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天意怜幽草,人间重晚晴——读沈国强先生的《树根集》(信息管理文集)
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作者 金恩辉 《图书馆工作与研究》 CSSCI 北大核心 2002年第6期16-16,共1页
关键词 沈国强 《树根集》 《信息管理文集》 图书馆学
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树根──给教师
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作者 李成功 《山东教育》 2001年第5期57-57,共1页
关键词 《树根——给教师》 李成功 现代文学 诗歌
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Effect of arbuscular mycorrhiza on the growth of Camptotheca acuminata seedlings 被引量:4
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作者 赵昕 于涛 +1 位作者 王洋 阎秀峰 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第2期121-123,共3页
Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi (AMF), Acaulospora m... Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi (AMF), Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves. 展开更多
关键词 Arbuscular mycorrhiza (AM) Camptotheca acuminata seedlings BIOMASS Nitrogen and phosphorus contents
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Effects of Ca^(2+)concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii 被引量:6
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作者 方升佐 候常英 洑香香 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第1期46-50,共5页
The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii wer... The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii were studied under controlled conditions. The types ofHoagland nutrient solution with three Ca^(2+) concentrations levels (200, 400 and 600 μg·g^(-1))and a control (without Ca^(2+)) were designed to culture Pteroceltis tatarinowii. After 6 months,contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and barkwere analyzed. The results indicated that Ca accumulations content in the root, leaf and bark hadpositively relation with Ca^(2+) concentrations (200, 400, 600 μg · g^(-1)), and the order of theCa content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g^(-1) Ca^(2+) concentrations was 5.5 times as high as that of the control, and about 1.4 times ashigh as that of the root treated in 200 and 400 μg/g Ca^(2+) concentrations respectively. On thecontrary, K and Mg contents in the root, leaf and bark were negatively related to Ca^(2+)concentrations, especially in the bark, and their accumulation trend followed the order ofleaf>root>bark. K content in the bark treated with 600 μg ·g^(-1) Ca^(2+) concentrations was 39.3%of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 μg ·g^(-1)and 400 μg ·g^(-1) Ca^(2+) concentrations respectively; Mg content in the bark treated with 600μg ·g^(-1) Ca^(2+) concentrations was 23.4% of that of the control, and was 27.1% and 35.4% ofthat of the bark treated with 200 and 400 μg·g^(-1) Ca^(2+) concentrations respectively. Comparedwith the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca^(2+)concentrations and their contents were in the order: root>leaf>bark. Based on the results of thisstudy, the experiment has been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil. 展开更多
关键词 pteroceltis tatarinowii hoagland nutrient solution Ca^(2+) concentrations mineral element COMPONENT
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Optimization of Preparative Separation and Purification of Total Flavonoids from Radix Puerariae by Macroporous Resin Method 被引量:11
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作者 刘火安 王伯初 +3 位作者 戴传云 邵志勇 何从林 贾云 《Journal of Chinese Pharmaceutical Sciences》 CAS 2006年第2期121-126,共6页
Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separat... Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed (BV) with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% (V/V) ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs. 展开更多
关键词 Radix Puerariae total flavonoids macroporous resin SEPARATION PURIFICATION
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Microbial Community Characteristics in the Rhizosphere of Atrazine-contaminated Soil by Dendroremediation of Poplar
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作者 姚斌 刘方 +1 位作者 刘昌勇 韦秀文 《Agricultural Science & Technology》 CAS 2017年第12期2423-2426,2519,共5页
