiaochang DONG 《Agricultural Biotechnology》 CAS 2019年第3期145-146,共2页
The reasonable tree and population structure parameters of various cylindrical pear orchards were studied.The results showed that for 3-year-old ‘Xinli No.7’,the tree height was 3.48 m,and the trunk height was 63 cm... The reasonable tree and population structure parameters of various cylindrical pear orchards were studied.The results showed that for 3-year-old ‘Xinli No.7’,the tree height was 3.48 m,and the trunk height was 63 cm;there were 63 branches per plant,which was equivalent to 19 971 branches per 667 m^2;the leaf area index was 1.62.For the 3-year-old ‘Xueqing’,the tree height was 3.03 m,and the trunk height was 74 cm;the number of branches per plant was 57,which was equivalent to 18 069 branches per 667 m^2;the leaf area index was 1.73.The cylindrical trees of the two varieties had the following characteristics: the canopy structure was tight;the branches were equally distributed,and the number of medium branches and short branches accounted for more than 60% of the total number of branches of the whole plant. 展开更多
关键词 PEAR sapling CYLINDRICAL
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Effect of Gamma Irradiation Doses on Morphological and Biochemical Attributes of Grape Saplings
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作者 A. F. M. Saiful Islam M. Muzahedul Islam +1 位作者 Md. Mehedi Hasan Md. Mehedi Hasan 《Agricultural Sciences》 2015年第5期505-512,共8页
The demand of grape in Bangladesh is fulfilled through import from foreign countries. The fruits of local cultivars of grapes are sour and seeded. Development of seedless grape varieties having increased sweetness, hi... The demand of grape in Bangladesh is fulfilled through import from foreign countries. The fruits of local cultivars of grapes are sour and seeded. Development of seedless grape varieties having increased sweetness, higher yield with better nutritional quality is necessary to reduce the import dependency. The present research activities are the part of a grape improvement project. A pot experiment was conducted at the Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh, during June to November 2011 to determine the suitable gamma irradiation doses on growth, leaf area and biochemical characters of grape saplings. Three vegetative bud stages viz. bud initiation stage, 4-leaf stage and 8-leaf stage, and four doses of gamma irradiation viz. 0, 5, 10, and 15 Gy were used as treatments. The experiment was laid out in a Randomized Complete Block Design with four replications. Different irradiation doses and vegetative bud stages showed significant variations in respect of plant growth characters, leaf area, soluble protein and total sugar content. Interaction effects also had significant variations on most of the parameters studied. Higher doses of gamma irradiation had showed detrimental effect on grape saplings. Generally, increased in irradiation doses showed decreased and detrimental effects on most of the parameters under study. Maximum numbers and length of roots, total dry matter, leaf area and chlorophyll-a and chlorophyll-b content were found at 5 Gy irradiation dose. Total soluble protein and sugar content of leaf were found maximum at no irradiation and 15 Gy, respectively. Higher number of roots and length, total dry matter, leaf area, chlorophyll-a, and b and soluble protein content of leaf were observed at bud initiation stage while 8-leaf stage showed maximum total sugar of leaf. In the combined effect of gamma irradiation and vegetative bud stages, all parameters showed best results in 5 Gy with bud initiation stage except total sugar content of leaf. 展开更多
关键词 GRAPE sapling Gamma Irradiation MORPHOLOGICAL and BIOCHEMICAL Parameters Leaf Area SOLUBLE Protein
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Effects of Different Water and Fertilizer Combinations on Tree Structure,Leaf Parameters and Photosynthesis of Apple Saplings
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作者 Ru CHEN Jinzheng WANG +2 位作者 Xiaomin XUE Peixian NIE Guiping WANG 《Agricultural Biotechnology》 CAS 2014年第6期4-7,13,共5页
[ Objective] This study aimed to investigate the effects of different water and fertilizer combinations on apple saplings. [ Method] ' Tianhong 2' Fuji /SH40/Malus robusta Rehd. was used as the experimental material... [ Objective] This study aimed to investigate the effects of different water and fertilizer combinations on apple saplings. [ Method] ' Tianhong 2' Fuji /SH40/Malus robusta Rehd. was used as the experimental material to analyze the effects of different irrigation modes and combinations of basal fertilizer and dressing fertilizer on tree structure, leaf parameters and photosynthesis of apple saplings. [ Result] The results showed that different water and fertilizer combinations ex- hibited varying effects on tree structure, leaf parameters and photosynthesis of apple saplings. To be specific, applying 432 000 kg/hm2 basal fertilizer, 480 kg/hm2 urea and 915 kg/hmz organic fertilizer + 0 + 915 kg/hm2 organic fertilizer as dressing fertilizer, and 1% urea as leaf fertilizer was conducive to promoting growth of branches and leaves, increasing leaf thickness, individual leaf area and SPAD, and improving photosynthesis of apple saplings under half root irrigation and whole root irrigation conditions. In addition, the effects were more significant under whole root irrigation conditions. [ Conclusion] Selecting the appropriate water and fertilizer combination is conducive to the growth of apple saplings. 展开更多
