3S技术在鄱阳湖洲滩植被研究中的应用

为了给鄱阳湖洲滩植被的监测、保护与合理利用提供必要的依据 ,将 RS技术 (Landsat-7ETM+ )与 GPS技术、GIS技术相结合 ,对鄱阳湖洲滩植被的分布、面积与生物量进行了研究 ,据假彩色合成图描绘了鄱阳湖洲滩植被图 .结果表明 :(1) Landsat-7ETM+假彩色合成图显示 ,鄱阳湖洲滩植被主要分布于该湖的南部和西部 ,东部只有少量分布 ,北部几乎无分布 ;(2 )到 2 0 0 0年 4月 16日止 ,鄱阳湖洲滩植被总面积为 10 18.74km2 ,占全湖总面积的 3 3 .65 % ,其中单位面积生物量≥ 4kg/ m2 的植被面积为 44 4.5 3km2 ;(3 ) ETM+ 4的亮度值 X与单位面积生物量 Y间的回归方程为 Y=-4 897.11+ 87.68X;(4 )全湖洲滩植被总生物量为3 .81× 10 6 t,洲滩植被平均单位面积生物量为 3 .73 60 kg/ m2 .     

不同取样时期对杜仲、黄柏、厚朴三种皮类药材质量影响的初步研究

对贵州省林业科学研究院树木园内的杜仲林、黄皮树林、凹叶厚朴林随机分别选取6株样树，从2001年9月至2002年8月每月定日取样，用烘干法测定其含水率，用醇溶性浸出物测定法测定其萃取率。结果表明，不同取样时期杜仲、黄柏、厚朴的含水率差异显著，三种药材含水率变化相对一致，在4、5、6、7月含水率较高，9、10月含水率较低。杜仲、黄柏的最佳取皮期为6月，其萃取率分别为7．92％、6．77％；厚朴的最佳取皮期为7月，萃取率为8．93％。     

枣粮间作密度初探

枣粮间作是广大劳动人民的创举,是提高土地资源利用率,增加单位面积产量、提高产值的有效途径.为探讨枣粮间作中枣树栽植的合理密度,遵循"枣粮并重"的原则,从1999年6月开始,在枣粮间作集中分布区,实际调查了不同枣树密度下粮、枣产量及产值,并运用数学分析的方法,模拟出枣粮间作的最佳理论密度.     

Influence of Ammoniacal Copper Quaternary treatments on mechanical properties of blue-stained Lodgepole Pine wood

Three concentrations （2.8%, 2.0%, 1.2%） of Ammoniacal Copper Quaternary （ACQ） was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modules of elasticity （MOE）, modules of rupture （MOR）, toughness and shearing strength parallel to grain on tangential surface, are tested according to the criteria GB1927-1943-91. Non-treated sample were also tested according to the same procedure. The results showed that the three groups specimen impregnated by different concentrations of ACQ solution met the AWPA standard 2003 of America （UC4A 6.4g/cm^3）. There were significant difference of toughness between treated wood and non-treated wood （p=0.01）, but there were no statistically significant differences among three concentrations in terms of toughness, and toughness of treated wood was approximately 20% lower than non-treated. MOR, MOE as well as sheafing strength parallel to grain were found to be not significantly different between treated wood and non-treated one, and there were no statistically significant difference among three concentrations of ACQ too. Toughness, MOR, MOE and sheafing strength parallel to grain increased with decrease of concentration of ACQ, but they were hardly affected by ACQ preservatives.     

Pyrolytic characteristics of burning residue of fire-retardant wood

In order to investigate the pyrolytic characteristics of the burning residue of fire-retardant wood, a multifunctional fire-resistance test oven aimed at simulating the course of a fire was used to burn fire-retardant wood and untreated wood. Samples at different distances from the combustion surface were obtained and a thermogravimetric analysis (TG) was applied to test the prrolytic process of the burning residue in an atmosphere of nitrogen. The results showed that: 1) there was little difference between fire-retardant wood and its residue in the initial temperature of thermal degradation. The initial temperature of thermal degradation of the combustion layer in untreated wood was higher than that in the no burning wood sample; 2) the temperature of the flame retardant in fire-retardant wood was 200°C in the differential thermogravimetry (DTG). The peak belonging to the flame retardant tended to dissipate during the time of burning; 3) for the burning residue of fire-retardant wood, the peak belonging to hemicellulose near 230°C in the DTG disappeared and there was a gentle shoulder from 210 to 240°C; 4) the temperature of the main peaks of the fire-retardant wood and its burning residue in DTG was 100°C lower than that of the untreated wood and its burning residue. The rate of weight loss also decreased sharply; 5) the residual weight of fire-retardant wood at 600°C clearly increased compared with that of untreated wood. Residual weight of the burning residue increased markedly as the heating temperature increased when burning; 6) there was a considerable difference with respect to the thermal degradation temperature of the no burning sample and the burning residue between fire-retardant wood and untreated wood. __________ Translated from Journal of Beijing Forestry University, 2006, 28(3): 133–138 [译自: 北京林业大学学报]     

配筋混凝土砌块高层设计时应注意的几个问题

针对配筋混凝土砌块高层设计,提出砌块空腔墙的应用,注意合理设置水平配筋,配筋砌块深梁,控制底框房屋层间抗侧刚度比及高层墙体的裂缝问题.     

