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1.
广义的Chapman-Richards函数及其在树木和林分生长中的应用   总被引:1,自引:0,他引:1  
The generalized Chapman-Richards model was derived from the Chapman-Richards function in which parameters η,κ and m were unconstrained.Based on the structure of solutions and biological interpretations,the model could be classified into eight cases(three categories)at all and among them only 4 kinds of cases are suitable in forestry that represent four typical growth patterns of trees and stands.For each of 4 equations,the model properties and biological interpretations for parameters were discussed in detail.The generalized chapman-Richards model was capable of describing a wide range of growth curves that was asymptotic or nonasymptotic,with or without inflection point.In order to illustrate the versatility of the model,it was fitted to a group of data sets conceming the DBH growth of cryptomeria plantations with 4 initial densities and the DBH and height growth of natural Korean pine tree.Comparing the generalized Chapman-Richards function and the Sohnute model,it was found that the parameters and expressions of the two modets were interchangeable in theory,and the fitting results were explicitly identical in empirical applications.  相似文献   

2.
The dynamic changes of protein polypeptide in endosperms of Gingkgo biloba seeds during seed germination were studied by SDS-PAGE and two-dimensional gel electrophoresis (2-DE). The results showed that 80 kinds of protein spots in endosperms of Gingkgo biloba were clear observed in the 2-DE spectrum. Protein molecular weights were in the range of 26-52kD, and their isoelectric points were in the range of 5.8-7.8. In the course of seed germination, 13 kinds of proteins were degraded, and 13 kinds of proteins were synthesized; 7 kinds of proteins with different molecular weights and isoelectric points of 35kD/pIr.8, 31kD/pIr.8, 29kD/pIr.8, 33kD/pI6.6, 33kD/pI 6.4, 34kD/pI7.7 and 31kD/pI7.7 were identified primarily as vegetative storage proteins (VSPs).  相似文献   

3.
The extraction of Artemisia hedinii Ostenf. et Pauls(A. hedinii) were rough and further isolated by chromatographic separation technology, and the antifungal activity of the component was evaluated by the the spore germination method. Furthermore, the composition of antimicrobial components was analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). The results showed that 13 kinds of components(Fr.1-Fr.13) were rough isolated from the extraction of A. hedinii, in which the component Fr.5 showed the best antifungal activity. Four kinds of components (Fr.5.1-Fr.5.4) were obtained by the further separation of the component Fr.5. The EC50 of A. hedinii crude extraction on Alternaria alternate (A.alternate) spores was 5.04 g/L, and that of the component Fr.5.2 was 0.57 g/L. The HPLC-MS results showed that the components of Fr.5.2 mainly contained deoxy double hydroxyl artemether (17 %),deoxy dihydroartemisinin (43.65 %) and deoxyartemisinin (16.15 %). The content of dihydroartemisinin of component Fr.5.2 was calculated as 40.95 % by using dihydroartemisinin as the standard. The EC50 of dihydroartemisinin on A.alternate was 2.70 g/L, indicating that the major antifungal matter in component Fr.5.2 was artemisinin derivatives. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.  相似文献   

4.
Bruguiera sexangula(Lour) Poir., a threatened mangrove tree, was inoculated with beneficial microbes in a nursery to assess any improvements in growth and biomass.From soil samples from the rhizosphere of B.sexangula in a mangrove forest in Panangadu of Kerala India, nitrogen-fixing bacteria Azotobacter chroococcum and Azospirillum brasilense were isolated.The phosphatesolubilising bacterium Bacillus megaterium and potassiummobilizing bacteria Frateruria aurantia were also isolated and cultured on suitable media.Later, ripe propagules of B.sexangula were collected from matured trees and raised in sterilized soil bags(13×25 cm) containing sterilized soil and sand(2:1 ratio).The cultured beneficial microbes were propagated and used to inoculate the ripe propagules of B.sexangula and maintained in the nursery for 6 months.After 6 months, growth and biomass of the inoculated propagules were greater than for the uninoculated control propagules.Shoot length, number of leaves, stem girth and root length were also significantly greater than in the controls.This study showed that the mangrove-specific beneficial microbes influenced the growth of B.sexangula in the nursery and will help in the establishment of B.sexangula in degraded mangrove forests.  相似文献   

