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集材作业是伐区木材生产的重要工序，集材成本约占伐区木材生产总成本的２／３左右．集材方式的选择对集材任务完成的好坏、提高效率、降低生产成本至关重要．目前，由于“天保工程”的实施，可采森林资源逐渐减少，承包经营的发展，使畜力原木集材方式转变为重要的集材方式．山河电林业局于１９８５年后全部采取伐区造材、畜力原木集材作业方式。现结合多年的生产实践，对畜力原木集材的特点、措施、发展方向探讨如下：ｌ畜力集材的特点 畜力集村适用于伐区坡度大、森林资源分散、公顷出材量小、集材距离长的林相。畜力集材具有机动灵活；… 相似文献
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据国内外调查研究表明:拖拉机集材对作业区面积的破坏为5-12.54%;对幼树的损伤率为13-50%;集材后使土壤容重提高20%,大孔隙减少40%、对水份的渗透速率降低47%.为减少拖拉机集材对林地破坏和对幼树的损伤及有利森林更新,应采取如下措施:(一)拖拉机集材应安排在冬季进行;(二)在择伐伐区,拖拉机原条集材应不离道,绞集单根抽;或拖拉机原木集材,集材道间距加宽到100M,以畜力或人力将原木小集中到集材道旁;(三)在皆伐伐区,拖拉机集材也应尽可能保护幼树和保留一定株数母树;(四)采用特宽低压轮胎轮式集材机集材. 相似文献
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据国内外调配研究表明：拖拉机集材对作业区面积的破坏为５－１２．５４％；对幼树的损伤率为１３．５０％；集材后使土壤容重提高２０％，大孔隙减少４０％，对水份的渗透速率降低４７％。为减少拖拉机集材对林地破坏和对幼树的损伤及有利森林更新，应采取如下措施：（一）拖拉机集材应安排在冬季进行；（二）在择伐伐区，拖拉机原条集材应不离道，集单根抽；或拖拉机集材，集材道间距加宽到１００Ｍ，以畜力或人力将原木小集中到集 相似文献
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亚布力林业局适宜集材方式的探讨 总被引：1，自引：0，他引：1
本文根据几种集材方式的特点,结合亚布力林区的实际情况,对目前亚布力林业局适宜的集材方式进行了探讨。通过比较论证,认为畜力原木集材是目前亚布力林区适宜的集材方式。今后集材方式的改革应是机畜结合,以畜力原木集材为主,机械原条集材为辅。 相似文献
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目前我国伐区使用的专用集材拖拉机都属于绳索式集材拖拉机,它们利用缠卷着钢丝绳的绞盘机和搭载装置达到收集原条(或原木)的目的.由于恶劣的现场条件和尺寸、形状各异的原条(或条木),集材拖拉机进行绞集作业时,钢丝绳的牵引阻力变化幅度很大,如使用不当,钢丝绳的损坏就会比较严重.正确使用集材拖拉机,能够减少钢丝绳耗损,降低木材生产成本. 相似文献
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周桂新 《林业机械与木工设备》1993,(6):31-32
JJX_1—2.5轻型自行式绞盘机。体积小、牵引力大、通过性能好、机动灵活、耗油量低,使用、操作简单,适合原条单根绞集生产.采用JJX_1—2.5轻型自行式绞盘机接力集材新工艺,就是把原条集材作业分解成绞集和拖运两个工序,并用两种机械分别完成的两个工艺过程。也就是自行式绞盘机完成原条的绞集工艺,J—50拖拉机完成原条搭载、拖 相似文献
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众所周知,我们的林区已是经营几十年的老林区了,原始林几乎殆尽,可采资源都是远离公路的山后堵、陡山脚与零星山帽,这对木材生产的伐区准备工作和集材作业带来很多不便。为此,我局专门组织集材作业小分队,用S-195拖拉机配合畜力倒接力及平坡集材作业。这样不仅能缩短集材作业时间,而且也能提高经济效益15%～17%,把S-195拖拉机应用在短材生产中是较为理想的尝试。 相似文献
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本文从研究运材汽车列车的随机振动和行驶平顺性出发,提出一种运材汽车列车随机振动的计算机模拟方法,将运材汽车列车简化为十自由度五点输入的数学力学模型。以LT-110+GT15C型运材汽车列车为研究对象,在IBM计算机上进行了模拟计算。通过实地试验表明,模拟计算结果和实测结果能较好的吻合,因此该数学模型可用来预测运材汽车列车的行驶平顺性,以及运材车辆结构参数对行驶平顺性的影响,也可对运材汽车列车结构参数进行优化设计。 相似文献
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本文对利用轻型绞盘机小集中作用进行了探讨。该方法对目前实行的大面积低强度择伐，低产林抚育和人工林间伐集材作业方式的改革将起到推进作用。 相似文献
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《Journal of Sustainable Forestry》2013,32(3):113-123
Abstract Single-tree selection logging will likely result in a 4.3% loss in the relative abundance and a 4.1% loss in basal area of trees of commercial species in one cutting cycle due to their removal by harvesting combined with their potential recolonization of only 31% of logging gaps in a Bolivian tropical dry forest. Densities of the most valuable species, Amburana cearensis and Cedrela fissilis, were particularly reduced by logging. To sustain the current harvesting rate, uses need to be developed for more non-commercial species and/or silvicul-tural treatments employed that increase regeneration of commercial species and remove non-commercial species using timber stand improvement techniques. 相似文献
