林火与水土流失

本文综述了林地用火与水土流失关系, 阐明在北方及南方平原林地"规定用火"或"迹地用火"后, 土壤渗透性能得到改善, 水土流失较为轻微; 而在南方山区, 强度火烧后水土流失较为严重, 陡坡地段可蚀性较强的土壤水土流失尤为严重。根据火后土壤生境特点及用火现状, 指出林业用火与耕作制度有机组合, 形成特定的"农林业系统", 将为南方林业生产带来重大改革。     

太行山片麻岩低山区水土流失规律研究

水土流失规律是配置水土保持林的依据,也是进行山区治理和开发的基础。不同性质岩石发育形成的土壤其水土流失特点不同。根据试验观测数据和洪水灾害考察结果,结合历史统计资料,对河北太行山的主要类型岩石———片麻岩低山区的水土流失特点进行了初步研究。结果表明:坡面面蚀发生范围广,程度重,但强度不大;重力侵蚀的诱因是暴雨,多发生在坡度大于35°的陡坡坡面;水的流失是低山丘陵区坡面水土流失的重要形式。     

山地林道路面土壤侵蚀的研究

本文采用标桩法和侵蚀沟调查法,研究了山地林道路面土壤侵蚀的内在规律、建立了侵蚀量与时间、坡长和坡度三个因子的关系。     

Erosive phenomenon in heavy snow mountainous regions in Japan

This paper reviews the studies conducted in Japan on the erosion caused by snow cover movement and presents erosion control measures and future visions about forest management in heavy snow regions. Japan is one of the heaviest snowfall countries in the world, more than half of whose land is situated in heavy snow regions. In addition, a large part of this country has steep mountain sites. Because of these geographical features, erosion is frequently caused by snow cover movement on mountain slopes and a lot of research on this phenomenon has been conducted. Snow-induced erosion is generated at forest fire sites, deforestation sites, and plantations by stumps uprooting, pulled-out bushes, and topsoil movement induced by snow cover movement. Due to its occurrence mechanism, the depth of the erosion is very shallow, 60 cm or less. The erosion area ranges from less than 10 m² to several hectares. In general, the number of small erosions, less than 100 m², is very large. The geomorphic features that generate snow-induced erosion almost always correspond to those of avalanche slopes. As for geological characteristics, snow-induced erosion is found in the Neogene area or older. The environment surrounding the snow-induced erosion sites is very harsh, so development of reforestation technology is still in the trial-and-error stage. In order to prevent additional devastation in heavy snow regions, clarification of slope erosive phenomenon from the aspect of slope stability under the snow cover, and progress in the research for establishment of diverse management of forest are required. Recipient of the Japanese Forestry Society Award 1998.     

山地丘陵坡度与林业施策问题的探讨

林业施策、森林经营与坡度关系密切。决策者通常依据山地丘陵坡度的大小制定各种技术体系规定,开展森林经营,决策层甚至将坡度作为制定政策的必要条件。通过分析坡度与林业法律法规、森林经营、水土流失、地类划分、森林资源调查的关系,提出了五点建议,旨在为决策者提供参考。     

Mitigating effects of slash on soil disturbance in ground-based skidding operations

Reinforcement of skid trails with slash has been shown to reduce soil disturbances, but there have not been any studies documenting the mitigating effects following traffic of harvest equipment traffic on steep mountainous skid trails. The objective of this study was to quantify potentially mitigating effects of slash cover on soil compaction and rutting on skid trails in mountainous hardwood forests. The effects of the placement of no slash (bare soil), light density slash (7.5 kg m^?2) and heavy density slash (17.5 kg m^?2) in a skid trail following one, five, and nine machine passes on both gentle slopes <20% and steep slopes >20% in a downhill skidding operation by a steel-tracked skidder were studied. Bulk density and rut depth increased following harvest equipment traffic on both slope gradients. Compared to bare soils, soil bulk density was not significantly reduced by light slash density; however, soil bulk density was significantly reduced by heavy slash up to five machine passes on steep slopes. Light and heavy slash significantly reduced rut depth in both slope classes. The study revealed a high protective role of slash, particularly on steep skid trails. However, benefits of slash to mitigate soil compaction were limited to five passes, after which the slash deteriorated and only provided benefits against rutting.     

