林间履带式多功能底盘的设计

针对林间运输需求,提出了履带式多功能底盘的整体设计方案,并对该底盘的几个关键部件进行了设计。     

自走式林业剩余物削片机设计与试验

针对目前林业采伐后产生大量枝桠等林业剩余物,丢弃在林区,从而造成资源巨大浪费,易形成火灾隐患等问题,提出了将林间剩余物原地进行收集、削片、储存等一体化回收方式,并设计一台自走式林业剩余物削片机,拟定了设备总体方案,并对行走、切削以及喂料等机构进行了设计。该研究进行了林业剩余物切削试验,设备行走速度为2~12 km/h,最大爬坡角度为25°,削片后的木片小于50 mm,合格率可达90%以上,生产率可达3~6 t/h。设备的设计不仅能够提高劳动生产率,降低林业剩余物回收成本,而且为林业剩余物的收集储运提供了新方法。     

森林生态系统中的姣姣者——棘托竹荪研究

该菌系在湖南会同县发现的分解能力和抗逆性很强,是营养及药用价值很高的木腐菌。它在林间栽培可有效地分解采伐剩余物,竹荪的抗污染能力很强,适于林间开放式生产,生产周期短,产量高,营养成份含量高于长裙竹荪及松花粉。     

移动式林间剩余物盘式粉碎机切削功率的理论研究

鉴于生物质发电对环境和能源的影响,提出设计一台移动式林间剩余物粉碎机;通过对比盘式粉碎机和鼓式粉碎机的优缺点以及两者对切削功率的影响,确定粉碎机构;对盘式粉碎机刀盘和飞刀的关键参数进行了分析,并建立刀盘与飞刀的三维模型;以松木为例,采用经验分析法,计算了盘式粉碎机从不同角度进料时的切削力和切削功率,为移动式林间剩余物盘式粉碎机的研究提供一定的理论依据。     

简易履带式行走机构的设计及通过性分析

研究了国内外林间运输机械的现状,针对我国林间科学研究的需求,提出了简易履带式行走机构的设计方案,并对其在林间的通过性能进行了分析。     

移动式制粒机的设计

随着人们对能源重视程度的提高,生物质能被人们所看好,回收利用林间三剩物是实现节能减排的重要方向.为了得到能量高、体积小的生物质燃料,人们研制了生物质制粒机,将粉碎后的木质材料通过挤压而得到高密度、高热值的生物质颗粒.它具有以下主要特征:有比较高的密度,一般1.0～1.3g/cm3;热值一般为16 000 ～ 17 000J/kg;灰份小,有害成分低,可以实现零的排放[1].在我国传统林间剩余物的加工技术研究中,人们要通过背负式割灌机将林间剩余物割倒,然后利用人背或者牲畜将剩余物从林间运输到集材道上,再用拖拉机将枝桠散装运输到林道上,打包捆扎运输到林场,在林场转运大型汽车运输到木颗粒加工厂.     

移动式高效生物质双向切碎机的设计与研究

为了高效利用生物质能源,本研究通过借鉴国外小型移动式双进料切碎机,采用反求工程设计法设计了移动式生物质双向切碎机,并对进料槽、刀辊的设计过程及主要参数进行分析和确定。切碎机自身配有行走机构,同时有鼓式切削、盘式切削两种切削方式的复合刀辊,能够在林间行走,并可根据用户需要选择切削方式,可快速、高效地加工采伐剩余物。     

森林采伐剩余物收集打捆压缩装置的设计

为了有效地利用森林采伐剩余物,设计了适应林区环境条件的采伐剩余物压缩装置,该装置尺寸为2 m×1.0 m×1.5 m,为森林采伐剩余物的压缩运输提供了合理有效的设备。     

履带式遥控风力灭火机的设计与研究

为了提高灭火效率、缩短灭火距离、解决灭火人员负载过重及灭火安全等问题,本文通过对履带式遥控风力灭火机工作原理的分析及总体方案的确定,设计了履带式遥控风力灭火机行走机构.设计的履带式遥控风力灭火机可以实现远程遥控且具有良好的爬坡能力和通过能力.     