关键词 Water and fertilizer Apple saplings Tree structure Leaf parameters PHOTOSYNTHESIS
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Eco-physiological characteristics of Tetracentron sinense Oliv.saplings in response to different light intensities
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作者 Rong Wang Xueheng Lu +4 位作者 Hongyan Han Xuemei Zhang Yonghong Ma Qinsong Liu Xiaohong Gan 《Journal of Forestry Research》 SCIE EI CAS 2024年第3期29-44,共16页
The regeneration of Tetracentron sinense Oliv.is poor in the understory and in open areas due to the charac-teristics of natural regeneration of the species on forest edges and in gaps.It is unclear whether different ... The regeneration of Tetracentron sinense Oliv.is poor in the understory and in open areas due to the charac-teristics of natural regeneration of the species on forest edges and in gaps.It is unclear whether different light intensities in various habitats affect eco-physiological characteristics of saplings and their natural regeneration.In this study,the light intensity in T.sinense habitats was simulated by artificial shading(L1:100%NS(natural sunlight)in the open;L2:50%NS in a forest gap or edge;L3:10%NS in understory)to investigate differences in morphology,leaf structure,physiology,and photosynthesis of 2-year-old sap-lings,and to analyze the mechanism of light intensity on sapling establishment.Significant differences were observed in morphology(including leaf area,and specific leaf area)under different light intensities.Compared to L1 and L3,chloroplast structure in L2 was intact.With increasing time,superoxide dismutase(SOD)and catalase(CAT)activities in L2 became gradually higher than under the other light intensities,while malondialdehyde(MDA)content was opposite.Shading decreased osmoregulation substance contents of leaves but increased chlorophyll.The results suggest that light intensities significantly affect the eco-physiological characteristics of T.sinense saplings and they would respond most favorably at intermediate levels of light by optimizing eco-physiological characteristics.Therefore,50%natural sunlight should be created to promote saplings establishment and population recovery of T.sinense during in situ conservation,including sowing mature seeds in forest edges or gaps and providing appropriate shade protection for seedlings and saplings in the open. 展开更多
关键词 Chloroplast ultrastructure Eco-physiological characteristics Light intensities sapling establishment Tetracentron sinense Oliv
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Photosynthesis and Water Use Efficiency of Platycladus Orientalis and Robinia Pseudoacacia Saplings under Steady Soil Water Stress during Different Stages of Their Annual Growth Period 被引量:6
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作者 Ming-Chun Wang Jin-Xin Wang +1 位作者 Qing-Hua Shi Jin-Song Zhang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2007年第10期1470-1477,共8页
A simulated drought experiment was conducted in a rain-free shed to test the physiological response of Platycladus orientalis and Robinia pseudoacacia saplings to steady soil water stress during different stages. The ... A simulated drought experiment was conducted in a rain-free shed to test the physiological response of Platycladus orientalis and Robinia pseudoacacia saplings to steady soil water stress during different stages. The five soil water treatments were: 100%, 87.84%, 70%, 52.16% and 40% of field capacity. The results showed that the net photosynthetic rate of R. pseudoacacia decreased as soil water potential decreased in the range between -0.041 MPa and -0.292 MPa. The threshold value at which the net photosynthetic rate changed significantly was -0.12 MPa. The relationship between net photosynthetic rate of P. orientalis and soil water potential could be described as a quadratic parabola in the range between -0.041 MPa and -0.648 MPa. Analysis of variance showed significant differences in the net photosynthetic rate of P. orientalis between soil water potentials of -0.061 MPa ~, -0.648 MPa. Average water use efficiency (WUE) increased as soil water potential decreased, but the influence mechanism of soil water stress on leaf WUE and photosynthetic rate for the two species were different evidently. 展开更多
关键词 growth stages PHOTOSYNTHESIS Platycladus onentalis Robinia pseudoacacia sapling steady water stress water use efficiency.