鄂西山地退耕还林模式探讨

鄂西山区是湖北省先期开展退耕还林试点工作的主要区域,通过深入调查研究与科学论证,提出了陡坡退耕地生态林治理、中山坡地水保林治理、坡耕地栽植生物埂治理、坡耕地林草间作治理、低山丘陵河谷生态林治理5种适合鄂西山地生态建设的典型生态治理模式。同时,分析了各种模式的特点、技术方案及适应范围。     

遥感数据分析林区的植被和土壤侵蚀特征

以大兴安岭根河林业局潮查林场为试验区,选择合适时间和空间分辨率的卫星遥感TM数据,从中提取植被类型等有关特征及其空间分布等信息,并将有关的信息转化为通用水土流失方程(USLE)中的地面覆盖因子,计算试验区的土壤侵蚀量,进行侵蚀强度区分,生成土壤侵蚀强度图.结果表明:试验区的水土流失主要受坡度的影响.土壤侵蚀强度图与林相图进行空间叠加分析,获得土壤侵蚀严重的小班分布,从而为试验区的水土保持和流域管理提供依据.     

四川退耕还林可持续经营模式探讨

退耕地是具有一定高度和坡度的特殊土地体系，受地形因素和自然规律的综合作用，孕育了经营模式上的多样性和复杂性。在分析四川水土流失现状和退耕还林工程总体布局的基础上，设计退耕还林经营模式，从宏观上提出特殊区域地方特色的退耕还林模式，以指导退耕还林工程。     

盈江县沙化土地的综合治理

山高坡陡，切割强烈；降水丰富，降水年内分配不均；土层深厚，土体疏松等是盈江县沙化土地形成的主要自然因素。森林植被遭到破坏，坡耕地面积逐年增加等是盈江县沙化土地形成的主要人为因素。盈江县现有沙化土地面积2520.5hm^2，有流动沙地、兰固定沙地、固定沙地、沙改田4个沙化土地类型。通过长期的治理，沙化土地各类型面积及利用状况发生明显变化，总体发展趋势呈现逆转，沙化土地得到有效利用。今后需以治理水土流失为中心，采取生物措施、工程措施、农业措施相结合，开发利用并举的综合治理措施。     

Effect of conversion of farmland to forest or grassland on soil erosion intensity changes in Yanhe River Basin, Loess Plateau of China

Dynamic changes of soil erosion affected by conversion of farmland to forest or grassland in the Yanhe River Basin were analyzed based on the revised universal soil loss equation (RUSLE). The RUSLE variables were selected and calculated reasonably using the GIS technique. Results show that: 1) After the conversion of farmland to forest or grassland, soil erosion decreased greatly. Compared with soil erosion in period of 1986 to 1997, the soil erosion amount had been reduced on the average by 30.6% by 2000; 2) Of the different land uses, slope farmland, especially the steep slope land had the greatest impact on soil erosion. The conversion of forest or grassland was the main driving force for the reduction of soil erosion; 3) In the short term, soil erosion was mainly controlled by C-factor, implying that the adjustment of land use structure might be an effective approach to reduce soil erosion. __________ Translated from Science of Soil and Water Conversation, 2007, 5(4): 27–33 [译自: 中国水土保持科学]     

滇东北山区生态环境恢复与重建探析

滇东北山区山高坡陡,水土流失严重,地质灾害频繁,是云南省生态环境恶化、人民生活贫困的特困山区之一。严重的水土流失,构成了对长江中下游地区的危害日益加剧。坡耕地是水土流失的主体,加快退耕还林步伐和加速坡耕地治理是当务之急。在当前实施西部大开发战略中,应把滇东北山区生态环境恢复与重建纳入重要议事日程,建议从加快生态经济型防护林(草)体系建设,建立滇东北生态经济科技示范园区,实行生态移民,积极进行水土保持型生态农业建设,强化法制意识,依法保护和治理生态环境和控制人口增长,提高人口素质。     

关于林业发展战略研究问题

文中阐述了林业发展战略研究的任务及其必要性,还分析了我国基本国情和林业面临的主要问题。根据我国自然生态和社会经济条件在地域上的分异,作者提出了关于林业战略布局和重点的构想。文章就各重点区域所处的地位、作用、存在问题和解决途径分别作了具体论述。     

广西石漠化地区环境因子对土壤肥力的影响研究

以广西17个典型岩溶地貌县域的石漠化区域土壤为研究对象,采用野外取样调查和实验室检测分析方法,研究石漠化区域环境因子植被覆盖度、坡度、坡位对土壤肥力的影响。结果表明：土壤水解氮、速效磷和有机质随植被覆盖度增加而增加;坡度增加不利于有机质积累;坡位越低,土壤肥力各项指标越高。建议在坡度陡、坡位高的地方种植浅根性或攀爬类植物或农作物,增加植被覆盖度以提高土壤肥力,改善石漠化状况。     

