落叶松人工林地位指数级导向曲线模型的研究

本文用约1000块样地资抖,系统地研究了黑龙江省落叶松人工林的地位指数级导向曲线模型。通过林业统计分析软件Statistica6.0对各落叶松人工林数据进行拟合、分析比较,结果为：从拟合精度、曲线走向与散点分布趋势、残差分布等综合考虑,舒马切尔曲线函数比较适合落叶松人工林地位指数级导向曲线模型的拟合。     

落桦混交林幼龄期Ⅰ级木分布规律研究

利用３６块落叶松一样树混交林标准地调查资料，研究其幼龄期林分Ⅰ级木单位面积株数与林分密度之间的关系，结果表明：Ⅰ级木的株数并非随密度的增加而直线递增，而是趋向“二阶常数”分布，且在同一年龄阶段，在较低的密度范围（２３２５～４８００株／ｈｍ２）或较高的密度范围（４８０１～６７５０株／ｈｍ２）．Ⅰ级木的株数变动幅度不太大。     

Floristic regeneration in five types of teak plantations in Thailand

Teak is the most important timber species in northern Thailand, and as such, large areas of teak forest have been disturbed or become highly degraded. Teak plantations have been established on this highly degraded land, where the rate of natural recovery is relatively slow. At the study site, five mixed or pure teak plantation types have been established to ameliorate limiting soil properties in order that long-term productivity is maintained. Observations within these plantations in northern Thailand have suggested that native species become established naturally under the shade of a “nurse” plantation, one that shades out early successional species. The objective of this study was to investigate the influence of the number of species in nurse plantations on the diversity and number of seedlings representative of mature native forests that become established within the plantations. Five types of plantations were investigated: (1) Tectona grandis L.f. (T); (2) T.grandis and Tamarindus indica L. (TT); (3) T.grandis and Gmelina arborea Roxb. (TG); (4) T.grandis, T. indica and G. arborea (TTG); (5) T.grandis, T.indica and Anacardium occidentale L. (TTA). These plantations were established primarily for the production of T.grandis (teak), with the other species introduced as economic trees. The plantations were surrounded by native stands of species representative of late successional and mature teak forests. In each of the plantations studies measurements were made on species density, species diversity, and evenness of plants regenerating in the understorey. Results showed that plantations consisting of several species in the overstorey had a higher diversity of native forest species in the understorey than the single-species plantation. Mixed plantation types were also found to reduce the density of the grass Imperata cylindrica (L.) P. Beauv. Consideration of the establishment of woody species found that TG and TTA had high densities of trees and shrubs. This suggested that if the goal of management was to regenerate forest with a high diversity of tree species similar to that found in native mature forests, multiple-species plantations, especially TG and TTA, would be more effective nurse communities than the single-species plantation in providing an environment into which seeds of native species could disperse and germinate. In addition, several climax species, such as Xylia xylocarpa (Roxb.) Taub. var. kerrii (Craib & Hutch) I.C. Nielsen, Pterocarpus macrocarpus Kurz, Largerstroemia sp., Afzelia xylocarpa (Kurz) Craib, Lannea coromandelica (Houtt) Merr., Spondias pinnata (L.f.) Kurz, Garuya pinnata Roxb., Terminalia mucronata Craib & Hutchison, Diospyoros mollis Griff., Irvingia malayana Oliv. ex Benn., Milletia leucantha Kurz, Dalbergia oliviri Gamble ex Prain, Chukrasia tabularis A. Juss and Schleichera oleosa (Lour.) Oken, were found in the early stages of succession, thus indicating that some may be suitable for planting in future restoration processes in order to accelerate natural succession and provide economic returns to managers.     

落叶松人工林重要害虫天敌——大腹圆蛛生物学特性及其对害虫控制作用的研究

大腹圆蛛(Araneus ventricosus)在吉林省2年完成1代,跨3个年度,以1-2龄和6-7龄若蛛越冬。该蛛除卵期及1、2龄蛛外,其它龄态的若、成蛛均张网捕食生活。该蛛喜居有光的栖境,在林缘、林窗处、路旁处结圆形垂直网,昼伏夜出,在小雨条件下可以正常活动。大腹圆蛛对小型猎物可直接取食,对中、大型猎物,需缠绕成束的捕获丝缚住再取食。在林间大腹圆蛛可取食多种蛾和叶蜂成虫,包括兴安落叶松鞘蛾、落叶松毛虫、黄褐幕枯叶蛾、舞毒蛾、栎毒蛾、松皮小卷蛾、松廮小卷蛾、伊藤厚丝叶蜂和落叶松叶蜂等多种落叶松害虫,是一种有效的害虫天敌。     

日本落叶松人工林重茬林地土壤养分含量变化及其对林木生长的影响

日本落叶松人工林重茬林地土壤养分含量变化及其对林木生长的影响＊孙翠玲郭玉文郭泉水关键词日本落叶松人工林重茬地力衰退日本落叶松（Ｌａｒｉｘｋａｅｍｐｆｅｒｉ（Ｌａｍｂ．）Ｃａｒ．）生长快，适应性强，是北方重要的速生造林树种。我国落叶松人工林栽培面积已达...     