5.
The static and dynamic diffusion coefficients are important coefficients todescribe the moisture transfer processes in particleboard.In this paper,the formula ofculculating the static and dynamic diffusion coefficients were deduced.At first,the staticdiffusion coefficients of four kinds of particleboards were determined by using diffusion cupmethod.The results demonstrated that the static diffusion coefficients parallel to panelsurface were 10-20 times as large as that of perpendicular to panel surface for test boards.To determine both dynamic diffusion coefficients and surface emission coefficients ofmoisture in particleboards in one experimental period,specimens in four different thickness-es of each kind of particleboard were used in the experiment.Then the method ofregression was used and the dynamic diffusion coefficients and surface emission coefficien-ts were determined based on the slope and intercept of the regressive line.  相似文献   

6.
The distributive characteristies of turbulence,turbulent vclocity,turbulent intensityand Rcynolds stress,in horizontal and vertical direction on leeward side of windbreak were dis-cussed in this paper.The results show that all the three kinds of parameters of turbulence have thesimilar distributive patterns in lec,their peaks were around 10H for houizontal and Z/H=1 forvertical.The windbreak is important barrier to affect the structure and distribution of wind speedand turvbulence.Porosities of windbreaks could alter the patterns of turbulence,therefore,affect theabilities and functions of windbreaks.  相似文献   

7.
8.
To investigate value in use of liquefied wood-based resin applications in molding material, Chinese fir (Cunninghamia lanceolata) and poplar (Populus tomentosa) wood meal were liquefied in phenol. The reactant was co-condensed with formaldehyde to obtain liquefied wood-based resin. For this paper, we investigated the characterization of the resin and its application in molding material. The result shows that the basic properties of liquefied wood-based resin were satisfactory; the bonding strength of plywood prepared with liquefied Chinese fir and liquefied poplar resin can reach 1.54 and 1.00 MPa, respectively. The compression strengths of the molding material prepared with two kinds of liquefied wood resin were 73.01 and 73.58 MPa, almost the same as that of PF resin molding material. The limiting volume swelling of molding material made with liquefied Chinese resin and liquefied poplar resin were 8.5% and 8.3%, thickness swelling rates of water absorption were 3.3% and 4.2%, and the maximum weight ratios of water absorption were 25.9% and 26.2%, respectively. The soil burial test result shows that the weight loss rate of the molding materials made with liquefied Chinese resin and liquefied poplar resin were 8.3% and 9.1% and that of the PF resin molding material was 7.9%. After the soil internment test, the reduction ratio of compression strength of the two kinds of molding material achieved 16.9% and 17.7%, while that of the PF resin molding material was 15.4%. The test results of wood fungi inoculation on the three surfaces of the molding material indicate the breeding rate of molding material prepared with liquefied Chinese resin and liquefied poplar resin were at level 4 and that of PF resin molding material was at level 1 of the ISO standard.  相似文献   

