共查询到20条相似文献，搜索用时 309 毫秒
1.
微型绞盘机是为森林采伐作业研制的小型机械。该机械具有体积小、重量轻、携带方便、机动灵活等特点,适用于高山陡坡集材、索道横向收集、抚育伐和代替人力、畜力集材作业,还可以作为架设索道的辅助设备。 相似文献
2.
针对天然阔叶林疏伐作业设计、施工与验收工作实际,通过在木兰围场选定具有代表性的试验区,开展不同标准地设置方式和施工作业模式,进行株数和蓄积偏差率对比分析研究.结果表明:分区布设标准地、确定保留木、全林标定采伐木、使用专业采伐队是山地天然阔叶林疏伐作业最佳选择方案. 相似文献
3.
杨少玲 《林业机械与木工设备》1990,(3)
由全苏林业机械设计科学研究院和中央森工机械与动力科学研究所高加索分部共同研制,并提交批量生产的自行式ЛЛ-31索道设备可进行全悬或半悬原条集材(顺坡或逆坡),它适用于坡长700m 以内的山地窄带采伐作业。该设备在伐区用半悬式集材作业可横向吸引索道 相似文献
4.
5.
6.
对马尾松木荷混交林开展不同采伐模式试验研究,结果表明:采伐时留下少许木荷能大幅度提高土壤有机质、全氮、全磷、速效氮、速效磷及速效钾含量,且土壤中团聚体含量高,非毛管孔隙度大,土壤疏松,贮水量大,留少许木荷不采伐可有效提高土壤肥力。而皆伐作业的林地化学性质差,土壤团聚体含量低,非毛管孔隙度小,贮水能力低。建议山地人工林采伐留适量林木以维持地力。 相似文献
7.
近年来,我们对北方林区山地带状整地机械进行了一些研究与探索,设计研制了SDZ型营林山地弹齿整地机(如图1)。样机的生产试验表明,其作业质量良好,符合营林生产的技术要求,与手工作业相比,工效提高50余倍。 SDZ型营林山地弹齿整地机可与东方红-54/75等中等功率的拖拉机配套,适宜于坡度15°以下的荒山荒地、次生林地、采伐迹地等造林前的带状整地。 相似文献
8.
辽宁省多功能森林作业法体系设计 总被引：1，自引：0，他引：1
该文针对辽宁森林类型特点和不同经营目标,结合经营对象、作业强度和采伐利用方式,在全国尺度的7种森林作业法(一级作业法层面)框架下,遵循森林多功能全周期经营理念,针对不同森林类型和地理区位条件下的经营目标,构建了辽宁多功能森林作业法体系(二级作业法层面)。根据辽宁省森林资源实际,针对具体森林类型和自然地理区位,围绕森林经营目标,结合经营对象、作业强度和主导的森林采伐利用方式,在7种森林作业法框架下进一步细化设计,构建了46种森林类型作业法。 相似文献
9.
10.
11.
12.
《Journal of Sustainable Forestry》2013,32(3-4):11-17
Summary A combination of social, economic and physical factors contribute to a decision to migrate for a peasant farmer. Seventy percent of Panamanian land comprises steep topography with low soil fertility. Campesinos (peasant farmers) must perpetually migrate when the land they have settled in the forest loses fertility. This process of continual migration results in deforestation and conversion of forest land to pasture land, which then becomes degraded and subsequently abandoned. Also, government policy has not favored the activities of small land owners, but loans from national banks have financed the promotion of large-scale cattle ranches. Migration patterns consist of moving to a forested area, clearing it for agriculture for one to three years, and thereafter sowing it for pasture. These conditions eventually result in low agricultural and cattle production. Campesinos therefore sell the land to cattle ranchers who can afford to invest in better management practices. Deforestation in the Canal Watershed, therefore, has left a pattern of land ownership comprising a matrix of a few large landowners, within which remain numerous but small peasant land holdings. A program for small land owners in and around the Watershed region that promotes social, cultural, and economic stability of land use is needed. Supporting and promoting agroforestry with uses of native tree species associated with subsistence and market crops is an alternative for slowing deforestation and promoting sedentary land use. 相似文献
13.