大兴安岭林区火烧迹地上兴安落叶松：天然苗的移植造林试验

在大兴安岭林区公路两侧大量地分布着兴安落叶松的天然幼苗。1988年夏在塔河林业局盘中经营所18支线进行了调查,对其两侧的幼苗数量、生长和分布进行了研究。结果表明,幼苗数量每公里达20万株(39株/m~2),幼苗的生长状况与林地上天然幼苗相比无明显差别,1988年夏又对4—6年生的幼苗进行了4ha的移植造林试验,试验是在盘中经营所的火烧迹地上进行的,试验地位于坡下部肥沃、湿润的土壤上,选择地径0.5 cm左右,苗高35 cm左右的苗木,在雨季随起随栽。秋末调查,成活率达96％。本文的研究表明,在大兴安岭林区火烧迹地上用天然落叶松苗进行移植造林是完全可行的。     

华北落叶松人工林叶内营养元素含量的变异

通过固定标准木、定期采样和化学测定, 分析了华北落叶松人工林叶内营养元素含量随冠向、冠层和生长季节的变化而变化规律 结果表明: 叶的营养元素含量在不同冠向间有一定的差异, 但差异不显著不同冠层间叶的营养元素含量变化有一定的规律, N、P、K由树冠底部到树冠顶部是逐渐增加的, Ca则是逐渐减小, Mg的变化无一定规律 方差分析表明林木不同冠层的N、P、K、Mg含量差异不显著, Ca的含量则差异显著 树冠各层次针叶营养元素含量的平均值与树冠中部针叶的营养元素含量很接近, 建议进行营养元素概算以树冠中部的针叶为样品 华北落叶松人工林叶的营养元素含量随季节的变化而呈现有规律的变化 刚展叶的华北落叶松N、P、K、Mg含量很高, 展叶期明显下降, 之后随季节的变化逐渐下降, 落叶前期显著下降; Ca的含量随季节变化相反, 刚展叶含量很低, 随季节变化一直呈上升趋势, 落叶前达峰值 根据叶的营养元素含量的季节动态和变异规律, 确定的最佳采样时间为7、8月份     

日本落叶松人工林生长预测的全林分模型研究

以长岭岗林场日本落叶松人工林中的固定样地以及临时样地调查数据为基础，从模型间的相容性出发，建立了包含立地指数SI、林分密度SDI、林分断面积生长模型、树高曲线动态模型和林分收获模型的全林分模型系统，着重探讨了用Korf方程构造林分断面积生长模型时有关参数与SI和SDI的关系。     

林豆复合生态系统土壤理化性质的研究

本文对混种大豆的落叶松.大豆、水曲柳-大豆复合生态系统土壤理化性质进行研究。结果表明,在一个生长季内混种后的土壤物理性质得到了改善。落叶松.大豆与水曲柳一大豆复合生态系统的土壤容重为1.112g/cm3和1.058g/cm3均低于相对应的纯林:混种大豆后土壤总孔隙度增加。两种林-豆复合生态系统土壤有机质分别比对应纯林高1.77倍和1.09倍:落叶松一大豆复合生态系统全氮和水解氮含量分别高于落叶松纯林4.2%和53.0/%,水曲柳-大豆复合生态系统全氮和水解氮含量分别高于水曲柳纯林75.5%和3.3%:混种大豆后全磷含量降低,而有效磷含量则增加:落叶松-大豆复合生态系统全钾和有效钾比落叶松纯林高0.6%和17.5%,水曲柳-大豆复合生态系统全钾和有效钾分别比水曲柳纯林高56.4%和21.8%。图1表3参27。     

日本落叶松无性系微纤丝角遗传变异的研究

对10个10年生日本落叶松无性系的早材和晚材微纤丝角进行了测定,结果表明:早、晚材微纤丝角无性系间差异极显著,同一年轮内早材微纤丝角大于晚材.日本落叶松微纤丝角的径向变异规律为:在髓心处最大,以后逐渐减小.早、晚材微纤丝角与树木年轮间的变异模式(径向变异)以对数和乘幂式方程拟合效果较好,R2(R为相关系数)均在0.8以上.早、晚材微纤丝角同树高、形率、树皮厚度、主枝粗、枝干比、主枝夹角、主枝长的相关关系不显著,早、晚材微纤丝角同胸径、冠幅的相关关系达到显著水平;早材与晚材的微纤丝角也相关显著.早材和晚材的微纤丝角受中到强度遗传控制,广义遗传力分别为0.767 4、0.804 3.按照20%的选择率,早材和晚材的微纤丝角的遗传增益分别为21.82%和29.75%.