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Relative effects of different leaf attributes on sapling growth in tropical dry forest 被引量:1
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作者 Ravi K.Chaturvedi A.S.Raghubanshi J.S.Singh 《Journal of Plant Ecology》 SCIE 2014年第6期544-558,共15页
Aims Soil moisture content(SMC)influences establishment,survival and development of plant species and is considered as the most important limiting factor in tropical dry forest(TDF).In this study we attempt to establi... Aims Soil moisture content(SMC)influences establishment,survival and development of plant species and is considered as the most important limiting factor in tropical dry forest(TDF).In this study we attempt to establish the relationship between leaf attributes and of tree saplings in TDF and address the following questions:(i)how are the functional attributes of dominant tree saplings of TDF affected by seasonal changes in SMC at different habitats?,(ii)what is the relationship of functional attributes with each other?,(iii)how are the functional attributes and their plasticity affected by habitat con-ditions?and(iv)can the functional attributes in single or in com-bination predict the growth rate of tree saplings of TDF?The study was conducted on four sites(Hathinala,Gaighat,Harnakachar and Ranitali,listed in order of decreasing SMC)within the tropical dry deciduous forest in northern India.Methods We analysed eight leaf attributes,specific leaf area(SLA);leaf dry matter content(LDMC);leaf nitrogen concentration(leaf N);leaf phosphorus concentration(leaf P);chlorophyll concentration(Chl);mass-based photosynthetic rate(Amass);mass-based stomatal con-ductance(Gsmass);intrinsic water use efficiency(WUEi)and three growth attributes,relative diameter increment(RDI);relative height increment(RHI);relative growth rate(RGR)of the 10 dominant tree saplings(viz.,Acacia catechu,Anogeissus latifolia,Boswellia serrata,Buchanania lanzan,Diospyros melanoxylon,Hardwickia binata,Lagerstroemia parviflora,Lannea coromandelica,Shorea robusta and Terminalia tomentosa)of a TDF and observed the effects of site,season and species for a period of 2 years.Saplings were selected in gradients of deciduousness.Step-wise multiple regression was performed to predict RDI,RHI and RGR from mean values of SMC and leaf attributes.Important Findings All the 11 attributes were interrelated and differed significantly among the 10 saplings.Species response varied across sites and seasons.Across the SMC gradient,the attributes showed variable plasticity that differed across species.Among the 10 saplings,the highly deciduous Boswellia serrata showed the maximum plasticity in seven functional attributes.According to the step-wise multiple regressions,65%variability in RDI and 67%variability in RGR were due to Gsmass,and for RHI,61%variability was due to Amass.SMC and the other attributes,viz.,SLA,Chl,WUEi and LDMC in combination could contribute only for~2-6%of the variability in RDI,RHI and RGR,which indicates that other traits/factors,not accounted in this study are also important in modulating the growth of tree saplings in TDFs.In conclusion,growth of the tree saplings in the tropical dry environment is determined by soil moisture,whereas the response of saplings of different tree species is modulated by alterations in key functional attributes such as SLA,Chl,WUEi and LDMC. 展开更多
关键词 tropical dry forest soil moisture content deciduousness tree saplings leaf attributes relative growth rate
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Cartilage Wear in Healthy and Osteoarthritis Joints
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作者 Zenon Pawlak Raghuvir Pai 《Open Journal of Orthopedics》 2023年第2期55-61,共7页
This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant diff... This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant differences in their concentration. While examining the surface properties of OA joints, we found that OA PLs molecules cannot support lubrication, and increased friction was observed. Our lubrication mechanism was based on a surface active phospholipids (SAPL) multibilayer which in OA condition was deactivated and removed from the cartilage surface under OA conditions. Cartilage wettability study clearly demonstrated a significant decrease in hydrophobicity, the contact angle, θ (theta), dropping from 103° from bovine healthy cartilage to 65° in surface partially depleted and 35.1° for completely depleted surface. These results are discussed in the context that surface active phospholipid (SAPL) and lubricin, each has specific roles in a lamellar-repulsive lubrication system. However, deactivated phospholipid molecules are major indicator of cartilage wear (model) introduced in this study. 展开更多
关键词 Cartilage Surface Friction (Cartilage/Cartilage) Osteoarthritis (OA) Surface Active Phospholipids (SAPL)/or Surface Amorphous Layer (SAL) Deactivated Phospholipids WEAR
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Tree regeneration in gap-understory mosaics in a subtropical Shorea robusta(Sal) forest 被引量:3
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作者 L.N.Sharma K.B.Shrestha I.E.Maren 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第6期2061-2068,共8页