Morphological variance and natural types' division of plus trees ofLarix principis-rupprechtii Mayr.

The phenotypic characteristics of the plus trees ofLarix principis-rupprechtii such as stem form, branch angle, branch/stem ratio, branch density, the crown width, crown length, number of short branch over 5-cm branch segment in length, and the leaf number of each short branch were investigated in seed orchard in the Changcheng Mountain, Shaanxi Province. According to the morphological characters, the plus tree clones ofLarix principis-rupprechtii were classified into 4 natural types: the narrow-dense-crown type, wide-dense-crown type, wide-sparse-crown type, and the narrow-sparse-crown type. The result of the cluster analysis showed there was a very significant difference in tree growth among the four natural types. While comparing the tree growth of four natural types for the last ten years, it was found that the performance order of various types from good to bad is as follows: the narrow-dense crown type > the wide-dense crown type > the wide-sparse crown type > the narrow-sparse crown type. The plus trees of narrow-dense-crown, as a fine type, should be paid great attention to production and prepared to popularize. Biography: ZHANG Xin-bo (1956-), male, Senior engineer of Shanxi Academy of Forestry Science and Northern Research Institute of Forestry of China, Taiyuan 030012, P. R. China Responsible editor: Chai Ruihai     

Hydraulic redistribution of soil water during summer drought in two contrasting Pacific Northwest coniferous forests

The magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status at multiple depths and root sap flow under drought conditions in a dry ponderosa pine (Pinus ponderosa Dougl. ex Laws) ecosystem and in a moist Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) ecosystem. The fate of deuterated water applied to small plots to create a strong horizontal soil water potential gradient was also monitored to assess the potential for horizontal redistribution of water and utilization of redistributed water by co-occurring shallow-rooted plants. In a 20-year-old Douglas-fir stand, approximately 28% of the water removed daily from the upper 2 m of soil was replaced by nocturnal hydraulic redistribution during late August. In an old-growth ponderosa pine stand, approximately 35% of the total daily water utilization from the upper 2 m of soil appeared to be replaced by hydraulic redistribution during July and August. By late September, hydraulic redistribution in the ponderosa pine stand was no longer apparent, even though total water use from the upper 2 m of soil was nearly identical to that observed earlier. Based on these results, hydraulic redistribution would allow 21 and 16 additional days of stored water to remain in the upper soil horizons in the ponderosa pine and Douglas-fir stands, respectively, after a 60-day drought. At both sites, localized applications of deuterated water induced strong reversal of root sap flow and caused soil water content to cease declining or even temporarily increase at locations too distant from the site of water application to have been influenced by movement of water through the soil without facilitation by roots. Xylem water deuterium values of ponderosa pine seedlings suggested utilization of redistributed water. Therefore, hydraulic redistribution may enhance seedling survival and maintain overstory transpiration during summer drought. These first approximations of the extent of hydraulic redistribution in these ecosystems suggest that it is likely to be an important process in both wet and dry forests of the Pacific Northwest.     

德宏局辖区边境口岸10年监测实蝇的结果与分析

利用德宏边境口岸10年的实蝇监测数据,从实蝇种类、种群数量和结构动态变化方面分析实蝇发生发展情况。结果如下:(1)10年间德宏地区共监测鉴定出13种实蝇,其中种群数量最多的是桔小实蝇、瓜实蝇和南瓜实蝇;(2)3种主要实蝇10年来发生数量呈上升态势,2009年增速最快,1年监测到的实蝇占10年总量的28.1%;(3)桔小实蝇已经成为德宏地区最大的优势种群,到2009年,它在3种主要实蝇中已占79.0%的绝对多数,增速也最快。     

稻瘟病菌拮抗细菌bio-2的抑菌作用及其鉴定

稻瘟病是水稻的重要病害,可引起大幅度减产.目前,利用水稻抗瘟性品种和使用化学农药仍是防治稻瘟病行之有效的方法,但因抗瘟品种的单一化、稻瘟病菌生理小种组成的复杂性和变异性、化学农药的毒性以及病原菌的抗药性,使水稻稻瘟病的防治受到一定的制约,因此,生物防治越来越受到人们的关注.