福建省天然林择伐研究

本文按照森林永续利用的原则,从采运作业角度出发,提出对天然林因林因地实行择伐是保护利用天然林资源的有效途径;对天然林择伐调查设计、择伐强度的选择、采集作业等进行了研究。     

国有林场天然林择伐作业技术探讨

针对福建省国有林场天然林资源现状,本文对择伐的必要性、择伐作业中采伐木的选择、择伐强度和郁闭度的控制进行了论述,从而提出既可充分利用好天然林资源、保护好幼苗幼树,又能保证伐区作业质量的择伐采运技术方法。     

国有林场天然林择伐采运技术探讨

本文针对福建省国有林场天然林资源现状，提出采用择伐方式的必要性，并对择伐作业中采伐木的选择、采伐强度和郁闭度的控制进行了论述，对充分利用天然林资源、保护幼苗幼树、保证伐区作业质量的择伐采运技术进行探讨。     

小陇山锐齿栎天然林空间结构特征

研究小陇山3个类型锐齿栎天然林的直径分布和空间结构参数(混交度、角尺度和大小比数),分析其空间结构特征.结果表明:王安沟100多年未经人为干扰的锐齿栎天然林和响潭沟皆伐迹地上经近40年封山后自然恢复的次生林均表现为异龄林的直径分布特征,但从q值来看,王安沟锐齿栎天然林直径分布较响潭沟次生林更加合理,白营西沟择伐林的直径分布虽然表现为小径木占的比重比较大,但各径阶间的变幅平缓,有明显人为干扰的痕迹;王安沟锐齿栎天然林和白营西沟次生林林木个体分布角尺度均值分别为0.489和0.487,林分内林木整体分布格局属随机分布,响潭沟次生林林分角尺度均值为0.520,其林木水平分布格局表现出轻微的团状分布,群落还处于演替的早期阶段;3个林分中王安沟锐齿栎天然林的树种隔离程度最高,响潭沟次之,白营西沟最低,混交度分别为0.598,0.542和0.451;白桦、华山松在不同的林分中所处的地位不同,从王安沟锐齿栎天然林、响潭沟次生林到白营西沟择伐林表现出大小比数依次降低的趋势,而锐齿栎、漆树等树种则在3个林分中所处的地位一致;人为干扰对白营西沟次生林的结构特征有明显的影响.     

天然林择伐经营技术的应用研究

按照森林可持续经营的原则，从天然林生态保护角度出发，以福建省永安市为例。利用森林分类经营方法对天然林经营进行科学分类，提出天然林因林因地实行合理的择伐方式是实现天然林可持续发展的有效途径，为天然林择伐经营的具体实施提供科学依据。     

检查法林分生长预测及择伐模拟研究

检查法是一种适合于异龄林经营的集约作业方法，由于目前试验时间还较短（第１择伐周期１９８７－１９９２年），需要对其长期经营效果作出预测。文中提出了一种修正参数预测模型（ＭＰＰＭ）和线性规划方法相结合对于林分进行生长预测和择伐模拟研究的方法。拟合林分直径分布采用了形状灵活的Ｗｅｉｂｕｌｌ分布形式，使得这种方法很适合于异龄林分（反Ｊ形直径分布）的生长预测（当然也适于同龄林），特别是当径阶株数出现突然变化     

天然林择伐作业技术探讨

本分析了天然林合理择伐的各个技术要素的选择与确定，这些技术要素包括择伐方式，择伐强度，择伐周期，应伐木与保留木，采集方式等，为天然林择伐的具体实施提供理论依据。     

择伐作业的研究

Ⅰ择伐作业的性质与结构本题是《关于森林作用的综合性利用与择伐作业的现代化研究》(1977～1978年日本文部省科研补助费)课题的组成部分。择伐作业是一种通过择伐达到更新为目的的作业法。因此,根据更新方式可分为天然更新     

择伐作业天然林林价问题的研究

对天然林进行择伐作业,是西北、西南高山林区森林经营的方向。处于长江、黄河上游森林水平和垂直分布边缘地带的森林,用皆伐方式进行森林采伐,对保持水土、涵养水源、国土保安和恢复森林植被,都是不适宜的。甘肃省洮河林区是一个开发了70多年的老林区,现在仍能青山常在,主要经验就是把择伐作为森林采伐的主要方式。因     

