吉文林业局柞矮林改造

针对吉文林业局自然地理状况及柞树林生长分布特点,论述了对柞矮林按类型进行改造所采取的技术措施。     

北大河林业局柞矮林经营初探

文章通过对柞矮林抚育前后的生长状况的研究 ,提出今后对柞矮林生产经营方向。     

内蒙古大兴安岭林区柞矮林培育经营策略探讨

文章针对内蒙古大兴安岭林区"十二五"时期木材生产产量减少、人员富余、柞树林资源破坏情况,对内蒙古大兴安岭林区如何开展柞矮林培育经营提出观点,供参考之用。     

东北林区天然林林分结构及林分生产力的研究

在林分整个生长过程中，各生长因子之间是遵从一定规律的，而林分直径株数分布规律是林分结构的基本规律，是树种生长环境条件及经营措施长期相互作用的结果。合理的林分结构是充分发挥森林各种功能的基础，研究林分的直径株数分布结构，可以为林分产量的利用价值及林分收获、森林经营提供科学依据。     

马尾松苦竹复合林分生产力研究

以采用疏林结构培育马尾松大径材兼营苦竹的复合林分为研究对象，分析了林分生长量、生物量、净生产量、顺面积以及叶的净同化率等。结果表明：低密度复合林分与高密度马尾松纯林比，平均胸径、平均树高、单株立木材积分别增加27.3%、22.2%和99.5%；苦竹能够正常生长发育；平均木年均净生产量、叶对树干净同化率分别增加45.84%和32.45%；有利于树干生物量的积累，是培育马尾松大径材，提高林地生产力的较好经营模式。     

林分结构、立地条件和经营措施对竹林生产力的影响*

１９８５－１９９１年对江西分宜县江下林场的毛竹林定位实验结果表明：竹林应在饱和立竹度条件下进行生产循环；影响产量的因子主要是土壤厚度、腐殖质层厚度、土壤全Ｐ和紧实度，证明采取松土施肥等抚育措施能显增产；江下毛竹林５个立地等级的合理经营密度依次为４９５０－５５５０、４３５０－４８００、３４５０－４２００、２４００－３３００、１８００－２２５０株／ｈｍ＾２；施用尿素２２５ｋｇ／ｈｍ＾２的增产效应依立     

人促闽粤栲林分结构及生产力的研究

对建瓯市房道镇境内30hm~2Ⅱ类地上16年生人促闽粤栲林分调查结果表明,林分生物量(地上部分)159.22t/hm~2,其中乔木层生物量155.32t/hm~2;林分年均净生长量10.59t/(hm~2·a),其中乔木层年均净生长量9.71t/(hm~2·a);林分平均胸径13.6cm,平均树高14.6m,平均密度2483株/hm~2,平均蓄积量269.0m~3/hm~2,平均蓄积生长量16.8m~3/(hm~2·a);林分叶面积指数4.771m~2/m~2,叶对树干净同化率166.8g/(m~2·a)。     

次生柞林抚育间伐最佳密度控制及林分生长预测

本文论述了次生柞林抚育间伐最佳密度控制标准,通过分析计算得出最佳经营密度公式和最佳蓄积公式,并确定了抚育间伐密度控制及生长预测方法。     

集水造林林分水分生产力研究

集水造林通过增加植树带汇流量改善了林地土壤水分环境 ,从而影响到林分物质生产水平。根据不同集水造林密度对林地土壤水分环境的改善程度与林分物质生产之间的关系 (水分生产力 ) ,以“双优”模式标准 ,可以确定出合理的集水造林密度。供试的 5年生和 1 0年生刺槐林 ,分别以小于 1 0 0 0株·hm-2 和不大于 840株·hm-2 为合理的集水造林密度 ,其林木水分生产力分别达到 6 71 4 4g·kg-1和 1 2 1 6 32g·kg-1,符合“丰产理想株型”模式标准 ;林分水分生产力分别达到 8 4 1 0 3kg·hm-2 ·mm-1和 2 1 6 6 46kg·hm-2 ·mm-1,实现了“最佳群体结构”模式标准。在发展“节水”型林业、提高水分利用效率中 ,这种以水分与林分物质生产的关系为理论依据 ,确定造林密度 ,在理论和实践上是可取的     

云南紫荆矮林的植物结构及生态特征

云南紫荆是１种良好的庭园绿化树种和石灰岩山地的造林树种。在对滇中云南紫荆集中分布区进行调查的基础上，通过分析云南紫荆矮林群落的植物成分和生态特征，对该树种的生物学特性及生态习性，适宜的生境条件有了较深刻的认识，为云南紫荆的引种驯化及栽培提供了依据。     

