厚皮香树皮单宁的化学组成及制胶性能的研究   总被引：7，自引：0，他引：7  

罗庆云  马文秀 《林产化学与工业》1994,14(3):15-20

  相似文献   

世界云杉无性系林业发展现状   总被引：36，自引：0，他引：36  

马常耕 《世界林业研究》1993,6(6):24-31

本文概述了世界上采用无性系选择和大量生产扦插苗方法来推行云杉无性系林业，以及加速实现云杉集约人工林良种化的发展和现状，介绍了一些国家文学推行无性系林业的策略，并希望我国在吸收国外已有成功经验的基础上，能多快多省地开展我国云杉良种化事业，满足营造去杉集约人工林对良种的需要。  相似文献   

Studies on insects and mites causing galls on the leaves of purple willow Salix purpurea L. in the Ojców National Park in Poland     

Małgorzata Skrzypczyńska 《Journal of pest science》2001,74(1):11-12

Analytical studies were conducted on the species composition of galls occurring on the leaves of Salix purpurea L. in the Ojców National Park in 1999?–?2000. The species composition of galls was identical in two consecutive years. Galls were caused by 5?species (a total of 480?galls). The most numerous species in both years was Pontania viminalis (L.). Index of occurrence frequency and Agrell's index of species co-existence have been calculated. This index reached the highest values in case of Pontania dolichura (Thoms.) and P. viminalis (L.) in 1999 as well as Phyllocolpa leucaspis (Tischb.) and P. viminalis (L.) in 2000.  相似文献   

华北落叶松边材透水性与叶面积空间分布的相关性的探讨   总被引：2，自引：0，他引：2  

刘志刚  马钦彦  潘向丽 《林业科学》1995,(3)

对华北落叶松林单木累积叶面积、树干边材面积、树干边材透水率及透水量的垂直分布规律及其相互关系进行了探讨。研究表明，引入树干边材面积与边材透水率的积可明显提高估测树冠叶面积垂直分布的精度，进而为精确估测林分的叶面积空间分布提供了新途径。  相似文献   

Altitudinal patterns of the flora of seed plants of Dawei Mountain in Yunnan Province, south China     

Juan Wang  Ma Qinyan  Du Fan  Yang Yuming 《Frontiers of Forestry in China》2007,2(1):40-46

Altitudinal gradient incorporates multiple resource gradients, which vary continuously in different fashions. It is important to study the mountain floristic patterns along altitudinal gradients, which reveal the regular pattern of the flora along the environmental gradients, the changing trend of biodiversity patterns along the altitudinal gradient, and relevance of biological fitness. To explore the compositional characteristics and ecological significance of floristic patterns along altitudinal gradient in China National Nature Reserve of Dawei Mountain in the southeast of Yunnan Province, field investigations have been made to the flora along the two routes of the southwest slope and the northeast slope of the said reserve, including a vertical vegetation transect. Meanwhile, further investigations have also been made to the flora of Dawei Mountain, which has been accounted for in the literature, as Flora Yunnan, The Seed Plant in Yunnan, and so on. The structural characteristics of the flora and the altitudinal distribution pattern of its floristic components were analyzed. By applying systematic cluster analysis, the altitudinal position of the dividing line of floristic changes along altitudinal gradient was detected, and the effects of the montane climate on the vertical variation of floristic composition were studied. Conclusions were put forward. This paper can be summarized as follows: (1) The obvious boundary that differentiates tropical floristic elements is located at the altitude of approximately 1,500 m; it is reasonable to stipulate the boundary line between tropical rain forests and the evergreen broad-leaved forests. (2) The vertical vegetation spectrum made by cluster analysis shows that humid rain forests are below 700 m a.s.l, montane rain forests are between 700 and 1,500 m, monsoon evergreen broad-leaved forests are between 1,300 and 1,800 m, and montane mossy evergreen broad-leaved forests are above 1,800 m a.s.l. Nonrepresentative montane mossy dwarf forests (above 2,100 m) in the area are distributed in windward sides and in barren land on the mountain slopes. __________ Translated from Acta Phytoecologica Sinica, 2005, 29(6): 894–900 [译自: 植物生态学报]  相似文献   

森林内雾水的水文和化学效应研究现状   总被引：1，自引：0，他引：1  

刘文杰  张一平  马友鑫  李红梅 《林业科学》2005,41(2):141-146

从森林对雾水的截留量、雾水对森林分布的影响及雾水的水文和化学效应方面 ,阐述国外在该领域的研究动态和取得的成果 ,以期推动我国在该领域的研究工作。国外的大量研究表明 ,雾水对于植物的生长、分布具有重要的生态意义 ,是森林生态系统水分平衡、养分循环不可忽视的输入项 ,其生态效应是多方面的。因而 ,进一步深入研究森林内雾水的水文和化学效应是必要的  相似文献   

我国杨树杂交育种的现状和发展对策   总被引：28，自引：0，他引：28  

马常耕 《林业科学》1995,31(1):60-68

在简要介绍了我国杨树资源并回顾了４０年来的杂交育种成就后，把我国杨树杂交育种过程划分成两个时期。第一个时期解决了北方杨树栽培的品种化问题，第二个时期在一定程序上用自己选育的无性系改变了黄河以南到长江中下游地区直接用引入无性系造林的现状。但由于两个时期是一个世代的短期育种活动，方法和程序上缺少改进，都把由种间杂种Ｆ１中选择无性系作为重点，加之基因资源有限，都存在推广无性系亲缘相近潜育的危险性，缺乏长  相似文献   

砂质土肥力状况及其与毛白杨生长关系的研究     

李惠卓  王文全  马艳平 《河北林果研究》1994,(1)

对黄河故道冲积砂质上的肥力状况和毛白杨生长因子之间的关系进行了研究，着重分析了土壤养分和水分在土体中的分布规律，及其与土壤质地的关系，以及不同生长季节毛白杨的叶片营养特征和树高、胸径生长量与砂质土水分、养分含量的相关性。结果表明：砂质土肥力低下；土壤质地、养分和水分变化状况与树木生长关系密切，尤其是土壤粘粒、水分和氮素含量与毛白杨生长呈明显的正和关。故可通过施肥、灌水、改善土壤保水保肥特性来调整和控制林木生长。  相似文献   

城市道路网信息管理系统研究   总被引：1，自引：2，他引：1  

马健霄  许家忠  张伟 《森林工程》2003,19(2):51-52

针对国内城市交通规划缺乏完整的道路信息资料 ,提出了如何利用功能完善的EMME/2交通规划软件结合中国的交通特性 ,进行城市路网信息资料的获取 ,并提出相应的数据库记录规定 ,据此研制开发了城市道路网信息管理系统。  相似文献   

装饰单板贴面胶合板与杉木复合制造地板技术   总被引：2，自引：0，他引：2  

马世春  杨文斌  林巧佳  饶久平 《木材工业》2005,19(3):44-45

为了降低实木复合地板生产的材料消耗和成本,直接采用装饰单板贴面胶合板与杉木组合制造实木复合地板.结果表明,按改进工艺制造的复合地板不仅具有国标所要求的物理力学性能,而且可降低材料成本30%左右.  相似文献