木材采运生产技术发展重点初探

木材采运生产技术由简单的手工作业,发展到半机碱化、机械化的阶段,无一不是木材生产和技术发展相互促进、相互制约的结果。目前,木材采运产业和产品结构已做了重大调整,木材产量也进行了战略调减,这一变化了的形势对采运生产技术发展产生了深刻的影响。以森林资源为主要作业对象的采运生产技术,会随着成过熟林资源的减少以及木材产量的逐年调减而发展缓慢,甚至停滞不前。因此,适应和扭转这种局面,使采运生产技术在新的形势下发挥其促进国     

对我国木材采运机械化道路的探讨

一、我国木材采运工业现状建国三十多年来我国木材采运工业有了很大发展。木材生产条件有显著改变。经过三十多年开发建设,木材生产已从手工作业向机械化过渡,木材采运机械化比重逐年提高。国有林采运的主要工序基本实现了机械化。据1980年统计,全国木材采运综合机械化程度为87.71％。目前可自行研究制造专用的采运机械及其各种配     

中芬采运技术比较与经济分析

本对中芬的木材生产工艺流程、经营方案，生产劳动组织以及不同采运方式做了技术和经济分析。     

山地木材采运生产技术发展重点探讨

探讨了山地丘陵地区的木材采运技术，尤其是集材设备的选择，可为今后的山地木材采运生产提供参考。     

《朗乡林业局木材采运生产技术发展研究》课题通过评审

《朗乡林业局木材采运生产技术发展方向研究》课题是黑龙江省林业科学院情报中心和朗乡林业局针对朗乡局的具体情况,为制定今后木材采运生产技术发展规划而共同研究的课题。黑龙江省森工总局科技处于1989年10月组织有关专家对该课题进行了全面的评审工作。专家们认为,该课题采用《科技计量模型》来评价采运企业总体技术水平的作法是新颖的,具有一定的学术性、实用性和先进性。对     

俄罗斯木材采运工业近况

俄罗斯木材采运工业近况随着俄国政治体制的变更和经济体制的变化，俄罗斯的木材采运工业也出现了许多新情况、新问题。最近，俄国采运专家著文介绍了一些情况，择其主要点介绍如下：１关于“世界林业大国”的不同看法前苏联在木材采运和锯材生产上都曾占居重要地位，被看...     

扩大经济效益提高木材采运作业水平

木材采运是收获森林主产品——木材的作业.因森林是可再生资源,所以在收获木材的同时,就要为森林更新及木材综合利用创造有利条件.因此,提高木材采运作业技术水平,是使森林经营走向合理化、集约化及重点发展木材综合利用的中心环节.对此,绝不应由于批判过去单一木材生产或大木头挂帅而削弱木材采运作业技术水平的提     

木材采运安全生产问题

木材采运是在露天、分散、大面积的环境条件下,用一定的机械和工具改变立木形态和木材位置移动的作业,因之十分笨重和危险.据调查,在黑龙江省1986年森工生产(包括木材加工和基本建设)全部工伤死亡人数中,木材采运占75.5%,发生在27个林业局,占40个林业局的67.5%。在这些事故中,没有一起是不可抗拒的天灾,没有一起是不可避免的人祸,因此,如何减少伤亡事故仍是今后木材采运作业中的首要任务。黑龙江省40个林业局的森工生产1984～1986年三     

基于GPS技术的木材采运系统设计

设计了一种基于GPS技术的木材采运系统,并给出了系统总体设计框图.设计了用于木材采运系统的GPS定位接收机,通过AT89C51单片机的控制作用,将定位点的三维信息和测量数据通过液晶显示器显示出来.     

21世纪(初)吉林省森工系统森林资源发展趋势

详细介绍了系统动力学的原理和方法。从森林资源结构和功能的机制出发,针对吉林省森工系统的更新造林、抚育间伐、木材生产等有关问题,采用了多种方案,构造了该系统的S·D模型,对该系统的森林资源消长规律、木材生产的发展趋势和规模进行了仿真实验,从中选择了一个切实可行的方案加以论述。     

遥感数据参数反演估计南京紫金山缺失小班蓄积量方法研究

如何对早期小班调查蓄积量缺失的数据进行修补,是进行森林资源动态分析急需解决的一个问题.以南京紫金山1988年森林经理调查数据和同期TM遥感数据为信息源,利用遥感生物参数反演技术,根据已知小班的光谱特征和蓄积量之间的相关关系,在建立蓄积量生物参数反演经验模型的基础上,对缺失小班蓄积量进行修补.研究表明:通过遥感数据生物参数反演进行缺失小班蓄积量数据修补的方法得到的小班蓄积量数据可靠性比较高,这种方法在森林资源调查和规划实践中具有较大的应用价值.     

Impact of Community Forest Management on Biomass Carbon Stocks in the Uatumã Sustainable Development Reserve,Amazonas, Brazil

Forest management can result in net losses of carbon stock. To quantify the impact of the management it is important to assess losses or gains of carbon, as well as the sustainability of the management system. This study quantified the impact management under a Small-Scale Sustainable Forest Management Plan, which is a recently created category of authorized management for small managers in the state of Amazonas, Brazil. Impact was quantified on the number of individuals, the biomass of natural regeneration, and the damage to the remaining trees 2 months after logging. The impact of these changes on carbon stock was estimated. The study was carried out in the Uatumã Sustainable Development Reserve, Amazonas, Brazil, where two areas of small-scale forest management and one control were evaluated. Average total carbon stock previous to logging was estimated at 161.25 ± 9.66 MgC ha^?1. Two months after logging, reductions were found of 3% in one managed area (MA1) and 8.3% in the other (MA3), including the carbon stock from the harvested timber. For each harvested tree, the logging caused damage to 12 trees in MA1 and four trees in MA3. The reductions in carbon stock and number of trees damaged per harvested tree were less than the reductions found for higher impact forest management and other experiences in community forest management. No significant alteration was found in the carbon stock of natural regeneration. However, there was an increase in the number of individuals, both in the logged areas and in their respective control areas.     

