Micropropagation of loblolly pine by somatic organogenesis andRAPD analysis of regenerated plantlets

IntroductionOrganogenesis and somatic embryogenesis haveben regarded as the in vitro system of choice withthe Pbtenhal for eventual mass propagation of superior and gen6tically engineering forest tree genotypesIn both conal6rous and hardwood (Gupts et al. 1991,Becwar et al. 1995). Somatic embryogenesis andorganeqenesis have been induced from more than 30ired speCies in conifers, but plant regeneration viaSOmahc embryogenesis and organogenesis remainsdffeutt cd a low rqeneration frequency (A…     

The elastic dynamics analysis of band saw tightening system

Structureandprinciple14Theeffectsuchasdifferenceofdiameter,rigidity,speedoffeed,tartnessofblade,andthedisfigurementwillbringtheinstantaneouschangeofsawbladelength.Ifitwasoutofcontrol,theflexuosityinthesectionsurfaceofsawwillarise,andevenleadstotheruptureofsawblade.Inordertoguaranteesawbladebetweentwosawwheelsworkingsteadily,manykindsoftighteningsystemareused,theuppersawwheelcanriseordescendalongwiththelengthchangeofsawblade(Reynoldsetal.1996).Thereby,thetighteningforceofsawbladeisheldconstant…     

Construction and analysis of a subtracted cDNA library of Betula platyphylla female inflorescence

Female inflorescence of Betula platyphylla was sampled at an interval of each two days to analyze the background of gene expression in floral phase. On the basis of SMART strategy, the driver cDNA was obtained from total RNA of the last sample and the tester cDNA was from that of the others by RT-PCR which were subsequently used to construct a subtracted cDNA library. The result of the ESTs (expression sequence tags) blastX showed that the genes in the subtracted cDNA library could be mainly clustered into 5 groups related to metabolism, transportation and signal transduction, cell cycle, stress response, and regulation. The relationship between gene expression and development was also discussed.     

Cloning and sequence analysis of atom gene from Sclerotimia sclerotiorum

An atom gene was cloned from genomic DNA of Scleortinia sclerotiorum by inverse PCR. The evolutionary relationships of S. sclerotiorum and other fungi in atom gene were studied. Results showed that the atom gene from of S. sclerotiorum has a single open reading frame of 4 773 bp and does not include any introns. The derived amino acid sequence consists of 1 590 residues, and it is homologous to all fungal AROM proteins studied so far. The theoretical isoelectric point （pl） and molecular weight （Mw） is 6.5 and 172.66 kD, respectively GC percentage of the arom gene is 44.94. According to the results of searching from CDD and Prosite database, AROM protein of S. sclerotiorum contains five conserve domains： 3-dehydroquinate synthase domain, 3-dehydroquinate dehydratase （3-dehydroquinase） domain, shikimate 5-dehydrogenase domain, shikimate kinase domain, and -enolpyruvylshikimate-3-phosphate synthase （EPSP sythase） domain, and four motifs： two EPSP synthase signatures, dehydroquinase class I active site, shikimate kinase signature. According to the PIR Site Rule PIRSR000514-1, four functionally important amino acid residues are found by alignment. Putative TATA box and CAAT box locate separately in -23 and -77 loci in 5＇ un-translated region, and two loci found in downstream atom gene are likely polyadenylation signals. In addition, phylogeny of atom gene is analyzed.     

Estimation of forest parameters based on TM imagery and statistical analysis

One of the primary forestry research interests lies in estimating forest stand parameters by applying empirical or semi-empirical model to establish the relationship between the forest stand parameters and remote sensing data. Using remote sensing image and the inventory data from 2 compartments in northeast Florida, U.S.A., this paper explored the correlation between forest stand parameters and Landsat TM spectral digital number （DN） value. Results showed that less than 50% of the total variance could be explained by linear regression models with only either a single band or such vegetation indices as vegetation index （VI） or normalized difference vegetation index （NDVI） as predicators. In consequence, multi-linear regression models which synthesized more predicators were introduced to estimate forest parameters. Regression results were tested in terms of the other group of data, and verification showed a better capability of explaining over 75% variance except for forest density. The weakness and further improvement of prediction models were also discussed in the article. This paper is expected to provide a better understanding of the relationship between TM spectral and forest characteristics     

Dynamic-mechanical analysis and SEM morphology of wood flour/polypropylene composites

Introduction It is well known that over the past few decades, polymers have replaced many conventional materials, such as metal and wood in many applications. This is due to the advantages of polymers over conventional materials (Maurizio et al. 1998; Adr…     

