公路景观设计   总被引：2，自引：1，他引：2  

刘宏凯 《森林工程》2004,20(2):40-41,45

介绍了公路沿线景观结构及景观设计的组成，并由此得出做好公路景观设计是公路设计不可分割的重要组成部分。  相似文献   

阳春市野生珍稀濒危植物和国家重点保护野生植物   总被引：1，自引：2，他引：1  

郑文经  邱祖械  肖志东 《广东林业科技》2003,19(3):38-40

阳春市植物资源丰富，东北部有百涌省级自然保护区，西南部有正在申报省级的鹅凰嶂自然保护区。据调查和现有资料统计，阳春市自然分布的珍稀濒危植物34种，国家重点保护野生植物19种。为保护好这批珍贵的植物资源，作者提出了具体的保护建议。  相似文献   

植物抗寒性的生理生态学机制研究进展   总被引：31，自引：1，他引：31  

徐燕  薛立  屈明 《林业科学》2007,43(4):88-94

综述植物在冷驯化过程中发生的一系列生理生化变化.环境对植物抗寒性的影响主要与光诱导、温湿度以及气候的变化有关.植物表面形成冰层会引起植物的无氧呼吸,导致植物受害;光抑制诱导活性氧的产生,从而导致植物光合系统的退化,抗寒能力下降,而短日照诱导植物休眠,有利于植物抗寒.光敏色素则被认为是启动冷驯化的光受体;植物通过冷驯化增加碳水化合物的积累及病原体相关蛋白的合成,以增强对低温病原体的抵抗能力;气候的变化使植物遭受了更大的冷伤害风险.微管最初遇冷时部分的解体可以有效诱导植物抗寒性;抗氧化酶活性增强,植物体内糖、脯氨酸、多胺等内含物含量上升.植物休眠状态中的生理变化(种子的休眠、芽的休眠)与ABA敏感性的差异有关.对植物抗寒性分子机制的研究表明:COR基因的表达对于植物抗寒性和冷驯化是十分关键的;与气候梯度有关的基因梯度的分布说明寒冷地区的树种更为抗寒;多表型性状的数量性状分析,为重要的农艺性状标记辅助选择(MAS)提供基础.对植物抗寒过程中的信号转导进行研究发现,Ca2 是低温下参与调节冷驯化应答机制中信号转导途径的重要的第二信使.未来植物抗寒领域的研究热点为信号转导和基因调节,低温抗性的遗传学和遗传应用及代谢组学,气候变化对于植物抗寒的影响等方面.  相似文献   

Understory plant communities of boreal mixedwood forests in western Canada: Natural patterns and response to variable-retention harvesting     

S. Ellen Macdonald  Treena E. Fenniak 《Forest Ecology and Management》2007

We examined patterns of variation in richness, diversity, and composition of understory vascular plant communities in mixedwood boreal forests of varying composition (broadleaf, mixedwood, conifer) in Alberta, Canada, before and for 2 years following variable-retention harvesting (clearcut, 20 and 75% dispersed green tree retention, control). Broadleaf-dominated forests differed from mixedwood or conifer-dominated forests in that they had greater canopy cover, litter depth, soil nitrogen, warmer soils, as well as greater shrub cover, herb and shrub richness and diversity (plot scale). In contrast, conifer, and to a lesser extent mixedwood, forest had greater β diversity than broadleaf forest. Overall, mixedwood and conifer forests were similar to one another, both differed from broadleaf forest. Several species were found to be significant indicators of broadleaf forest but most of these also occurred in the other forest types. Understory composition was related to canopy composition and edaphic conditions. Variable-retention harvesting had little effect on understory cover, richness, or diversity but resulted in reduced richness and β diversity at a larger scale. The clearcut and 20% treatments affected composition in all forest types. Early successional species and those common in disturbed sites were indicators of harvesting while evergreen, shade-tolerant understory herbs were indicators of the control forest and 75% retention harvest. We conclude that it is important to maintain a range of variation in canopy composition of mixedwood forests in order to conserve the associated understory communities. The presence of conifers in these forests has a particularly important influence on understory communities. The threshold for a lifeboat effect of variable-retention harvesting is between 20 and 75% retention. Examination of richness and β diversity at a variety of scales can provide interesting information on effects of harvesting on spatial reorganization and homogenization of understory plant communities.  相似文献   

