大同市沙棘苗圃地和林地病虫害种类及防治技术

沙棘的经济、社会和生态价值日渐受到人们的重视，对沙棘优良品种进行苗木培育和规模化栽植时，需采取有效的沙棘病虫害防治措施。笔者介绍了大同市沙棘分布区概况，分析了大同市沙棘苗圃地和林地主要病虫害的种类、危害部位和危害情况，并提出了相应的病虫害防治技术。     

沙棘产品的生产技术现状其发展

介绍了沙棘在我国分布的情况，沙棘产品在国内外外的现状及其发展，我国的主要沙棘吸其生产工艺，阐述了对进一步开发沙棘产品的认识。     

黑龙江省沙棘主要病虫草害及综合防治

通过对黑龙江省沙棘园主要病虫草害调查表明，黑龙江省危害沙棘的主要病害为沙棘猝倒病、沙棘干缩病等；主要地下害虫为蝼蛄、金龟子、地老虎等；主要食叶害虫有春尺蠖、蚜虫、天幕毛虫等；果实害虫为沙棘蝇；主要蛀干害虫为柳蝙蛾；主要杂草有葶苈、稗草、羊草、荠菜、山苦菜、苣荬菜、蒲公英、铁苋菜、藜、大蓟、小蓟、节节草、兰花菜等。查清了主要病虫草害种类，提出了相应的综合防治措施。     

甘肃省沙棘资源现状及开发利用调查研究

根据甘肃省1986年沙棘资源清查数据和1995年、1999年统计数据，对比分析了甘肃沙棘资源现状，其资源丰富，在国内天然林面积列第3位，但沙棘开发利用较为落后。研究甘肃沙棘发展主要存在的问题，提出在现阶段应对沙棘进行分类经营和积极发展生态经济型沙棘林等对策。     

林木新害虫沙棘木蠹蛾的控制策略

该文对我国沙棘木蠹蛾的发生现状和主要成灾原因进行了简要评述，指出沙棘木蠹蛾已成为制约沙棘事业发展的主要因素之一。立地条件差、树种或品种单一、对该害虫生物生态学特性了解很少以及监测技术缺乏是沙棘木蠹蛾大发生的主要原因。控制策略是在系统进行生物生态学特性研究的基础上，开发性引诱剂和环境协调性药剂应用技术，保护和利用天敌资源，开展沙棘抗旱抗虫品系选育，转变营林模式，最终建立起有效控制沙棘木蠹蛾灾害的综合技术体系。     

开发沙棘资源致富一方百姓

开发沙棘资源致富一方百姓蔡玉轩沙棘是敖汉旗的主要造林树种之一。它适应性强，品质优良，全身都是宝。十几年来，敖汉旗把营造沙棘林作为改善生态环境、致富百姓的一项主要工作来抓，坚持以基地建设形式全力发展。敖汉旗现有沙棘经济林４０万亩，既保持了水土，改良了土...     

发展沙棘资源，加速开发利用

发展沙棘资源，加速开发利用内蒙古自治区林业厅我区是全国沙棘主要分布区之一。自１９８５年以来，全区进行了较大规模的沙棘资源建设和开发利用，以及与沙棘有关的科学研究。１沙棘资源与资源建设沙棘是我区的乡土树种。赤峰市、哲里木盟、乌兰察布盟、伊克昭盟、锡林郭...     

瑞典沙棘育种及商品化栽培简介

瑞典沙棘的自然分布主要在北海岸沿线上，那里的人们习惯把它作为庭院绿化植物，尽管从前的资料中也零星记载了沙棘，当地人仅知道沙棘可治疗败血症，现在只是少数人制造沙棘果酱，并且在市场上少量的沙棘产品销售，人们基本上是利用野生和花园内种植的沙棘果实，到目前为止，瑞典还没有大面积栽植，在瑞典，尽管仍有问题没有解决，但介绍沙棘栽培及其产品是有积极意义的，在沙棘栽培中主要的问题是病原菌引起的病害，金黄地鼠危害及     

沙棘木蠹蛾生物学习性及防治研究

沙棘木蠹蛾(Holcocelus vicarius walker)是目前沙棘林区主要蛀干害虫，造成沙棘大面积死亡。该虫2年1代跨3个年度。其防治方法主要用磷化铝堵塞虫孔熏杀幼虫，化学药剂喷杀初孵幼虫及灯诱、性诱、人工捕杀等实行综合治理，效果可达90％以上。文中还记述了沙棘两种主要蛀干害虫沙棘木蠹蛾与沙柳木蠹蛾在幼虫与成虫形态上的主要区别，便于在防治工作中的识别。     

