国有林业产业对地区经济发展贡献度的动态演绎分析

基于1998~2018年黑龙江省国有林业产业数据,从发展规模、产业结构、投入产出效益、专业化水平等4个方面对黑龙江省国有林业产业发展现状进行总体概述和分析。借助产业贡献度指标测算国有林业产业对黑龙江省经济发展的贡献水平,并基于三次产业构成进一步对国有林业产业贡献度进行了结构性动态评价。研究得出:黑龙江省国有林业产业对地区经济发展贡献呈现稳步上升的特征,第一产业表现突出,第二、三产业呈小幅下降、小幅上升的反向变动特征。基于结果分析,从产业自身发展和持续推进多种经营产业转型两个方面提出方向性建议。     

广州市公益林生态效益价值分析及管理对策

在对广州市公益林分布和现状特点分析的基础上 ,从林种的生态功能角度对效益进行了分析。结果表明 :广州市水源涵养林生态效益比较高 ,生态效益从大到小排序为 :水源涵养林 >水土保持林 >风景林、自然保护区和小片林 >护岸林 ,从单个效益分析 ,维持大气平衡效益最大。最后提出了公益林管理对策     

海南岛尖峰岭次生热带山地雨林的边缘效应

对海南岛尖峰岭热带山地雨林采伐迹地次生林及周围的保留林进行了群落调查．组建了一个基于分割线段模型的边缘效应测度公式：Y=α e0[1-(D／Dmax)](式中Y为与边缘垂直距离D处的测定指标值，e0为边缘效应强度的最大值，Dmax为边缘效应作用的最大距离，α为常数)，研究了热带山地雨林群落的边缘效应，结果表明：(1)用组建的测度公式来分析热带山地雨林采伐迹地边缘的次生林及保留林的边缘效应强度及其作用距离，结果是有效和可靠的；(2)热带山地雨林采伐后形成的边缘，其效应的作用距离一般都不超过15m；(3)边缘对保留林和次生林的效应没有显著差异。     

利用"指数选择"的方法选择马尾松二代优树研究

“开发马尾松子代优树选择技术”是中日合作林木育种科技中心项目正在实施的“开发多世代选择育种技术”的课题之一。该项目主要是在生长量、材质等性状方面选择出比上一代更好的优树 ,并将选择的优树进行杂交 ,建立育种群体林。为开发出非常有效的、比较先进的优树选择技术和分析方法提供借鉴。     

现行森林资源调查方法存在问题及对策研究

对我国现行森林资源调查方法存在的问题进行了分析研究,提出应解放思想、转变观念,改进和完善调查方法,主张森林资源一类、二类调查应实行"分离"制,以更好地适应时代的发展和新形势的要求.     

长白山典型阔叶红松林土壤二氧化碳排放通量

随着大气CO2浓度的升高,主要由其引起的温室效应与对生物新陈代谢的影响变得越来越显著。森林生态系统在全球碳循环中扮演着重要的角色。为了评估和理解森林土壤CO2通量及其随空气和土壤温度的季节和昼夜变化规律,我们在长白山北坡典型阔叶红松林内利用静态箱技术进行了原位观测。实验在整个生长季(6月初至9月末)昼夜进行,利用气相色谱进行气体分析。结果表明: 长白山阔叶红松林土壤是大气二氧化碳源,其CO2通量具有明显的季节和昼夜变化规律。通量的变化范围是(0.30-2.42)μmol穖-2穝-1,平均值为0.98μmol穖-2穝-1。土壤CO2排放的季节规律表明,土壤CO2通量的变化与气温和土壤温度的变化有关。CO2平均通量的最大值出现在7月((1.27±23%)μmol穖-2穝-1),最小值出现在9月((0.5±28%)μmol穖-2穝-1)。土壤CO2的昼夜波动与土壤温度变化有关,而在时间上滞后于温度的变化。森林下垫面土壤CO2通量与土壤温度显著相关,与6cm深度土层温度相关系数最大。基于气温和土壤温度计算的Q10值范围为2.09-3.40。图2表3参37。     

Small-scale forestry development in Leyte,Philippines: The central role of nurseries

This paper presents results of survey research into the role of the forestry nursery sector in the development of smallholder forestry in Leyte, Philippines. Seedling production in the province is basically carried out by three categories of nurseries: individual, communal and the government. Seedlings in the government nurseries are primarily raised for free distribution to landholders but the extension scheme fails to reach the majority of the smallholder farmers. Seedling demand of landholders is mostly catered for by the more numerous and accessible individual and communal nurseries. However, problems of capital outlay, sources and supply of germplasm, technical knowledge in nursery management for both timber and fruit trees and low sales are among the major impediments in the sustainability of small-scale nurseries. Most of the communal nurseries fail to sustain the operation after the withdrawal of supporting agencies. Knowledge on site-species matching is needed not only by small-scale nursery operators but also by the managers of government nurseries. It is concluded that the seedling industry in the province is not well established and there is a need to organise better the overall nursery system so as to improve the availability of seedlings and promote appropriate site and species combinations.     

Research needs for restoring seasonal tropical forests in Thailand: accelerated natural regeneration

Accelerated natural regeneration (ANR) is a relatively cheap method of reforestation, which encourages natural establishment of indigenous trees and shrubs. It requires a low input of labour, but a high input of ecological information. In this paper, the knowledge required to predict and manipulate the natural regeneration of seasonal tropical forest is reviewed and areas in need of further research are identified. Regeneration will be influenced by five groups of potentially limiting factors; site resources (soil and microclimate); competition with weeds; site disturbance; occurrence of established woody plants or their propagules; seed dispersal by wild animals and birds. This paper considers each of these, their interactions with seasons, and each other. Collation of existing information on these topics, combined with the suggested further research, should facilitate the creation of tools that will enable practitioners to judge the regeneration potential of sites and to select the most appropriate ANR techniques.     

森泰除草剂防除香椿幼林地杂草的试验研究

使用25%森泰水剂和5%森泰颗粒剂防除香椿幼林地的杂草研究试验结果表明:25%森泰水剂和5%森泰颗粒剂均能够有效防除香椿幼林地的五节芒、苦竹、刚竹、芒萁骨等多年生恶性杂草,防除效果均可达93%以上。使用25%森泰水剂除草比人工除草可减少用工56 1%～92 2%,降低除草成本36 1%～61%。同时,可根据幼林地杂草的种类、高度、盖度和水源等因素选择合适的森泰除草剂的剂型和剂量组合,以达到理想的防除杂草效果。     

天童林场杉木人工林间伐后林下植物结构特征的研究

对种植26a的天童林场杉木人工林林下植物的群落结构进行了初步的调查研究。结果表明，杉木人工林林下共有植物59种，主要包括樟科、壳斗科、山茶科等．其中分布最多的树种是红楠、栲树、薄叶润楠、细枝柃、南酸枣、枫香、细叶青冈、赤皮青冈、山杜英等；大多数林下植物的高度在2．0～2．5m，有10．6％的植株高度在3．5～4．0m，大于6m的植株数量约占全部的6．8％。林下常绿树种的胸径多在1．0—3．5cm，落叶树种南酸枣和枫香的平均胸径较大，分别为3．6和6．2cm。