小叶黄杨播种育苗技术研究

经过多年试验研究，结果表明，小叶黄杨种子具有胚轴休眠特性，小叶黄杨种子含水量低于１２．５％时，种子生命力下降，在辽西地区适宜９月上旬播种，播种量为５０￣７０ｇ／ｍ＾２，覆土厚度１．５ｃｍ，覆草厚度１￣２ｃｍ，冬季要重点保护胚根不受危害，留苗密度７００株／ｍ＾２；小叶黄杨１￣２年生苗木对湿度敏感，在风沙干旱地区越冬必须覆盖防寒。     

黄杨粕片盾蚧生物学特性,发生动态及其防治研究

黄杨粕片盾蚧在北方严重为害小叶黄杨，１ａ发生２代，多以成虫、部分以２龄若虫越冬。第１代１龄若虫高峰日为５月１２日－６日，第２代１龄若虫盛期为７天下旬，以第１代发生较为整齐。该蚧虫在小叶黄杨上主要分布于１ａ生枝叶，并以１龄若虫逐年向新生枝呈主动扩散，在较大范围内扩展较快，在３－４ａ内可造成严重为害。对其防治的关键时期是１龄若虫活动期和雄成虫期。喷洒４０％氧化乐果１０００倍液、洗衣粉５００倍液防治１龄     

日本卷毛蚧的空间分布型及应用

对油茶林内日本卷毛蚧母蚧期的空间分布型进行研究的结果表明:日本卷毛蚧在油茶林内,在叶片和枝条上,在上、中、下层叶片上的种群均呈聚集分布。今将其应用到序贯抽样技术中,并计算出最适抽样数,找出最佳取样方式。     

云杉阿扁叶蜂卵分布规律和抽样技术的研究

通过林间抽样调查，对云杉阿扁叶蜂ＡｃａｎｔｈｏｌｙｄａｐｉｃｅａｃｏｌａＸｉａｏｅｔｚｈｏｕ卵的分布规律作了研究。经归纳分析，７５％的卵集中分布于２年生针叶上，７８％的卵为１枚叶上１粒卵。受害程度不同的单株间卵在树冠上的垂直分布因各冠层针叶数量而有明显差异：树冠各层针叶较健全时，卵集中分布于下冠层；下层针叶稀少，中、上层针叶较健全时，卵集中分布于中冠层；连年严重受害株中下冠针叶稀少，卵则集中于上冠层。严重成灾的林分中，卵在各林冠层的分布已无明显差异。卵的空间分布属聚集型，个体间相互排斥。运用分布信息，求算了不同卵密度下的最适抽样数，设计了决策防治的序贯抽样方案。     

枣林梨笠圆盾蚧生物学及发生规律的研究

梨笠圆盾蚧Ｑｕａｄｒａｓｐｉｄｉｏｔｕｓｐｅｒｎｉｃｉｏｓｕｓ（Ｃｏｍｓｔｏｃｋ）是枣林的重要微小害虫，在山西一年发生２代，以第２代的２龄若虫于１—３年生的枝条上越冬，次年３月下旬开始活动，雌雄若虫均为两龄，第２代和第１代成虫分别于５月上旬和７月中旬开始羽化，５月下旬和８月上旬分别产出第１代和第２代若虫。雌雄性比分别为１：０．２６和１：０．３５。本文也研究了寄主不同部位、不同方位与各代虫口密度、自然死亡率的变化规律；若虫在叶面的分布规律；寄主枝龄与寄生密度对种群的影响；各虫态发生的起迄日期；发育进度与温湿度的关系；发育所需天数。为测报成虫羽化盛期和产仔盛期提供了理论依据     

青冈齐盾蚧生物学特性的观察

青冈齐盾蚧Ｃｈｉｏｎａｓｐｉｓ ｓａｉｔａｍｅｎｓｉｓ Ｋｕｗａｎｓ是板栗的重要害虫，在浙江余姚一年发生３代，以卵在板栗的１－２年生枝条上越冬。雄蚧大多危害板栗叶片，雌蚧在板栗叶片正面（赵冬代及第１代）与枝条上（第２代）危害。若虫孵化后２４小时内就固定在寄主上，２龄若虫期在形态上出现雌雄分化。１龄若虫期用５０％甲胺磷乳油、４０％氧化乐果乳油、２．５％敌杀死乳剂喷雾，有较好的防治效果，黄蚜小蜂Ａｐｈ     

黄杨白粉病的发生与防治

黄杨白粉病的发生与防治潘建芝王娜（晋冀鲁豫烈士陵园邯郸市０５６００１）黄杨，也叫大叶黄杨、冬青卫矛、大叶冬青、四季青等，是常绿阔叶灌木。黄杨萌芽力强，生长茂盛，易修剪，寿命长，是园林绿化，尤其是作绿篱的理想树种，深受人们的喜爱。但黄杨易受白粉病为害，...     

