马尾松幼龄林地水土流失的研究

在马尾松造林后的４年内,设置径流小区对林地水土流失进行定位观测。结果表明：不同造林整地方式的林地水土及其养分流失量,第１年最大,全垦林地径流量１０４９７０ｔ／ｈｍ２、土壤流失量５３５ｔ／ｈｍ２、径流养分流失量１２９１ｋｇ／ｈｍ２、土壤养分流失量４１０４４ｋｇ／ｈｍ２;穴垦林地分别为９２１２０ｔ／ｈｍ２、５７９ｔ／ｈｍ２、１０８０ｋｇ／ｈｍ２、４６７９３ｋｇ／ｈｍ２;荒坡地分别为１１９５５０ｔ／ｈｍ２、２８７ｔ／ｈｍ２、８９６ｋｇ／ｈｍ２、２０００５ｋｇ／ｈｍ２。第２～４年流失量依次降低。３种整地方式均以第１年流失最严重、第４年流失很轻微,第２、第３年全垦＞穴垦＞荒坡,流失量较轻。观测结果可为马尾松速生丰产林营建与地力维护的方案制定提供依据。     

营林措施对杉木幼林地水土流失的影响

通过建立１６个径流小区,对不同整地方式、抚育方式、间种绿肥和营造林模式等营林措施的杉木造林地的水土流失进行了５年的定位观测研究,结果表明,不同整地方式林地５年的土壤流失量表现为全垦＞带垦＞穴垦,穴垦比全垦、带垦分别减少４０３３％和２５４８％的土壤流失量;不同抚育方式林地５年土壤流失量表现为扩穴连带抚育（９８６９５ｔ／ｈｍ２）＞块状抚育（９２５８７ｔ／ｈｍ２）＞不抚育（４０６６ｔ／ｈｍ２）,块状抚育比扩穴连带抚育减少６１９％的土壤流失;不同造林模式林地５年的水、土、肥流失均表现为：传统模式＞世行模式＞生态型模式,其中世行造林模式林地水、土、有机质和养分（Ｎ、Ｐ、Ｋ）流失量比传统模式造林地可分别减少６６０％的水、６０８％的土壤、１０２６％的有机质流失和１０３６％的养分流失量;在造林地上间种绿肥增加地表覆盖是防治林地水土流失的有效措施之一。     

湿地松新造幼林地水土流失规律研究

为了解高度集约化经营湿地松林对环境的影响,以湿地松新造幼林地为对象,设置径流场进行了连续６年系统定位观测研究。结果表明,观测期间降水量为６４３５３ｍｍ,林地径流量为１６１１２４１ｔ／ｈｍ２,泥沙流失量为２７８４４７７７ｋｇ／ｈｍ２,流失Ｎ、Ｐ、Ｋ等主要养分为１３１ｋｇ／ｈｍ２,径流系数为３１６％;在安徽丘岗地区营造湿地松林,实行大块状（８０ｃｍ×８０ｃｍ×５０ｃｍ）整地,并集约经营,不致引起严重的水土流失,造林当年土壤侵蚀模数为１９５５９ｔ／ｈｍ２,属于无明显侵蚀类型,该区可提倡高规格整地和实行集约经营;５～８月为集中降水期,应避免相关营林活动;水土流失量与降水量呈幂函数关系,随着林木生长和植被的恢复,径流量逐渐减少,泥沙流失量则显著减少。     

不同整地马尾松工程幼林地水土保持效益的研究

１９９１～１９９６年,通过建立径流小区的方法,对广西桂平市不同整地马尾松工程幼林地的水、土、肥进行了连续的定位观测。结果表明：不同整地马尾松工程幼林地的年平均液体径流量为全垦（１３４８５０ｔ／ｈｍ２）＞带垦（１１３８３９ｔ／ｈｍ２）＞穴垦（１０９４９１ｔ／ｈｍ２）;年土壤流失量为全垦（９３１３ｔ／ｈｍ２）＞带垦（４０９０ｔ／ｈｍ２）＞穴垦（１９１７ｔ／ｈｍ２）;年平均水土养分流失量为全垦（１６６１７ｋｇ／ｈｍ２）＞带垦（７６２７ｋｇ／ｈｍ２）＞穴垦（３９８２ｋｇ／ｈｍ２）,分别是灌草坡（２０１４ｋｇ／ｈｍ２）的８２５１％、３７８７％和１９７７％。不同整地造林后第６年时的土壤养分含量（有机质、全Ｎ、水解Ｎ、速效Ｋ）比造林前存在下降趋势,下降的总频率为全垦（２０４％）＞带垦（１０６％）＞穴垦（５３％）。结果表明,穴垦整地（４０ｃｍ×４０ｃｍ×３０ｃｍ）马尾松工程幼林地具有显著的水土保持效益。建议在我国南方推广应用。     