The change of microbial community characteristics in the different rhizo- sphere zones of hybrid poplar (Populusdeltoidsxnigra, DN34) under atrazine stress were investigated by rhizo-boxes and Biolog system in a gre... The change of microbial community characteristics in the different rhizo- sphere zones of hybrid poplar (Populusdeltoidsxnigra, DN34) under atrazine stress were investigated by rhizo-boxes and Biolog system in a greenhouse experiment, with sublimed sulfur and calcium hydroxide as soil pH regulators. Data from the measurement by the Biolog ECO plate demonstrated that the value of average well color development (AWCD) and the carbon source utilization of soil microorganisms in the treatments with pH regulators were promoter than CK during the initial 30 days; while the results from the 90 days indicated that the activity and the carbon source utilization of soil microbes in acid regulator treatment began to fall down, even lower than that of poplar implant treatment, then the alkaline treatment could still stimulate and promote the activity and the carbon source utilization ability of soil microbes. Overall, the activity and community structure of soil microbes in rhizo- sphere zones of atrazine-contaminated soil did not show steady regularity during the phytoremediation process by using hybrid poplars. For the reason that the Biolog E- CO plate, which only had 31 kinds of carbon sources, could not really indicate the detail information about the function diversity of community structure of soil mi- crobes. So it's essential for us to take more sophisticated analysis tools for further study. 展开更多
关键词 POPLAR RHIZOBOX ATRAZINE Microbes Average absorbance Diversity
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Study on the Explant Disinfection of Root Culture of Hevea brasiliensis
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作者 姜泽海 周权男 李哲 《Agricultural Science & Technology》 CAS 2011年第4期514-516,共3页
[Objective] The aim was to look for an effective way of decreasing explants contamination in the root tissue culture of Hevea brasiliensis.[Method] In order to study root tissue culture of H.brasiliensis,new roots fro... [Objective] The aim was to look for an effective way of decreasing explants contamination in the root tissue culture of Hevea brasiliensis.[Method] In order to study root tissue culture of H.brasiliensis,new roots from forest section after treatment for one month were as explants,and 1 g/L carbendazim,75% ethanol,0.1% mercuric chloride and Yipeilong with different concentrations were used as disinfectants for roots disinfection.[Result] Before conventional disinfection,root explants were treated by 1 g/L carbendazim for 2.5 h,and disinfected by 75% ethanol for 30 s and 0.1% HgCl2 for 6 min,then cultured on the callus induction medium supplemented with 0.1% Yipeilong.The results showed that the contamination rate of explants decreased to 44.59%,and 25.60% explants survived after cultured for 30 d.[Conclusion] The study could provide theoretical foundation for the decrease of explant contamination in the root tissue culture of H.brasiliensis. 展开更多
关键词 Hevea brasiliensis Root explants Contamination control CARBENDAZIM Yipeilong
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Research of Ecological Restoration of Mycorrhizal Mulberry in Karst Rocky Desertification Area 被引量:2
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作者 邢丹 王震洪 +2 位作者 张爱民 付文婷 韩世玉 《Agricultural Science & Technology》 CAS 2014年第11期1998-2002,共5页
Mycorrhizal mulberry is a plant, whose mulberry root and Arbuscular Myc-orrhizal fungi came into being a symbiotic relationship by a mean of natural or artifi-cial inoculation. Mycorrhizal mulberry coupling with main ... Mycorrhizal mulberry is a plant, whose mulberry root and Arbuscular Myc-orrhizal fungi came into being a symbiotic relationship by a mean of natural or artifi-cial inoculation. Mycorrhizal mulberry coupling with main ecological barriers, such as barren soil drought in rocky desertification area, wil be beneficial to recovering the karst degraded ecosystem by removing these stresses. So, mycorrhizal mulberry is considered a new effective way in ecological control of karst rocky desertification. The research summarized the structures and the characteristic eco-physiological functions of arbuscular mycorrhizal fungi (AMF), and preliminarily discussed its availability and research in karst rocky desertification restoration ,including investiga-tion of AMF diversity, the key affecting factor of AMF species diversity, the sym-biosis mechanism between AMF and mulberry, promoting the development of agri-cultural economy in Karst Rocky Desertification area by mycorrhizal mulberry. These elaborate efforts are to demonstrate mycorrhizal mulberry adapting to karst environ-ment from a new view, lay a theoretical basis for karst degraded-ecosystem restoration, and final y guarantee sustainable development of mycorrhizal mulberry in rocky desertification area. 展开更多