小陇山油松天然林结构特征

利用固定样地每木定位调查数据和相关分析统计软件,对小陇山林区油松天然林的结构特征进行了分析。结果表明:油松天然林树种组成丰富,群落中共出现18个树种,油松占绝对优势,但样地树种隔离程度较低,属于弱度混交。油松天然林的直径分布为多峰山状曲线,油松种群的直径分布近似于正态分布,可用3参数Weibull分布拟合;树高随胸径的增大而增加,胸径与树高的关系可运用幂函数进行拟合。林分中油松个体的胸径、树高和冠幅的大小分化差异明显,整体上表现为中庸状态;油松天然林林木分布格局为随机分布,油松种群分布格局也为随机分布。     

Diameter distribution of trees in natural stands managed on polycyclic cutting system

Diameter frequency distribution in a specific stand provides basic information for forest resources management.In this study,four probability models were applied to analyze diameter distribution of natural forests after selective cutting with different intensities (low intensity of 13.0% in volume,medium intensity of 29.1%,high intensity of 45.8%,and extra-high intensity of 67.1%).The results show that the skewness and kurtosis of the four models are positive except that of low intensity selective cutting,which suggest that the number of small-size trees dominate the stand.The more intensity of selective cutting,the wider range of diameter distributions.The diameter structure of selective cutting with low intensity met Weibull and Beta distributions;that of medium intensity met Weibull,negative exponential as well as Gamma distributions;that of high intensity cutting met Weibull and negative exponential distributions,but that of extra-high intensity could not meet any above model.Weibull distribution model fits better than others regarding the structure of diameter distribution in natural forests managed on polycyclic cutting system.The results will provide basic information for sustainable management for mixed natural stands managed on a polycyclic cutting system.     

不同间伐强度对阔叶混交林生长及径级结构的影响

通过对辽东山区阔叶混交林进行抚育间伐试验,结果表明:适度的抚育间伐可促进阔叶混交林林木胸径和蓄积生长,林分平均胸径和蓄积生长率随着间伐强度的增加先升高后降低,其中弱度间伐区林分平均胸径生长率最大,中度间伐区林分蓄积量生长率最大。间伐效果表现在伐后最初几年,随着时间的推移,林分平均胸径和蓄积生长率逐渐降低,各间伐区差异逐渐变小。随着间伐强度和林龄的增加,峰值向大径级位置偏移,分布范围明显地向大径级扩展。由不同间伐强度林分径级分布范围看,伐后4~21a,经过间伐的林分,径级分布峰值比对照区提高1~2径级。与对照区相比,各间伐区林分自然径级最大值、极差和直径离散度均有所增加,总体上表现出随着间伐强度和林龄增加而加大的趋势。综合考虑,中度间伐最有利于提高林分生产力,改善林分直径结构。     

Review of Studies on Structural Features,Regeneration Features and Management of Natural Spruce-Fir Mixed Stand of Coniferous and Broadleaved Trees in China

Natural spruce-fir mixed stand is one of the main forest types in the world,and also has huge ecological,economic and social benefits.According to the structural characteristics and succession laws of natural spruce-fir forest,it is urgent and significant to develop scientific management measures for natural spruce-fir mixed stand in line with local conditions.The article outlined the characteristics of the distribution and structure, regeneration and succession laws of natural spruce-fir forest,and analyzed the current situation and existing problems of natural spruce-fir forest management.The following recommendations were eventually made:1) In no cutting area,all logging activities should be banned.In a restricted cutting area,the cutting intensity should be generally controlled within 15%of the stock volume before cutting.On the commodity forest management area, the appropriate cutting intensity should be determined according to the volume per hectare,determine and classification management should be implemented in accordance with the characteristics of forest,to ensure the scientific selective cutting.2) Closure for afforestation,planting and repair planting should be adopted on vegetation-intensive land,sparse shrubs covered land and harvesting slash,in order to accelerate natural regeneration.3) The in situ conservation should be conducted in nature reserves and scientific experiment stations of rare and endangered species,such as Abies chensiensis,Picea neoveitchii,Abies vuanbaoshanensis,to reduce human destruction.4) It is supposed to collect seeds in time,establish nursery,actively establish forest, expand artificial population and promote natural regeneration.     

长白山森林的采伐更新方式

This paper discussed the characteristics of degenerated forest ecosystems in Changbai Mountain area,which include over-harvest natural forest,typical secondary forest,derived forest,and artificial forest.Forest cutting and regeneration methods that were historically used in the region were summarized.They lnclude diameter-class selective cutting,clearcutting,upbringing selective cutting,and selective sutting.We proposed cutting methods for the broad-leaved Korean pine mixed forest,spruce-fir forest,and larch forest.The measures for restoring the original mixed forest ecosystems were recommended.     