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Alexandre M. Sebbenn Bernd Degen Vânia C.R. Azevedo Marivana B. Silva André E.B. de Lacerda Ana Y. Ciampi Milton Kanashiro Francimary da S. Carneiro Ian Thompson Marilyn D. Loveless 《Forest Ecology and Management》2008
In the last three decades, Amazon tropical forests have experienced high rates of deforestation, both by clearing for agriculture and by logging. In this study, we use computer simulations to examine the potential effects of forest logging on genetic diversity and demographic recovery (basal area development) of four neotropical tree species over a time frame reflecting multiple logging events. The study species, Bagassa guianensis Aubl., Hymenaea courbaril L., Manilkara huberi (Ducke) Chevalier, and Symphonia globulifera L.f., are all taxa which are commonly exploited for timber in the Brazilian Amazon. The simulations were parameterized using empirical data from field studies in the Tapajós National Forest, Pará State, Brazil, including genotypes at microsatellite loci, demography, ecology and growth for each species. Eight scenarios, combining two different cutting cycles and two minimum cutting diameters, were examined for each of the four species. The scenarios represent the actual forest practices used in Brazil and French Guiana (cutting diameter 45 and 60 cm, and cutting cycle of 30 and 65 years, respectively). Logging scenarios were applied for six cutting cycles, and final genetic and demographic data were compared to baseline data from corresponding control scenarios. At the end of the simulated period the basal area was strongly reduced under all conditions in B. guianensis, H. courbaril, and M. huberi. In only two scenarios was a species able to recover its basal area following logging (S. globulifera with both 45- and 60-cm cutting diameters under a 65-year cutting cycle). In the logging scenarios, all species showed a loss of alleles and genotypes and an increased genetic distance (calculated between each population at the start and the end of the simulations). These effects were higher under the most intensive logging cycles (30 years, 45 cm). However, effective number of alleles, expected and observed heterozygosities, and the fixation index were little affected by the logging simulations. Over all, we conclude that, even under very optimistic conditions for growth and recruitment, current logging practices are not sustainable in terms of basal area. Our simulations show that different species respond differently to logging, both demographically and genetically. No single set of logging parameters can be applied to the forest as a whole. Rather, forest management practices must be species-specific, taking into account not only growth parameters but also ecological and reproductive variables, in order to move toward long-term forest sustainability. 相似文献
