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初论我国沙棘资源建设区划 总被引：1，自引：0，他引：1
沙棘有相对较广的生态适应性，在我国西部和北部有大量适宜种植沙棘的土地。为使沙棘种植建立在科学的基础上。发挥沙棘的生态和经济效益，必须研究沙棘的种植区域，制定种植区划，指导沙棘资源建设。本文在总结以往研究的基础上，依据相关区划和沙棘的特性，采用温度、水分等自然因子和水土保持、农村经济等经济社会因子将我国适宜发展沙棘的区域划分为6个一级沙棘种植区：松辽河沙棘经济林种植区，海河水系上中游沙棘生态经济林种植区，黄河中上游（黄土高原）沙棘生态经济林种植区，长江上游沙棘生态经济林种植区，蒙新及内陆河沙棘生态林种植区和青藏高原沙棘种质资源保护区。 相似文献
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沙棘是右玉县重点发展的经济林产业,做好沙棘育苗和造林工作是沙棘产业可持续发展的重要保障。介绍了沙棘生物学特性、扦插育苗及造林技术,以期为沙棘育苗及造林提供技术借鉴。 相似文献
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再谈沙棘栽培的几个问题 总被引：8，自引：2，他引：6
沙棘是一个种群系统,不同的分类单元或不同的品种,都有不同的特性,沙棘造林时,不能用笼统抽象的概念,代替对不同品种生态特性的具体分析;沙棘造林要从生态学的角度,适地适树适品种,营造生态经济林,以使营造的林分能够可持续发展和利用;适度推广杂交种的沙棘种苗,建立沙棘生态与经济效益兼顾的生态经济林。 相似文献
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介绍了两种沙棘育苗——即沙棘种子生态林育苗和沙棘生态经济林育苗的方法和技术要点，可供沙棘生产工作者应用参考。 相似文献
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沙棘是一个优良的灌木经济林树种,具有良好的生态效益和经济效益。介绍了沙棘营养成份、作用以及大同市发展沙棘的必要性及意义,提出了大同市发展沙棘的措施建议。 相似文献
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森林病虫害防治是国家减灾工程的重要组成部分,对保护森林资源,改善生态环境,促进国民经济和社会可持续发展具有十分重要的意义。 相似文献
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我国桉树木材性质及其变异规律研究进展 总被引：1，自引：0，他引：1
概述了国内桉树木材解剖性质、物理力学性质、化学性质及其变异规律的研究现状,对桉树木材性质变异的影响因子及其材性遗传相关性研究进行了总结,最后分析其存在的问题,并展望了桉树材性遗传改良的研究前景。 相似文献
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D. G. Hunt 《Wood Science and Technology》1989,23(4):323-333
Summary Non-linearity of softwood in axial mechano-sorptive creep during moisture cycling can be characterised as departure from linear behaviour. Linear behaviour is shown by experimental measurement to be a gradual approach to a creep limit with exponentially decreasing increments of compliance, Ji, per moisture cycle, when tested under a constant stress. On the other hand, when the stress is progressively increased by a small increment after each moisture cycle, the compliance increments will progressively increase, having a value of
, where n is the cycle number. By subtracting one compliance increment from the succeeding one, the value of Ji can be obtained. Analysis of experimental results in bending tension and compression showed that the compression test pieces departed from linearity at total strains around 0.14% to 0.15%, the bending test pieces showed slight evidence of non-linearity at about the same strain, whilst the tensile pieces were approximately linear up to 0.18% strain.This project was supported by the U.K. Science and Engineering Research Council and by the European Commission 相似文献
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文章简要地分析了围垦湖沼、上游截流、过度利用及工艺技术落后等人为因素对湿地资源的破坏情况与负面影响,给人们赖以生存的湿地生态环境带来严重的不可逆转的后果,并有针对性地提出了几点建议。 相似文献
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以德国南部小城镇加米施-帕滕基兴(Garmisch-Partenkirchen)市为例,在介绍该市园林绿化概况的基础上,重点介绍其民居庭院绿化与阳台绿化的特色;并对如何更好地发展中国小城镇绿化进行了探讨。
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The composition of the endophytic fungal assemblages in Quercus cerris, Q. pubescens and Q. robur, three oak species most susceptible to decline, was investigated in Fagarè (Padova), Ulignano (Pisa), and Radda in Chianti (Firenze). The endophytic assemblages were studied as a function of health status of the whole tree and of twigs and leaves. The effect of station altitude was tested on Q. cerris. Samples were gathered from healthy and declining trees. In April (bud opening time) 20 twigs and 10 leaves were collected from each tree. Fungi were isolated from twig segments and leaf portions. A total of 23 fungal genera with 27 different species were isolated, in addition to a few sterile mycelia. Eleven species were found to be common to all three oak species, while other species were found only on one oak species, suggesting host specificity. Among the fungal species isolated, some were known to be pathogenic (Apiognomonia quercina, Colpoma quercinum, Diplodia mutila, Phomopsis quercina). The colonization frequency (CF) of pathogenic species varied between 0.9% for A. quercina in Q. cerris and 60.2% for P. quercina in Q. robur. Analysis of variance showed a statistically significant difference among the oak species tested. The CF was higher in declining trees in comparison with healthy trees, and also in twigs vs. leaves. The CF was found to be higher for Q. cerris trees growing at sea level as compared with those situated at an elevation of 350–400 m. In stands where, on account of particular ecological conditions, pathogenic behaviour is displayed simultaneously by more than one endophytic fungal species, trees accentuate their decline. 相似文献
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园林植物病虫害发生特点与防治进展 总被引：7，自引：0，他引：7
本文从园林植物病虫害防治的重要性入手,分析了园林植物病虫害的特点,指出了园林植物病虫害防治的发展方向,为今后开展园林植物病虫害防治工作提供了有益的借鉴。 相似文献
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澳大利亚辐射松遗传育种及其借鉴 总被引：1，自引：0，他引：1
澳大利亚辐射松遗传改良在过去的几十年中取得了较大的成绩, 其育种计划与育种策略在一定程度上反应了当前世界林木育种水平。较详细地介绍与分析了澳大利亚辐射松遗传改良的历程与成就, 供我国林木育种工作者参考。 相似文献