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1.
介绍了种苗与营造林机械的主要种类及其发展,分析了各种机械的特点及适用场合。 相似文献
2.
采用3参数Weibull生长方程,对15块杉木密度试验林26年连续观测数据进行分析,计算了林分材积年平均生长量(MAI,包括净材积年平均生长量(MAInet),总材积年平均生长量(MAIgross));利用相关分析及逐步回归分析,研究了林分净材积(Vnet)和总材积(Vgross=Vnet+枯死木材积累积(∑Vm))年平均生长量的峰值及峰值林龄与初植密度、立地质量的关系。结果表明:(1)MAInet峰值与立地指数呈显著正相关,而受林分密度影响很小,其在立地指数级22 m的样地内平均值比立地指数级12 m的样地增加了8.33 m3·hm-2·a-1;MAIgross峰值与立地质量及林分初植密度均呈正相关(r=0.813 5,p=0.000 4;r=0.926 1,p=0.000 0);(2)MAInet峰值林龄主要受初植密度的影响,初植密度太大或太小对MAInet峰值林龄有显著影响,E密度(1 m×1 m)样地的MAInet峰值林龄平均值比A密度(2 m×3 m)样地的小3.88年,而中间密度的MAInet峰值林龄变化不明显。 相似文献
3.
The low proportion of forested land and continuing degradation of existing forest cover are serious threats to the sustainability
of forestry in Pakistan. Farm forestry has been identified as a feasible solution, particularly in the plain areas. Applying
the Theory of Planned Behaviour in a survey of 124 farmers in Dera Ismail Khan district of Pakistan’s North West Frontier
Province showed that farmers’ willingness to grow trees on their farms is a function of their attitudes towards the advantages
and disadvantages of growing trees, their perception of the opinions of salient referents and factors that encourage and discourage
farm level tree planting. Farmers viewed farm forestry as economically beneficial and environmentally friendly. Tree planting
was perceived as increasing income, providing wood for fuel and furniture, controlling erosion and pollution and providing
shade for humans and animals. Farmers saw hindrance in agricultural operations and the harbouring of insects, pests and diseases
as negative impacts of tree planting; however, these were outweighed by their perceptions of positive impacts. Tree growing
decisions of farmers were influenced by the opinions of family members, owners/tenants, fellow farmers and village elders.
The factors that significantly predicted farm level tree planting were availability of barren land, lack of markets, lack
of nurseries and damage caused by animals and humans. Farm forestry programmes are more likely to be successful if they acknowledge
and address the factors which underlie farmers’ reasons for planting or not planting trees. 相似文献
4.
Current Indonesian beef production only meets 45% of local demand. Increasing local beef production through integration of cattle production in pre-existing oil palm plantations is a possible solution to meeting this shortfall. The oil palm understorey provides feed, alleviating the need to convert additional land to agriculture. Smallholders are important contributors to both Indonesian cattle and palm oil production. This case study research seeks to understand key aspects of smallholder cattle management in palm oil production areas, to highlight opportunities and barriers to cattle integration. Thirty-nine smallholder cattle farmers from four villages in South Kalimantan were individually interviewed. The lack of alternative feed sources was the major driver towards the adoption of cattle production using oil palm understorey as feed. Cattle grazing was uncontrolled due to labour shortages and occurred in individually owned and ‘plasma’ plantations, with cattle penned at night where possible to avoid theft. Arrangements on land access and use between stakeholders are needed for systematic cattle grazing and to control cattle theft. 相似文献
5.
The paper reviews modern attitudes to and uses of imperata grasslands in parts of Southeast Asia, including government and NGO efforts at reforestation. It is argued that the perspective of small farmers has usually been inadequately considered in planning the rehabilitation of Imperata. A historical overview of the impact of changes in land use, population, vegetation dynamics and human adaptation on the creation, disappearance or persistence of Imperata provides a context for the present concerns and emphasizes the wide variability of the situation at the local level. Nine questions are proposed as needing consideration whenever changes are planned to a grassland-based system. They cover three main areas: 1) the origins, past and present uses of the grasslands (including the present land tenure position and variations in uses by ethnic group, socio-economic status and gender); 2) perceptions by farmers of the opportunities and constraints provided by local micro-environments, particularly vegetation types; 3) farmer suggestions for ways of improving their economic status and the potential benefits of agroforestry innovations. These questions are applied to one case study area, the Riam Kiwa valley of South Kalimantan, Indonesia. 相似文献
6.
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
7.
