森林影响降水水质研究概述

水质型缺水是当今社会面临的重大难题,充分利用森林对水质的净化调节作用是解决该难题的有效方法之一。文中在归纳国内外森林水质研究历程的基础上,将森林影响水质整个过程划分为大气降水输入,森林林冠层、枯落物层和土壤层再分配,以及溪流输出3个部分,概述这3个部分降水中的不同阴阳化学离子的变化规律及响应机制,分析不同空间层次（林冠层、枯落物层和土壤层）对水质的影响因素和理化过程;探讨了存在的问题并提出未来研究重点:细化研究枯落物层和土壤层与降水发生相互作用的内在机理,重视森林影响溪水和周边流域水质的作用机制,丰富研究树种,并将野外试验与室内控制试验相结合,提高实验结果的准确性,同时在时间和空间尺度上进行长期和系统观测,定量评价森林净化水质的能力,从而了解森林净化水源的作用机制,为我国解决水质型缺水问题和相关研究提供参考。     

森林采伐作业对迹地径流水质的影响

在综合国内外有关研究成果基础上,本文对森林采伐作业对迹地径流水质的影响进行了研究,结果表明,采伐强度越大,对水质影响越显著。     

森林对水环境影响浅议

通过调查研究和资料分析认为,大面积优质森林可增加林区大气降水,使河川径流总量、平枯期流量和地下水增加;同时具有减少洪水流量,净化水质等有益作用。     

鸡公山森林生态站固定样地植物群落调查分析

以河南省鸡公山森林生态站6块固定样地植物群落调查为研究对象,按三级(植被型、群系、群丛)对植被类型进行划分,描述了各个样地的植物群落特征,对主要植物进行了详细介绍,从各植被层高度和数量上分析相互影响因素,最后对造成相近样地植被不同的影响因子进行分析。     

我国森林水文研究现状及发展趋势概述

在简要介绍我国森林水文研究历史的基础上，概述了我国森林与降水、径流、蒸发散、水循环和水质等方面的研究现状及主要成果，并对我国森林水文研究的未来民展方向进行了初步分析。     

鸡公山自然保护区森林植被生物量及活碳蓄积量研究

运用鸡公山科学考察资料及1999年森林资源清查资料,采用森林材积源生物量推算方法研究了鸡公山森林植被生物量及其活碳蓄积量。结果表明:鸡公山森林植被生物量总值为309 202t,平均森林植被生物量为111.7t／hm2,高于全国平均水平(77.4t／hm2);鸡公山森林植被的总活碳蓄积量为154 601t,平均活碳密度为56MgC／hm2,高于中国森林植被活碳密度的平均水平(38.7 MgC／hm2),但低于全球平均碳密度(86MgC／hm2)。不同林型活碳蓄积密度分析结果表明,马尾松、杉木和栎类林木的活碳蓄积密度分别为30MgC／hm2,39 MgC／hm2和70MgC／hm2,均高于全国同类型森林植物的活碳蓄积密度的平均值,而次生阔叶混交林的碳蓄积密度略低于全国平均水平。鸡公山自然保护区67％的森林为中龄林,27％的森林为幼龄林,在增加碳蓄积方面还有巨大的潜力。     

丹江口库区主要森林类型树干茎流研究

对丹江口库区马尾松林、柏木林和栎类阔叶林3种主要森林类型及单木树干茎流特征进行了研究,结果表明:3种森林类型树干茎流率为0.58%～7.69%,树干茎流量与降水量成线性相关,回归方程达到极显著水平;不同树种间的树干茎流量差异显著,影响树干茎流量的主要因子是冠型结构、胸径、树皮特征和分枝角度。     

阿什河源头水源涵养林在水分传输过程中对水质的影响

对阿什河源头地表水来源过程中各环节(包括大气降水、穿透水、树干径流和地表径流)的水化学性质进行分析比较.结果表明:树干径流的酸化最为明显,地表径流对林分水质酸化有很好的缓冲作用;大气降水经过落叶松人工林生态系统后,穿透水和树干径流的电导率、总溶解固体、K和Mg元素含量增加;穿透水7、8、9月Na元素含量都低于大气降水,为负淋溶;对穿透水、树干径流和地表径流而言,Zn元素含量在观测时间内变化趋势相同,都是6-9月逐渐降低;各月树干径流和地表径流的Mn和Fe元素平均含量都高于大气降水和穿透水;地表径流经过林地土壤层的深层交换和净化后汇集成溪水,浊度和总溶解固体含量明显降低;溪水和河水中的Mg和Zn元素含量在观测时间内变化趋势一致,Mg元素含量变化都呈"W"形,Zn元素含量都是6月最高,9、10月份未检出;各月河水中总N、总P、电导率和总溶解固体都高于溪水,且Na、Mg和Ca元素含量也都高于溪水;溪水综合评价结果属于Ⅱ类水体,河水综合评价结果属于Ⅳ类水体.     

