马尾松林下补植阔叶树后森林凋落物量、养分含量及周转时间的变化

在25年生的马尾松林下分别补植拉氏栲、青栲、闽粤栲、格氏栲和苦槠,形成针阔混交异龄林。补植16年后,对上述5种混交林类型及马尾松纯林的森林凋落物量、养分含量及周转时间进行研究。上述5个混交群落和马尾松纯林的年凋落物量分别为6149·1、7533·2、6741·1、7151·5、8041·7和3442·8kg·hm-2。各混交群落总凋落物量的季节动态呈双峰型,第1次峰值出现在2—4月份,第2次峰值出现在8、9月份。在凋落物组成中,枯叶占绝对优势,占凋落物总量的50%~71%,其余依次为枯枝6%~26%、树皮9%~19%、果实和其他组分5%~17%。各混交群落中来自马尾松的凋落物占50%~58%,来自阔叶树的凋落物占42%~50%,且两者的组成有明显差异。凋落物各组分的养分含量存在较大差异,N、P、K、Ca、Mg的含量范围分别为3·25~12·98、0·24~0·97、0·37~6·55、12·77~35·40、2·35~6·10g·kg-1。各林分类型凋落物中养分元素的年归还总量为Ca>N>Mg>K>P。5个混交林群落及马尾松纯林凋落物中的养分年归还总量分别为238·05、213·77、223·93、289·90、304·12和142·01kg·hm-2。6个群落的森林地被物现存量分别为8448·0、15565·8、11993·7、12718·6、6974·2和5020·0kg·hm-2,其中L层在各群落中所占比例分别为47·2%、59·6%、51·3%、61·0%、85·4%及86·3%,平均为61·7%。森林地被物中各养分元素的含量在群落和组分之间存在明显差异,但总的趋势表现为Ca>N>Mg>K>P。最后,通过对年凋落量和林地凋落物积累量的比较分析,上述6个群落的凋落物周转时间预测值依次为0·76、1·42、0·97、1·17、0·84及1·52年,其中枯枝的周转时间明显大于枯叶,且马尾松的枯叶和枯枝的周转时间普遍大于阔叶树。     

祁连山南麓退耕地人工植物群落的枯落物容水性能

对位于祁连山南麓的青海省大通县退耕地人工植物群落的枯落物容水性能进行了研究。该地区从20世纪80年代初期陆续退耕还林的人工植物群落年龄虽只有10~27 a,但其枯落物层厚度已达2.9 cm,相当于天然植物群落(30~200 a)的56.9%;其枯落物容水量平均达4 mm,相当于天然植物群落的35.7%。研究表明退耕地植物群落的林龄越大,植物垂直层数越丰富,则枯落物干物蓄积量和容水率越大,枯落物容水量也越大。在人为去除枯落物层后,其地表径流速度较去除前增加了33%~35%,枯落物层的缓流、滞流作用十分明显。经逐步回归分析,影响植物群落枯落物容水量的因素99.8%的为枯落物干物的蓄积量、林龄、植物层数和枯落物容水率。     

刚果12号桉施肥效应研究

在贫瘠低丘上对刚果１２号桉进行不同肥料配合和不同用量的施肥试验，结果表明ＮＰＫ，ＮＫ，ＮＰ和ＰＫ配合施用的能极显著地促进刚果１２号桉的生长，５年生时蓄积比对照分别增加１９．４０，１８．４５，１６．４０，１５．０５ｍ＾３／ｈｍ＾２，Ｎ，Ｐ，Ｋ肥单施的蓄积比对照纷别增加５．３０，５．２５，４．８０ｍ＾３／ｈｍ＾２肥料的配合施用极显著地优于Ｎ，Ｐ，Ｋ单施，材积的增长量随施肥量的增加而增加。     

复塑竹帘胶合板的工艺改进

通过对现行复塑竹帘胶合板生产工艺的分析，认为在竹帘、竹席浸胶后的第二次干燥和热压时采用的冷—热—冷工艺，存在着能耗高、产量低等弊端，进行了施胶方式及其相关工艺的改革和热压方式及其相关工艺的改革研究，并在此基础上提出了相应的车间工艺改造方案．改革后的生产工艺，可在原年产量4000m3生产线上达到年产9000m3的生产能力，每年还可节约能源费用216万元，具有较显著的经济效益．     

Spatially distributed morphological characteristics of macropores in forest soils of Hitachi Ohta Experimental Watershed, Japan

