共查询到20条相似文献,搜索用时 62 毫秒
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木棉(Gossampinus malabarica)又名攀枝花、红棉、英雄树、烽火树,属木棉科木棉属落叶高大乔木.木棉广泛分布在我国四川、云南、贵州、广西、广东,生长在江河沿岸、山地阳坡及村边道路旁,喜光、耐高温,对土壤要求不苛刻.在四川攀枝花地区木棉树于1月-2月份开花,先花后叶,花色艳丽,有红色、金黄、淡黄色等颜色,树形高大伟岸,是优良的园林绿化树种.木棉树现是攀枝花市市花和广州市市树,在园林绿化中常作行道树、庭荫树、景园树、盆景树等.木棉经嫁接后2 a-3 a开花,嫁接苗可作盆景矮化栽培,观赏价值高.本文介绍了木棉的嫁接育苗技术. 相似文献
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One compound approach combining factor-analytic model with AMMI and GGE biplot to improve multi-environment trials analysis 总被引:1,自引:0,他引:1
To improve multi-environmental trial(MET)analysis,a compound method—which combines factor analytic(FA)model with additive main effect and multiplicative interaction(AMMI)and genotype main effect plus genotype-by-environment interaction(GGE)biplot—was conducted in this study.The diameter at breast height of 36 open-pollinated(OP)families of Pinus taeda at six sites in South China was used as a raw dataset.The best linear unbiased prediction(BLUP)data of all individual trees in each site was obtained by fitting the spatial effects with the FA method from raw data.The raw data and BLUP data were analyzed and compared by using the AMMI and GGE biplot.BLUP results showed that the six sites were heterogeneous and spatial variation could be effectively fitted by spatial analysis with the FA method.AMMI analysis identified that two datasets had highly significant effects on the site,family,and their interactions,while BLUP data had a smaller residual error,but higher variation explaining ability and more credible stability than raw data.GGE biplot results revealed that raw data and BLUP data had different results in mega-environment delineation,test-environment evaluation,and genotype evaluation.In addition,BLUP data results were more reasonable due to the stronger analytical ability of the first two principal components.Our study suggests that the compound method combing the FA method with the AMMI and GGE biplot could improve the analysis result of MET data in Pinus teada as it was more reliable than direct AMMI and GGE biplot analysis on raw data. 相似文献
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Natural spruce-fir mixed stand is one of the main forest types in the world,and also has huge ecological,economic and social benefits.According to the structural characteristics and succession laws of natural spruce-fir forest,it is urgent and significant to develop scientific management measures for natural spruce-fir mixed stand in line with local conditions.The article outlined the characteristics of the distribution and structure, regeneration and succession laws of natural spruce-fir forest,and analyzed the current situation and existing problems of natural spruce-fir forest management.The following recommendations were eventually made:1) In no cutting area,all logging activities should be banned.In a restricted cutting area,the cutting intensity should be generally controlled within 15%of the stock volume before cutting.On the commodity forest management area, the appropriate cutting intensity should be determined according to the volume per hectare,determine and classification management should be implemented in accordance with the characteristics of forest,to ensure the scientific selective cutting.2) Closure for afforestation,planting and repair planting should be adopted on vegetation-intensive land,sparse shrubs covered land and harvesting slash,in order to accelerate natural regeneration.3) The in situ conservation should be conducted in nature reserves and scientific experiment stations of rare and endangered species,such as Abies chensiensis,Picea neoveitchii,Abies vuanbaoshanensis,to reduce human destruction.4) It is supposed to collect seeds in time,establish nursery,actively establish forest, expand artificial population and promote natural regeneration. 相似文献
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《技术与市场》2007,(1):23