烧结余热双压发电系统动态特性研究

分析了双压余热锅炉的换热特性和结构特性,建立传热过程的数学物理模型,以此为依据,建立了动态参数优化模型,对系统的热端温差、窄点温差和接近点温差进行了动态优化,利用该模型,求得使系统达到最佳配置性能的热力参数匹配方式。研究结果为余热锅炉的优化设计和控制系统的设计提供了理论依据。     

青海云杉抚育前后林分生长和蓄积变化数学模型的建立

在对祁连山西营河及哈溪两个试验区不同类型青海云杉林抚育前后林分部分生和茵子和蓄积量变化规律的研究中，以５种单因变量回归曲线对抚育前后两类型青海云杉林的单株胸径定期平均生长量，单株材积定期平均生长量以及林分蓄积量按径阶变化的规律分别进行模拟，以相关系数和离散系数两参数结合进行选优，最选选定一种模拟效果最佳的模型为最后模型。     

云南省集体人工商品林采伐管理改革思考

随着集体林权制度改革的不断深入，传统的林木采伐管理制度已越来越不能适应现代林业发展的需要，必须进一步优化限额管理机制，逐步建立与集体林权制度改革相配套、与发展现代林业相适应的林木采伐管理机制。针对现行集体人工商品林在采伐限额管理、采伐指标分配、采伐申请审批等方面存在的一些问题，提出实行森林采伐分类管理，推行伐区资格审查制度和伐区简易设计等对策与建议。     

应用GM（1，1）包络灰平面对林木年采伐限额的控制

赤峰市松山区现有林木年蓄积量虽然呈增加趋势，但由于各种因素的影响，使全区林木年蓄积增加量变化幅度较大，为合理采伐利用林木资源，本文根据全区林木年蓄积增长量原始数据列，建立GM（1，1）包络灰平面，并按GM模型建模机理，用微分自吹自擂心合原始数据，求得预测曲线，使预测值落在某一范围内，为确定最佳年采伐限额提供了科学依据。     

林区道路网系统动态模型的研究

本文运用系统动力学原理,建立了林区道路网系统的动态模型,并以某林业局真实系统为背景,对该模型进行了仿真实验。结果表明,所建模型正确有效,能为制定林道网建设计划及其与林业生产协调发展的规划,提供决策的理论依据。     

A Model for comparing reduced impact logging with conventional logging for an Eastern Amazonian Forest

Using data from a logging experiment in the eastern Brazilian Amazon region, we develop a matrix growth and yield model that captures the dynamic effects of harvest system choice on forest structure and composition. Multinomial logistic regression is used to estimate the growth transition parameters for a 10-year time step, while a Poisson regression model is used to estimate recruitment parameters. The model is designed to be easily integrated with an economic model of decisionmaking to perform tropical forest policy analysis. The model is used to compare the long-run structure and composition of a stand arising from the choice of implementing either conventional logging techniques or more carefully planned and executed reduced-impact logging (RIL) techniques, contrasted against a baseline projection of an unlogged forest. Results from “log and leave” scenarios show that a stand logged according to Brazilian management requirements will require well over 120 years to recover its initial commercial volume, regardless of logging technique employed. Implementing RIL, however, accelerates this recovery. Scenarios imposing a 40-year cutting cycle raise the possibility of sustainable harvest volumes, although at significantly lower levels than is implied by current regulations. Meeting current Brazilian forest policy goals may require an increase in the planned total area of permanent production forest or the widespread adoption of silvicultural practices that increase stand recovery and volume accumulation rates after RIL harvests.     

森林采运系统协调发展模型及其应用

应用灰色系统理论,建立了森林采运系统协调发展的动态模型。并用这一模型,对某森林采运企业的自然发展势态和某些因素间的定量关系作了具体分析。结果表明,这种方法是有效的,严密的,具有较高的精度,能为经营决策者提供系统协调发展的大量有用信息。对森林采运系统实现管理决策的科学化,具有一定的现实意义。     

Do logging,followed by burning,and wildfire differ in their decadal scale effects on tall open-forest bryophytes and vascular plants?

There has been only one time-controlled study, in Canada, comparing the occurrence of bryophyte species in forests regenerating after wildfire with that in those regenerating after logging and regeneration burning. Previous work on vascular plants in Tasmanian tall open-forest dominated by Eucalyptus showed that filmy ferns were less common in areas that had been logged and regeneration burned than in areas burned by wildfire two decades after the events, which suggested that hygrophilous species, such as bryophytes, might be vulnerable to this silvicultural system. Bryophytes, vascular plants structural and environmental data were collected from 50 sites, which had been burned in wildfires or clearfelled and burned by prescribed fires 31–39 years previously. Eighteen percent of the vascular plant species for which it was possible to develop a multiple regression model had logging/wildfire as a component, whereas the equivalent figure for bryophytes was 17%. The negative effects of logging were concentrated on the more hygrophilous species, and the positive effects were concentrated on the basal area of tree species and some of the mosses dependent on them. We conclude that wildfire and logging followed by regeneration burning result in vegetation differences that last more than three decades after disturbance, that these differences are no more pronounced for bryophytes than for vascular plants, and that hygrophilous taxa are favoured more by wildfire than logging.