蓝桉不同整地方式造林水土流失监测初报

采用径流小区定位观测法，对保山砂页岩发育的山地红壤进行不同整地方式营造蓝桉林，经过三年的监测研究表明：未整地自然土壤侵蚀量达１．６５７～１．４０２ｔ／ｈｍ２·ａ，有机质流失量达８０．４８３～６８．１１３ｋｇ／ｈｍ２·ａ，土壤肥力退化显著；撩壕整地及挖塘整地造林当年土壤侵蚀量分别达３．３６６ｔ／ｈｍ２·ａ及２．４６４ｔ／ｈｍ２·ａ，均属轻度侵蚀级，第二年土壤侵蚀量为０．５９２ｔ／ｈｍ２·ａ及０．３６７ｔ／ｈｍ２·ａ为微度侵蚀。有机质流失量为７５．８１１ｋｇ／ｈｍ２·ａ及４７．１２２ｋｇ／ｈｍ２·ａ。随着桉树幼林生长，林地覆盖度和地表稳定程度增加，土壤侵蚀急剧下降。     

豫西伏牛山区日本落叶松林水文效应研究

测定了豫西伏牛山区日本落叶松林的林冠截流降雨、土壤渗透速度和地表径流。结果表明,生长期林冠截流降雨１８５１ｍｍ,截流率为２４４％,饱和截流量５ｍｍ,截流量随降雨量增加而增加,截流率随降雨量的增加而减少;土壤渗透速度在１０ｍｍ．ｍｉｎ－１左右;地表径流系数在１１％～２０％之间;泥沙流失量７５×１０３ｋｇ·ｈｍ－２～１２×１０３ｋｇ·ｈｍ－２;土壤渗透速度、地表径流量随造林整地方式不同而变化。     

杉木幼林水土流失及养分损耗的研究

对设置于江西分宜县中国林科院亚林中心５组不同整地方式水土流失多年观测结果进行了综合分析。地表径流量从１４７～１３２２ｍｍ,平均为５４６ｍｍ。径流系数从００９８％～０８５２％,平均为０３６９％,年均土壤侵蚀量从０００５１～０２５１０ｔ／ｈｍ２,平均为０１００５ｔ／ｈｍ２。整个幼龄林阶段,地表径流量５４６０ｍ３／ｈｍ２,土壤侵蚀总量为１００５０ｋｇ／ｈｍ２;养分损失量：Ｎ１９５６０ｋｇ／ｈｍ２,Ｐ２２３７０ｋｇ／ｈｍ２,Ｋ２６７７７ｋｇ／ｈｍ２,有机质５００４９ｋｇ／ｈｍ２。分析认为在板、页岩风化物上发育的黄红壤,特别是腐植质层较厚结构良好的土壤,具有较强的抗腐蚀能力,不管采用哪种整地方式均无明显的水土流失和养分损失,但比较而言,以穴垦为最佳选择。水土流失还不是此种土壤上杉木人工林的地力退化的最主要的原因。     

The Property of Soil Loss and the Time Distribution on Forest Stand in Granite Region of the Three-gorges of the Yangtze River

本文研究了长江三峡花岗岩地区林地土壤流失特性．结果表明由鳞片状面蚀导致的土壤流失量月分布与月降雨量的分布趋势基本一致，二者呈现出较为明显的线性相关关系．植物盖度≥０．７０的林地土壤流失多集中发生在６～９月份，土壤流失量在５０００ｔ·ｋｍ－２·ａ－１以下．盖度＜０．７的林地土壤流失年内分布时间多在３～１０月份，土壤流失量为５００～６０００ｔ·ｋｍ－２·ａ－１．     

主要树种新造丰产林地水土流失定位观测研究

本文对设置在世界银行贷款“国家造林项目”１２个项目省（区）的７个主要造林树种新造丰产林地上的１８个水土流失定位观测点连续５年的观测数据进行了综合分析。结果表明，造林施工会导致造林地不同程度的水土流失，在全部１８个观测点中，在发生水土流失相对最严重的造林后当年或次年，８４％的点只发生了微度或轻度土壤侵蚀，１１％的点发生了中重度土壤侵蚀，只有１个点发生了重度土壤侵蚀。水土流失主要发生在造林当年和次年，从造林后第３年（或第２年）起，地表径流量降低到一定水平，以后历年随降雨量波动，而土壤流失量则迅速减少，以后逐渐消失。高强度的整地作业是造成水土流失的重要原因，全垦整地与穴垦整地相比可使土壤流失量增加１００％。造林地土壤养分流失量年变化与水土流失年变化同步，在流失的养分总量中，土体有机质＞土体全Ｎ、Ｐ、Ｋ＞水体Ｎ、Ｐ、Ｋ＞土体速效Ｎ、Ｐ、Ｋ。建议改变大强度造林清场、整地和幼林抚育作业方式，以减少或消除造林地的水土流失。     