9.
Microbial community functional diversity is a sensitive indicator of soil.Forest fires can change microbial community functional diversity.In this research,the fired soil samples were collected from Huzhong of Daxing’anling in Heilongjiang Province. The functional diversity of soil microbial community was detected by BIOLOG system.The average well color development(AWCD) in BIOLOG plates indicated the ability of carbon substrate utilization of microbial community.The indices of Shannon, Simpson and Mcintosh were calculated to show the richness,dominance and evenness of the functional diversity,and the principal component analysis of substrate reactions reflected the main carbon sources utilized by microbial community.The results showed that all the samples exhibited the reduction of AWCD during the first 144 hours of incubation,but there were obvious differences in the reduction degree among the samples.All kinds of fire intensities could influence microbial community functional diversity. The low fire intensity increased the richness (Shannon),dominance(Simpson) and evenness (Mcintosh) of microbial community.However,the intermediate and high fire intensity reduced these parameters,suggesting that the burned soil emitted gaseous nitrogen,a number of organic carbon and available phosphorus,which caused the reduction of the microorganism in quantity and type,and change in soil ingredients.The organic material reduced in the burned soil,in the same time,the pH values rose,which changed environment in which microorganism lives.The changed environment might not be conducive to activities of the microorganism.The principal component analysis showed that the main carbon sources for soil microbes were carbohydrates and amino acids and the carbon substrate utilization patterns in different samples were significant different.The results indicated that functional diversity of soil microbes were altered by forest fires,and the ability of microbes to utilize carbon source and the type of carbon sources were affected by dif  相似文献   

10.
A survey on the symptom and severity of the leaf spot disease of Pongamia pinnata L. was conducted in the nurseries of the Institute of Forestry and Environmental Sciences, University of Chittagong (IFESCU), Bangladesh Forest Research Institute (BFRI) and Aronnak Nursery in Chittagong. The highest infection percentage and disease index were found in IFESCU nursery, followed by BFRI and the lowest was recorded in Aronnak nursery. The associated organism of leaf spot disease of P. pinnata was isolated from the diseased plant parts and the pathogenicity was established with the isolated fungus. Colletorichum gloeosprioides Penz was proved to be pathogenic. The inhibition of mycelial growth of C. gloeosporioides was observed and identified as suitable fungicides (Bavistin, Cupravite and Dithane M-45) and doses (0.05, 0.10, 0.50, 1.00, 1.50 and 2.00). The lowest and highest mycelial growth were respectively found on Bavistin and on Cupravite at the concentration of 0.05 after 8th day of incubation. It indicates that out of the three tested fungicides, Bavistin showed most effective, followed by Diathane M-45, and Cupravite was ineffective for its very little inhibition on mycelial growth.  相似文献   

11.
作者于2002年6月至2003年6月,通过调查和查阅文献资料,总结出8种适应湖南人工养殖的主要经济蛇类的区系组成、资源利用价值和食性分析,并就湖南8种主要经济蛇类的资源现状进行评价和提出保护性建议。  相似文献   

12.
经过5年的调查研究,基本澄清了西峡黑烟镇自然保护区内野生经济植物资源现状。调查结果发现,保护区内有药用植物154种,用材树种51种,淀粉植物69种,油料植物61种,芳香植物37种,野生果类26种,野生花卉及绿化植物83种,蜜源植物24种,野菜植物65种,纤维植物52种,鞣质类植物50种,染料植物26种,树脂胶类植物16种,有毒植物38种。并根据野生经济植物的开发利用现状提出了资源保育对策。  相似文献   

13.
An integrated tree plantation approach combining indigenous livelihoods and industrial wood production is being implemented in West Kalimantan, Indonesia. In this study the economics of land-use was investigated in villages within the plantation scheme. The effect of three alternative land-use scenarios and costs and benefits of each land-use type were studied using linear programming. The scenarios were based 1) on the current land-use, 2) on the integrated tree plantation system with incentives and government regulations, and 3) on a financially optimal land-use distribution. Additionally, plant species richness in different land-use types was surveyed. The scenarios had different kinds of effects on villages varying in respect to their possibilities for land-use intensification. In villages with extensive land use, establishment of tree plantations without any land-use regulations increased the potential economic return on land, resulting in conversion of natural and man-made semi-natural forests into swidden fields. In villages with more sedentary agriculture, the plantation scheme did not create pressures towards remaining forests even in the case of financially optimal land-use distribution. Incorporation of land-use regulations prevented further deforestation but also decreased households' economic returns. The results also showed that conversion of Imperata grasslands to any other land-use increased species richness. Incentives, restrictions or regulations aiming at conserving natural and semi-natural forests are needed to ensure conservation of biodiversity and long-term improvements in local livelihoods. It can be concluded that tree plantations can be combined with other land-use practices: They can improve the economic return on land without further degradation of the environment.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