关键词 AMF Mulberry Restoration Karst Rocky Desertification
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Tolerance of Salix matsudana to Heavy Metals Determined by Root Elongation Method
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作者 田胜尼 周疆丽 +1 位作者 张玉琼 占明 《Agricultural Science & Technology》 CAS 2010年第4期98-101,171,共5页
[Objective]The research aimed to discuss the tolerance of Salix matsudana to single or compound heavy metals and provide theoretical basis for renovating polluted soil by heavy metals with woody plants.[Method]Using r... [Objective]The research aimed to discuss the tolerance of Salix matsudana to single or compound heavy metals and provide theoretical basis for renovating polluted soil by heavy metals with woody plants.[Method]Using root elongation method,the effects of heavy metal Cu^2+,Pb^2+,Zn^2+ and their mixed solution on the adventitious roots growth of S.matsudana cuttings were studied.[Result]The adventitious roots growth of S.matsudana cuttings was obviously affected by different concentrations of heavy metals solution.Adventitious roots of S.matsudana cuttings could not grow while the concentration of Cu^2+ was higher than 15 mg/L,the mixture solution concentration was higher than 20 mg/L and Zn^2+ concentration was higher than 30 mg/L.When the solution concentration reached 40 mg/L,adventitious roots of S.matsudana cuttings could grow only in Pb^2+ treatment group.With the increasing of the solution concentration,the number of adventitious roots of S.matsudana cuttings gradually decreased.In 5 mg/L Zn^2+ treatment group,the number of adventitious roots of S.matsudana cuttings was the most,the longest root length and average root length were the longest and the rooting rate was the highest.[Conclusion]The tolerance of S.matsudana to Pb^2+ was strongest and its tolerance to Cu^2+ was the weakest.The tolerance order of S.matsudana to three kinds of heavy metals and their mixed solution was as following:Pb^2+〉Zn^2+〉Cu^2++Pb^2++Zn^2+〉Cu^2+. 展开更多
关键词 Root elongation method Salix matsudana Heavy metals TOLERANCE
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Effect of Ryegrasses on Soil Runoff and Sediment Control 被引量:31
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作者 ZHOU Zheng-Chao SHANGGUAN Zhou-Ping 《Pedosphere》 SCIE CAS CSCD 2008年第1期131-136,共6页
Living plants and plant roots can reduce runoff and soil erosion. Using a rain simulator, a series of soil erosion experiments were conducted to study the influence of living roots and canopies of ryegrasses (Lolium ... Living plants and plant roots can reduce runoff and soil erosion. Using a rain simulator, a series of soil erosion experiments were conducted to study the influence of living roots and canopies of ryegrasses (Lolium perenne L.) during the growing season on sediment yields and runoff of a silt loam soil. The results indicated that during the growing season, decrements in runoff and sediment yields increased with time. Sediment yields (τ^2 = 0.999) and decrements in runoff (τ2 = 0.946) were closely related to the root surface area density. The contributions of roots and canopies of ryegrasses to the reductions in runoff and sediment yields were different. Canopies usually contributed more to the runoff decrement than the roots, whereas roots contributed up to 96% of the decrease in sediment yields in the late stage of the growing season. 展开更多
关键词 CANOPY ROOT RUNOFF RYEGRASS sediment yield
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Profiles of carbon stocks in forest,reforestation and agricultural land,Northern Thailand 被引量:7