Water absorption of xeromor forest floor samples

Samples from the xeromor type humus horizon with different initial water cotents were irrigated and the water absorption studied. Four samples were used: from the litter (AoL), fermentation (AoF) and epihumus (AoFH) subhorizons and from the humus-mineral horizon (Ah). The samples were sprinkled continuously under laboratory conditions with an intensity of 10 mm h^?1.Irrigated samples with low initial moisture contents showed the lowest rate of water absorption, whereas in those with highest initial moisture content a quick increase in water content was observed. Two phases were distinguished: that of total absorption of irrigated water and that of partial absorption and outflow. The duration of the first phase was about 10 min for the samples with the lowest initial moisture content and about two hours for samples with higher initial moisture content. Significant differences in the first phase of water absorption were connected with the degree of humification. When the humification degree increases, so do the differences in absorption properties of the organic material due to initial moisture content. The ratios of water content increase in samples from subhorizons AoL, AoF, AoFH with the lowest initial water content were 0.82, 0.36 and 0.47, respectively. This shows that the initial water content has the least effect on the first phase of water absorption in the least humified material from subhorizon AoL. The water properties of the organic horizon significantly affect absorption by the forest floor.     

STUDY ON SPECIES DIVERSITY OF RUST FUNGUS IN FIVE FOREST TYPES

INTRODUCTIoNSSPCCiesdiversityistheoneofthreekcysubjcctS(Theglobalweatherchange,speiesdiversltyandsustainedecologysystem)inccologicalandenvironmentalscienceinrecenttenyears.Williams(I943)firstputfonvardsPecicsdiversitywhenhestUdiedtherelationbctx`centhcabundanccandinsectspecicsofLcl,i`mptcra.In6()'s~7()'s-ccologicaIscicn-tistshadgotagreatofachicvementsonsPCcicsdlt'crslti'stud\.Sinccl98()-s.somcscientistsstartcdtostud}'sPCcicsdivcrsityinCl1ina.Thcy'havcgotsolnercsultsol1artl1roPOdcom…     

土壤温度和水分对长白山3种温带森林土壤呼吸的影响

为了研究土壤温度和土壤含水量对阔叶红松林(山地暗棕壤)、云冷杉暗针叶林(山地棕针叶林土壤)和岳桦林(生草森林土)的土壤呼吸的影响,于2001年9月在长白山进行了土壤实验。利用增加土壤样柱的含水量,将土壤含水量分为9%,、21%、30%、37%和43%5个等级,土壤样品分别在0、5、15、25和35的温度下保持24小时。阔叶红松林土壤在0~35范围内,土壤呼吸速率与温度呈正相关。在一定的含水量范围内(21%~37%),土壤呼吸随含水量的增加而升高,当含水量超出该范围,土壤呼吸速率则随含水量的变化而降低。土壤温度和水分对土壤呼吸作用存在明显的交互作用。不同森林类型土壤呼吸作用强弱存在显著差异,大小顺序为阔叶红松林>岳桦林>云冷杉暗针叶林.红松阔叶林土壤呼吸作用的最佳条件是土壤温度35,含水量37%;云冷杉暗针叶林下的山地棕色针叶土壤呼吸作用的最佳条件是25,21%;岳桦林土壤呼吸作用的最佳条件是35,含水量37%。但是,由于长白山阔叶红松林,云冷杉林和岳桦林处在不同的海拔带上,同期不同森林类型土壤温度各不相同,相差4~5,所以野外所测的同期的山地棕色针叶林土呼吸速率应低于暗棕色森林土呼吸速率,山地生草森林土呼吸速率应高于山地棕色针叶林土的呼吸速率。图2表1参25。     

江西省生态公益林5种典型林分类型土壤性质特点分析

以江西省生态公益林5种主要林分类型为研究对象,从土壤水分—物理性质、土壤化学性质方面对5种典型林分类型进行比较,并应用SPSS 18.0软件采用主成份分析法对各林分类型土壤性质进行综合分析评价,结果表明:针阔混交林的土壤具有较好的土壤渗透性,具有较强的持水能力,其土壤养分含量与其他林分相比也更高,采用主成分分析对各林分类型进行综合评价,土壤性质的综合排序为针阔混交林>竹林>阔叶混交林>针叶纯林>针叶混交林.     