Natural forces and anthropogenic activities greatly alter land cover,deteriorate or alleviate forest frag-mentation and affect biodiversity.Thus land cover and forest fragmentation dynamics have become a focus of concern for natural resource management agencies and biodiversity con-servation communities.However,there are few land cover datasets and forest fragmentation information available for the Dhorpatan Hunting Reserve (DHR) of Nepal to develop targeted biodiversity conservation plans.In this study,these gaps were filled by characterizing land cover and forest frag-mentation trends in the DHR.Using five Landsat images between 1993 and 2018,a support vector machine algorithm was applied to classify six land cover classes:forest,grass-lands,barren lands,agricultural and built-up areas,water bodies,and snow and glaciers.Subsequently,two landscape process models and four landscape metrics were used to depict the forest fragmentation situations.Results showed that forest cover increased from 39.4％ in 1993 to 39.8％ in 2018.Conversely,grasslands decreased from 38.2％ in 1993 to 36.9％ in 2018.The forest shrinkage was responsible for forest loss during the period,suggesting that the loss of for-est cover reduced the connectivity between forest and non-forested areas.Expansion was the dominant component of the forest restoration process,implying that it avoided the occurrence of isolated forests.The maximum value of edge density and perimeter area fractal dimension metrics and the minimum value of aggregation index were observed in 2011,revealing that forests in this year were most fragmented.These specific observations from the current analysis can help local authorities and local communities,who are highly dependent on forest resources,to better develop local forest management and biodiversity conservation plans. 相似文献
14.
环境因子对浙江省重点公益林生物量的影响研究 总被引：4，自引：0，他引：4
利用在浙江省200万hm2重点公益林范围内取得的854个典型样地的调查资料,分析比较了不同地貌、坡度、坡向、坡位、土层厚度等条件下样地的生物量及其组成,结合林龄、立木数等指标,研究了环境因子对浙江省重点公益林生物量的影响,结果表明,(1)重点公益林现存生物量与地貌、坡向、坡位、坡度等地理特征密切相关,往往与平均生长量呈负相关。现存生物量随着地势的下降而下降,即中山>低山>丘陵;从坡向分析,西北向的平均生物量最大,南坡、东南和西南次之;从坡度看,以陡坡最高,急坡、斜坡次之,缓坡和险坡最低;从坡位分析,以上坡最高,中坡和山脊次之,下坡最低。(2)土层厚度是影响林地生物量的重要因素,随着土层厚度的加深,林地生物量迅速增加。年均生物量生长也与立地状况密切相关。年均生物量以丘陵最高,低山次之,中山最低;各坡向年均生物量由高到低依次为南、西南、东南、西北、东北、西、东、北;从下坡、中坡、上坡至山脊也呈逐渐下降趋势。 相似文献
15.
《Scandinavian Journal of Forest Research》2012,27(2):120-127
Abstract This study quantified, across a landscape in Eastern Finland, the influence of administrative land-use and technical land-form constraints on timber production. Spatially explicit data about the nature conservation areas, land use plans and steep slopes were integrated with Multi-source National Forest Inventory (MS-NFI) data. The Finnish forestry model MELA was used in the calculations related to updating forest data and estimating different scenarios of timber production with and without constraints. In the study area, the annual volume of maximum sustainable cutting removal defined for the next 30 years was decreased by one-third due to restrictions. The presented approach could be used, for example, to assess timber availability at the landscape level. Future challenges include ensuring the compatibility of spatially explicit data obtained from different sources, identifying the feasibility of forest management operations in the restricted area, and incorporating near-nature forest management operations in the forest planning system in order to estimate the timber production. 相似文献
16.
17.
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。 相似文献
18.
为了降低林农抚育劳动的强度,利用模块设计原理试制林地抚育垦复机。该机器由电动机车、旋耕机、前后视屏摄像机组成,具有抚育效率高、体积小、操作灵活等特点。其工作原理是由电动机车运载旋耕机前进,旋耕机在林地旋耕作业达到抚育林地的目地,前后视屏摄像机可遥控指挥机车前进后退避开障碍物,实行无人驾驶遥控抚育垦复作业。可提高普通劳动力的垦复力5～8倍,特别是在林地上,林木树冠低矮不便人行穿越时可提高工作效率10-15倍。 相似文献
19.
泸西县为云南省石漠化程度较高的区域之一,属喀斯特地貌.为了掌握泸西县林地及天然林资源特征,以泸西县2019年森林资源监测数据为基础,从土地利用、林地类型、优势树种及林地管理属性等方面进行了分析,为该区域森林资源保护、监测及相关规划提供依据.结果表明:泸西县林地面积占比较低,仅占国土面积的47.16％,森林覆盖率偏低,仅... 相似文献
20.
基于江西省毛竹林经营现状，调查分析了竹阔混交林分中山顶阔叶林与山体中下部毛竹纯林所构成的复合系统（简称"上阔下竹"）特征及其对毛竹林生长指标的影响。结果显示：江西上阔下竹系统可分为4种类型，分别为高阔中海拔陡坡多石型、中阔低海拔缓坡中石型、低阔低海拔缓坡少石型、低阔中海拔斜坡中石型，其中以中阔低海拔缓坡中石型生物多样性最为丰富、竹林生物量也最高。各类型系统中上位阔叶林树种多样、层次分明、生物多样性丰富，有利于提高林分的生态安全。同时，上位阔叶林能有效保持林地水分和养分并供给下位毛竹林，促进毛竹生长，提高毛竹林的胸径和生物量。 相似文献