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作者 P. Pibumrung N. Gajaseni A. Popan 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第1期11-18,共8页
A study was conducted to assess carbon stocks in various forms and land-use types and reliably estimate the impact of land use on C stocks in the Nam Yao sub-watershed (19°05′10″N, 100°37′02″E), Thaila... A study was conducted to assess carbon stocks in various forms and land-use types and reliably estimate the impact of land use on C stocks in the Nam Yao sub-watershed (19°05′10″N, 100°37′02″E), Thailand. The carbon stocks of aboveground, soil organic and fine root within primary forest, reforestation and agricultural land were estimated through field data collection. Results re- vealed that the amount of total carbon stock of forests (357.62 ± 28.51 Mg·ha^-1, simplified expression of Mg (carbon)·ha^-1) was significantly greater (P〈 0.05) than the reforestation (195.25 ± 14.38 Mg·ha^-1) and the agricultural land (103.10 ± 18.24 Mg·ha^-1). Soil organic carbon in the forests (196.24 ± 22.81 Mg·ha^-1) was also significantly greater (P〈 0.05) than the reforestation (146.83 ± 7.22 Mg·ha^-1) and the agricultural land (95.09± 14.18 Mg·ha^-1). The differences in carbon stocks across land-use types are the primary consequence of variations in the vegetation biomass and the soil organic matter. Fine root carbon was a small fraction of carbon stocks in all land-use types. Most of the soil organic carbon and fine root carbon content was found in the upper 40-cm layer and decreased with soil depth. The aboveground carbon:soil organic carbon: fine root carbon ratios (ABGC: SOC: FRC), was 5:8:1, 2:8:1, and 3:50:1 for the forest, reforestation and agricultural land, respectively. These results indicate that a relatively large proportion of the C loss is due to forest conversion to agricultural land. However, the C can be effectively recaptured through reforestation where high levels of C are stored in biomass as carbon sinks, facilitating carbon dioxide mitigation. 展开更多
关键词 carbon stock aboveground carbon soil organic carbon fine root carbon land use Thailand
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Bio-Mobilization of Potassium from Clay Minerals: I. By Ectomycorrhizas 被引量:10
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作者 YUAN LING, FANG DEHUA, WANG ZHIHUI, SHUN HONG and HUANG JIANGUO (College of Resources and Environment, Southwest Agricultural University, Chongqing 400716 China) 《Pedosphere》 SCIE CAS CSCD 2000年第4期339-346,共8页
A pot experiment was carried out to investigate effect of ectomycorrhizal fungi on eucalyptus growth and K bio-mobilization from soils and clay minerals. In the experiment, sands mixed with soil, KCI-saturated vermicu... A pot experiment was carried out to investigate effect of ectomycorrhizal fungi on eucalyptus growth and K bio-mobilization from soils and clay minerals. In the experiment, sands mixed with soil, KCI-saturated vermiculate and mica, respectively, were used to nurse eucalyptus seedlings which were nonectomycorrhized or ectomycorrhized by an ectomycorrhizal fungus Pisolithus tinctorius strain XCI (Pt XC1) isolated from a forest soil from Xichang, Sichuan Province, China, and a worldwide well-known ectomycorrhizal fungus Pisolithus tinctorius strain 2144 (Pt 2144) obtained in Australia. More depletion of HCl-soluble K by mycorrhizas from the soil and minerals than nonmycorrhizas suggested that mycorrhizas had a great ability to mobilize K present in the interlayer and feldspar. Mycorrhizal seedlings depressed greatly K digested with HF-HCIO4 from substrates after consecutive extractions of soils and minerals by water, ammonium cetate and boiling HCl, while nonmycorrhizal seedlings reduced it little if any, showing that the mycorrhizal seedlings could mobilize and then utilize the structural K in mineral lattice. Ectomycorrhizal fungi played a very important role not only in promoting the growth of eucalyptus seedlings but also in mobilizing K in soils and minerals. The infection of Pt XC1 led to a better growth of eucalyptus seedlings and more K accumulation in the seedlings than that of Pt 2144. The large differences in K accumulation by the seedlings might be due to different abilities of the two ectomycorrhizal fungi to mobilize K in interlayer and lattice pools in the clay minerals. 展开更多
