森林与环境     

I.C.M.Place  何方 《湖南林业科技》1979,(Z1)

森林是加拿大最突出的风景。从大西洋到太平洋3,000哩广阔的土地上处处是森林。森林工业现在使用着多种多样的资源。每一年的造林面积是2.5百万亩。(1英亩=6.072市亩=0.447公顷—译者)森林不仅仅影响着环境的性质,并且有适合于各种用途的资源。  相似文献   

雨豆树播种前预处理对种子发芽和种苗发育的影响     

Mohammed Alamgir  M. K. Hossain 《林业研究》2005,16(3)

播种前对雨豆树(Albizia saman (Jacq.) F. Muell.)的种子进行了5 种预先处理,研究种子预先处理对种子发芽和苗圃种苗发育的影响。实验是在孟加拉吉大港大学林业与环境研究所的苗圃进行。研究结果表明,在种子末端修剪(处理4)提高种子发芽率50%,在冷水中浸泡24 小时(处理1)提高种子发芽率42%,在开水中浸30 秒后再在冷水中浸泡24 小时(处理2),种子发芽完全被抑制。处理4 和处理1 的种子发芽率、种苗初期形态生长和生物量都明显高于对照组。因此,这2 种播种前的种子预处理方法,可用于提高雨豆树种子发芽率和促进早期壮苗生长。图2 表3 参30。  相似文献   

Strategic Trend of Chinese Urban Forestry Development     

LIZhiyong* Project Secretariat of ChineseSustainable Development Forestry Strategic Research Scientificand Technological Information Institute of Forestry  Chinese Academy of Forestry  Beijing  P.R.China 《中国林业科技(英文版)》2004,3(3):19-23

1 STRATEGY BACKGROUND1.1 Quickening of Urbanization ProcessSince the reform and opening-up in China in 1978,economic community developed rapidly. By the endof 2003, GDP has exceeded $1 000 billion. With therapid development of Chinese economy, residentialmode focusing on rural population is now changing,urbanization process is quickening, traditional cityscale is expanding into metropolis (Tianjin, Xi’an,Chengdu, Chongqing, etc.) or super cities (Beijing,Shanghai, Guangzhou, etc.…  相似文献   

The biochemical control of the cell cycle by growth regulators in higher plants     

TANGWei LatoyaHarris RonaldJ.Newton 《林业研究》2004,15(3):227-232

The cell cycle is an important research field in cell biology and it is genetically and developmentally regulated in animals and plants. The aim of this study was to review knowledge about the biochemical regulation of the cell cycle by plant growth regulators through molecular checkpoints that regulate the transition from G0-G1-S-phase and G2-M in higher plants.Recent research has shown that zeatin treatment led to the up-regulation of CycD3 in Arabidopsis. Benzyladenine treatment can also shorten the duration of S-phase through recruitment of latent origins of DNA replication. Kinetin is involved in the phosphoregulation of the G2-M checkpoint; the major cyclin-dependent kinase (Cdk) at this checkpoint has recently shown to be dephosphorylated as a result of cytokinin treatment, an effect that can also be mimicked by the fission yeast Cdc25 phosphatase. Gibberellic acid (GA) treatment induces internode elongation in deepwater rice, this response is mediated by a GA-induced up-regulation of a cyclin-Cdk at the G2-M checkpoint. Recent evidence has also linked abscisic acid to a cyclin-dependent kinase inhibitor. A new D-type cyclin, recently discovered in Arabidopsis may have a key role in this process. A brief review on plant growth regulator-cell cycle interfacing during development and a cytokinin-induced continuum of cell cycle activation through the up-regulation of a plant D-type cyclin at the G1 checkpoint and the phosphoregulation of the Cdk at the G2/M checkpoint had been concluded. This review could be valuable to research on cell and developmental biology in plants.  相似文献   

Intratree Variability of Tensile Strength Parallel to Grain in Chinese Fir and I-214 Poplar from Plantation     

XU Ming REN Haiqing LI Xiazhen Research Institute of Wood Industry  Chinese Academy of Forestry  Beijing  P.R.China 《中国林业科技(英文版)》2007,(3)