Spatial variation in tree-regeneration density is attributed to the specialization of tree species to light availability for germination and growth.Light availability,in turn,varies across the gap-understorey mosaic.C... Spatial variation in tree-regeneration density is attributed to the specialization of tree species to light availability for germination and growth.Light availability,in turn,varies across the gap-understorey mosaic.Canopy gaps provide an important habitat for the regeneration of tree species that would otherwise be suppressed in the understory.In subtropical forests,there is still a knowledge-gap relating to how canopy disturbances influence tree-regeneration patterns at local scale,and if they disproportionately favor regeneration of certain species.We aim to analyze whether canopy gaps promote tree regeneration,and tree species are specialized to gaps or understory for germination and growth.We sampled vegetation in 128 plots(0.01 ha),equally distributed in gaps and below canopy,in two subtropical Shorea robusta Gaertn.(Sal)forests in Nepal,recording the number of tree seedlings and saplings in each plot.We compared the regeneration density of seedlings and saplings separately between gaps and the understorey.The mean densities of seedlings and saplings were higher in the gaps at both sites;although there was no difference in the seedling density of the majority of the species between the habitats.No species were confined to either gap or understorey at the seedling stage.We conclude that gaps are not critical for the germination of tree species in Sal forests but these are an important habitat for enabling seedlings to survive into saplings.The classification of trees into regeneration guilds mainly based on germination does not apply to the majority of tree species in subtropical Sal forests.Our results reaffirm that gap creation promotes tree regeneration by favouring seedling survival and growth and can influence forest management for conservation,as well as for plantations. 展开更多
关键词 Canopy-gap Density Regeneration saplingS Seedlings SHADE tolerance
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Surface wildfire in conifer broad-leaved forests of the Hyrcanian region of Iran:short-term effect on regeneration and damage to trees 被引量:1
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作者 Seyed Abdolkhalegh Yadegarnejad Mehdi Dylam Jafarabad Najmeh Mohammadi Savadkoohi 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第2期425-434,共10页
Wildfires in recent years have resulted in degradation and damage to the Hyrcanian forest ecosystems in Northern Iran.This study was carried out to investigate fire damage to trees and changes in regeneration in early... Wildfires in recent years have resulted in degradation and damage to the Hyrcanian forest ecosystems in Northern Iran.This study was carried out to investigate fire damage to trees and changes in regeneration in early-season growth after wildfires in the Golestan Province.For this purpose,a random sampling plan was used,with 60 circular plots(each plot is 1000 m2) for each stand and 240 circular(25 m2) plots for regeneration within the burned and unburned areas,respectively.In each plot,habitat factors were recorded,including crown canopy percentage,forest stratum,herb-layer cover percentage,species,diameter at breast height,tree and regeneration quality,and quantity of seedlings and saplings.Our results showed that bark is an important factor for fire resistance in Hyrcanian forests.The Persian ironwood and European yew has the highest and lowest fire resistance;as broad leave species are more resistant than needle leaf species.Density of regeneration in unburned area was higher than burned area,and statistical analysis showed significant differences for all species between two areas.Fire effects on sapling were different among species which indicates sapling has different resistance to fire.Forest floor fuel,season,stand composition and microclimate have more effects on fire severity while environmental factors,regeneration and management practices shaping future composition stands. 展开更多
关键词 Broad leave European yew Seedling and sapling WILDFIRE
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Tree mortality and regeneration of Euphrates poplar riparian forests along the Tarim River,Northwest China 被引量:1
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作者 Ayjamal Keram Umut Halik +3 位作者 Tayierjiang Aishan Maierdang Keyimu Kadeliya Jiapaer Guolei Li 《Forest Ecosystems》 SCIE CSCD 2021年第4期659-671,共13页
