浅议精确林业

精确林业是由信息技术支持的现代化林业操作技术与管理系统,是个新生事物。本文介绍了精确林业含义、主要支撑技术、发展现状等,可以帮助林业工作者正确认识发展精确林业的重要性。     

苏州林业建设中精确林业技术的应用现状及展望

简述了精确林业的概念和作用,介绍了精确林业技术在苏州林业建设中的应用概况,并对精确林业技术在苏州林业建设中的应用前景作了探讨。     

精确林业传感技术和无线传感器网络研究进展

林业生产过程由多种生产作业分享时间和资源,需要实现以最少资源投入、最小环境危害、获得最大林业收益的精确林业目标。笔者围绕精确林业,综述了树木生长信息检测、树木胁迫信息检测、立木识别、林区立地检测、林区气候监测等林业作业目标识别与作业环境监测,以及林业机械作业参数监控的传感技术,并就林业多传感器融合、林业无线传感器网络及新型林业传感器进行了分析并提出研发建议,其中首次将精确林业传感器从工作环境角度分为固定式、移动式和随机式传感器3类,分析并提出相应林业传感器供电方式的建议。     

浅谈GPS技术在林业中的应用

文章简单介绍了GPS系统,并结合GPS的特点提出了一些GPS在林业中的一些应用。重点讨论了GPS技术在林业面积测量,森林资源管理中的应用及使用方法,阐明了GPS技术在林业中的广泛应用必将给林业带来向着精确、高效、现代化的方向发展。     

智能决策支持系统及其在林业中的应用研究

在分析专家系统、智能决策支持系统的基础上，探讨智能决策支持系统在林业中的应用，提出了精确林业工程智能决策支持系统平台设计框图及其系统功能。     

GPS结合GIS在宁都林业工作中的应用

GPS、GIS作为一种崭新的技术手段正被许多行业所应用,它的准确、方便、快捷正改变着行业的发展方式.GPS及GIS在林业工作的发展与应用加速了森林资源经营管理由粗放型向集约型、精确型的发展.宁都林业近几年在这方面做了一些有益的探索,取得了一些成绩和经验,为宁都林业发展提供了有力的技术支撑.     

物联网技术在我国智慧林业建设中的应用现状及发展策略

智慧林业是现代林业发展的新方向,是改善生态环境、提高林业生产力、促进林业现代化和建设美丽中国的必然要求。物联网技术具有实时感知、快速响应、精确控制等特点,在林业信息感知、获取等方面起着重要作用,是智慧林业的关键技术之一。文中简介物联网相关技术,概述国内外利用林业物联网技术在森林资源监管、林业灾害监控、林业生态监控、林产品安全质量监管等智慧林业建设中取得的应用进展,比较其在国内外智慧林业建设发展现状中的差异,探讨林业物联网技术在标准建设、林业专用传感器研究、林业信息传输、林业信息处理等方面存在的不足,提出我国林业物联网的发展策略,以期为我国林业物联网的发展及智慧林业建设提供参考。     

县级森林资源管理系统的构建

信息技术的发展为林业的高效管理创造了有利条件.资源管理系统作为现代化森林资源管理的重要工具,是发展"数字林业"必备的系统工具.针对县级森林资源,由于发展水平的制约,构建森林资源管理系统还需要结合实际,分析存在的制约因素,制定精确、科学的对策,推动森林资源信息化的管理水平,为实现数字化林业奠定坚实的基础.     

辽宁省林业外业调查采集系统设计

基于Android的移动端林业调查采集系统扩展性和兼容性强,应用广泛,是移动端采集软件的发展趋势。文章介绍了辽宁省林业外业调查采集系统的开发环境、总体设计理念、功能模块和系统特色,系统创新设计了精确采点、影像批量加载、小班定位、地图纠偏、造林核查等功能,极大地提高了林业外业采集的工作效率,尤其是外业调查结果与内业森林资源管理系统的无缝衔接设计和面向多业务的一体化框架设计,对林业行业外业调查系统软件的设计和发展能够起到一定的借鉴意义。     

3S技术在我国精准林业中的应用及前景

一、精准林业概念的提出及其内涵 精准林业是指尽可能地采用现代高新科学技术建立一体化、智能化、数字化的现代林业技术体系，进而使森林最大限度地发挥生态、经济、社会效益，实现森林可持续经营和区域可持续发展新的林业建设、管理及经营模式。“精准林业”的概念，是北京林业大学冯仲科教授于2000年在他的一篇论文中首次提出的。他认为，精准林业的技术核心在于对森林生长实现精确的定量计测和监测，从而克服传统粗放林业体系中各种不可定量因素所带来的弊端。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.