长江流域森林植被的水土保持作用

根据长江流域特别是三峡库区的调查和研究资料，论述了长江流域历史上自然植被的破坏情况，指出自然植被的破坏历史，就是长江流域水土流失的发展史。对三峡库区１９个县市５０年代与８０年代森林覆盖率比较和森林现状分析，表明三峡库区森林植被破坏十分严重，目前森林覆盖率平均只有１９．５％；同时库区自然植被出现逆向演替，即植被退化，并指出了植被退化的一般规律。根据对三峡库区不同土地利用状况下土壤侵蚀和产沙情况的调查资料分析，表明这一区域侵蚀产沙的主要面上来源是沿江的农田，库区长江河谷两岸大量存在的崩塌和滑坡也是侵蚀产沙重要的点来源。通过对三峡库区各类土地利用方式侵蚀程度、面积和比例的统计分析，反映出三峡库区土壤侵蚀状况是随着森林植被的逆向演替而相应发展和加剧的，森林植被保护和建设是长江流域水土保持的根本性措施。     

创新管理模式,提升森林资源质量——对兴国林业发展的思考与建议对策

江西省兴国县曾经是一个水土流失极为严重的山区县,被称为"江南沙漠"。在山上绿起来的阶段性建设目标基本实现后,兴国县森林资源质量存在问题,要充分发挥林业的生态、经济和景观效益,就必须提升森林资源质量。     

层次分析法在森林土壤持水评价中的应用

不同森林类型的持水功能是当今研究的热点问题之一,针对小兴安岭南部山区3种主要森林类型土壤和枯落物持水性能,从层次选择模型和判断矩阵的构建入手,在设定多层次指标体系的基础上采用AHP法计算各指标权重,以确定森林的持水能力强弱。结果表明：在总排序中,所构建的判断矩阵的随机一致性比率（Consistency Ratio）CR=0．03337414〈0．10,具有满意的一致性和可靠性。选择出的土壤持水性能较强的森林类型与现实生产实际相吻合,说明层次分析法在不同森林类型土壤持水性能的定量化选择上的应用是可行的。     

红松陡坡丛状造林效果分析

在立地条件较差的陡坡山地进行丛状造林,可以充分利用一切可以利用的山地,提高造林的成活率和保存率,迅速恢复森林的生态环境。通过对红松(Pinus koraiensis Sieb.et Zucc.)陡坡丛状造林效果的研究分析,结果表明,陡坡丛状造林以3株一丛或5株一丛为宜,在不易发生水土流失的林地,初植密度以4 400株.hm-2为宜;立地条件较差,坡度较陡,易发生水土流失的林地,以6 600株.hm-2为宜;丛状造林保存率能达到70%以上,蓄积量比对照区提高38%～50%。     

梁山慈竹在退耕还林中的水土保持效应研究

利用小型径流观测场对比观测降雨时间集中的梁山慈竹林和未退耕种植红薯的耕地的17次降雨、10次水土流失过程进行效益对比,分析侵蚀量、径流量与降雨因子的关系。结果表明,退耕还梁山慈竹林的穿透降水率为89.14%,茎流率平均为1.57%,林冠截持降水率为9.29%;凋落物层的最大持水量约为27.54 t.hm-2,相当于水深2.4～3.3 mm,占降水量的14.46%～19.88%;与未退耕地相比,梁山慈竹林的平均径流量比耕地减少24.6%,而耕地侵蚀量约是林地的4.7倍,林地降水的泥沙侵蚀平均减少量达到78.56%。梁山慈竹有较好的水土保持作用,能够明显地减少地表径流和泥沙侵蚀。     

Benefit measurement of the soil and water conservation for ecological forestry engineering

IntroductionThelossofwaterandsoilhasbeentheglobatprobIem.Itstotalareais25millionkm'.or16.8%ofgIobalIandarea.ThefertileSurfacesoilof6obiIIiontflowsintoriverseachyeaIBecauseofsoiIcorrosionthelandof21obillionhm2hasIostfertiIityand...,otbeusedasagricuIturalIand.HumanrecognizestheseverityofIossofwaterandsoilwhileheusesjandresources.Thediff6rentmeasuresarebeingtakeninordertoincreasesoilandwaterconservation.Sev-eralecoIogicaIforestryengineeringshavebeencar-riedoutInChinaforenvironmentconserva…