森林病虫灾害的天空地协同监测技术体系示范

针对森林病虫灾害监测周期性、全覆盖和及时性的特点,笔者提出了建立天空地协同监测技术体系的解决方案,并在山西省关帝山国有林管理局二道川林场进行了应用示范。初步实现了小班级灾害的月度监测、树丛级(点状和块状)灾害的年度监测、单木级灾害的精准监测,以及地面调查数据的准实时共享,可为山西省建立森林病虫害监测预警体系提供参考。     

“高分辨率遥感林业应用技术与服务平台”项目荣获2017年度地理信息科技进步奖一等奖

<正>"高分辨率对地观测系统"(简称高分专项)是《国家中长期科学和技术发展规划纲要(2006-2020年)》中部署的16个国家重大专项之一。"高分辨率遥感林业应用技术与服务平台"是为支撑高分专项(民用部分)应用系统建设而立项实施的行业应用示范项目。该项目成果已直接应用于全国森林资源、湿地资源、荒漠化、林业生态工程、森林灾害等的调查和监测业务,促进了国产高分遥感数据在林业行业的广泛应用,提高了行业的遥     

森林面积多阶遥感监测方法

【目的】从林业数据采集的迫切需求出发,采用遥感技术实现森林资源数据的快速年度出数,以及时掌握区域森林资源变化信息。【方法】建立遥感3阶抽样与地面调查技术相结合的森林资源遥感监测技术体系,并以辽宁省为例,利用2013—2014年高、中、低多源遥感数据,进行基于多阶抽样的省级森林面积监测方法实践。【结果】遥感结合地面样地实测,建立了地面样地与高分样地,高、中分样地以及中、低分样地的森林面积回归模型,其模型确定系数(R2)分别为0.99、0.91和0.70,模型精度较高;基于3阶分层抽样的遥感监测方法得到辽宁省2014年森林面积预测值为590.83×10~4hm~2,森林覆盖率为40.54%,略高于清查结果(40.49%);从抽样精度来看,采用分层抽样方法得到的森林面积最为可靠,抽样精度达99%以上;通过精度分层控制,基于MODIS NDVI阈值法制作了辽宁省森林分布图,实现了辽宁省森林面积和空间分布的年度产出。【结论】基于遥感抽样与地面调查技术相结合的森林面积多阶遥感监测方法可行,既可提高监测成果的时效性,又能缩短成果产出周期,具有很好的应用前景,可为下一步建立全国遥感监测体系提供重要的技术支持。     

基于MODIS-NDVI数据的大区域森林病虫害理赔指数构建及应用

大区域森林病虫害险发展理赔是森林保险面临的紧迫难题。以内蒙古东部森林为试验区,基于时间序列MODIS-NDVI数据、地面调查数据,构建了以旗县为单位的大区域森林病虫害理赔指数,并针对2016年内蒙古东部森林病虫害理赔进行了应用。结果表明,采用理赔指数具有计算简单、覆盖范围广、时空连续的优点,可对重度受灾及针叶林的中度受灾情况进行有效监测,进而能够为森林病虫害灾害的理赔工作提供参考与支持。     

基于XGBoost的高分二号影像树种识别

树种分布是森林资源监测的一个重要指标,也是遥感影像在森林资源监测应用中的难点之一。基于国产高分二号卫星影像数据、森林资源二类调查数据、DEM数据,结合光谱、纹理、指数及地形因子等多种特征,比较支持向量机、随机森林和XGBoost等3种分类算法,根据分类精度选择最优算法(即XGBoost)进行特征筛选,对龙泉市的阔叶树、马尾松、杉木和毛竹等4种主要优势树种进行分类。结果表明:采用XGBoost分类模型的分类总精度为83.88%,Kappa系数0.78,较支持向量机和随机森林分类方法有明显提高。经特征选择后,虽未明显提高树种分类精度,但可以减少特征的冗余,为小样本数据下特征的选取降维提供了一定的参考。     

基于遥感和物联网技术的森林火灾协同监测体系建立

针对我国森林火灾长期以来存在的监测不及时、不准确、林火监测方式独立、数据难以共享等诸多问题,本研究以物联网技术架构为基础,以"3S"技术为支撑,采用气象卫星热红外波段遥感数据解译与地面传感器热红外探测相结合的方法,初步研讨并建立了两位一体的森林火灾协同监测体系,实现数据共享与监测方式的协同,为森林火灾信息及时、准确的获取提供一种新的模式。     

林业部南方林业遙感试验场建场概况

林业部南方林业遥感场是1980年作为长期固定的遥感应用技术试验基地建立的。为此,就必须有一个相应的地面观测体系,配合遥感的需要,为现时及将来长期进行各种遥感试验定期提供地面实况数据,这是建立试验场地固定样地体系的出发点。建立试验场地固定样地体系的目的是为应用遥感手段进行多资源调查、资源动态监测等方面长期提供各种遥感技术所需的实况数据,并兼顾其它科学以及地方森林经营的需要。几年来,场部建成,多次进     

基于高分辨率遥感影像的森林信息提取方法综述

传统的森林资源调查需要耗费大量的人力和物力。高分辨率遥感影像由于具有亚米级的空间分辨率,给森林类型的识别和森林数量因子的测量提供了可能。目前应用高分遥感影像提取森林信息的方法越来越多,通过文献调研,分析高分辨率数据在树高、树冠、树种、郁闭度、蓄积量参数方面的提取方法和存在的问题。对基于高分数据的森林信息提取方法及研究发展趋势进行了展望。     

基于国产高分数据的森林蓄积量反演研究

以内蒙古旺业甸林场为研究区,结合地面调查,对高分二号遥感数据进行预处理,并提取光谱信息、植被指数及纹理信息等48个遥感因子,采用Pearson相关系数法筛选出8个因子进行建模。采用多元线性回归、多层感知机、K-近邻、支持向量机、随机森林模型估测森林蓄积量,得到研究区内森林蓄积量反演图。结果表明:1)高分二号影像提取的遥感因子中,基于二阶矩阵的纹理特征均值(Mean)与森林蓄积量的相关性较高;2)随机森林相对于多元线性、多层感知机、K-近邻、支持向量机等方法具有更好的森林蓄积量估测精度,其相对均方根误差(rRMSE)为25.40%;3)研究区内森林蓄积量高的地区主要分布在西部和东南部;森林蓄积量低的地区主要分布在西北部、中部及北部,与实际调查情况一致。国产高分二号影像利用随机森林算法在森林蓄积量反演方面具有一定的潜力。     

国家森林资源与生态状况综合监测理念及其技术体系——以2007年广东省试点为例

介绍了2007年广东省开展国家森林资源与生态状况综合监测试点时所采用的监测理念与方法体系,供全国开展此类工作借鉴参考。试点以连清固定样地体系为依托,构建了融植被监测系统、林地土壤监测系统、物种多样性监测系统于一体的样地调查体系;设计了森林资源、湿地资源、石漠化土地资源以及森林健康、森林土壤状况、森林景观、森林固碳、涵养水源、保育土壤、生物多样性保护等功能效益的指标体系;形成了以固定样地调查为主体,地面调查结合实验测定,以及遥感监测、模型测算结合指数分析的综合评定技术体系。     

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.