关键词 clay minerals ECTOMYCORRHIZAS EUCALYPTUS K mobilization
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Occurrence and Culture of Mycorrhizal Fungi Associated with Oaks in Dandong Region, Liaoning Province 被引量:4
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作者 WANGHui DAILi-Min +2 位作者 YANGBao-Shan LANGQing-Long GUHui-Yan 《Pedosphere》 SCIE CAS CSCD 2005年第2期232-237,共6页
With both field investigation and pure culture experiments, the occurrence and optimal essential growth of mycorrhizal fungi with oaks in Dandong Region of Liaoning Province, China were investigated from 1997-2002 A t... With both field investigation and pure culture experiments, the occurrence and optimal essential growth of mycorrhizal fungi with oaks in Dandong Region of Liaoning Province, China were investigated from 1997-2002 A total of 36 species of mycorrhizal fungi associated with oaks were observed. The results showed that the occurrence of mycorrhizal fungi was related to tree species, tree ages, and months of the year, with at least 20 fungi species being associated with more than two oak species. The highest Sim… 展开更多
关键词 mycorrhizal fungi rnycorrhizal relationship OAK pure culture
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Dihydrochalcones and phenanthrene derivatives from Fissistigma bracteolatum 被引量:2
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作者 Zhu Hongping Lu Xiaoling Sun Xiaohong Xu Qiangzhi Jiao Binghua 《Journal of Medical Colleges of PLA(China)》 CAS 2010年第4期226-234,共9页
Three dihydrochalcones derivatives 1-3, flavone 4 and phenanthrene derivative 5 were isolated, together with 9 known compofinds, from the air-dried root bark of Fissistigma bracteolatum Chatterjee. Their structures we... Three dihydrochalcones derivatives 1-3, flavone 4 and phenanthrene derivative 5 were isolated, together with 9 known compofinds, from the air-dried root bark of Fissistigma bracteolatum Chatterjee. Their structures were determined by spectroscopic (NMR, MS) and chemical methodologies. 展开更多
关键词 Fissistigma Fissistigma bracteolatum Chatterjee DIHYDROCHALCONE PHENANTHRENE
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Vegetative propagation ofAesculus indica through stem cuttings treated with plant growth regulators 被引量:9
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作者 Mumtaz Majeed M.A. Khan A.H.Mughal 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第2期171-173,I0004,共4页
Cuttage propagation of Aesculus indica was tested by treatments with different concentrations of indole-3-acetic acid (IAA) @ 2000, 4000 (ppm), indolebutyric acid (IBA) @ 2000, 4000 (ppm) and naphthlcetic acid... Cuttage propagation of Aesculus indica was tested by treatments with different concentrations of indole-3-acetic acid (IAA) @ 2000, 4000 (ppm), indolebutyric acid (IBA) @ 2000, 4000 (ppm) and naphthlcetic acid (NAA) @ 2000, 4000 (ppm) in dry formulation in the Forest Nursery, Faculty of Forestry, SKUAST-K, Shalimar. The cuttings treated with IBA @ 4000 ppm and IBA @ 2000 ppm had a sprouting rate of 75% and 50%, respectively, which was significantly higher than that of control and other treatments. The highest rooting rate (50%) was recorded in the cuttings with the application of IBA @ 4000 ppm. The cuttings treated with IBA @ 2000 ppm had 25% rooting rate. All other treatments along with control (talc powder) failed to induce rooting. It was concluded that IBA @ 4000 ppm was a better-applied concentration for vegetative propagation ofA. indica under Kashmir conditions. 展开更多
关键词 Aesculus indica indolebutyric acid rootingi stem cuttings vegetative propagation
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Effects of Soil Fertility and Atmospheric CO_2 Enrichment on Leaf, Stem and Root Dark Respiration of Populus tremuloides 被引量:6
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作者 X. Z. WANG P. S. CURTIS +2 位作者 and C. S. VOGEL Columbia University, Palisades, New York 10964-8000 (USA) The Ohio State University, Columbus, Ohio 43210-1293 (USA) University of Michigan Biological Station, Pellston, Michigan 49769 (USA) 《Pedosphere》 SCIE CAS CSCD 2001年第3期199-208,共10页