The variation of tensile strength parallel to grain in Chinese fir and I-214 poplar wood from plantations was studied in this paper. Aaccording to the national standards The Testing Methods for Physical and Mechanical Properties of Wood (GB 1927 to 1943 ? 1991), the small clear wood samples were cut and tested, which represent the south and north of trees with heights of 1.3, 3.3, 5.3 and 7.3 m. The results showed: the tensile strength parallel to grain of the north wood was higher than that of south wood. ANOVA shows that the tensile strength parallel to the grain with height is of significant difference (at 0.05 level).  相似文献   

A Study on the Effects of Insect Pests and Diseases on Intensively Managed Plantations     

YU NmglouWorld Bank Loan Project Management Center. State Forestry Administration. Beijing . China 《中国林业科技(英文版)》2002,(3)

Basedon the results of monitoring the environment of China National Afforestation Project (NAP) and the investigation on insect pests and diseases in 1.2 million ha of plantations, the author elaborates the areas, species and causes of insect pests and diseases occurring in the project's areas and provides fundamental theory for guiding environmental protection and plantation establishment in a sound way. Since the project's activities strictly follovved the guideline of environmental protection in past five years, little losses were caused by some commonly insect pests and diseases.  相似文献   

Guidelines for Managing Wildlife Habitats in Southwestern Ponderosa Pine Forests of the United States     

PeterF.Ffolliott 《林业研究》1997,8(2):108-110

IntroductionEcoledcalrelahonshipsanddePendenceofwildlifesPe-ciesonsouthwesternPOnderosapine(Pineponderosa)fOrestsarecloselyrelat6dtohabitatuse.Foraginghabits,seasOndfoodPreferences,anduseoftreesforfeedingarelawtydePendentuponthestrUctureandspahalar-rangme…  相似文献   

临沂市引种茶树现状及高产栽培技术措施   总被引：2，自引：1，他引：2  

陆发利  王玉谦 《山东林业科技》1995,(6):14-16

山东省沂蒙山区近３０年的茶树引种栽培实践及试验研究表明：北方地区可以利用当地的小气候条件发展茶叶生产。通过合理选择园地、加强越冬保护、实行适密适矮栽培、茶园间作、改良土壤培肥地力等技术措施，能实现茶叶生产高产优质高效。  相似文献   

Correlation between Chemical Structure and Biological Activity of Host-Selective Plant Pathogen Mycotoxins     

WEI Shuhua LIANG Jun YE Jianren ZHANG Xingyao** . School of Resources  Environment of Nanjing Forestry University  Nanjing  P.R. China . Institute of Forest Ecology  Environmental  Protection  Chinese Academy of Forestry  Beijing  P.R. China 《中国林业科技(英文版)》2007,6(1):62-68

Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.  相似文献   

沙棘叶子提取物对白化病白鼠由铬诱导氧化胁迫的抗氧化活性评估     

郭海  赵明  S.Geetha  M.Sai Ram  S.S.Mongia  Virendra Singh  G.Ilavazhagan  R.C.Sawhney 《陕西林业科技》2006,(1):90-94

本研究报道沙棘(胡颓子科)对雄性白化病白鼠由铬诱导氧化胁迫的抗氧化活性。氧化胁迫通过对小白鼠进行强制性喂养30 d,以浓度为30 m g/kg的铬相对体重比例的重铬酸钾盐实现。铬促使体重下降,而却明显增加了器官与体重比例。铬处理明显减少了谷胱甘肽的降低,增加了丙二醛和肌氨酸磷酸激酶的水平;而且它还加强了血清中谷氨酸草酰乙酸转移酶和谷氨酸丙酮酸转移酶的浓度。用不同剂量的沙棘叶子提取物(乙醇提取)对保护铬元素诱导的氧化胁迫进行了评估,结果表明叶子提取物在浓度为100到250 m g/kg铬与体重比的情况下可以明显保护动物避免由铬所诱导的氧化伤害。  相似文献