黑龙江省森林采伐方式与森林生态系统稳定性探讨

采伐是人为影响森林生态系统的一种重要方式,对森林景观和森林的生态结构影响具大。过去的采伐方式大多以皆伐为主,严重地破坏了森林生态系统的稳定性,也破坏了原有的森林景观,使森林的生态效益大大降低;目前采用的择伐方式,由于忽略了森林生态的保护,更没有进行科学地采伐论证,所以对森林生态系统也具有较大的破坏。综述了生态采伐的必要性,探讨了生态采伐和森林生态系统稳定性维持的关系,对森林采运理论的研究和森林生态系统的保护具有一定的参考价值。     

大兴安岭林区森林采伐方式的探讨

根据大兴安岭东部林区森林资源现状及存在的问题,结合森林分类经营区划和林业发展区划,本文提出了该林区在森林资源调整恢复阶段,应以抚育采伐为主,实现优化森林资源结构的目的。     

基于减少对环境影响的采伐方式的森林采伐作业规程进展

介绍了国际上基于减少对环境影响的采伐理念的区域级或国家级的森林采伐作业规程, 包括: 斐济的??森林采伐作业规程 、联合国粮农组织的??标准森林采运方法规范 、亚太林业委员会的??亚太区域森林采伐作业规程 和中国的??森林采伐作业规程 。这些规程以生态优先、以人为本、注重效率为基本原则, 目的是通过技术的改进, 严格控制森林的过度消耗, 减少采伐活动对森林及其环境的负面影响, 提高劳动效率和木材的利用率, 处理好经济、生态和社会的平衡, 促进森林可持续发展。文章最后针对我国森林采伐规程实施中存在的问题, 提出了分类制定不同区域的森林采伐作业规程, 加强科学研究工作, 提供技术支撑和理论依据及建立有效的监测和监督体系的建议。     

森林采伐与作业迹地森林景观

本文着重从森林景观角度出发,探讨了不同森林采伐模式对作业迹地森林景观的影响。在实地调查的基础上。采用定性定量相结合的方法对作业地的森林景观进行了评价。提出了一套评价标准。初步研究结果表明,楔形采伐为一种既维持生态景观又兼顾木材生产的采伐方式,且对森林景观具有较积极的影响。     

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.     

森林采伐限额编制与实施若干问题的探讨

森林限额采伐制度是国家对林业进行宏观调控的重要手段。文章介绍现行森林采伐限额的编制方法,并对现行编制方法中的若干问题提出不同的见解,并就森林采伐限额的实施进行探讨。     

森林采伐限额管理中存在的问题与对策

通过对华东监测区某省８个县森林采伐限额执行情况的调查，对限额管理中存在的超证采伐、无证采伐等问题进行分析，指出存在问题的原因，提出对策与建议。     

加格达奇林业局森林经营中采伐方式的探讨

加格达奇林业局根据本局森林资源状况,在2001年停止了木材主伐生产,森林经营由以木材生产为主,向以发挥森林生态功能为主的方向转变。本文通过分析该局森林资源现状、管理方式的变迁、经营思路的转变,以提高森林资源质量,改变林分结构,恢复原有植被群落为方向,探讨了森林经营中的采伐方式,以实现森林资源的稳定增长和可持续发展的目标。     

现代森林采伐方式的探讨

本文对森林采伐的历史进行了回顾,提出采伐方式的选定要弄清条件。因地制宜地选用采伐方式     

浅议采伐对环境的影响

本文详细论述了采伐量和采伐方式对森林生态环境的影响,强调选择合理的采伐量和采伐方式对维护生态平衔的重要性,提醒人们强化生态意识,以防大自然对人类的再次惩罚。     

谈“生态平衡”作为宏观理论指导森林采伐实践时存在的问题

本文阐述了生态平衡的概念.把它做为宏观理论指导森林采伐时要注意不能片面地强调生态系统的维持.而忽视人类采伐利用森林为人类造福的必然性;恢复和维护生态平衡不能脱离森林采伐利用的价值.同时说明了忽视生态变化发展在时间和空间上的不可逆性和随机性.     

Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow plus salvage logging as to wind disturbance alone, by most vegetative measures.     

A conceptual model to characterize disturbance severity in forest harvests

I present a three-dimensional disturbance severity model and illustrate the potential usefulness of the model for characterizing disturbance conditions caused by forest harvesting. Disturbance is most often described in terms of disturbance type, size and frequency, with less emphasis on severity. In addition, studies of disturbance impacts have emphasized the dominant tree and woody understory layers, overlooking the species-rich herbaceous layer. For a wide range of harvesting treatments (clearcutting to selection systems with and without site preparation), I characterized disturbance severity based on hypothesized patterns of canopy removal, understory vegetation removal and forest floor and soil modification. To illustrate the application of the model, I plotted the data from three studies in North American coniferous and mixed coniferous–deciduous forests in the three-dimensional diagram of disturbance severity, using actual measures of the degree of disturbance on each axis or estimates inferred from other related variables. The plotted points showed general agreement with the hypothesized ranges of disturbance severity for the treatments represented in these studies. The three axes of disturbance severity can be affected differently depending on disturbance type, emphasizing the importance of characterizing the degree of disturbance on each of these three axes. Short-term responses of the herbaceous layer are strongly influenced by disturbance severity on each of these three axes. Disturbance conditions must be quantified before vegetation indicators of these conditions can be identified. The conceptual model provides a framework for comparing forest harvesting treatments to natural disturbance events. These comparisons are critical to designing ecologically sustainable forest management strategies.     

