共查询到19条相似文献，搜索用时 187 毫秒
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介绍了南通市的地理位置、气候条件,行道树的定义及作用、行道树树种的选则原则、南通行道树的现状及存在的问题、树种选择应用的建议。 相似文献
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城市的行道树作为城市绿化系统的重要组成部分,对城市的生态环境的改善起着重要的作用。本文对昆明市五华区24条不同等级道路行道树进行实地调查,结果表明:昆明市五华区行道树共有21科、26属、31种,存在种类单一,乡土树种应用较少,特色不明显;行道树布局结构单调,缺乏变化等问题。针对以上问题提出了合理配置行道树和提高行道树管养水平的建议。 相似文献
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本文首先对即墨市的气候学特点和树种资源进行了阐述,接着分析了即墨市行道树的分布和存在的问题,最后对即墨市行道树树种的选择提出了建议。 相似文献
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本文对行道树的选择与应用进行了研究,简要的说明了行道树选择过程中需要考虑的树木是否美观、对于当地气候环境的适应程度以及养护和管理工作的难易程度等问题,并阐述了行道树应用需要注意的配置形式科学合理、外来树种与本地树种相结合以及栽培方式多样化等因素,给出了合理的建议。 相似文献
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我国果树营养研究的现状和展望─文献述评 总被引：7，自引：0，他引：7
以大量的文献及北京农业大学果树矿质营养研究室十年来的工作为基础，以果树营养领域的国际水平为方向，对我国在该领域的研究成果和尚需研究的主要问题，包括果树标准叶样及叶内矿质元素含量标准值的建立、果实采前与采后的营养生理、菌根与果树营养、种质资源与矿质元素关系的多样性、以及果树营养与生理生化、组织解剖学、根际学等的关系进行了述评。 相似文献
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本文介绍了天津市盘山地区古树名木的基本现状,分析了近些年来在古树名木的保护上出现的一些问题,进而提出了加强古树名木保护的几点建议 相似文献
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行道树绿化是城镇密集区绿化的骨干,反应城市的景观风貌.对行道树结构特征研究分析,可以为今后城镇密集区绿化发展提供有益的指导、建议.现以成都市为例,选取城镇密集区内20条特色街道,参考多度、频度、重要值、常绿落叶树种比及乡土外来树种比等指标,对行道树种类、数量、生长情况进行分析研究.结果表明:成都市城区内行道树树种单一,常绿树过多,乡土树种开发利用不够等,需要进一步优化行道树树种格局,增加生物多样性,丰富城市景观. 相似文献
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随着现代城市绿化水平的不断提升,观赏果树被越来越多地运用到城市绿化中。对观赏果树在承德绿化中的应用作了阐述;对承德市绿化中发展果树类的优势及问题做了分析;对观赏果树在城市绿化中的发展提出了一些建议。 相似文献
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H. J. D. Palmer R. Diack S. Seymour D. Dayatilake D.S. Tustin 《The Journal of Horticultural Science and Biotechnology》2013,88(5):623-627
SummaryPrecocity is particularly important for the economic production of intensively planted apple trees. Unfortunately some cultivars show a propensity for barewood on young trees, which limits early production on 2 year-old spur sites. The new cultivar, ‘Scifresh’ (Jazz?) has shown serious problems of barewood under New Zealand conditions on M.9 and M.26 rootstocks. Barewood has been associated with excessive flowering on feathers and 1 year-old wood. Weak flower clusters develop towards the base of the shoots which do not set fruit and drop off, leaving blind buds. Although there are larger, more well-developed flower clusters on the distal parts of the 1 year-old shoots, cropping these can result in spur extinction. Therefore, in both cases, there is a lack of spur development for the following season resulting in barewood. Experimental treatments have focused on: 1) the effect of timing (January-May) and concentration (400 and 133 mg l–1 gibberellic acid GA3) sprays in the nursery to reduce flowering on 1 year-old wood; and 2) the effect of concentration and timing of localised cytokinin applications in the Spring to re-invigorate blind buds. Two applications of 400 mg l–1 GA3 in late January and late February in the first year in the nursery were effective in eliminating flowering on “knip boom” trees in the following Spring after cutting back. Two applications of 400 mg l–1 GA3, in early and late January, to “knip boom” trees in their second year in the nursery reduced flowering by over 40% when the trees were planted in the orchard. Twelve months later these trees showed an increased density of spur flowers on the original feathers. Aqueous solutions of the cytokinins benzyladenine and thidiazuron, at 500 mg l–1 or 2500 mg l–1 respectively, were applied by brush, prior to, during and post-budbreak, to sections of barewood on 2 year-old or 3 year-old wood on main branches of ‘Scifresh’/M.9 trees. Thidiazuron (at 2500 mg l–1) was far more effective than benzyladenine at inducing growth of dormant buds, even resulting in multiple bud-breaks at individual sites. 相似文献
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Ole K. Hansen Pernille Thomsen Christine Waage Rasmussen 《Urban Forestry & Urban Greening》2014,13(3):543-552
As part of the restoration process of an avenue of common lime (Tilia × europaea) from 1760 in the Royal Danish Gardens, all remaining trees were genotyped with DNA markers before they were felled. As such, information about the nature of the plant material (clonal versus non-clonal) and mode of propagation was obtained, revealing that a single clone constituted 92% of the remaining trees (106 out of 115). Five trees were of another clone, while the remaining four trees had unique genotypes. Mode of clonal propagation was most likely layering since the genotype of the crown and the roots of a subsample of the trees had the same genotype. Trees from four other locations with historical avenues/plantings from the 17th century were also genotyped. The two clones registered in the first location were also found at the other four locations. Of 76 trees from the other historical avenues/plantings, only two trees did not belong to either of the two clones. Genotyping of commercial common lime trees that would be planted in place of the felled trees during the restoration project was also performed. Samples of 20 newly planted trees all possessed the same genotype as the majority of the old felled trees and, thereby, were the same clone as the trees planted nearly 250 years ago. Altogether, the current study shows that the genetic diversity of common lime planted in Danish historical plantings is extremely narrow, and that the same clones have been produced for decades/centuries by private nurseries in the Netherlands and Germany. It also provides evidence that it is possible to obtain the same genetic material as originally planted when common lime trees are to be replaced in historical plantings. Furthermore, the utility of DNA markers in the management of plant material in parks is demonstrated. 相似文献