关于当前伐区集材的几点意见

伐区集材是伐区工艺设计中不可缺少的内容、是影响生产效率和生产成本的一个重要因素.当前,由于林业资源不断减少,伐区分散,作业面积缩小.导致伐区集材与以往相比有了很大变化.就这些变化.根据方正林业局的生产现状和经验.对伐区集材提几点意见.     

国内外伐区集材现状与发展趋势

国外,目前正在改进伐区集材传统工序。国内由于伐区自然条件的不同,森林所有制的不同,因此,伐区集材方式、机械化程度也相差很大。国外伐区集材总的发展趋势是:朝着取消辅助工种的手工劳动方向发展;山地索道集材向移动式钢架杆集材索道方向发展。我国伐区集材由于自然条件和所有制的千差万别,势必要在相当一段时间内形成机械化、半机械化、手工作业并存的多层次结构。为适应我国伐区生产向”高、散、远”方向发展和非皆伐比重加大的趋势,伐区集材将采用各种适用技术,以满足生态和经济效益的要求。     

低强度择伐伐区集材方式的探讨

这篇文章探讨了低强度择伐伐区集材方式，分析了各种集材方式的优缺点，讨论了新的集材工艺和集材方式。新的集材工艺和集材方式是：由轻型绞盘机或小型拖拉机或畜力将原木或原条运到集材道两侧，完成小集中作业；再由拖拉机或索道或畜力将这些原木或原条运到伐区楞场，完成集材作业。     

发挥集材机械在山地伐区的作用与效率探讨

对现有的J50系列集材机通过加装起重架,在牵引钢绳的头部设计一个北方雪橇形状的工具铁撬、加装绞盘卷筒等对其进行改装,使其成为适应山地林区作业的集材机械,达到一机多用,从而降低购置设备的成本。     

伐区采育作业系统综合效益评价的研究

在定量计算各伐区采育作业模式的经济效益指标和定位测定由这些作业模式所造成的土壤肥力、迹地更新效果和蓄水保土等指标变化量的基础上，采用多目标决策和层次分析等方法，定量计算各伐区采育作业模式的综合效益（经济效益和生态效益），改变单纯以经济效益为唯一目标确定伐区工艺方案的传统方法。计算结果表明，“４０％择伐－原木人力集材－归带处理采作伐剩余物－人工促进天然更新”这一作业模式是马尾松天然次生林伐区作业的优     

下陡上平伐区联机作业工艺

采用辅助作业道解决下陡上平伐区的集材,实践证明是一种充分利用机械设备的性能,又比较经济合理的方式。本文详细总结叙述这种特殊地形的集材工艺。     

自行式缆索起重集材机集材作业工艺研究

基于从欧洲最新引进的自行式缆索起重集材机(KOLLER-K303H)及集材作业技术,"陡坡山地森林择伐作业技术及其设备引进"项目组对森林采运的缆索集材作业工艺进行了研究,旨在为提高森林集材作业的效率、降低成本,减轻集材作业过程对森林生态系统的破坏,并消化吸收和完善所引进的集材作业技术,为其推广应用做准备。根据引进设备的机构功能特点,本研究详叙了"塔架上置式"和"塔架下置式"集材作业工艺技术,及探讨了"正反坡同步集材"和"超范围集材"的集材技术。伐区实地的集材试验结果表明:本研究所探讨的集材作业工艺效率高,能较好地适应中国南方林区复杂地形集材作业的需要。     

森林可持续发展与伐区作业技术

本文通过伐区作业对森林生态产生影响的经验与教训.特别是教训.提出了使森林可持续发展的伐区作业技术,在此基础上.提出了在今后的伐区作业中应注意的几点建议。     

浅谈伐区造材与市场营销关系

本文简述了伐区造材与市场营销的关系,提出建立企业模拟市场。造出适销对路的木材的建议并对模拟市场的运作及保证措施做了具体的说明。     

关于季节生产与常年作业适宜比例的探讨

本文通过对季节生产与常年作业的优缺点及其影响因素的分析,提出了生产作业的适宜比例,从而提高木材生产的整体经济效益。     

森林采伐方式对伐后迹地光照条件及更新质量的影响

本文应用野外观测方法,对森林采伐方式（皆伐、择伐、带状皆伐）对迹地光照条件和作业后天然更新质量进行了局部性研究。结果表明,更新树种不仅与种源有关,而且还与光照条件显著相关,即与森林采伐方式有关。     

Short-term effects of retention felling at mire sites on boreal spiders and carabid beetles

