共查询到20条相似文献,搜索用时 156 毫秒
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竹类植物在园林中的应用研究 总被引:3,自引:1,他引:2
竹类植物在园林中应用广泛。文中从竹秆形态及繁殖特点、竹秆高度以及园林用竹的观赏部位3个方面概述园林竹类植物分类,归纳总结竹类植物在园林中栽植应用的主要模式,从国外以竹造景概况、我国古代竹景和当前竹类植物常见的搭配组景3个方面对竹类植物园林应用造景进行评述,从竹类植物的景观价值、生态价值和社会经济价值3个方面对其园林应用价值进行总结,提出竹类植物园林应用的生产和研究展望。随着我国城镇化水平的不断提高,竹类植物的园林应用前景将更加广阔。 相似文献
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道路交点设站测定中桩方法 总被引:1,自引:1,他引:0
本文介绍了施工放样过程中.在交点安置仪器测定曲线中桩点位的方法。给出了计算公式、测定步骤及计算实例。特别对高等级公路的施工定线.即能提高放样精度。又能加快放样的速度.是只得推广应用的有效方法。 相似文献
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四川西部生物多样性调查队 《四川林业科技》2006,27(5):1-58
在全球环境基金(GEF)的项目援助下,通过对布拖乐安地区的植物、植被、真菌、鱼类、两栖爬行类、兽类及影响干扰情况和社会经济状况进行调查,提出可行的管理措施和保护对策。本报告还附有8幅彩图和6个表对本地区的生物多样性作了进一步说明。 相似文献
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根据哈尔滨市瓦盆窑路段交通量调查数据,结合该路段交通量一速度关系模型,和交通量一密度关系模型,得出该路段小时平均车速变化规律和月平均小时车速变化规律、密度小时变化规律和月平均小时道路密度变化规律。对哈尔滨市瓦盆窑路段进行道路服务水平分析,该路段的交通流属于自由流状态,道路服务水平为A级。 相似文献
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碳源排碳量估算办法研究进展 总被引:13,自引:0,他引:13
本文对碳源排碳量估算中相关问题的研究及其进展做了系统的阐述。在碳源的分类的基础上,着重讨论了碳源排碳量的测算办法、排碳量估算中的不确定性,并介绍了如何提高估算的精确性等相关问题。 相似文献
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Hiromi Mizunaga Shizuo Sako Yuri Nakao Yoshitaka Shimono 《Journal of Forest Research》2005,10(6):481-486
The refugee population of Fagus crenata in the Takakuma Mountains, Kyushu, Japan, represents the southern limit of this species' distribution area. Because this
population is the most exposed to the global warming effect, records of this population are likely to provide useful information
on the response of this species to global warming. The aim of this study was to record the present status of this valuable
population, enabling judgment of its sustainability. The density of successive F. crenata trees and saplings was low regardless of the coverage of dwarf bamboo. Moreover, the proportion of empty nuts observed was
considerably high, suggesting to be the likely major factor limiting recruitment of saplings or successors in this population.
Radial growth of F. crenata was shown to have been decreasing for the past 50 years, and there was a significantly negative correlation with the warmth
index. The decreasing growth rate and poor regenerative ability caused by the high proportion of empty nuts suggest the possibility
that this population will degrade further in the future, possibly being replaced by shrubs and small tree species. 相似文献
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辽河三角洲湿地生态旅游资源评价与开发 总被引:2,自引:0,他引:2
生态旅游以其独特内涵吸引了众多游客,成为现在主要的旅游活动形式之一。辽河三角洲拥有丰富的湿地生态旅游资源,文章在分析辽河三角洲湿地生态旅游资源特征的基础上,结合辽河三角洲生态旅游开发现有问题,对辽河三角洲开展湿地生态旅游的前景作了分析,提出了开展湿地生态旅游的对策。 相似文献
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采用光合衰减法,计算陕北6县1970~2000年各年度牧草的生产潜力,对影响该区域牧草生产力的主要因素加以分析。结果表明,气候条件中的降水因子直接影响着牧草的生产力,加之人文因素的干扰作用,导致牧草生产力水平下降。并通过对该区域自然、经济和社会条件的综合分析,探讨草场资源合理利用的有效途径。 相似文献
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A comprehensive study was carried out on a typical indigenous agroforestry system, called kebon tatangkalan, in the changing agricultural landscape of the Upper Citarum Watershed, West Java, Indonesia. The main objectives of the study are to elucidate the structural patterns, multidimensional functions, and dynamics of this multi-layered agroforest. The study has identified 12 groups of different plant assemblages indicating that this type of agroforest contributes considerably to the heterogeneity of the agricultural landscape in the study area. Multivariate analysis suggests that elevation and slope are the biophysical factors that correlate most significantly with the distribution of plant species in kebon tatangkalan. The presence of this man-made vegetation is currently declining from the landscape due to population growth and rapid regional economic development. Serious effort to revitalize this traditional agroforest is needed to prevent its disappearance. Introduction of highly productive species and establishment of integrated policies in regional land-use planning and management are measures that should be taken into account in preserving this traditional agroforestry system. 相似文献