对林业建设项目的多准则模糊评估

本文应用多准则模糊决策，对赤峰市松山区拟定开发建设的营造２０４ｈｍ２落叶松丰产林、７３ｈｍ２全日光温室蔬菜和２６７ｈｍ２苗圃苹果园３个项目进行了评估，为建设项目安排资金、技术和组织实施提供了科学依据。     

干热河谷发展径流林业的潜力

干热河谷是造林困难区域,过去造林遵循以树、草种的选择和造林时间、造林方法的选下来适应或逃避不利因素.但在经济条件制约下,采用现代育苗技术和造林方法受到限制,同时可选树、草资源十分有限,长期以来严重影响造林工作的进行和造林质量的提高.作者提出通过整地和防渗处理,人工引起并拦蓄地表径流,改善林木生长的上壤水分条件,以达到林木在干旱区域正常生长.     

森林水文效应研究进展

地球陆地表面的1/3是森林,森林植被对区域水文过程和水资源的特性产生重大的影响。本文以过去许多研究结论为基础,系统客观地分析和阐述了森林生态系统与水分循环的关系以及森林在各方面的调节功能,旨在寻找其中科学规律,为森林生态环境建设和保护提供科学依据。     

贵州开阳喀斯特山地几种不同植被类型的地表径流研究

对贵州开阳喀斯特山地几种不同植被类型,用设置径流小区方法,观测降雨量及径流量,对各种植被类型的地表径流进行比较。结果表明:几种植被类型中,全年的地表径流量为:退耕还林新造林>针叶林>针阔混交林>阔叶林>灌木林。不同植被类型对径流有着不同的调节作用,几种植被对径流的调节作用大小为:灌木林>阔叶林>针阔混交林>针叶林>退耕还林新造林。     

杉木幼林地水土流失规律的研究

在4个坡度级的山场上建立12个径流小区,连续4年对炼山的杉木幼林地定位观测,分析了杉木幼林从炼山起至郁闭止,林地的水、土、肥流失的季节和年度的变化规律,划分了水土流失时期,分析坡度与流失的关系。结果指出,炼山后第一年水、土、肥流失最严重,泥沙冲刷量达24.81t·ha~(-1),以后逐年递减,至第4年趋于稳定,与不炼山的接近。常规幼林抚育措施加剧了林地水土流失,建议调整幼林抚育方式和季节,并采取必要的生物措施。     

Managing water use from forest plantations

Tree plantations have developed a reputation for excessive water use, with age commonly used as an explanatory variable to predict water loss – but many factors have the potential to affect plantation water use, and few of these alternatives have been considered. Changes in forest cover may be correlated with other environmental changes that may affect precipitation, transpiration, and runoff, indicating that more thorough investigation is required in both field and simulation studies. Several factors influencing water use by plantations are amenable to management control, so there is scope to design and manage forest plantations deliberately for water use efficiency. Research is needed to elucidate the relative contributions of forests and grasslands to atmospheric moisture; the influence of vegetation on the distribution of rainfall; the effect of air turbulence from plantation edges, firebreaks and streamlines; the potential to modify atmospheric coupling of forest plantations through plantation design, including the use of mixed species plantations, and by softening hard edges by thinning and pruning plantation edges.     

Review of runoff forestry in Shanxi Province and sustainable development tactics of forestry

IntroductionInaridandsemi-aridareas,shortageofwaterresourceswasamajorf8ctorlimitingsustainabledevelopmentofagricuIture,forestryandanimalhus-bandryItreIateddirectlywithlocaltheecoIogicaIforestryandthesocial/economicdeveIopment.lnShanxiProvince,themountainousareasholdsabundantland,Iightandheatresources.buttheseoriginalresourcessuperioritycannotbeusedeff6ctivelybyplantcommunitybecauseofaIong-termsuff6ringfromairorsoildroughtandwatershortage.Especially,becauseofthedestroyactivi-tiesonforestryi…     

