新银合欢施石灰与根瘤菌接种效应的研究          下载免费PDF全文

徐英宝  郑镜明 《林业科学研究》1990,3(4):398-402

新银合欢(Leucaena leucocephala cv.Salvador)又叫萨尔瓦多银合欢,是热带低地湿润地区树种,在适生条件下非常速生,是优良的多用途树种之一。 在自然条件下,新银合欢在中性和碱性土壤上生长良好,而适于该树生长的热带、亚热带气候区,土壤酸化现象日趋严重。许多国家试用施石灰、施肥、根瘤菌接种以及选种等  相似文献   

银杏高干枝,根同接法研究     

许映江  沈建 《江苏林业科技》1996,23(3):36-37

介绍了银杏高干枝、根同接的培良床制作、枝干、接根、接穗的选择，退接时间、方法及接后管理的方法。  相似文献   

英德跳生物学特性和防治研究          下载免费PDF全文

陈世兰  徐世多  赖新红  胡斯林  林隆福 《林业科学研究》1994,(2)

英德跳是我国森林昆虫竹节虫目的一新虫种。在广东省英德县首次发现危害黎蒴栲林成灾得名。若虫和成虫危害黎蒴栲为主的壳斗科树叶，以成虫危害最烈。该虫在英德县１ａ发生２～３代，世代重叠。以第１、２代成虫产的卵在枯枝落叶层下越冬，翌年２月下旬卵开始孵化，５月中、下旬为越冬代成虫高峰期。在５月上、中旬使用３％６６６烟剂１５ｋｇ／ｈｍ２防治，效果达８５％以上，使用绿僵茵１．５×１０１３个／ｈｍ２孢子防治，效果可达７０％以上。  相似文献   

Impacts of mixed litter decomposition from <Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> and other tree species on C loss and nutrient release in the Loess Plateau of China     

Xiaoxi Zhang  Zengwen Liu  Bochao Zhu  Yuanhao Bing  Nhu Trung Luc  Liangzhen Du  Zhenhua Zhu 《林业研究》2016,27(3):525-532

The productivity of Robinia pseudoacacia (R.p.) pure forest usually declines at the late growth stage, and reforming it into mixed forests could be a promising way to resolve this problem. When choosing a suitable tree species that can be mixed with R.p., the interspecific relationship is an important issue. Therefore, we gathered the autumn litter fall from R.p. and 10 other species from the Loess Plateau of China were mixed in dual species litterbags (R.p. + each other species) and buried them in soil for a 345 days lab decay incubation. We measured the litter mass loss and nutrient contents to determine whether the nutrient release was affected by mixed species litter decomposition. The impacts of mixed litter decomposition on macro-elements release were more obvious than on micro-elements. The litters with similar substrate quality might show variable impacts on nutrients release in mixed decomposition. The C loss and release of nutrient was improved by descending order when R.p. litter was mixed with Hippophae rhamnoides, Ulmus pumila, Populus simonii, Larix principis-rupprechtii and Quercus liaotungensis (Q.l.). But, except for Q.l., only the other species were recommended as suitable mix-plants for R.p. since promoting a high turnover of the nutrient in the litter compartment and a rapid availability for tree.  相似文献   

公路桥梁中无粘结部分预应力混凝土梁计算模式的采用     

杜栩  周子兵 《林业科技情报》2003,35(4):65-66

计算UPPC梁(板)的抗弯强度,关键是确定构件在极限承裁能力时无粘结预应力筋的极限应力值。在UPPC梁的设计中,应根据结构的断面形式、受力状态采用不同的计算方法加以比较,以增加UPPC结构设计的准确性及合理性。同时建议结合现行“公桥规”中对有粘结预应力混凝土结构的计算原理与方法较全面、系统地研究UPPC梁桥的设计原理,并给出相应的实用计算方法和公式,从而为UPPC桥梁设计和“公桥规”的完善提供有价值的参考。  相似文献   

阔叶红松林倒木贮量动态研究   总被引：4，自引：2，他引：4  

代力民  李扬等 《林业研究》2002,13(2):107-110

本文研究了中国吉林省长白山区阔叶红松林倒木贮量的动态变化规律。阔叶红松林倒木贮量包括其现有倒木及其年输入量等贮量的变化规律。阔叶红松林现有倒木贮量开始为16.25 t·hm-2,以后随时间减少,到100年分解掉其干重的85%左右,300年后所剩无几。倒木年输入量平均约为0.6 t·hm-2,其贮量是随时间而增加,200年后稳定在31 t·hm-2,可保持到该群落的顶级时期。倒木总贮量的变化在初期呈增加趋势,而后随着现有倒木的完全分解,倒木贮量就与其倒木的年输入趋于一致,最后稳定在上述水平上。图4表2参9。  相似文献   