Carbonization mechanism of bamboo（phyllostachys） by means of Fourier Transform Infrared and elemental analysis

Bamboo was carbonized at different temperatures ranging from 200℃ to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Fourier Transform Infrared (FTIR) spectra of the residual solid products.The results showed:(1)Below 200℃,hemicellulose in bamboo wasdecomposed and a large amount of hydroxyl groups are dislocated from hemicellulose and cellulose,accompanied by the evolution of water to escape.(2)200℃-250℃,cellulose in bamboo was brastically decomposed whereas the net structure of lignin keep stable,with the except of the dislocation of methoxyl groups from lignin.(3)250℃-400℃,the net structure of lignin collapse,up to 400℃,followed by that the more position in aryl groups are substituted.(4)For bamboo carbonization,the aromatization of residual carbon has approximately completed at the temperature as high as 600℃.But the fusion of aromatic rings possibly does not occur.     

Loss function analysis of private forest owners’ timber price change expectations

Loss function analysis was introduced to timber market price analysis. Methods found in Bayesian statistical decision analysis were applied to expectations of market price changes. These were obtained from a forest owner survey conducted in Finland in 2009. Forecast errors of heterogeneous price expectations of the individual private forest owners were derived with observed price changes in six different timber price regions. The forecast errors were complemented with random number simulations to control for unobserved response heterogeneity. The properties and estimation of generalized loss functions – LIN-EX and flexible loss functions – allowing for asymmetry in individual forecast errors were introduced into the analysis. Estimation results for different price regions implied that forest owners’ perceived costs related to positive forecast errors of negative price changes that took place in 2009 were larger than those related to negative errors. This under-prediction vs. over-prediction asymmetry was large in some price regions. The forest owners exhibited an aversion to losses reflected in price expectations errors in the year 2009. The observed loss aversion means that forest owners were cautious in their selling decisions during periods of declining market prices. This has a negative impact on the recovery of slack timber markets.     

AFLP analysis of genetic variation of Hyphantria cunea （Drury） populations in Beijing and a nearby site

Hyphantria cunea(Drury) is a severe invasive pest in Beijing.It is important to understand the reason for its successful invasion and outbreak.Accordingly,this study was tailored to assess molecular variation and genetic relationships among three H.cunea populations in Beijing and one population from Sanhe in Hebei Province as control(totally 100 individuals).A silver-labeled amplified fragment length polymorphisms(AFLP) DNA profiling method was used to detect the genetic diversity and relationship among th...     

浅析深圳居住区绿地景观特色

居住区绿地的景观规划建设会受到——地理位置、气候特点、文化组成、经济条件等因素的综合影响。以深圳为例,简要介绍影响深圳居住区景观建设的基本因素,并从横向和竖向两个方面来阐述深圳居住区绿地在绿化上的景观特色,总结景观特色表达的方式,最后对深圳居住区的绿地景观建设进行展望。     

Effect of terrain on landscape patterns and ecological effects by a gradient-based RS and GIS analysis

Terrain is an important environment factor that plays a vital role in human development by influencing the spatial layout of land use patterns. The terrain niche index, combined with slope and elevation, can comprehensively present detailed information about spatial differences in terrain and is superior to single terrain factors. We applied remote sensing and geographical information system to terrain gradient, used the non-dimensional distribution index to examine spatial distribution characteristics of various landscape types, and analyzed the ecological effects of landscape were quantitatively on terrain gradients. Eco-environment quality (EEQ) was evaluated using the forestry operation area as the evaluation unit. The spatial distributions in various landscapes were significantly influenced by terrain factors, especially by bodies of water, cropland and residential land. The spatial distribution varied greatly in different terrain gradients for similar landscape types. The areas associated with good, intermediate and poor EEQ were occupied primarily by natural landscape, semi-natural and largely artificial landscapes, respectively.     

绵阳市城市景观水体富营养化调查与分析

城市景观水体通常为静水,或者流动缓慢,常会因管理不善而出现富营养化,失去原有景观价值.观测了绵阳城区公园和居住区的5处水体的水质和周围环境,分析了绵阳市城市景观水体富营养化的状况.结果表明:城市景观水体水质较差,均为Ⅴ类水质.不同水体类型间富营养化程度存在差异,居住区富营养化程度高于公园.其中,居住区景观水体为中度富营...     