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Three operational-sized watersheds in pine flatwoods of the Lower Coastal Plain in north Florida were isolated and continuously monitored for years. Recording flumes assessed quantity of runoff water. After 1 year of calibration monitoring, two of the watersheds were, harvested, site-prepared, and planted under distinct harvest and regeneration practices.Minimum practices, imposed on one watershed, consisted of manual shortwood harvest of pinelands, roller drum chopping of harvest residues and residual understory, bedding, and planting. Maximum practices, imposed on another, consisted of tree-length logging of pinelands with heavy equipment, extraction of lightwood stumps, burning and windrowing of logging residue and residual understory, harrowing, bedding, and planting.Both silvicultural systems increased stormflow volumes; maximum practices moreso. Under both systems stormflow volumes apparently increased immediately following tree harvests. The increase persisted through site preparation, planting, and subsequently for years without further detectable change.Results of this and two earlier reports on the effects of silviculture on hydrologic regimes of flatwoods forests are reviewed and summary conclusions drawn. 相似文献
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这篇文章通过生产率和生产成本讨论了黑龙江林区二次集材选型问题。研究结果表明，Ｊ—５０集材拖拉机分别与Ｊ—８０和解放汽车匹配最适宜。Ｊ—８０接运最短距离为０．７３ｋｍ，最长接运距离为１２ｋｍ；解放汽车最适接运为８．４３ｋｍ，超过１２ｋｍ时用汽车直运最合理。 相似文献
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影响伐区作业的生态因子分析研究 总被引：9，自引：1，他引：9
本文从森林生态和森林采伐的关系入手,分析影响伐区作业的生态因子。这些生态因子包括林地坡度,林分结构、地表植被、采伐方式、采伐强度、集材方式、集材道间距、迹地清理方式,以及更新方式等,而林地坡度、采伐方式、集材方式、迹地清理方式和更新方式等是影响伐区作业的主要生态因子。 相似文献
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合理的森林采伐能开发利用森林资源,促进林木生长,但盲目采伐会导致生态环境的破坏。以生命周期评价法的B2B（business-to-business）模式为基础,采用过程分析法,核算森林采运过程各阶段的温室气体排放量。结果表明：采运过程中产生的碳排放约为7.530 6~11.659 8 kg/m3,约占其固碳能力的2.2%~5.7%;燃油消耗是最主要的碳排放源,CO2是其排放的最主要温室气体,碳排放量与集运材距离呈正相关;采伐段碳排放最少,仅0.573 6 kg/m3,索道集材、拖拉机集材排放分别是采伐段的1.04、1.72倍,运材段产生的排放量最多,当运材距离为40 km时,汽车运材和农用车运材排放量分别是采伐段的11.1和17.6倍;油锯采伐＋索道集材＋汽车运材为最优作业模式。研究结果可为森工作业的减排提供理论参考。 相似文献
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周新年 《中南林业科技大学学报(自然科学版)》1988,(2)
本文编制了用悬索曲线理论设计单跨索道的BASIC程序。经验证,能进行单跨索道承载索的设计计算,绘制出索道的纵断面图,并能检验索道跨越农田、道路和建筑物等地面控制疑点时,木捆最低点与其所保持的高度,为选择集材方式(全悬或半悬)和集材方法(原木、原条或伐倒木)提供依据。使用本软件进行索道设计,具有工效高,操作简便,运算迅速,精确和通用性好等优点,可以在有条件的地方推广使用。 相似文献
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毛竹周年采伐的伤流规律研究 总被引：2，自引：0，他引：2
毛竹周年采伐是适应竹材加工业发展和市场经济的要求而提出的迫切要求解决的课题。伤流规律的研究是为周年采伐技术提供重要理论依据之一。通过测定分析表明:毛竹在1个生理周期内的伤流量呈两峰两谷分布,一般昼少夜多,降水会增加伤流量。伐桩上的伤流液主要来自鞭系,呈双向运输,以正向运输为主。伤流液营养成分含量因竹龄不同而差异显著,4度竹含量较低。挖笋也会产生伤流,从而引起养分损失。若仅从伤流养分损耗的角度考虑,以正常疏笋为养分损耗参照值,则1个毛竹生理周期中有16个月可以实施采伐。 相似文献