14.
通过对四川马尾松枯萎林分木居真菌和线虫种类分析结果,在健康木、衰弱木和枯死木中均能分离出多种真菌,但健康木木居真菌数量较少。分离出的真菌种类主要有木霉属(Trichoderma sp.)、镰孢霉属(Fusarizn sp.)、多毛孢属(Pestalotia sp.)、砖格孢属(Steganosporium sp.)和曲霉属(Asperigllus sp.)。分离出的线虫为伞滑刃属(Bursaphelenchus sp.)线虫,未分离到松材线虫和拟松材线虫,分离出的木霉、多毛孢属、砖格孢属均可培养松材线虫,说明四川马尾松林区目前还属于松材线虫非疫区,但有发生松材线虫的可能性。  相似文献   

15.
2006-2009年从内蒙古中西部林木、花卉病害部位分离鉴定出链格孢属Alternaria 19种,分别寄生在39种植物上;黑腐皮壳属Valsa 2种,寄生在5种林木上;茎点霉属Phoma 1种,寄生在3种林木上;大茎点霉属Macrophoma 1种,寄生在1种林木上;叶点霉属Phyllosticta 6种,寄生在6种林木上;丝核菌属Rhizoctonia 1种分别寄生在5种林木上。  相似文献   

16.
为减少坡耕地水土流失现状,提高种植经济收入,在秭归县九畹溪镇实施5种农林复合种植优化模式.以农作物作为对照,对这5种模式生长情况进行调查,同时对经济效益和生态效益进行评估.结果表明:①主要树种成活率在90%以上,保存率在85%以上,保存面积达100%;②从经济效益上来看,农林复合种植模式总收入远高于单纯农作物种植模式,进入盛产期后以核桃+茶叶埂模式收入最高,未进入盛产期时以香椿 药材+茶叶埂模式收入最高;③从生态效益来看,项目的实施每年平均可减少土壤流失532.61 t,年均径流量减少15 998.40 m3,全氮、全磷、有效钾年均流失量分别减少12.89,12.58,2.05 t.  相似文献   

17.
对西双版纳普文试验林场营造的 6种类型的人工林进行了经济效益评价。从投资回收期、投入产出比、财务盈利能力等方面进行了量化分析 ,结果表明 6种类型人工林都具有实施的可行性 ,是云南热区较具发展前景的人工林经营模式  相似文献   

18.
国内外城市废弃植物纤维材料的利用   总被引:8,自引:1,他引:7  
文章介绍了国外利用城市废弃植物纤维材料的概况,阐述了目前国外利用废弃植物纤维材料制造的几种产品,包括:木塑复合材料、湿法成型纸质人造板、干法成型纸质板、湿法成型废纸复合板、纸质结构板、再生刨花板和无机胶结人造板。对我国利用废弃木质材料的情况也进行了简要概括。  相似文献   

19.
研究了超临界二氧化碳萃取法和水蒸气蒸馏法提取香榧(Torreya grandis cv.Merrillii)假种皮精油的化学组成,采用气相色谱-质谱联用仪分别对两种方法提取的精油成分进行分析。结果表明,从超临界二氧化碳萃取法精油中分离出58种组分,含有较多的大分子香味成份和非挥发性成份;从水蒸气蒸馏法提取精油中分离出62种组分,其中以挥发性组分居多。两种方法提取的精油中有11种组分是相同的,主要挥发性组分均为α-蒎烯和柠檬烯。  相似文献   

20.
落地的水曲柳种子自然染菌率较高,未染菌的种子占6.7%;经分离鉴定,从水曲柳种子上共分离出22种真菌,其中接合菌2种、子囊菌1种、半知菌18种、待鉴定1种,交链孢菌是优势种群。在种仁、种皮、种翅3个部位上分离到的真菌种类、数量差别较小。  相似文献   

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