枣树的地上部分与根系的关系的相互依存,彼此制约的辩证统一关系,密度与根系关系就是从密度影响二者的矛盾中体现的,枣权索性密植园,栽植密度显著地影响着根系的生长发育,幼树期,密度从栽植后第2年或第3年起便开始制约枣树的生长发育,首先表现在根系对土壤有限养分水分的竞争上,到8年生时,不同密度植株根系在坡面上和水平沟内的分布数量和大小是不相同的,根的分布趋势是,粗大根随着密度的增加逐渐减少。 相似文献
8.
为保证天津市“十四五”造林绿化规划的科学性、针对性和可实施性,针对高速公路、高铁、一级河道两侧100~150 m绿色廊道,从森林分布、森林结构和森林健康3方面,对小班的林分质量进行调查,并按层次权重分析法汇总各评价指标分数,得到典型森林小班质量等级后,利用航片影像特征将结果反推至剩余森林小班,最后获得了绿色廊道林分质量情况。 相似文献
9.
The delivery of sustainable development goals (SDGs) through a participatory land and forest conservation initiative was evaluated in South Kalimantan Province, Indonesia. The initiative focused on the rehabilitation of a 410 ha forest that was managed by local villagers. A forest rehabilitation and management initiative was developed through participatory action, establishing a well-managed rubber plantation that provided new livelihood opportunities. Poverty reduction was promoted, evidenced by a reduction in inequality amongst the local community. Between 2010 and 2018 the Gini coefficient of inequality declined from 34.6% to 31.3%, demonstrating a contribution to SDGs 1 (No Poverty) and 10 (Reduced Inequalities). In addition, forest rehabilitation resulted in improved carbon stock and biodiversity management contributing to SDG15 (Life on Land). This was attributed to successful forest rehabilitation and the reduced incidence of forest fires. Cooperation amongst local villagers categorized as living in poor households was improved, facilitated by capacity building. This focused on rubber plantation management, cooperative action, and firefighting activities. This capacity building contributed to the delivery of SDG 17 (Partnerships for the Goals). Results from a socio-economic survey demonstrated that group activities and cooperation amongst stakeholders were essential to improve both livelihoods and forest management practices. 相似文献
10.
介绍陇川县柠檬引种、推广种植现状,根据多年柠檬种植的生产经验,总结出柠檬优质高产栽培技术。 相似文献
11.
近年来,许多城市公共绿地建设中营造了大量的草坪,针对这种情况,本文以广州为研究对象从城市公共绿地建设的生态效益,经济效益的角度进行了比较,提出在城市公共绿地建设中不宜“以草代树”。 相似文献
12.
角尺度作为测度林木空间分布格局的林分空间结构参数之一,具有检验能力强,调查简单易行等优点,现已得到了广泛应用。目前,有很多研究对这一参数应用不当并因此得出不合理的结论,究其原因是对角尺度理论基础缺乏了解。本文从角尺度概念的提出、相邻木个数的选择、标准角和随机分布阈值的确定、角尺度的应用等几个方面作详细阐述与总结,并指出目前的研究方向为空间结构单元大小对角尺度分析的影响及如何利用点抽样调查数据对种群分布格局进行检验等。 相似文献
13.
我国南北方的文化地缘差异较为明显,因此其文化基础在环境因素、人文因素方面也存在着一定的差异性。基于此,与民众日常生活息息相关的家具设计与应用也存在着一些较为明显的不同。简述了我国家具文化的形态,分析了南北家具设计文化元素差异,在此基础上,探讨了新时代南北家具设计理念融合的思路。 相似文献
14.
目的 揭示南亚热带不同密度和立地条件下杉木人工林蓄积量发育规律。 方法 以广西大青山36 a生杉木密度试验林为研究对象,分析A(1 667株·hm-2)、B(3 333株·hm-2)、C(5 000株·hm-2)、D(6 667株·hm-2)、E(10 000株·hm-2)5种初植密度杉木人工林总蓄积、活立木蓄积动态变化。 结果 初植密度与立地对林分活立木蓄积生长的影响与总蓄积一致。中幼龄阶段林分总蓄积与初植密度和立地正相关,初植密度愈高,立地指数愈大,林分蓄积生长量愈大;但15 a后中等密度林分总蓄积最大。林分蓄积连年生长高峰随密度增大而愈早;平均生长达高峰后下降,密度越大下降越早、下降趋势越明显;林分蓄积连年生长量、平均生长量大多分别在10、14 a达到高峰,林分蓄积生长率降到3%时林龄为19~25 a。 结论 随初植密度增大,立地指数对林分总蓄积的影响程度减弱。若以蓄积生长量最大为培育目标,16指数级以C密度为最适宜造林密度。南亚热带杉木林首次间伐、最后间伐、主伐时间分别为10、14、25 a;主伐林龄不宜早于19 a,且初植密度愈低主伐林龄更晚,A、B密度林分的主伐林龄可推迟到25 a。 相似文献
15.
