基于计算机断层扫描技术的木材密度检测研究

使用计算机断层扫描技术进行原木无损检测,通过对原木树种断层 CT 值的统计,对 CT 设备在检测过程中的窗宽与窗位进行了设定,同时拟合出了木材 CT 值一密度值的线性方程,为原木缺陷的无损检测及木材密度的测定提供一种新方法。     

岷江上游干旱河谷辐射松种子育苗试验研究

经过连续 3年对辐射松种苗特性及育苗技术的试验研究 ,结果表明 :( 1)辐射松种子在 5℃的低温条件下贮藏 2年其发芽率比对照提高 6 4 5 % ;( 2 )用 0 5 %的高锰酸钾液对种子进行消毒处理其幼苗出苗率提高 39 2 % ;( 3)用湿润河砂层积催芽的种子其苗木平均苗高 2 4 0cm ,平均地径 0 33cm ,比对照苗高多 4 8cm ,地径大 0 12cm ;( 4)酸性土上培育的苗木平均苗高比碱性土上培育的苗木平均苗高多 9 8cm ,平均地径大 0 16cm ;( 5 )营养袋规格 10cm× 15cm ,营养土配方为腐殖含量 5 0 %的平均苗高 2 3 3cm ,平均地径 0 3cm ,达到一级苗标准 ;( 6 ) 2月底 3月初播种的苗木比 4月底 5月初播种的苗木苗高多 9 1cm ,平均地径大0 16cm ,出苗率提高 35 6 %。经过综合试验研究 ,场圃出苗率由 40 %提高到 80 %以上 ,每公顷产一年生合格营养袋苗达 12 0万株。     

Seasonal variations in photosynthesis of Picea morrisonicola growing in the subalpine region of subtropical Taiwan

From January 1999 to May 2001, we investigated seasonal variations in the photosynthetic capacity of Taiwan spruce (Picea morrisonicola Hay.) growing in the subalpine region of subtropical Taiwan (23 degrees 29' N, 120 degrees 53' E, 2600 m a.s.l.). Photosynthetic capacity (near light-saturated net photosynthetic rate, Pnsat, chlorophyll fluorescence (Fv/Fm) and soluble protein concentration of needles all increased from mid or late spring to early winter. Even when minimum air temperature of the measuring day dropped to near 0 degrees C, Pnsat remained at about 20% of the highest value observed in winter. There was a curvilinear relationship between Fv/Fm and the minimum or mean air temperature of the measuring day. The increase in Fv/Fm with temperature was slowed when the daily mean air temperature was above 7 degrees C, or the minimum air temperature was above 3 degrees C; however, when air temperatures dropped below these values, Fv/Fm varied sharply. Seasonal variations in Pnsat paralleled those in Fv/Fm and needle soluble protein concentration. In early or mid spring when air temperature and Fv/Fm increased, Pnsat and soluble protein concentration remained low. Multiple regression analysis showed that seasonal variations in Pnsat were affected by Fv/Fm, air temperature and needle soluble protein concentration, and the multiple regression equation could be used to estimate Pnsat in different seasons. We conclude that the decrease in photosynthetic capacity of Taiwan spruce in winter and its subsequent recovery in spring were mainly caused by photoinhibition and its reversal, and changes in needle soluble protein concentration. Another possible explanation for the delayed recovery of photosynthetic capacity in spring may be associated with the slow increase in needle soluble protein concentration.     

昆虫病原线虫对木麻黄毒蛾侵染能力的初步研究

本文报道应用昆虫病原线虫Steinernema spp.室内对木麻黄毒蛾的侵染能力。通过斯氏属九个线虫品系对木毒蛾的侵染力测定筛选出S.feltiae Agriotos为最佳品系;能寄生低、中、高龄幼虫及蛹;可在3天内把害虫致死。供试的其它八个线虫品系也能不同程度地致死害虫,并在死虫体内繁殖。S.f.Agriotos线虫的剂量对木毒蛾的致死速度及效果有影响,以1000条线虫/害虫侵染期线虫为最适宜剂量,林间对木毒蛾幼虫的致死率平均为89.6%。     

老鸦柿的开发利用

经过５年的试验实践，将野生灌木老鸦柿按其浆果形态的差异区分成３个类型。并对其栽培利用作了较为系统的归纳，将为今后的开发利用提供参考。     

新亚欧大陆桥经济带沙区土地利用及环境变迁的时空分析模型

本文分析了新亚欧大陆桥经济带及其沙区的发展问题，介绍了国内外对沙漠土地的研究与利用情况，提出了新亚欧大陆桥沙区的经济模式和土地利用及环境变迁的时空分析模型。     

中东欧前社会主义国家森林私有化概况与发展趋势

概括介绍了中东欧前社会主义国家林权私有化的现状、面临的种种挑战和发展趋势。     

长瓣短柱茶施肥研究初报

长瓣短柱茶施肥研究初报＊洪顺山翁月霞杨婉琴庄珍珍关键词长瓣短柱茶施肥肥料配方长瓣短柱茶（ＣａｍｅｌｉａｇｒｉｊｓｉＨａｎｃｅ），俗名攸县油茶或薄壳香油茶，是个珍稀油茶物种。原野生，现只在湖南攸县有较多的分布和栽培，浙江有少量引种。由于其具有抗病、早实...     

修枝间伐对松突圆蚧抑制作用的研究

严重危害广东省沿海地区马尾松的松突圆蚧(Hemiberlesia pitysophila Takagi),自1982年在深圳、珠海等地发现后，至今危害面积约43万ha，其中枯萎或涉死的约8万ha。     

槭叶苹婆60Co-γ射线辐射诱变初报

用60Co-γ射线辐射槭叶苹婆种子,并对种子的萌发和幼苗生长进行观察.结果表明:辐射对槭叶苹婆的种子萌发、成苗率、幼苗高生长、叶面积存在影响.3 kR的辐射剂量对种子萌发有一定的促进作用,大于3 kR的高剂量则有抑制作用;辐射降低幼苗成苗率;辐射抑制苗高生长和叶片生长,但过高剂量叶片会增大并扭曲;初步认定槭叶苹婆种子辐射的半致死剂量为4 kR,适宜辐射剂量为3.0～4.5 kR.