中国晋盾蚧雌戍虫空闻分布型及抽样技术研究

本文对中国晋盾蚧雌成虫空间分布型及抽样技术进行了研究,研究表明,该虫在旱柳防护林的树冠内和林间均为负二项分布;虫口密度在树冠上的分布,具有东侧>西侧>北侧>南侧和上层>中层>下层之特点;在防护林带或块状林地内,用折线式取样均有较高精度;以着虫末级枝为取样单位,在树冠西侧三层各抽一枝所得虫口密度均值对整株虫口密度均值有很强的代表性。     

La—m幂法则模型的抽样方法

基于笔者提出的研究生物种群空间格局的Ｌａ－ｍ幂法则模型（Ｌａ＝βｍ＾δ），本文推导出如下抽样设计方法：（１）种群密度的简易估计方法；（２）简单随机抽样最适理论抽样数的确定方法；（３）分层随机抽样最适理论抽样数的确定方法；（４）二阶抽样最适配额的确定方法；（５）按临界密度划分不同种群水平的序贯抽样方法；（６）最适样方大小的确定方法；（７）种群密度与负二项分布参数ｋ的关系以及Ｌａ－ｍ幂法则模型的非线性     

黄杨绢野螟空间分布型 生物学及防治的研究

黄杨绢野螟(Diapania perspectalis Walker)在国内分布于北京、西安、上海、南京、贵阳、成都等10多个城市,危害黄杨、大叶黄杨、小叶黄杨、瓜子黄杨、雀舌黄杨、朝鲜黄杨、冬青、卫矛、匙叶黄杨等树木。据在西安调查,黄杨受害率在52-98％,冠径80cm的黄杨口密度最多高达112头/株。由于幼虫多为害新叶,且将叶片缀合在一起吐丝结巢,致使叶片,生长发育受阻。为了有效地防治此种害虫,我们于1989年9月-1990年8月,对黄杨绢野螟幼虫的空间分布型进行了调查,对其生活习性及化学防治作了进一步研究。     

松黄叶蜂幼虫空间分布型的研究

研究了松黄叶蜂幼虫在林内和树冠内地北方位及各小区的分布。通过聚集指标测定,幼虫在林内,树南北方位,上、中、下三层均为聚集分布。树冠内南中和北上层小区为均匀分布,其余小区为聚集分布。适合于松黄叶抽样方法为以抽样,最佳抽样区为树冠下层。     

白蜡虫在寄主植物上的分布特征研究

白蜡虫在寄主上的分布与方向和寄主枝条的位置有关，不同虫基分布特征不同，在定叶期，白蜡早咎群方位上差异不太大，但雌雄虫在方位分布上有明显差异。种群数量分布依次为东（２８．０５％），南（２６．５５％），西（２５．０６％），北（２０．３４％），雌虫依次为东（３２．１６％），南９２７．３６％），北（２０．３４％），西（１８．６５％）；雄虫依次为西（３０．７６％），南（２５．８４％），东（２４．２９％），北     

Relationships between tree size and reaction wood formation in 23 Japanese angiosperms

The objective of this study is to clarify the relationships between tree sizes and the anatomical, chemical, and physical characteristics of reaction wood. Naturally inclined stems or branches in 23 Japanese angiosperms, including 3 tree sizes at adult trees, 7 arbor, 7 subarbor, and 9 shrub species, were used. The presence of a gelatinous (G-) layer, basic density, vessel frequency, and lignin content were examined on the upper and lower sides of each sample. Almost all the species showed a decrease in vessel frequency and lignin content on the upper side, which are typical characteristics of reaction wood in angiosperms. A G-layer was formed in four arbor, one subarbor, and two shrub species. The ratio of the upper and lower sides in vessel frequency and lignin content gradually decreased with an increase in tree size. Based on the results of the principal component and cluster analyses, shrub species were classified into the different groups: from arbor and subarbor groups. These results indicate that the magnitude of alteration in the characteristics due to reaction wood formation of arbor and subarbor might differ from that of shrub, although the characteristics changed by reaction wood formation might be the same in the three tree sizes at adult trees.     