Morphological characteristics of macropores in forest soil profiles were investigated at Hitachi Ohta Experimental Watershed in Japan. Nine individual profiles at different locations (various spatial scales in a catchment) and twenty profiles at one site (a small spatial scale) were excavated to the bedrock to investigate density, origin, diameter, direction, and gradient of macropores. Macropore densities in a soil profile ranged from 3.5 to 29.1 per m and from 5.4 to 75.1 per m², respectively. Subsurface erosion, root channels, and interactions between subsurface erosion and root channels accounted for 36.9, 36.5, and 19.0%, of the described macropores. The mean macropore diameter in organic-rich soil layer (17–20 mm) was larger than in the B horizon (11–14 mm) at both spatial scales. The dominant gradients of all macropores in the organic-rich soil layer and B horizon were at negative oblique angles. Approximately 90% of the macropores in the organic-rich soil layer and approximately 80% of the macropores in the B horizon fell within the range between −50 and 50 degree planar direction. Subsurface flow and root systems are believed to play important roles in determining the morphological characteristics of macropores. These characteristics appear to have variable influences in different soil horizons rather than at different spatial scales. A part of this paper was presented at the 103th (1992) and 105th (1994) Annual Meetings of Japanese Forestry Society.     

浙北地区薪炭林高产栽培研究

浙北地区薪炭林高产栽培研究＊葛万川周健关键词薪炭林栽培体系浙北地区富阳市位于浙江省北部，地貌属浙江西北部低山丘陵区，气候上属我国中亚热带北缘。它在长江下游，中、北亚热带丘陵山地中具有一定的代表性。薪柴是富阳市的主要能源，１９８５年全市耗柴３８万ｔ，占...     

PV聚氨酯密封胶在高寒地区水泥混凝土路面的应用

详细地介绍了PV聚氨酯密封胶在高寒地区水泥混凝土路面接缝养护上的应用情况，阐述了PV聚氨酯密封胶的施工工艺和施工方法，对接缝料的配比试验和施工工艺提出了相应的技术要求。同时，分析了使用该材料的经济效益，肯定了在高寒地区的可用性和可推广性。     

宣威地区松叶蜂种类及其防治措施

松叶蜂是宣威地区针叶林的重要食叶性害虫。近年来，通过开展松叶蜂种类的专题调查，发现该区有松叶蜂科昆虫4属6个种，占目前云南省记载6属16个种的37．5％。其中，在宣威分布较广泛且危害严重的是广西新松叶蜂、南华松叶蜂和迪萨小松叶蜂。对这3种主要的松叶蜂进行了生物学特性观察和药物防治试验，并提出了综合防治措施。     

Allometric model of the height–diameter curve for even-aged pure stands of Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>)

We derived an allometric model of the height–diameter curve for even-aged pure stands, which was a modification of the earlier model proposed by Inoue (2000a). An individual-dependent allometric equation was used as the height–diameter curve. Using the discriminant analysis method, all trees composed of a stand were stratified into upper and lower trees. It was assumed that both relationships between mean tree height H _m and upper tree height H _u and between mean DBH D _m and mean DBH of upper trees D _u could be described by the time-dependent allometric power equations. The height–diameter curve showed an average relationship between tree height and DBH of a given stand at a given time, and hence it could be assumed that the height–diameter curve contained two points (D _m , H _m ) and (D _u , H _u ). With these assumptions, we derived an allometirc model of height–diameter curve, which allowed the coefficients of the curve to be estimated from mean tree height and mean DBH. The proposed model was fitted to Japanese cedar (Cryptomeria japonica D. Don) data. The error ratio of the allometric model ranged from 2.254% to 13.412% (mean = 6.785%), which was significantly smaller than that of the earlier model. When the error of mean tree height was ±1.0 m or less, the effect of the error of mean tree height on the error ratio was comparatively small. This suggested that the error of ±1.0 m in mean tree height could be accepted in the estimation of height–diameter curve using the allometric model. These features enable us to combine the allometric model with Hirata’s vertical angle-count sampling or growth models. In conclusion, the allometric model would be one of the most practical and convenient approaches for estimating the height–diameter relationship of even-aged pure stands.     

林用索道索系的分类及其代号

索系是指索道各工作索相互关联的配置系统,主要包括索道各工作索相互关联而成的各种承载方式、起重方式、牵引方式和落勾方式。而索道的起重方式基本上包含了索道的承载方式,牵引方式基本上包含了落勾方式。本文根据索道工作索的总根数及其起重方式和牵引方式,对林用索道的索系进行了分类,并编制了代号。