共查询到20条相似文献,搜索用时 125 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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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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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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为改善江西梅岭国家森林公园道路状况,满足周边居民出行、旅游活动及科学开发湾里自然生态资源的需要,通过全面分析罗梅公路改造升级对森林资源、风景、环境生态等所造成影响,就如何减轻影响针对性地提出相应保护与恢复措施,促进森林公园生态及经济效益提升,也对湾里区经济的增长及旅游业发展发挥显著推动作用. 相似文献
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太阳岛风景区生态旅游与景观生态的持续发展 总被引:2,自引:0,他引:2
依据生态旅游与景观生态的基本概念,应用生态学、景观学的原理和方法,将旅游、环境和景观规划有机结合起来,对哈尔滨太阳岛风景名胜区现有生态资源及现存问题进行分析,论述太阳岛风景区生态旅游景观规划的原则,在原有生存环境的基础上突出游憩休假型风景区的特色,因地制宜,整体综合设计、分地段景观设计,使其在自然生态基础上,将社会效益、经济效益、环境效益统筹,推动该地区经济建设与生态环境平衡的良性合理的持续发展。 相似文献
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森林旅游在发展森林景观和改善森林环境的同时,也留下了隐患,造成了森林生态不平衡。基于此现状,需要对森林生态进行补偿。要求在发展森林旅游的同时兼顾森林生态保护。分析了森林旅游生态补偿的组成要素,并在此基础上进行了对策的可行性研究。 相似文献
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生态旅游是集普及生态科学知识,提高自然保护意识与旅游观光为一体的旅游事业,是国家森林公园与自然保护区充发挥宣传教育作用的最佳形式。生态与旅游相结合是当前世界旅游事业发展的必然趋势。旅游资源应该包括自然景观与人文景观,利用的原则是:1。保护管理与旅游经营的统一;2。以生态是主观为主体,维护持续续利用的生态体系;3.突出生态知识性与寓教游。 相似文献
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Nowadays Songshan National Nature Reserve attracts a rapidly increasing number of tourists. However, the development of a tourist economy and the further exploitation of the natural landscape threaten the ecology and management of the reserve. Therefore, defining the relationship between ecological tourism and ecological protection can provide a framework for the management and exploitation of the reserve. Based on the analysis of current situation and questions of the reserve, this paper probes into the re... 相似文献
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磐石市森林生态旅游以"吉林官马莲花山国家级森林公园"为主打品牌,以开发自然景观为主,建设人文景观为辅,全面开发旅游资源.针对目前存在的主要问题,提出了进一步发展的对策. 相似文献