宁夏南部山区沙棘种植技术

宁南山区水土流失面积2．58万km^2，是国家沙棘生态建设的主要地区之一，每年需要提供大量的沙棘苗木，经分析宁南山区生态环境特点、沙棘的生物学特性及主要用途，有针对性地提出了当地沙棘种植技术，可在同类地区试验推广。     

The effects of topography on forest soil characteristics in the Oregon Cascade Mountains (USA): Implications for the effects of climate change on soil properties

Forest soil measurements were made at over 180 sites distributed throughout the H.J. Andrews Experimental Forest (HJA) in the Oregon Cascade Mountains. The influences of both elevation and aspect on soil variables were measured in the early (1998) and late summer (1994). Increased elevation significantly increased soil moisture, mean annual precipitation, soil organic matter, labile C and mineralizable N, microbial activities, extractable ammonium, and denitrification potentials. In contrast, bulk density, pH and soil temperature (1998 only) were significantly lower at the higher elevations. Relative to labile C, mineralizable N was preferentially sequestered at higher elevations. Aspect significantly affected annual mean temperature and precipitation, soil moisture and temperature, soil organic matter, mineralizable N, extractable ammonium, denitrification, and microbial activities. There were no significant higher statistical interactions between elevation and aspect on climatic or soil factors. Soil organic matter (SOM) accumulation at higher elevations is likely driven by a reduction in decomposition rates rather that an increase in primary productivity, however, SOM accumulation on north facing slopes is probably due to both a decrease in decomposition and an increase in primary production. Models of climate change effects on temperate forest soils based on elevational studies may not apply to aspect gradients since plant productivity may not respond to temperature–moisture gradients in the same way across all topographical features.     

东北地区主要植物种子特征及扩散类型

论述了东北东部地区主要植物种子的特征,以及具有这些特征的种子所特有的扩散方式、特点与类型。     

Incidence and severity of annosus root rot in Loblolly pine plantations in Virginia

Fourteen plots of 25 loblolly pines each were excavated by bulldozers in order to determine incidence and severity of Heterobasidion annosus in asymptomatic loblolly pine in Virginia. Of the 350 trees sampled, 85% were infected with H. annosus. Basidiocarps were found on 9% of the sampled trees. The average frequency of roots infected per tree with H. annosus, for all measured trees (trees with > 1% infection evident), was 30% of the primary roots and 31% of the secondary roots. The average root length infected for all the measured trees was 14% for primary roots and 15% for secondary roots.     

甘肃中部干旱区柠条生物量特征及利用途径

通过对甘肃省中部干旱区47个柠条样地生物量结构特征分析,选以丛生物量为因变量,丛高、冠幅为自变量的二元线性回归方程W=-1.7537+0.9637H+1.7144C 为估算该区丛生物量的有效模型,并依该模型编制生物量表。为保护柠条资源及提高其生产力,提出了合理的平茬技术措施。     

西安高新区园林绿地结构特征研究

对西安高新区主要绿地的树种组成、水平结构和垂直结构等进行调查。计算得出8个样地的树种丰富度Margalef指数（R）值为1.674 3-2.670 5,多样性Shannon-Wiener指数（H）值为1.054 9-2.231 6,均匀度Pielou指数（J）值为0.693 1-0.968 8,和单调度Simpson指数（M）值为0.125-0.413 6。8个样地的群落密度在130-1 000株/hm2,聚集度指数值为0.4-1.72之间。覆盖度在0.124-1.32之间。8个样地的第一林层比例在14.20%-72.20%之间,第二林层比例在20%-45.50%之间,第三林层比例在0-50%之间。针对高新区园林绿地的结构特征,作者提出了绿地建设的建议。     

Swiss stone pine trees and spruce stumps represent an important habitat for Heterobasidion spp. in subalpine forests