An open-top chamber experiment was conducted at the University of Michigan Biological Station near Pellston, Michigan, USA, to study the effects of soil fertility and CO2 on leaf, stem and root dark respiration (Rd) o... An open-top chamber experiment was conducted at the University of Michigan Biological Station near Pellston, Michigan, USA, to study the effects of soil fertility and CO2 on leaf, stem and root dark respiration (Rd) of Populus tremuloides. Overall, area-based day-time leaf Rd (Rda) was significantly greater at elevated than at ambient CO2 in high-fertility soil, but not in low-fertility soil. Mass-based leaf Rd (Rdm) was overall greater for high- than for low-fertility soil grown trees at elected, but not at ambient CO2. Nighttime leaf Rd. and Rdm were unthected by soil fertility or CO2, nor was stem Rda, which ranged from 1.0 to 1.4 μmol m-2 s-1 in the spring and 3.5 to 4.5 μmol m-2 s-1 in the summer. Root Rda. was significantly higher in high- than in low-fertility soil, but was unaffected by CO2. Since biomass production of P. tremuloides will be significantly greater at elevated CO2 while specific Rd will either increase or remain unchanged, we predict that carbon loss to the atmosphere through respiration from this ecologically important species would increase at higher CO2. Soil fertility would also interact with elevated CO2 in affecting the carbon flow in the plant-soil-air system. 展开更多
关键词 leaf dark respiration Populus tremuloides root respiration soil fertility stem respiration
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Organic matter contribution to soil fertility improvement and maintenance in red Alder (Alnus rubra) silvopastoral systems
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作者 Ronnie M. Mmolotsi Zewge Teklehaimanot 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第1期49-52,共4页
An investigation was conducted to quantify fine roots and roots nodules over the four seasons in forestry and agroforestry alder (Alnus rubra) stands in North Wales. Soil samples collected in each season were excava... An investigation was conducted to quantify fine roots and roots nodules over the four seasons in forestry and agroforestry alder (Alnus rubra) stands in North Wales. Soil samples collected in each season were excavated at three sampling points (0.30 m, 0.57 m and 1.00 m distance from the base of each tree) from nine trees of the agroforestry and forestry plots. Result showed that the density of live fine root had significant differences in between seasons and treatments (P 〈 0.001). The mean weight density of live fine root over the four seasons in agroforestry and forestry was 0.27±0.01 kg·m^-3 and 0.54±0.03 kg·m^-3, respectively. Weight density of dead root in each system remained constant throughout the year. The mean weight density of dead root was also significantly different (P 〈 0.01) between forestry and agroforestry systems. Weight density of live and dead root nodule was both constant throughout the year and between the different sampling distances. The mean weight densities of live and dead root nodule over the four seasons were 0.09±0.03 kg·m^-3 and 0.05±0.03 kg·m^-3 in agroforestry and 0.08±0.02 kg·m^-3 and 0.03±0.01 kg·m^-3 in the forestry plots, respectively. 展开更多
关键词 ALDER Alnus rubra root nodule fine root NITROGEN
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Roots of pioneer trees in the lower sub-tropical area of Dinghushan, Guangdong, China
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作者 HAO Yan-ru PENG Shao-lin +4 位作者 MO Jiang-ming LIU Xin-wei CHEN Zhuo-quan ZHOU Kai WU Jin-rong 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第5期377-385,共9页