栎木应力木生长偏向性分析

该实验的目的是观察栎木枝条的年轮偏向性和应拉木的显微及化学特性。结果表明,栎木枝桠木髓心偏向上侧,即下侧的生长比上侧迅速。双染色法和SEM的观察发现,胶质层同时发生于枝桠木上下侧的纤维细胞,但上侧的应拉程度比下侧稍显严重。化学分析结果显示,枝桠上下侧的a-纤维素含量仅比正常木高2%~3%,木质素含量仅比正常木低2%~4%。该实验的结论是,栎木枝桠木中反应木同时发生在上下两侧,只是应拉程度有差异,而枝桠木下侧生长迅速造成髓心偏向上侧。     

柑桔全爪螨空间分布型的研究

对4个柑桔产区抽样调查,采用卡方检验判断柑桔全爪螨的空间分布型,其主要空间分布呈负二项分布。进一步计算聚集度指标,表明各种群存在个体群。分层随机抽样调查上、中、下三个树冠层,各层空间分布型均呈负二项分布,而虫口密度以上层最高,下层最低。     

Formation and structure of reaction wood in Buxus microphylla var. insularis Nakai

Summary Anatomical differences in xylem between the upper and lower sides formed in the inclined stems of Buxus microphylla with different angular displacement from the vertical were examined microscopically. B. microphylla exhibited a pronounced growth promotion on the lower side of the inclined stems. Formation of tension wood (gelatinous fibers) was not observed. Xylem formed on the lower side showed some interesting features resembling the compression wood formed in gymnosperms. The reaction wood tracheids and vessels showed an excessive lignification in their secondary walls but lacked both helical cavities and an S₃ layer, features that were almost the same as those of primitive gymnosperms. These results indicate that B. microphylla has an ability to form compression wood, suggesting that in the genus Buxus a different mechanism in the conducting elements was developed in the phylogenetic evolution.The first author would like to express his sincere thanks to Dr. T. E. Timell, College of Environmental Science and Forestry, State University of New York, Syracuse, New York, for his invaluable suggestions in connection with this research     

Spatial heterogeneity of dead fuel moisture content in a Larix gmelinii forest in Inner Mongolia using geostatistics

Spatial heterogeneity of fuel moisture content determines the spread rate and direction of a forest fire.Research on the spatial heterogeneity of the moisture content of dead fuel of Larix gmelinii Rupr.showed that:(1) fuel moisture content in litter layer semi-humus layer humus layer,and the coefficient of variation decreased with sampling depth;(2) the sill value of the semi-humus layer was highest,the humus layer moderate,the litter layer the smallest,overall,the spatial heterogeneity of the semi-humus layer was the highest.The humus layer in the slant direction and three layers in a vertical direction showed strong spatial correlation with the lowest nugget coefficient of 0.0968;(3)the fuel moisture content of the humus layer showed strong spatial anisotropy;and,(4) estimating the total moisture content of the sampling site by stimulated sampling reasonable control of the sampling interval,and increasing the sampling intensity can reduce the error.When the sampling intensity is increased to more than 16 and the sampling interval 3 m,the standard error is 15%.The spatial heterogeneity of fuel moisture content is best revealed by increasing sampling density,sampling in different fire seasons,and in different slope directions and positions.The results can provide a scientific basis for forest fire prediction and prevention.     

Pilodyn评估大花序桉活立木木材基本密度

以广西东门林场33株17年生大花序桉为研究对象,测定活立木南北向Pilodyn测定值,生长锥钻取过髓心南北向木芯,木芯分为内部、中部、外部3部分测定木材基本密度,Pilodyn测定值与木材基本密度建立的回归方程。结果表明：指数函数方程拟合效果最好;Pilodyn测定值与树干外部基本密度呈极显著的负相关关系,树干外部决定系数R2值（0.568）最大,且回归方程拟合度好;Pilodyn测定值与中部基本密度呈显著的负相关关系,与内部基本密度负相关关系不显著;南向的回归方程拟合度好于北向。预测模型的建立,为今后快速无损评估活立木木材基本密度提供新的方法。     

Effect of board density and layer structure on the mechanical properties of bamboo oriented strandboard

This study examined the effects of density and layer structure on the mechanical properties and dimensional stability of strandboard manufactured from moso bamboo (Phyllostachys pubescens). The strandboard was fabricated in a laboratory at five densities and three different structures including a randomly oriented homogenous board, a unidirectionally oriented homogenous board, and a three-layered board with a cross-oriented core layer (BOSB). Bamboo strand alignment distribution could be predicted using the von Mises distribution function. Bending properties increased with increasing density and were affected by layer structure. The modulus of rupture (MOR) of the threelayered board in the parallel direction increased remarkably compared with the random board MOR; in the perpendicular direction, it exhibited less strength reduction. Elastic properties of the three-layered board could be predicted using elastic constants of the unidirectional board. Internal bond strength (IB) was greatly affected by density, but the layer structure effect did not appear in IB. Linear expansion per unit moisture change ranged from 0.017 to 0.022 for random and three-layered boards; these values are comparable with or lower than values for commercial board.     

提高低密度杨桦林林分生产力的经营技术

对低密度的杨桦林经营过程中需要解决的主要技术问题进行了研究，包括上层林及林冠下栽植密度的确定，最小栽植空间的确认以及红松最适宜的透光时间和透光方法。