文章研究了广东省东莞清溪山地常绿阔叶林群落组成和立木结构,并用丰富度指数、Shannon-Wiener多样性指数、均匀度指数及Simpson指数分析了群落物种多样性的变化。结果表明:林分内立木的树高和胸径变化总趋势均为小级别的个体占大多数,而且各主要树种的重要值差异不大,这些都表明该群落处于进展演替阶段;处于南亚热带的东莞清溪山地常绿阔叶林Shannon-Wiener多样性指数在0.673~2.539,物种均匀度为0.619~0.977,Simpson指数则为0.480~0.905,其物种多样性指数与陈和洞自然保护区常绿阔叶林的多样性指数相近。总的来说,东莞清溪山地常绿阔叶林的物种多样性指数、均匀度和Simpson指数都比较高。并通过对物种多样性指数的分析,探讨了如何才能维持较高的生物多样性。 相似文献
16.
事业有成是高校青年教师的基本要求,也是青年教师思想政治素质的集中体现。高校青年教师思想政治工作要适应其内在需求,其核心是要遵循知识分子的成长规律。新形势下,高校青年教师的思想政治工作必须超越以往的物质利益观或问题观,从有利于实现高校教师思想政治工作目标、调动青年教师积极性、实现青年教师价值、沟通融合思想、抓住热点问题入手,才能取得好的效果。引导青年教师事业有成是个体成才与高校思想政治工作相结合的最佳切入点,是高校青年教师思想政治工作最根本的动力。 相似文献
17.
2006~2013年10月,在云南省新平县建兴乡不同密度人工龙竹林分内设置10 m×10 m样地进行生长情况调查。对竹丛秆龄结构、秆径生长量、竹材产量、发笋率和成竹率、种植效益等进行分析。结果认为,对于人工龙竹林分,不加强抚育管理而使其处于自然生长状态是导致竹林提早衰退的重要原因之一,这在高密度林分中表现尤为明显。藉此提出高效的经营管理模式及方法。 相似文献
18.
土壤微生物和土壤酶活性是反映土壤肥力最为重要的生物学指标之一。文章综合论述了不同林分土壤微生物种群和数量的分布及其影响因素,并对土壤酶活性对土壤肥力的影响做了分析,显示土壤微生物、酶活性与土壤养分有显著的相关关系。 相似文献
19.
本研究的目的是确定不同功率微波烫漂对青花椒酶活性与感官品质的影响。结果显示:合理的微波烫漂条件能提升青花椒感官品质,有较好的灭酶效果,过度的微波烫漂则使青花椒产生褐变和水分损失等不良影响。以不影响青花椒品质为前提,微波功率420 W,烫漂40 s灭酶效果较好,多酚氧化酶相对酶活为32.79%,过氧化物酶相对酶活为40.61%。 相似文献
20.
An integrated tree plantation approach combining indigenous livelihoods and industrial wood production is being implemented in West Kalimantan, Indonesia. In this study the economics of land-use was investigated in villages within the plantation scheme. The effect of three alternative land-use scenarios and costs and benefits of each land-use type were studied using linear programming. The scenarios were based 1) on the current land-use, 2) on the integrated tree plantation system with incentives and government regulations, and 3) on a financially optimal land-use distribution. Additionally, plant species richness in different land-use types was surveyed. The scenarios had different kinds of effects on villages varying in respect to their possibilities for land-use intensification. In villages with extensive land use, establishment of tree plantations without any land-use regulations increased the potential economic return on land, resulting in conversion of natural and man-made semi-natural forests into swidden fields. In villages with more sedentary agriculture, the plantation scheme did not create pressures towards remaining forests even in the case of financially optimal land-use distribution. Incorporation of land-use regulations prevented further deforestation but also decreased households' economic returns. The results also showed that conversion of Imperata grasslands to any other land-use increased species richness. Incentives, restrictions or regulations aiming at conserving natural and semi-natural forests are needed to ensure conservation of biodiversity and long-term improvements in local livelihoods. It can be concluded that tree plantations can be combined with other land-use practices: They can improve the economic return on land without further degradation of the environment.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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