基于AHP法的森林小镇藤蔓景观期望度评价

基于AHP法(层次分析法)构建藤蔓景观营造对森林小镇的影响、对人的影响、社会效益等3个项目层因子、7个因素层因子、22个指标层因子组成评价体系,利用九级标度法使其量化,通过求根法计算出评价体系中各指标的权重,对广西七坡森林小镇藤蔓景观期望度进行评价。结果表明:指标体系通过一致性检验,建立的判断矩阵合理可行;3个项目指标的比重大小依次为对人的影响>社会效益>对森林小镇的影响;7个因素层指标中,生态功能质量(0.7500)、心理感受质量(0.6667)、植物文化意蕴(0.5500)权重最高;在22个指标层因子中,净化空气功能综合权重最高(0.1937),植物种类多样性最低(0.0027)。     

不同植物配置与住宅绿地类型的降温增湿效益分析

通过对杭州城市住宅小区不同绿地类型和植物配置对温湿度变化影响的研究,结果表明,大量乔灌草结合的绿地类型,绿量高,林下光照强度低,夏季降温增湿效益非常显著;多种乔木,营造湿地水景,将是住宅区夏季降温效益明显的环境绿化绿地类型;城市各种住宅绿地在夏季均有明显的增湿、蔽阴效果。     

城市园林绿化质量可拓综合评判方法研究

为客观、准确地对城市园林绿化质量进行评判,依据国际花园城市标准、国家生态园林城市标准、国家园林城市标准、城市绿化规划建设指标规定和部分省级园林城市标准,筛选了建城区绿化覆盖率、建城区绿地率、建城区人均公共绿地面积三大指标为园林绿化质量的评判特征因子。在此基础上,引入可拓学理论,建立了城市园林绿化质量评判物元模型,给出了基于关联函数的可拓评判方法。并结合某城市园林绿化现状,实际评判了其质量综合水平状况。     

我国林业有害生物预防体系构建模式探讨

介绍了我国林业有害生物预防体系的基本概念、组成和功能,指出了预防技术和支撑预防技术的基础设施是决定预防体系构建质量的关键因素,提出了我国林业有害生物预防体系的构建模式。该模式包括全局性执行信息分析的有害生物风险评估系统、边界口岸防控外来入侵的检疫除害系统、重点区域防控境内传播的监测预警系统、一般区域防控突发灾情的监测防灾系统和跨省（市）区域防控局部灾情的联防联治系统等5个系统。根据每一种系统的功能,进一步明确了组成该系统的具体项目种类。     

贵州省册亨县林业发展区划数量化划分研究

为确定区域森林的主体功能和林业建设重点,使其形成各具特色的区域林业经济和优势明显的生态服务体系格局,选取贵州省册亨县自然地理、社会经济、生态环境和森林状况等指标,用因子分析与系统聚类相结合的数量化划分方法,进行了县级林业发展区划数量化分区,结果表明:先用因子分析建立因子分析模型,再用较少的几个载荷大量信息的因子进行系统聚类的林业发展区划数量化划分方法,不仅克服了以往区划以定性分析为主的弱点,而且还能剔除常规划分方法中各指标间的相关性;通过对影响册亨县各乡镇林业发展的30个指标的因子分析,建立因子分析模型,用6个载荷89.945%信息量的因子对贵州册亨县的14个乡镇进行系统聚类,结果可将册亨县分为5个区。此研究不仅丰富了林业发展区划理论,而且还可对贵州林地保护利用等林业规划及其相关产业的区划、规划提供借鉴。     

基于变权欧式距离模型的森林流域地表水水质评价

为满足经济建设对木材及木质产品日益增长的需求,我国人工林的种植面积快速增加,其中,华南地区的桉树(Eucalyptus L’Hérit.)人工林的发展速度极快,至2008年我国桉树林面积为260万hm2[1]。桉树人工林在我国国民经济中发挥了很大的经济、社会和生态效益[2-4];然而,部分桉树种植区的居民甚至少数政府部门人员认为桉树污染水体,出现停     

华中农业大学校园环境质量两级模糊综合评价

在分层抽样问卷调查的基础上,运用方差分析、因子分析及模糊综合评判等方法对华中农业大学校园环境质量主观评价因子进行了具体分析.方差分析结果表明:不同成长环境的学生对"校内的交通体系"和"文娱场所适用性"等因子的评价结果有显著差异,而对其它因子的评价结果没有显著差异;不同性别的学生对"总体环境品质"、"宿舍适用性评价"和"到教室时间满意度"等因子的评价结果有显著差异,而对其它因子的评价结果没有显著差异;不同专业的学生对大多数因子的评价结果有显著或极显著差异.因子分析结果为:对23个因子进行旋转因子分析从而得到主成分、并依次命名为交通可达性因子、总体环境意象因子、建筑适用性因子、校园生活环境因子及物理环境因子.模糊评价结果表明:该校的环境质量主观评定等级为"一般"至"好".