沙质岸黑松海防林更新属于改造技术的研究   总被引：2，自引：0，他引：2  

许景伟  王卫东  辛斌  张义浩  荀守华  康智 《山东林业科技》2001,(5):1-6

应用典型调查与定位试验相结合的方法,探讨了黑松海防林低质低效的形成原因,据其成因将这些林分划分为5种类型,提出了相应的改造意见,并编制出黑松海防林密度管理表。通过更新造林和抚育技术试验,提出了较合理的更新方式,主要有林冠下更新造林、留伐桩萌芽更新、隔行更新造林、人工促进天然更新、带状更新等,其中,带状更新适于在林分条件相对较好的情况下应用,其它几种更新方式较适于低效林的更新改造;采用稀疏林补植、林下种植灌木或绿肥压青、封禁保护枯落物等技术,可有效地改善林分状况。  相似文献   

臭椿、新疆杨混交林对光肩星天牛选择寄主行为的影响   总被引：2，自引：0，他引：2  

曹兵  徐锡增 《林业科学》2006,42(9):56-60

利用3年生臭椿、新疆杨在室内建立混交林进行光肩星天牛成虫放飞试验.结果表明:臭椿、新疆杨混交林对天牛成虫的寄主选择有显著影响,天牛成虫的交尾行为只在新疆杨植株上进行;天牛成虫在林内植株上着落的总虫次随新疆杨株数的减少而下降,交尾次数也减少;臭椿、新疆杨植株数量在林分中所占比例在一定范围时,天牛成虫在新疆杨和臭椿上着落的虫次比均趋于稳定;新疆杨与臭椿以行状3:2和2:3混交时林分的抗虫效果较好.  相似文献   

Genetic variation in foliar nutrient concentration in relation to foliar carbon isotope composition and tree growth with clones of the F₁ hybrid between slash pine and Caribbean pine     

N.V. Prasolova  Z.H. Xu  K. Lundkvist 《Forest Ecology and Management》2005,210(1-3):173-191

The objectives of this study were: (1) to quantify the genetic variation in foliar nutrient concentration in relation to foliar carbon isotope composition (δ¹³C) and tree growth of 122 clones of ca. 4-year-old F₁ hybrids between slash pine (Pinus elliottii Engelm var. elliottii) and Caribbean pine (P. caribaea var. hondurensis Barr. et Golf.) grown at two experimental sites with different water and nutrient availability in southeast Queensland, Australia and (2) to examine the potential of using foliar nutrient concentration of the 4-year-old tree canopies for selecting elite F₁ hybrid pine clones with improved nutrient-use efficiency (NUE) and water-use efficiency (WUE), and ultimately enhanced tree growth under ambient growing conditions. There were significant differences in foliar nutrient concentrations between two canopy positions (upper outer and lower outer canopy) sampled, between summer and winter, and between the two sites. This highlights that foliar nutrient concentrations are influenced by sampling and environment. Significant genetic variations in foliar nutrient concentrations were detected between the clones, between the female parents, and between the male parents of the clones in both sampling seasons at both sites. Depending on the nutrient concerned, canopy position, season, and site sampled, the clones accounted for 4.7–33.9% of the total variation in foliar nutrient concentrations, the clone female parents for 0–25.1% and the clone male parents for 0–28.6%. The site-by-clone interactions were statistically significant for foliar N, P, Mg, Cu, Zn, Mn, Fe and mineral concentrations at the upper outer canopy in summer, and for foliar N concentration in winter. There were significant, positive correlations between clone means of foliar δ¹³C and N concentration at the upper outer canopy in summer for the wet site, while clone foliar δ¹³C was also positively related to clone foliar N concentration at both canopy positions in summer for the dry site. This suggests that clone WUE as reflected in foliar δ¹³C may be improved by selecting elite clones with higher foliar N concentration and increased photosynthesis, leading to enhanced tree growth when both water and N are the major growth-limiting factors. This is supported by the positive correlation detected between clone tree height and foliar N concentration at the upper outer canopy for both sites. Thus, foliar nutrient (particularly N) concentration, together with foliar δ¹³C, may be useful for assisting in selection of exotic pine clones with improved NUE and WUE, and enhanced tree growth under the nutrient- and water-limiting environments.  相似文献   

我国松树种子园结实规律的研究进展   总被引：1，自引：0，他引：1  

许玉兰  蔡年辉  翁海龙  段安安 《山东林业科技》2007,(1):86-89

对松树种子园球果与种子产量变异、空间分布规律、性状变异、产量预测、败育分析、结实量与生长性状的关系等方面的研究状况作了较为系统的综述;并对今后的发展提出了展望。  相似文献