Background:Tree mortality and regeneration(seedling and sapling recruitment)are essential components of forest dynamics in arid regions,especially where subjected to serious eco-hydrological problems.In recent decades... Background:Tree mortality and regeneration(seedling and sapling recruitment)are essential components of forest dynamics in arid regions,especially where subjected to serious eco-hydrological problems.In recent decades,the mortality of the Euphrates poplar(Populus euphratica)along the Tarim River in Northwest China has increased.However,few studies have quantified the causes of mortality and regeneration in this azonal riparian forest type.Methods:The present study describes the annual hydrological response of tree mortality and regeneration in forest gaps.A total of 60 canopy gaps were investigated in six replicate grid plots(50m×50 m)and the annual runoff and water consumption data during the period of 1955–2016 were collected from hydrological stations in the middle reaches of the Tarim River.We compared the regeneration density of seedlings and saplings within the canopy gap areas(CGAs),undercanopy areas(UCAs),and uncovered riverbank areas(RBAs)through detailed field investigation.Results:Our study found that the mortality of young and middle-aged gap makers has increased remarkably over recent decades,particularly since the year 1996.The main results indicated that regional water scarcity was the primary limiting factor for long-term changes in tree mortality,as shown by a significant correlation between the diameter at breast height(DBH)of dead trees and the annual surface water.The average density(or regeneration rate)of seedlings and saplings was highest in the RBAs,intermediate in the CGAs,and lowest in the UCAs.Compared with the UCAs,the CGAs promote tree regeneration to some extent by providing favorable conditions for the survival and growth of seedlings and saplings,which would otherwise be suppressed in the understory.Furthermore,although the density of seedlings and saplings in the CGAs was not as high as in the RBAs,the survival rate was higher in the CGAs than in the RBAs.Conclusion:Forest canopy gaps in floodplain areas can play a decisive role in the long-term germination and regeneration of plant species.However,as a typical phreatophyte in this hyper-arid region,the ecosystem structure,functions and services of this fragile P.euphratica floodplain forests are threatened by a continuous decrease of water resources,due to excessive water use for agricultural irrigation,which has resulted in a severe reduction of intact poplar forests.Furthermore,the survival of seedlings and saplings is influenced by light availability and soil water at the regional scale.Our findings suggest that policymakers may need to reconsider the restoration and regeneration measures implemented in riparian P.euphratica forests to improve flood water efficiency and create canopy gaps.Our results provide with valuable reference information for the conservation and sustainable development of floodplain forest ecosystems. 展开更多
关键词 Tree mortality Regeneration strategy Seedling and sapling recruitment Gap makers Riparian forest Tarim River
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Growth Performance, Undergrowth Diversity and Carbon Sequestration Potentials of Tree Species Stand Combinations, Ghana 被引量:1
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作者 Samuel Novor Simon Abugre 《Open Journal of Forestry》 2020年第1期135-154,共20页
The limited number of studies on mixed plantations makes it difficult to accurately predict success of mixed-species combination especially with regards to growth, undergrowth diversity and carbon sequestration potent... The limited number of studies on mixed plantations makes it difficult to accurately predict success of mixed-species combination especially with regards to growth, undergrowth diversity and carbon sequestration potentials. This study therefore provides information on the effects of Ceiba pentandra, Terminalia superba, Cedrela odorata and Khaya anthotheca in three different stand combinations on growth, undergrowth diversity and carbon sequestration potential. A 15-year-old coupe of 32 ha of mixed tree species stand combinations was selected for the study. The coupe was stratified based on the species combinations. Nested sub-plots (25 m × 25 m) were randomly laid in different species stand combinations for growth data collection. In each nested sub-plot, 1 m × 1 m plots were also randomly laid for undergrowth diversity study. The results revealed that two species stand combination of Ceiba pentandra and Terminalia superba performed better in terms of growth, carbon sequestration and carbon content as compared to the other species stand combinations. The saplings on the other hand, were more diverse under the three species stand combination plots. Also, the effective number of species, species richness, evenness, and dominance were higher in the four species stand combination plots. Generally, Ceiba pentandra and Terminalia superba are compatible as it produced the highest growth and carbon sequestration potential. 展开更多
关键词 Species Combination Growth FLORISTIC Composition Carbon Content saplingS
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Susceptible conditions for debarking by deer in subalpine coniferous forests in central Japan
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作者 Hayato lijima Takuo Nagaike 《Forest Ecosystems》 SCIE CSCD 2016年第1期63-69,共7页