我国天然云冷杉针阔混交林结构特征、更新特点及经营管理

天然云冷杉林是世界主要森林类型之一, 具有重要的生态、经济和社会效益。探明天然云冷杉林结构特点和演替规律, 制定科学的经营管理措施, 因地制宜地合理经营云冷杉林意义深远而迫切。文中概述了我国天然云冷杉林的分布、结构和更新演替特征, 分析了经营管理现状及存在的问题, 并提出建议:1)对禁伐区内的云冷杉林分, 坚决杜绝一切采伐活动; 对限伐区要严格控制采伐强度, 一般控制在伐前蓄积量的15%以内; 对商品林经营区可按每公顷蓄积量的大小确定适宜采伐强度, 并按照林分特点进行经营, 做到科学择伐。2)对林地草本植被密集、灌木覆盖度不大、采伐迹地上有种源条件的进行封育、栽植或补植, 人工促进天然更新。3)建立秦岭冷杉、大果青杄、元宝山冷杉等珍稀濒危物种自然保护区和科学试验站, 积极开展就地保护, 减少人为破坏。4)适时采种, 就地建立苗圃, 开展育苗造林, 扩大人工种群, 促进天然更新。     

Impacts of forest management on liana diversity and community structure in a tropical forest in Ghana: implications for conservation

We studied the impacts of liana cutting as a forest management tool on liana diversity(species richness,Shannon diversity index) and community structure(diameter distribution, basal area, species dominance) in the Asenanyo Forest Reserve, Ghana. Two types of silviculturally treated forests were studied: Logging treated(LT)and Tropical Shelterwood System(TSS) treated forests. An untreated primary forest was included as a control, resulting in three forest management systems. Lianas with diameter C2 cm were identified in ten 40 9 40 m2 plots within each management system. Liana cutting significantly reduced liana species richness, Shannon diversity index, and basal area in the LT forest after two decades.However, liana species richness and basal area werecomparable in the TSS treated and untreated forests, indicating significant recovery in the former after over six decades. S?rensen similarity index of liana species composition between the untreated forest and each of the treated forests was moderate. Our findings suggest that liana cutting most likely influenced the dominance of some liana species. In view of the adverse impact of blanket liana cutting on liana diversity, selective liana cutting is recommended as a means of controlling liana numbers while maintaining liana diversity.     

湖北木林子自然保护区常绿落叶阔叶混交林干扰特征

常绿落叶阔叶混交林是木林子自然保护区的1种主要植被类型。在各种自然干扰和人为干扰的协同作用下,形成了木林子常绿落叶阔叶混交林特有的干扰体系。在常绿落叶阔叶混交林的保护和经营中,要利用封山育林、森林抚育、合理择伐和人工促进天然更新等增益性人工干扰,坚决阻止过渡的森林采伐和毁林开荒等破坏性人工干扰。应参照以自然林窗干扰,采用择伐方式经营常绿落叶阔叶混交林。     

Selective harvesting at rational intervals promotes carbon sequestration in temperate coniferous and broad-leaved mixed forests in China

Evidence-based selective cutting at prescribed intervals as part of good forest management can enhance the carbon sequestration capacity of the forest. The effect of forest management on carbon sequestration has, however,not been quantified. Thus, carbon content of various organs was measured for 323 tree species, 247 shrub species, and233 herb species in seven temperate coniferous and broadleaved mixed forests that were subjected to selective cutting with restoration durations of 100, 55, 45, 36, 25, 14, and6 years to explore dynamic changes in carbon storage. The results showed that biomass carbon allocation in different organs followed a pattern: trunk root branch leaf for all forests. With longer restoration durations, more carbon accumulated in different organs and in soils. Interestingly,when the restoration duration exceeded 50 years, carbon storage in ecosystem was larger than that in primary forests with 100-year cutting intervals, suggesting that a reasonable selective cutting interval can increase forest carbon sequestration. Mean diameter at breast height(DBH) and forest carbon storage were significantly positively correlated, and carbon storage of selectively cut forests exceeded that of primary forests when the stand mean DBH exceeded 15.66 cm. Therefore, mean DBH of forests can be an indicator for combining sustainable forest management and forest carbon sequestration. Additionally, the classic coefficients of 0.45 and 0.50 used to estimate carbon sequestration underestimated values by 2.65% and overestimated by 8.16%, respectively, in comparison with the measured carbon content from different plant organs.     

天然沙棘林复壮改造技术

笔者运用完全平茬复壮、截干平茬复壮、择伐复壮、疏伐复壮、嫁接改造及综合改造等方法对山西省杨树局油坊中心林场的天然沙棘进行了探索性改造研究。研究发现,各种方法均有优劣,以综合改造方法为佳。改造后应加强除藥、定株、整形修剪等管理。