当前现代化的航天、航空、汽车、机械、电子、民用建筑、化工等行业迫切要求具备很高的力学性能及耐热、耐磨、耐化学性能的材料.因此高分子材料发展的一个重要方向就是通过对现有聚合物进行物理和化学改性,使其进一步高性能化、结构化、工程化.北京化工大学研制的聚氯乙烯合金是通过挤出机的力学、化学作用及接枝、复合技术使聚氯乙烯塑料工程化,成为物理性能可与ABS相比拟的新材料.聚氯乙烯合金具有高流动性、高韧性,完全可以代替ABS注塑计算机、电视机、冰箱、照相机、仪表等外壳.聚氯乙烯合金还具有良好的耐寒性,可制作各种规格的异型材,包括门窗、上水管道等.产品市场前景好,具有很强的竞争力,有很好的经济效益和社会效益. 相似文献
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This paper proposes an automatic method of pore combination recognition,which is an important feature to hardwood recognition.After extracting edge from wood microscopic cross-section, based on area histogram of the similar circle regions,the method classifies all regions into two classes with maximum between-class variance,so as to distinguish the pore from other textures,which are similar in shapes but different in sizes.Meanwhile, second objective function about average area of closed regions is used to improve the pore segmentation performance.At last,the method uses adjacency degree of pore set to judge pore combination.The experiments demonstrate that the task of pore segmentation can be completed successfully for all kinds of pore distribution and combination,and also the correct combinations of pores are given. 相似文献
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According to the unification principle of system structure and system function of the Water Resource Conservation Forests,seven factors were selected from stand spatial structure,trees structure and healthy of woods,the multifunction management optimization model target was confirmed by using nonlinearity multi-objective programming approach, and the target function-stand spatial structure homogeneity index was defined to establish spatial optimization models with restraining conditions set up in diversity of stand structure and spatial structure.The spatial structure of available typical stand in the wet land area in southern Donting Lake was optimized by means of selective cutting and reinforcement planting.The results showed that the spatial structure was improved obviously and trees diversity and stand health were not weakened.It’s suggested that the established optimization model can effectively guide multifunction management,stand structure optimization and the steadiness of ecological ecosystem and it is convenient and operable in practice,and it’s very important to protect and recover ecosystem of Water Resource Conservation Forests. 相似文献
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"无刺丰"与"深秋红"沙棘品种的选育及其特征 总被引:2,自引:0,他引:2
1990年从芬兰和俄罗斯引入沙棘优树或品种沙棘种子45份,于1991年在阜新县育苗,1992年造林,1995年和1999年在阜新市郊区经两次易地移栽,2001年取其分生株,植于内蒙古库伦,经14年的多次被动迁移过程,最终以实生选种法选育出两个沙棘无性系品种。“无刺丰”全株无刺,树冠披散形,采果容易,单株产果量可达20kg,宜作经济型林木栽培。“深秋红”为无刺或少刺的主干型灌木或亚乔木,果实密集、色红、鲜亮,并经冬不落,为我国北方理想的秋冬景观型品种。 相似文献
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贵州古树名木保护与管理对策探讨 总被引:4,自引:1,他引:3
文章从贵州古树名木现状、古树生长发育规律及环境条件对古树影响出发,分析古树名木衰老原因及其复壮的理论基础,提出了贵州古树名木保护、管理的措施和建议。 相似文献
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浅谈园林树种的选择配置与病虫害防治 总被引:7,自引:0,他引:7
裴淑兰 《内蒙古林业调查设计》2005,28(3):51-52,56
在园林绿化工作中,园林树种的选择搭配与病虫害的发生有一定的必然联系。文章从不同侧面阐述了二者的关系,并提出了通过合理选择配置园林树种防治和减少病虫害的措施。 相似文献
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喷播绿化与喷播机械的技术概况 总被引:4,自引:0,他引:4
赵平 《林业机械与木工设备》1999,(11)
介绍了喷播绿化种植技术及部分国外喷播机械,分析了喷播机械的结构特征及应用范围,论述了喷播设备的国产化现状及存在的问题。 相似文献
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汤世保 《绿色中国(A版)》2008,(3):104-106
钦州,是一座古老而又年轻的城市。说古老,因为她已历经1400年的沧桑,在历史上曾写下过辉煌的一页,在中国近代史上曾涌现出爱国将领、民族英雄冯子材和刘永福等著名历史人物;说年轻,因为1994年撤地设市至今只有14年,在新的历史起点上,她犹如一颗明珠闪烁在北部湾畔。 相似文献
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温州名木古树资源及其开发利用价值 总被引:4,自引:0,他引:4
温州名木古树资源极为丰富,据调查已鉴定名木古树有104种,隶属40科75属;地理成份复杂、热带、亚热带成份占优势;并拥有较多的孑遗种、特有种、单种属;具有古、稀、奇特色;同时还拥有较多的国家级保护树种、创分布新记录和温州特有种。为温州市现代林业的发展提供了科学的依据和丰富的物种基因库,为温州市旅游风景资源展示了自然美的珍贵价值,又是为研究温州古代原始森林植被起源、演替、树种组成、结构特征和历史各进 相似文献
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汤世保 《绿色中国(A版)》2008,(5)
钦州,是一座古老而又年轻的城市。说古老,因为她已历经1400年的沧桑,在历史上曾写下过辉煌的一页,在中国近代史上曾涌现出爱国将领、民族英雄冯子材和刘永福等著名历史人物;说年轻,因为1994年撤地设市至今只有14年,在新的历史起点上,她犹如一颗明珠闪烁在北部湾畔。 相似文献
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森林是陆地生态系统的主体,是人类社会发展的重要条件,是生态建设的一个重要组成部分。由于自然因素和人为因素的影响,森林的各类灾害影响着国民经济的持续发展。文章从生态学、自然资源学、灾害学的观点入手,分析了中国森林的基本现状,探讨森林灾害对生态系统的影响,提出抗灾防灾的对策,为森林生态系统的恢复与重建提供新的思路。 相似文献