Background: Recently, deer have expanded their distribution to higher altitude ranges including subalpine forests However, culling deer and construction of deer fence in subalpine forests are difficult because of ste... Background: Recently, deer have expanded their distribution to higher altitude ranges including subalpine forests However, culling deer and construction of deer fence in subalpine forests are difficult because of steep slopes and complex topography. Thus it is necessary to clarify the factors which are associated with debarking by deer for the effective protection of subalpine forests. In this study, we examined which factors are associated with debarking b: sika deer (Cervus nippon) in subalpine coniferous forests. Methods: We conducted our survey in Minami-Alps National Park, central Japan. We established 24 10 m × 40 m plots and surveyed the occurrence of debarking on saplings 〉30 cm in height and 〈3 cm in diameter at breast heigh (DBH) and on trees 〉3 cm in DBH, as well as sapling density within each plot. Minimum distances to nearest grasslan( of plots were calculated (tentatively assuming grassland would attract deer and would cause high debarking pressure in the surrounding subaipine forests). Results: The mean percentage of debarked live saplings was higher than that of live trees. The mean percentage of debarked saplings which had already died was 81.6 %. Debarking of saplings increased with lower elevation taller sapling size, and marginally increased near grassland. Sapling density was lower in plots with low basa area of conspecific trees near grassland and differed among species. Sapling density marginally decreased with decreasing elevation and increasing stand tree density. Debarking of trees was positively related to small DBH and Io~ elevation, and marginally increased near grassland and differed among species. Conclusions: Our results suggest that tall saplings in subalpine forests of low elevation or near subalpine grassland were susceptible to debarking by deer and monitoring of these areas may permit the early detection of the impacts of deer in subalpine coniferous forests. 展开更多
关键词 ABIES Cervus nippon DEBARKING Grassland PICEA sapling density Subalpine region
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Vegetation Structure and Regeneration Status of the Western Escarpment of the Rift Valley of the Gamo Zone, Southern Ethiopia
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作者 Temesgen Dingamo Serekebirhan Takele +1 位作者 Zerihun Woldu Sebsebe Demissew 《Open Journal of Ecology》 2022年第1期94-111,共18页
Understanding the structure and regeneration of forest resources contributes to identifying the elements of diversity, endemism, threatened and endangered species. This study was conducted in the western escarpment of... Understanding the structure and regeneration of forest resources contributes to identifying the elements of diversity, endemism, threatened and endangered species. This study was conducted in the western escarpment of the Rift valley of the Gamo Zone, Southern Ethiopia. The main objective was to investigate structure and regeneration status of the study area. A systematic sampling method was used to collect vegetation data from a total 102 quadrats, each 20 × 20 m (400 m<sup>2</sup>) and five 1 × 1 m (1 m<sup>2</sup>) sub-quadrats were established at the four corners and at the centre for sapling and seedling estimation. Tree and shrub species were listed;Height (H ≥ 1.5 m) and DBH ≥ 2 cm were measured and recorded. R-statically software and Microsoft Excel were used to record and analyse the data. A total of 126 plant species belonging to 43 families and 90 genera were identified. The most dominant families were Fabaceae, followed by Anacardiaceae and Euphorbiaceae. Most frequent species were <em>Euclea divinorum </em>(84.3%), followed by <em>Rhus natalensis</em> (83.3%),<em> Terminalia brownii</em> (74.5%). DBH class ≤ 5cm had highest density (63.6%) and DBH ≥ 25.1 cm had the lowest density (0.87%). Three population patterns have been observed;inverted J, J-shaped and irregular shaped. 93% of species had IVI values b/n 1 - 4, 65% of species IVI values < 1% and 7% of species had IVI values ≥ 5.28. <em>Pappea capensis</em>, <em>Combretum molle</em>, <em>Terminalia brownii</em>, <em>Euclea divinorum </em>had highest IVI values. In the vertical stratification, lower story was 91.3% of the individuals. Only a few species contributed to the high density of saplings (440.2/ha) and seedlings (825.49/ha) while most had very little or no saplings and seedlings at all. Thus, in order to revert the current forest structure and regeneration to the previous natural state, it is considered important to minimize the influence of the human interference, grazing and raising awareness to surrounding community. 展开更多
关键词 Importance Value Index REGENERATION Seedling/sapling Vegetation Structure
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Tree Planting
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作者 于浩洋 冯会丽(指导) 《天天爱英语》 2019年第3期38-38,共1页
Our school organized a tree planting activity on Thursday afternoon.The weather was fine that day.We came to a desolate place.The first thing I did when I got there was to dig a hole for my sapling.
关键词 SCHOOL TREE sapling
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警用44mm双管手枪及SD88SAPL手枪
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作者 李义 《轻兵器》 北大核心 1991年第6期52-54,共3页
关键词 警用44mm双管手枪 SD88SAPL手枪
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