木材剩余物制备缓/控释肥料壳体的设计

介绍了物理包被缓/控释肥料的类型及研究现状,总结了该类型的缓/控释肥料的特点、存在问题及其发展方向,当前包膜肥料存在成本高、材料不降解、易造成污染等。提出利用木材剩余物制造缓/控释肥料壳体的设计,并分析了木材剩余物缓/控释肥料壳体的制备方法及其肥料释放机理。木材剩余物缓/控释肥料壳体能通过木材自身的空隙逐步释放肥料,淀粉胶降解能形成新的肥料释放通道。该壳体具有成本低、制造简单、易降解、无污染等优点。     

Comparison of uncertainties in carbon sequestration estimates for a tropical and a temperate forest

We compare uncertainty through sensitivity and uncertainty analyses of the modelling framework CO2FIX V.2. We apply the analyses to a Central European managed Norway spruce stand and a secondary tropical forest in Central America. Based on literature and experience we use three standard groups to express uncertainty in the input parameters: 5%, 10% and 20%. Sensitivity analyses show that parameters exhibiting highest influence on carbon sequestration are carbon content, wood density and current annual increment of stems. Three main conclusions arise from this investigation: (1) parameters that largely determine model output are stem parameters, (2) depending on initial state of the model, perturbation can lead to multiple equilibrium, and (3) the standard deviation of total carbon stock is double in the tropical secondary forest for the wood density, and current annual increment. The standard deviation caused by uncertainty in mortality rate is more than 10-fold in the tropical forest case than in the temperate managed forest. Even in a case with good access to data, the uncertainty remains very high, much higher than what can reasonably be achieved in carbon sequestration through changes in forest management.     

Willingness of Nonindustrial Private Forest Owners in Norway to Supply Logging Residues for Wood Energy

Norway has set ambitious targets for increasing bioenergy production. Forest residue extraction levels are currently very low, but residues have the potential to be an important component of the wood energy supply chain. A representative sample of Norwegian nonindustrial private forest owners having at least 8 ha (20 acres) of productive forest land was surveyed about their willingness to supply logging residues for wood energy production. About 59 % responded that they were willing to do so. Logistic regression analyses revealed that the following factors were positively associated with the likelihood of being willing to supply logging residues: total forest area, education level, living in a region with active timber markets and a history of forest production, and having positive perceptions of residue extraction and forestry’s role in mitigating climate change. Four variables were negatively associated with the likelihood to supply residues: living on property, being older than 65 years, having family or friends who are opposed to residue extraction, and having negative perceptions of residue extraction. The study provides insight regarding nonindustrial forest owners’ attitudes towards extraction of forest residues that may aid policy-makers designing effective means to meet national bioenergy production goals.     

Effects of bioenergy production on environmental sustainability: a preliminary study based on expert opinions in Italy and Turkey

In future decades, initiatives on biomass-based energy development in Europe should reduce fossil fuel dependence and help to combat climate change as required by the conference of the parties 21. In this context, forest biomass can play a key role within the bioenergy sector due to its high growth potential. The use of forest biomass for energy has positive and negative effects on other ecosystem services, on stand characteristics, and on forest management practices. The aim of this study is to analyse the effects of forest bioenergy production on six ecosystem services (biodiversity, recreation, landscape aesthetics, carbon sequestration, soil erosion protection, water quality). These effects have been assessed by 80 experts in two countries (Italy and Turkey), considering two different forest management practices (clear-cutting of coppices and woody residue removal after felling in high forests). The results show that coppice clear-cutting has negative effects on almost all ecosystem services according to the experts’ opinions. The highest negative effects are on landscape aesthetics and soil protection. The effects of woody residue removal on biodiversity, carbon sequestration, soil erosion protection, and water quality are considered negative by the experts, while the effects on recreation activities and landscape aesthetics are considered positive. The highest negative effects of this forest management scenario are on soil protection and biodiversity. The experts’ opinions about the effects of forest management practices on ecosystem services can provide information to understand the environmental sustainability of bioenergy development in future years.     

贮木场平曲线原木输送机设置的探讨

平曲线原木输送机目前在贮木场中应用广泛,本文对平曲线原木输送机受力进行了分析,对如何减轻平曲线输送机运转中各部件的损伤提出了解决措施,并从理论上探讨了平曲线原木输送机曲线设置中各项参数的选择.     