黄土高原荒坡径流生产潜力研究

运用“单株平衡法”，测定了油松、刺槐优势木单株年耗水量。并以此作为林地水分生产力评价的依据，提出了“期望最低水分潜势标准”及“降雨径流期望生产力指数”，并指出径流系数是决定径流生产力的主要因素。对黄土高原荒坡径流生产力进行了必要的理论探讨。计算求得了利用自然坡面径流，油松、刺槐可望成林、成材的降雨量下限均为５００ｍｍ；在４００ｍｍ降水地区，仅能形成郁闭度为０．３左右的稀疏林地。     

Biogeochemical cycling in forest soils of the eastern Sierra Nevada Mountains,USA

We review some of the unique features of biogeochemical cycling in forests of the eastern Sierra Nevada Mountains, USA. As is the case for most arid and semi-arid ecosystems, spatial and temporal variability in nutrient contents and fluxes are quite high. “Islands of fertility” are common in these forests, a result of spatial variations in both litterfall and decomposition rates. Dry summer conditions greatly inhibit biological activity in the O horizon, and thus most annual litter decomposition takes place beneath the snowpack when moisture is available. Snowmelt duration is shortened near tree boles because of local warming, resulting in earlier drying of the O horizon, significantly lower decomposition rates, and increased O horizon mass. Water and nutrient fluxes vary spatially because of snowdrift in winter and surface runoff over hydrophobic soils in summer and fall. Moisture variability in the vertical as well as the horizontal dimension has significant consequences for nutrient fluxes. Because of the very dry summers, rooting in the O horizons is absent in these forests, and thus competition between microbes and trees for nutrients in that horizon is non-existent. Nutrients mineralized from the O horizon and not taken up by plants enrich runoff through the O horizons over hydrophobic mineral soils, resulting in very high concentrations of inorganic N and P in runoff waters. Substantial temporal variations in water and nutrient fluxes occur on a seasonal (with snowmelt being the dominant hydrologic event of the year), annual, and decadal basis. The most significant temporal variation is due to periodic fire, which we estimate causes annualized N losses that are two orders of magnitude greater than those associated with leaching and runoff. We hypothesize that fire suppression during the 20th century may have contributed to the deterioration of nearby Lake Tahoe by allowing buildups of N and P in O horizons which could subsequently leach from the terrestrial ecosystem to the Lake in runoff. In general, we conclude that biogeochemical cycling in these forests is characterized by greater spatial and temporal variability than in more mesic forest ecosystems.     

亚热带杉木、马尾松人工林水文功能的研究

1984-1990年,在江西省分宜县山下林场,对22年生杉木,马尾松人工林中的主要水文要素:降雨、林冠截留、树干茎流、土壤水分含量、径流及各种水的养分含量进行了测定,结果表明:人工林林冠的截留率为10.20-17.56％,茎流率为0.98-1.40％。土壤层较薄,含水率低,水文物理性质较差,土壤蓄渗性能较弱。林地径流量较小,且多为表层流。降雨输入林地的养分量大于径流的输出量。林内雨和树干茎流淋溶的养分量占养分还原总量的48-53％。其淋溶的K、Mg、N的养分量超过凋落物归还量。     

A comparative analysis of forest cover and catchment water yield relationships in northern China

During the past few decades, China has implemented several large-scale forestation programs that have increased forest cover from 16.0% in the 1980s to 20.4% in 2009. In northern China, water is the most sensitive and limiting ecological factor. Understanding the dynamic interactions between forest ecosystems and water in different regions is essential for maximizing forest ecosystem services. We examined forest cover and runoff relationships in northern China using published data from a variety of sources. In the Loess Plateau region, forest cover is not correlated with annual precipitation (r = 0.08, p > 0.05) at micro (<50 km²) and meso scales (50-1000 km²), while they are positively correlated at macro (>1000 km²) scale (r = 0.77, p < 0.05). Moreover, forest cover is negatively correlated with the runoff coefficient (r = −0.64, p < 0.05). In Northwest China, natural forest distribution is highly correlated with annual precipitation (r = 0.48, p < 0.05) but not with the runoff coefficient (r = −0.09, p > 0.05). In Northeast China, we found a positive relationship between forest cover and the runoff coefficient (r = 0.77, p < 0.05), but the correlation between forest cover and precipitation was not significant (r = 0.28, p > 0.05). The multiple stepwise regression analysis indicated that runoff was influenced by altitude, annual precipitation, forest cover, and PET (potential evapotranspiration) in Northeast China. We concluded that geographic differences could mask the true role of forests in the partitioning of rainfall into runoff and evapotranspiration (ET) in a catchment. In determining the forest-water relationship, one must consider climatic controls on ET in addition to forest cover. Forests could potentially enhance the complementary relationship between ET and PET. Therefore, a greater amount of ET in forested areas may decrease the PET on a regional scale.