In the Western Italian Alps (WIA), the three European species of the forest pathogen Heterobasidion spp. can coexist in the same area. Heterobasidion parviporum Niemelä & Korhonen and Heterobasidion abietinum Niemelä & Korhonen are normally found in areas with a significant presence of their respective primary hosts, spruce (Picea spp.) and fir (Abies spp.). The host/niche occupied by Heterobasidion annosum (Fr.) Bref. in the region still remains unclear. Although Scots pine (Pinus sylvestris), a major host for this fungal species in other parts of Europe, is abundant in the region, little or no evidence of disease caused by H. annosum is visible in this tree species. Two different, but not mutually exclusive, hypotheses can explain the presence of H. annosum: (1) Scots pines are infected but largely asymptomatic and (2) H. annosum has adapted to different hosts. An analysis of Heterobasidion species was performed in two natural, mixed‐conifer forests using traditional isolation techniques and novel direct molecular diagnosis from wood. In a subalpine stand of mixed spruce (Picea abies), larch (Larix spp.), and Swiss stone pine (Pinus cembra), 18 naturally infected spruces and larches only yielded H. parviporum. A Swiss stone pine in the same stand was extensively colonized by both H. parviporum and H. annosum. In a second subalpine stand, an analysis of 18 spruce stumps and nine Swiss stone pine stumps yielded both H. parviporum and H. annosum isolates. Pine stumps had been mostly colonized by H. parviporum prior to tree felling, suggesting that this species may be secondarily infected by the locally predominant Heterobasidion species (i.e. H. parviporum). Results of our analysis also indicated that primary colonization of spruce stumps (e.g. through basidiospores) was caused by both H. parviporum and H. annosum, while secondary infection of such stumps was mostly because of H. parviporum.     

云南省红豆杉树种生态特性的比较研究

于1996年、1997年两次进行的云南省红豆杉资源调查，共区划792个小班6107个样地，经过统计分析。总结了云南省红豆杉树种的适生环境、生态特性。揭示了云南省红豆杉树种的分布特点，提出了对红豆杉宜采取的造林方式。     

A simple method for measuring acetylene reduction of intact, nodulated black locust seedlings

A simple method is described for measuring acetylene (C(2)H(2)) reduction of nodulated black locust (Robinia pseudoacacia L.) seedlings. The C(2)H(2) reduction chamber consists of a standard plant pot sealed at one end with a stopper having holes for the seedling and a gas inlet port, and sealed at the other end with a stoppered collar with a gas port. The chamber temperature is regulated by circulating water at a controlled temperature through a copper coil surrounding the plant pot. A pump recirculates an approximately ten percent C(2)H(2) atmosphere through the system. Nine-week-old black locust seedlings, grown in sand culture and inoculated with Rhizobium, were used to obtain ethylene (C(2)H(4)) production curves. Ethylene production was linear for up to 60 minutes indicating that, for this particular symbiosis, (1) a simple closed system is adequate and (2) a short duration assay (10 minutes) will reliably estimate C(2)H(2) reduction over a longer period (up to at least 60 minutes). The water content of the soil medium had no influence on the C(2)H(2)/(C(2)H(2) + C(2)H(4)) ratio, which supports the suitability of C(2)H(2) as an internal standard for calculating C(2)H(2) reduction. This system has several desirable features. First, plant disturbance is minimized. Second, plants can be grown in inexpensive pots and no transplanting is necessary. Third, gas exchange and mixing are facilitated by a recirculating pump. Finally, root and nodule temperature can be controlled.     

Feature extraction of wood-hole defects using wavelet-based ultrasonic testing

The primary bottleneck to extracting wood defects during ultrasonic testing is the accuracy of identifying the wood defects. The wavelet energy moment was used to extract defect features of artificial wood holes drilled into 120 elm samples that differed in the number of holes to verify the validity of the method. Wavelet energy moment can reflect the distribution of energy along the time axis and the amount of energy in each frequency band, which can effectively extract the energy distribution characteristics of signals in each frequency band; therefore, wavelet energy moment can replace the wavelet frequency band energy and constitute wood defect feature vectors. A principal component analysis was used to normalize and reduce the dimension of the feature vectors. A total of 16 principal component features were then obtained, which can effectively extract the defect features of the different number of holes in the elm samples.     

白榆无性系数量性状遗传相关分析

对24个白榆无性系的6个性状进行遗传相关分析表明，主干高、胸径、全高、冠幅与主干材积呈极显著正相关；竞争枝数与主干材积呈极显著负相关。通径分析表明主干高、胸径对主干材积直接作用最大，选择时是首要因素。竞争枝数对主干材积直接作用和剩余效应均为负，减少竞争枝数对增大主干材积有利。冠幅对主干材积直接作用为负，与主干高、胸径呈负相关。选择丰产窄冠白榆无性系是可能的。