紫胶虫优良寄主植物久树的繁殖技术     

孙永玉  李昆  陈晓鸣 《林业科学》2003,39(5):129-132

综述了紫胶虫优良寄主植物及久树繁殖技术的研究进展，特别是久树的种类、生物学、生理学和生态学的研究与进展，提出了寄主植物无性繁殖研究的思路和对策，展望了寄主植物的研究发展方向。  相似文献   

杨树伐根嫁接不同保留株数生长对比研究     

贾素苹  李文芳  周静  张庆春  贾建学  王艳华 《山西林业科技》2020,49(1):16-18

伐根嫁接在残次林改造中发挥了重要作用。笔者通过对16年生小美旱杨伐桩嫁接中林46杨的生长状况进行研究,结果发现,每个伐桩保留1株~3株苗木的胸径、单株材积和蓄积有显著差异,胸径和单株材积保留1株的最大,蓄积保留2株的最大。经方差分析,各研究性状的重复力在0.8以上,说明各性状差异受较强遗传控制。综合分析,小美旱杨伐桩嫁接中林46杨保留2株,其综合性状表现最好。  相似文献   

Effects of leaf area and auxin on rooting and growth of rooted stem cuttings of neem     

M. Kamaluddin  M. Ali 《New Forests》1996,12(1):11-18

Green stem cuttings, obtained from 2-year old managed stockplants, with 30, 50 or 100% leaf area were rooted in a non-mist propagator following treatment with 0, 0.2, 0.4 or 0.8% IBA solution. The rooted cuttings were transferred to polythene pots and grown in a nursery for 12 weeks. Rooting percentages of IBA treated cuttings did not significantly differ from those of control cuttings. Likewise leaf area did not significantly influence the percentage of cuttings that rooted. The effects of leaf area and/or IBA treatment in the propagation unit were manifested on the growth of rooted cuttings in polythene pots. Number of roots increased with the increase in IBA concentration and this response was enhanced by increasing leaf area. Root biomass increased with the increase in leaf area even in the control cuttings. Root development was highly influenced by the leaf area and IBA, and hence the growth of rooted cuttings. Cuttings treated with 0.2 or 0.4% IBA at 100% leaf area yielded the best performing rooted cuttings.  相似文献   

黑杨派杨树组培再生系统的研究   总被引：12，自引：4，他引：12  

于志水  金红  苘胜军  王丽钧  赵继梅  梁德军 《辽宁林业科技》2002,(6):11-13

建立高效杨树组培再生系统，为杨树良种选育、遗传转化等研究，提供材料和基础手段。采用1／2MS基本培养基，通过不同外植体获得无菌苗，经培养基配方筛选，获得继代和生根苗，再选取组培苗的不同部位为材料，分别诱导形成再生植株，优化成高效的黑杨派杨树组培再生系统。  相似文献   

乡土植物在城市绿化中的应用   总被引：6，自引：0，他引：6  

应求是  丁华娇  朱秋桂 《江西林业科技》2006,(1):51-52,54

介绍乡土植物在城市绿地系统中应用的重要性,分析了乡土植物在城市绿地中的生态、景观、经济等方面的作用,认为人类生存必须依附于自然,城市的建设要尽最大可能减少对自然的破坏,增加乡土植物应用的比例,建立健康的生态系统。同时根据植物景观的需要,介绍了部分在城市绿地有应用前景的野生植物类型。  相似文献   

彩叶植物的观赏价值及应用前景探讨   总被引：12，自引：0，他引：12  

刘维华  李梅 《四川林勘设计》2005,(2):25-27

文章在阐述彩叶植物具有极高观赏价值的基础上，概括了彩叶植物在园林中的应用形式，并指出彩叶植物具有广阔的市场发展前景。  相似文献