发达国家木材采运工业现状和发展趋势

发达国家木材采运生产在进入全面机械化阶段以来的２０多年里，不仅主伐的主要生产作业和准备、辅助作业，而且疏伐作业率成倍增长。技术进步的主要特点是：机械系统更新换代速度加快，推广少剩余物、无剩余物生产工艺；节约能源消耗；重视发展森林作业保护技术。９０年代是木材采运向高技术迈进的１０年，电子计算机，作业机器人、接收卫星信号的环球地理定位系统、遥控以及专家系统等技术将得到推广应用。     

链盘式投苗全自动插条机的研究

链盘式投苗全自动插条机的研制,可为丰产原料林插条作业提供一种新机型,以提高林业机械化装备整体水平.介绍了链盘式投苗全自动插条机整机及其主要机构的设计.     

采伐对森林土壤碳库影响的不确定性

森林土壤有机碳(SOC)是全球碳循环的重要组成部分,然而,多样的森林类型和不同森林经营措施的干扰,使得森林土壤碳库维持机制以及碳固存过程的研究和森林土壤碳库的估算存在较大的变异。作为主要的森林经营措施之一,采伐对森林土壤碳储量以及碳过程均产生直接或间接地影响。为深刻理解森林土壤碳库对于采伐干扰的响应,本文综述了近十几年来不同采伐方式下森林土壤碳储量及其主要碳排放过程——土壤呼吸的研究现状,综合分析了采伐方式、森林类型、采伐剩余物管理以及微生物因子等对土壤碳库的影响及其不确定性,并在此基础上阐述了研究中尚未解决的主要问题:1)生物因子作为CO₂产生的主体,在应对干扰时结构、功能的变化直接影响着土壤碳排放以及碳固定,但它们具体作用机制以及过程并不清楚,需展开进一步的调查;2)不同森林采伐方式对不同地区和不同类型森林土壤的影响的复杂性,亟须在进一步加强实验研究的基础上,发展森林土壤碳循环的过程或机理模型,为森林生态系统完整的碳循环过程表达及碳计量提供技术支撑,以期为我国森林经营以及碳汇等方面研究提供参考。     

ROBOT型林木球果采集机

应用林木球果采集机可以在基本不损伤母树的前提下，进行大面积机械化采集林木球果。对森林生态保护，森林更新、减轻工人劳动强度，保 证人工安全，提高采种效率等方面都有重要意义。     

森林理化参数高光谱遥感反演研究进展

近年来, 成像高光谱遥感技术在森林资源信息提取方面取得了进一步发展。文中介绍国内外在轨运行的主要机载和星载高光谱传感器及其技术参数; 分别从叶面积指数和森林含水量反演及森林树种识别3个方面概述国内外基于高光谱遥感技术的森林物理参数反演方法及模型, 从叶绿素含量及森林养分元素反演2个方面概述基于高光谱遥感技术的森林化学参数反演方法及模型; 分析目前研究中存在的主要技术问题, 并展望其应用和研究前景。     

Modelling the effects of forest management intensification on base cation concentrations in soil water and on tree growth in spruce forests in Sweden

The study investigated the effects of forest residue extraction on tree growth and base cations concentrations in soil water under different climatic conditions in Sweden. For this purpose, the dynamic model ForSAFE was used to compare the effects of whole-tree harvesting and stem harvesting on tree biomass and the soil solution over time at 6 different forest sites. The study confirmed the results from experimental sites showing a temporary reduction of base cation concentration in the soil solution for a period of 20–30 years after whole-tree harvesting. The model showed that this was mainly caused by the reduced inputs of organic material after residue extraction and thereby reduced nutrient mineralisation in the soil. The model results also showed that whole-tree harvesting can affect tree growth at nitrogen-poor forest sites, such as the ones in northern Sweden, due to the decrease of nitrogen availability after residue removal. Possible ways of reducing this impact could be to compensate the losses with fertilisation or extract residue without foliage in areas of Sweden with low nitrogen deposition. The study highlighted the need to better understand the medium- and long-term effects of whole-tree harvesting on tree growth, since the results suggested that reduced tree growth after whole-tree harvesting could be only temporary. However, these results do not account for prolonged extraction of forest residues that could progressively deplete nutrient pools and lead to permanent effects on tree growth.