山海关林场油松－槲树林种群结构的研究

本文将山海关林场的油松－槲树林划分为５种类型，并对各种类型的种群空间分布格局、年龄结构、胸径结构、树高结构等进行了研究。结果表明：槲树幼树分布格局为聚集分布；油松幼树只存在于郁闭度不超过０．７的油松林分中，其分布格局偏离聚集分布。油松和槲树混交时，次要树种林木常呈聚集分布，优势树种林木呈随机分布。以年龄结构表示的林木发生过程显示，油松先发生，槲树后发生，但有时两树种的年龄结构是隔离的，有时是略有重叠的。油松的树高和胸径结构呈山形分布，槲树往往呈倒Ｊ形，这表示了两树种在演替中的地位。     

Species composition of Modellidae and Cerambycidae (Coleoptera) in a coppice woodland

A continuous sampling of canopy beetles was carried out to determine variations in the abundance, species diversity, richness, and composition of the Mordellidae and Cerambycidae in a coppice woodland. Changes in the abundance and the species richness were monitored at three heights in the forest throughout the season in 1999, using yellow and blue water pan traps. The results showed significant variations in the abundance of Mordellidae among the canopy layers, while little variation was found for Cerambycidae. The abundance, species diversity, and richness were generally greater in summer. The results showed distinct species compositions in both families among layers.     

Simulation of harvester productivity in selective and boom-corridor thinning of young forests

Abstract

Forest management practices may change in the future, due to increases in the extraction of forest fuel in first thinnings. Simulation models can be used to aid in developing new harvesting systems. We used such an approach to assess the productivity of innovative systems in various thinnings of young stands with wide ranges of mean breast height diameter (1.5–15.6 cm), stems per hectare (1000–19,100), and mean height (2.3–14.6 m).

The results show that selective multiple-tree-handling increases productivity by 20–46% compared to single-tree-handling. If the trees are cut in boom-corridors (10×1 or 2 m strips between strip roads), productivity increases up to 41%, compared to selective multiple-tree-handling. Moreover, if the trees are felled using area-based felling systems, productivity increases by 33–199%, compared to selective multiple-tree-handling. For any given harvesting intensity, productivity increased the most in the densest stands with small trees.

The results were used to derive time consumption functions. Comparisons with time study results suggest that our simulation model successfully mimicked productivity in real-life forest operations, hence the model and derived functions should be useful for cost calculations and evaluating forest management scenarios in diverse stands.     

The Physiology of Epicormic Bud Emergence in Pedunculate Oak (Quercus robur L.) Responses to Partial Notch Girdling in Thinned and Unthinned Stands

The physiology of epicormic bud development in Quercus roburwas studied by recording the effect of partial notch girdlesapplied at different dates, in the spring and summer of 1985,on epicormic shoot emergence in stands of thinned and unthinnedtrees. The girdles were applied singly or in tandem pairs oneabove the other. In one experiment they were applied in combinationwith the synthetic auxin 1-napthaleneacetic acid (NAA) or werereplaced by treatment with 2, 3, 5-triiodobenzoic acid (TIBA),an inhibitor of auxin transport. Thinning had no consistent effect on the numbers of epicormicshoots emerging, only on their later vigour, and did not consistentlyaffect the response to girdling or the growth regulator treatments.Epicormic shoot emergence was stimulated only by girdling treatmentsapplied in April and May, and not in June or August, indicatingthat the epicormic buds enter dormancy early in the season.The pattern of responses to the single and tandem girdles wasconsistent with a suppression of the buds in the spring by abasipetally-transported inhibitor, from the inhibitory effectof NAA observed, probably auxin. The development of the budswas not controlled by an acropetafly-transported promoter whosesupply could be interrupted by the girdling treatments.     

弯曲的柞木刨光材回窑处理试验

对刨光后发生弯曲的厚度为３０ｍｍ的柞木刨光材进行回窑处理试验。试验结果表明，采用ＣＬＺ型侧风干燥窑在指接干球温度７０℃，平衡含水率１４．７％的干燥介质条件下，维持该干燥介质条件１７ｈ后，使弯曲的柞木刨光材基本恢复了平直。     

Effect of Betula pendula Admixture on Tree Growth and Branch Diameter in young Pinus sylvestris Stands in Southern Finland

The effects of a birch admixture on the height and diameter growth and maximum branch diameter in planted Scots pine stands was studied using models constructed with a data set from 13 stands of 9–16 yrs of age and 2–8 m dominant height on average sites on mineral soils in southern Finland. The density and height of the birch varied highly between and within stands. Simulated results indicated that the pines were capable of keeping up in height growth with birches that had originated from seed. Even a very high number of birches (10?000 stems ha^?1) had virtually no effect on the height growth of the pines. The number of birches had a pronounced effect on the diameter growth and the maximum branch diameter in pine. Retention of a temporary birch component in young pine stands seems a feasible way of mitigating the adverse effects of low planting densities on the external quality of pine.