Green-tree retention is an integral part of forest management in the boreal zone. Retention of small spruce mires, proposed as ‘key habitats’ for many forest organisms, is recommended while logging, but the efficiency of such practices for the maintenance of forest species is poorly understood. Hence, we studied boreal spiders and carabid beetles at 11 retained mire patches (up to 0.55 ha) in Eastern Finland during 1998–2001. The adjacent surrounding drier forests of the focal mires were clear-cut during the winter of 1998/1999. We evaluated the importance of micro-habitat type (retention, edge or clear-cut plot), time since logging, and retention-patch size in determining the assemblages of spiders and carabids. Following logging, species associated with forests and mires generally decreased both in the retained mire patches and in their adjacent clear-cuts. In a GLMM, the number of standing trees in a retention patch – a surrogate for retention-patch size – had no significant effect on most of the tested species, but plot type (retention patch, its edge or clear-cut) was significant for many species. Semi-open-habitat species and open-habitat specialists increased following logging, especially in the clear-cut plots but even within the retention patches. In contrast, mature-forest and moist-habitat specialists became significantly less abundant in clear-cuts than in retention patches following logging. Spider assemblages showed pre-harvest differences among the mires, their edges and adjacent drier forests, but the fauna of logged plots rapidly diverged from that of mire and edge plots. However, after a 1–2 summers time lag, the spider fauna of mires and edges changed toward clear-cuts. For spiders, the post-harvest sample heterogeneity was significantly lower in clear-cuts than in retention patches, including their edges. Carabid responses were generally ambiguous. Multivariate regression trees showed that the number of trees in a forest patch better determined the spider assemblage structure than study area, study year or micro-site type (retention patch, its edge or clear-cut), indicating a strong impact of logging. For carabids, however, the study area better determined the assemblage structure; the other factors were of minor importance. Our results suggest that, as the spider and carabid faunas of the retention patches had drastically changed following logging, (i) retention patches should be considerably larger than the studied size range to efficiently maintain a ‘mire core’ spider and carabid assemblage; (ii) the effect of logging may take years to appear; (iii) spiders were more sensitive to habitat change than carabids; and (iv) harvesting not only changes the relative abundances of forest- and open-habitat associated species but it may also locally decrease the faunal variation.     

Seasonal variation in classification accuracy of forest-cover types examined by a single band or band combinations

In vegetation remote sensing, classification accuracy cannot be fixed, due to seasonal variations in spectral reflectance characteristics. This study aims to clarify the seasonal variability of classification accuracy by forest-cover type. In particular, this paper describes seasonal variability by each band or band combinations. The study area is located in the vicinities of Hisayama and Sasaguri in Fukuoka Prefecture, Japan. Natural broadleaved, coniferous plantation, and bamboo forests were studied. Supervised classification was applied to six SPOT/HRV images taken in 1997. Kappa analysis was applied to assess the classification accuracy and compare any two error matrices. The results revealed that some single band or two-band combinations were as accurate as, or more accurate than, the full band (all three bands). The disadvantages of using a full band were especially apparent in the season with high classification accuracy. This study indicates that using all given bands does not necessarily result in the highest classification accuracy. This study also suggests that band selection within the scope of forest type and seasonal variability can contribute to better forest-cover-type classifications.     

漳州林业生产经营体系建设的研究

本讨论的漳州市林业生产经营体系的建设模式，可为非传统林区的林业建设提供参考。     

鸡爪槭园艺品种分类及栽培研究综述

该文概述了国内外鸡爪槭品种资源、园艺品种分类以及栽培管理等方面的研究进展,并提出了促进我国鸡爪槭品种的园林绿化栽培应用和种质创新的建议。     

Effects of selection felling and gap felling on forest arthropod communities: a case study in a spruce-beech stand of southern Bavaria

The effects of selection felling and gap felling on arthropod communities were studied over 3 years in a spruce-beech stand in southern Bavaria, Germany. The arthropods were sampled in three strata, using pitfall traps on the forest floor as well as flight-interception traps near the forest floor and in the tree crowns. Coleoptera, Araneae, Opiliones, Heteroptera, Isopoda, Diplopoda and Neuropterida were determined to species level and assigned to ecological guilds. In general, the effects of both treatments on arthropod communities were small. An increase of eurytopic species and species of open woodland as well as of indwellers of deadwood was observed, mainly in the first year after felling. However, forest species dominated the communities in all plots, strata and years. In contrast to selection fellings, gap fellings might favour potential pest species. Nevertheless, in the studied managed spruce-dominated forest site out of the natural growth range of spruce, negative ecological effects such as the repression of forest arthropod species are not expected by small scale fellings.     

不同立地、土壤类型对土壤含水量和苹果新梢生长的影响

为了给苹果园土壤水分管理提供依据,以‘长富2’苹果为试材,选取粘壤土平地、粘壤土梯田、壤土平地、壤土梯田、沙土平地、沙土梯田、上层壤土、下层尾矿砂平地7种不同立地、土壤类型苹果园,研究其对土壤含水量及苹果新梢生长的影响。结果表明:不同时期粘壤土平地的土壤含水量均极显著高于沙土平地、沙土梯田、上层壤土下层尾矿砂平地的土壤含水量,沙土平地、沙土梯田的土壤含水量均极显著低于其他立地、土壤类型。各立地、土壤类型长、中、短新梢均只有一次生长,迅速生长期基本一致,在4月初到5月底;除沙土平地和沙土梯田类型外,其他5种立地、土壤类型徒长新梢均出现了二次生长,第1次迅速生长期与其他新梢一致,第2次生长期在7月至8月。不同立地、土壤类型土壤含水量与苹果各类新梢长度均呈正相关,达到显著相关水平的时期多出现在新梢生长高峰期,其中,4月22日至5月13日,壤土梯田、沙土平地的土壤含水量与长梢长度的相关系数分别为0.968、0.966,5月14日至5月31日,壤土梯田的土壤含水量与徒长新梢长度的相关系数为0.986,壤土平地的土壤含水量与长梢长度的相关系数为0.980。     

中德财政合作湖南小农户造林项目森林可持续经营操作方法

主要从规划设计、目标树选择、林木采伐利用、林区道路建设、技术措施、现场标记等方面介绍了中德财政合作湖南小农户造林项目森林可持续经营的操作方法、技术标准和要求、以及在实际工作中应该注意的事项,以便为基层林业技术人员在实际工作中提供参考。