Impacts of selective logging on above-ground forest biomass in the Monts de Cristal in Gabon

Selective logging is an important socio-economic activity in the Congo Basin but one with associated environmental costs, some of which are avoidable through the use of reduced-impact logging (RIL) practices. With increased global concerns about biodiversity losses and emissions of carbon from forest in the region, more information is needed about the effects of logging on forest structure, composition, and carbon balance. We assessed the consequences of low-intensity RIL on above-ground biomass and tree species richness in a 50 ha area in northwestern Gabon. We assessed logging impacts principally in 10 randomly located 1-ha plots in which all trees ?10 cm dbh were measured, identified to species, marked, and tagged prior to harvesting. After logging, damage to these trees was recorded as being due to felling or skidding (i.e., log yarding) and skid trails were mapped in the entire 50-ha study area. Allometric equations based on tree diameter and wood density were used to transform tree diameter into biomass.Logging was light with only 0.82 trees (8.11 m³) per hectare extracted. For each tree felled, an average of 11 trees ?10 cm dbh suffered crown, bole, or root damage. Skid trails covered 2.8% of the soil surface and skidding logs to the roadside caused damage to an average of 15.6 trees ?10 cm dbh per hectare. No effect of logging was observed on tree species richness and pre-logging above-ground forest biomass (420.4 Mg ha⁻¹) declined by only 8.1% (34.2 Mg ha⁻¹). We conclude from these data that with harvest planning, worker training in RIL techniques, and low logging intensities, substantial carbon stocks and tree species richness were retained in this selectively logged forest in Gabon.     

保证山场合理造材的有效措施

保证山场合理造材的有效措施是：林业局要建立一支强有力的检量员队伍，由林业局检验站统一管理，并建立一套相适宜的制约激励机制，才能消除长材短造、优材劣造、坏材带好材和超长短尺等不合理现象。     

“天保”工程实施后森林采伐的探讨

国家实施天然林保护工程,作为森工企业存在不同程度的采伐。“天保”实施后,如何执行森林采伐。本文作者以方正林业局为例,谈了自己的见解。     

Bird use of logging gaps in a subtropical mountain forest: The influence of habitat structure and resource abundance in the Yungas of Argentina

Selective logging is one of the main economical activities in tropical and subtropical forests. While most of the effects of this activity on bird communities have been studied by comparing exploited vs. non-exploited areas; the use of human-created treefall gaps by birds is relatively unknown. We studied habitat structure, resource abundance (fruits, flowers and arthropods) and bird activity in logging gaps of different age (1-year-old and 10- to 20-year-old) in a mountain forest (Yungas) of northwest Argentina in both dry and wet seasons. In less than a year after creation, short herbs colonize logging gaps increasing the abundance of arthropods in the ground and the activity of understory insectivores. During dry seasons recently created gaps become an important source of resources for understory frugivores-insectivores. Later on in succession logging gaps are invaded by exotic graminoid vegetation and tall herbs (dispersed through extraction tracks) which can impede the colonization and development of pioneer trees and natural regeneration. Probably as a consequence of a high abundance of fruits and flowers in the understory and a very low abundance of these resources in the canopy, old gaps were mainly used by understory frugivores-insectivores while arboreal frugivores were rare. Because arboreal frugivores disperse most tree seeds in tropical and subtropical forests, the low activity of this guild in logging gaps contribute to the low observed regeneration. Sustainable timber harvest in tropical and subtropical forests should include gap and logging track management to minimize the invasion by exotic graminoid vegetation and facilitate natural succession.     

Ant community responses to experimental fire and logging in a eucalypt forest of south-eastern Australia

Sustainable forest management requires a sound understanding of the impacts of forestry management practices, especially prescribed fire and timber harvesting, on biodiversity. Many studies have examined the impacts of fire and logging separately, but few have considered them together. Here we describe the combined effects of selective logging and repeated prescribed fire on ants in eucalypt forest near Eden in south-eastern Australia. The study was conducted within 18 experimental coupes comprising three replicates of each of six treatments, representing combinations of two logging (selectively logged and unlogged) and three prescribed burning (unburnt, routine and high fire frequency over 20 years) practices. Ants were sampled using terrestrial and arboreal pitfall traps in two plots within each of the 18 coupes. A total of 92 species from 35 genera were recorded, with ant species richness increasing with both increasing fire frequency and selective harvesting. We also found significant differences in ant species composition between management treatments; however, these differences were rather modest, and apparent only between extremes of fire and harvesting combinations. Logging on its own was not a significant factor contributing to variation in ant species composition. However, the responses of two common species and a key functional group to fire depended on logging treatment; in each case their abundance decreased with increasing fire frequency at unlogged sites, but increased at logged sites. The general resilience of ant communities suggests that forests remain in good functional health even when subject to a combination of selective logging and frequent burning. However, our study under-sampled species with specialist microhabitat requirements, and these might have been more heavily impacted. We have also revealed some significant interactions between the effects of fire and logging, which highlights the importance of considering combined impacts of forest management practices.     

经济转型期国有林业采育场的发展对策

根据福建省国有林业采育场的现状,分析了目前国有林业采育场所处的发展时期以及造成国有林业采育场陷入“两危”(资源危机和经济危圉)的原因。阐述了采育场发展产业经济的必要性。并在此基础上对企业的发展提出几点对策。