Representative pioneer tree root systems in the subtropical area of South China were examined with regard to their structure, underground stratification and biomass distribution. Excavation of skeleton roots and obser... Representative pioneer tree root systems in the subtropical area of South China were examined with regard to their structure, underground stratification and biomass distribution. Excavation of skeleton roots and observation of fine roots of seven species including the Euphorbiaceae, Theaceae, Melastomataceae, Lauraceae and Fagaceae families was carried out. The results showed that: (1) Pioneer tree roots in the first stage of natural succession were of two types, one characterized by taproot system with bulky plagiotropic branches; the other characterized by flat root system with several tabular roots. The late mesophilous tree roots were characterized by one obvious taproot and tactic braches roots up and down. Shrub species roots were characterized by heart fibrous root type featured both by horizontally and transversally growing branches. Root shapes varied in different dominant species at different stages of succession. (2) Roots of the different species varied in the external features-color, periderm and structure of freshly cut slash. (3) In a set of successional stages the biomass of tree roots increased linearly with the age of growth. During monsoon, the total root biomass amounted to 115.70 t/ha in the evergreen broadqeaved forest; 50.61 t/ha in needle and broad-leaved mixed forest dominated by coniferous forest; and 64.20 t/ha in broad-and needle-leaved mixed forest dominated by broad-leaved heliophytes, and are comparable to the underground biomass observed in similar tropical forests. This is the first report about roots characteristics of forest in the lower sub-tropical area of Dinghushan, Guangdong, China. 展开更多
关键词 Pioneer tree Tree roots Lower subtropical forest Dinghushan China
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Application and Verification of Logarithmic LinearCorrelation Model of Element Contents Between Tree Ringsand Soils near the Tree Roots
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作者 QIANJUNLONG YINZHUOSI 《Pedosphere》 SCIE CAS CSCD 1998年第1期65-70,共6页
Nine Platanus acerifolia (Ait.) Willd. trees growing in the Nanjing Children Teacher’s School, Nanjing,China, were selected to determine the contents of 13 chemical elements both in the 1994’s growth rings,C(Z, t), ... Nine Platanus acerifolia (Ait.) Willd. trees growing in the Nanjing Children Teacher’s School, Nanjing,China, were selected to determine the contents of 13 chemical elements both in the 1994’s growth rings,C(Z, t), and in the soils near the roots, C’(Z, t), of the trees. The results showed that the relationship between C(Z, t) and C’(Z, t) followed the logarithmic linear correlation model, lgC’(Z, t)=a(Z)+b(Z) ig C (Z, t).Based on this model the chrono-sequences of chemical element contents in the soils were reproduced from those in the tree rings; i.e., the dynamic variations in the chemical element contents of the soils at the sites were traced. In this study the chrono-sequences of the chemical elements including Cd, Ph, Mn, Co and Zn in the soils near the roots of a Platanus acerifolia tree from 1957 to 1994 were established, and the background values of Cd, Pb, Mn, Co and Zn in the soil were calculated by taking the lowest values of the chrono-sequences of the element contents as upper limits of the background values. 展开更多
关键词 chemical elements correlation model Platanus acerifolia (Ait.) Willd. SOIL tree rings
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Study on Model of Correlation Between Chemical Ele-ment Contents in Tree Rings and Soils near Tree Roots 被引量:3
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作者 KESHAN-ZHE QIANJUN-LONG 《Pedosphere》 SCIE CAS CSCD 1994年第1期19-26,共8页
The chemical element contents in tree rings are correlated with those in the soils near the tree roots. Theresults in the present study showed that the correlation between them could be described using the followinglo... The chemical element contents in tree rings are correlated with those in the soils near the tree roots. Theresults in the present study showed that the correlation between them could be described using the followinglogarithmic linear correlation model:lgC'(Z) = α(Z) + b(Z)lgC(Z).Therefore, by determining the chrono-sequence C(Z, t), where Z is the atomic number and t the year ofelemental contents in the annual growth rings of trees, we could get the chrono-sequence C'(Z, t) of elementalcontents in the soil, thus inferring the dynamic variations of relevant elemental contents in the soil. 展开更多
关键词 correlation model elemental contents SOILS tree rings
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