紫金山森林资源动态分析

根据近40a南京紫金山5次森林资源调查的资料，分析了当地森林资源变化规律，认为紫金山森林资源的质量正逐步提高。有林地面积从1953年的1101．0hm^2增加到2002年的2107．6hm^2，疏林地和灌木林地明显减少，从1986年到2002年均净增率分别达-35．22％和-41．90％，森林覆盖率由1953年的36．0％增加到2002年的70．2％，年均增长速度为1．37％，蓄积量年均增长速度为3．52％。     

旅游活动对鸡公山自然保护区视觉环境的影响

以鸡公山自然保护区为例,通过发放调查问卷获得评分,用层次分析法确定各指标的权重,利用韦伯-费希纳定律改进后的评价模型得到综合评分,针对开展旅游活动后保护区视觉环境受到的消极影响进行了研究评价。     

长白山典型林区森林资源变化及目前质量分析

利用研究区1985年和1999年两期遥感数据,将两期图像的矢量化图像中变动幅度较大的主要类别进行叠加,通过图像单元统计及图像叠加分析,得知各类地物在十五年间的变化情况及相应类别变化的量化归属。研究表明,十五年间采伐迹地、人工幼林变化剧烈,人类活动是造成研究区地物剧烈变化的最主要原因。选择研究区中二个干扰与经营状况不同的林场进行重点剖析,结果表明经营强度及方式的不同,对森林资源质量有较大的影响。东升林场采伐利用强度相对较小,目前仍保存有面积约占该林场1/3左右的地带性植被,过熟林面积比例较高,成熟针叶林单位面积蓄积量高达536.27m3hm-2,与长白山自然保护区的阔叶红松林单位面积蓄积量大体相当;西林河林场因采伐强度较大,目前林分多为原始林被破坏后形成的次生林,成过熟林比例相对较低,单位面积蓄积量也较小。二个林场森林状况以及营林措施方面具有一定代表性,其森林演替具有天然、人为干预两个方面的性质,作为重点剖析对象对研究区未来森林资源经营具有一定的指导意义。本文还就研究中发现的问题进行了剖析,并对当地的营林策略提出了可行性建议。图6表4参13。     

Quality and change analysis of forest resource in typical Changbai Mountain forest region

The utilization and changes of forest resources were studied in the Lishuihe Forest Bureau. Based on remote sensing images in 1985 and 1999, changes of major forest resources were analyzed by statistical and overlap method and classified quantitatively. The results showed that in recent 15 years, logging spots and man-made young forest changed violently, which was due to human activities. Different forest management manners and harvesting intensity played an important role in forest resources change. Dongsheng and Xilinhe tree farms were typical cases of different forest status and management for the Bureau, where forest succession was intervened by either human or natural disturbance. Dongsheng Tree Farm underwent a lighth arvest intensity and maintained a unit stock volume of 536.27 m^3. hm^-2, as much as that of broadleaf/Korean pine forest of Changbai Mountain Natural Reserve; Xilinhe Tree Farm underwent an intense harvest and was composed of secondary forests,where mature forests just had a small percentage and the unit stock volume was low. The study was useful to guide future forest management. What‘s more, problems found in the research were also analyzed and reasonable advice was given to the local forest management.     

不同林分林下枯落物持水功能研究

对鹰嘴界自然保护区阔叶林、杉木毛竹混交林和杉木林的林下枯落物贮量与持水性能等进行了研究。结果表明：3种不同林分林下枯落物总贮量在5．13～6．50t／h㎡之间,其大小顺序为：杉木毛竹混交林〉阔叶林〉杉木林。枯落物最大持水量差异明显,其大小顺序为阔叶林（19．00t／h㎡。）〉杉木毛竹混交林（15．72t／h㎡）〉杉木林（11．09t／h㎡）。枯落物有效持水量在0．93～1．62mm之间。     

Variations in fine root dynamics and turnover rates in five forest types in northeastern China

Quantifying fi ne root(≤ 2.0 mm in diameter) distribution and turnover is essential for accurately estimating forest carbon budgets. However, fi ne root dynamics are poorly understood, possibly because of their inaccessibility. This study quantifi es fi ne root distribution and turnover rates for fi ve representative Chinese temperate forests types. Fine root number, diameter, biomass, necromass, production, mortality, and turnover rates were measured using a minirhizotron over a 12-month period. More than 90% of the fi ne roots were < 0.5 mm in diameter, with thin fi ne roots at shallow layers, and thicker ones in deeper soil layers. The fi ne root dynamics were signifi cantly diff erent among the forest types. Coniferous plantations had fewer fi ne roots, less biomass, necromass, production and mortality but greater average diameters than fi ne roots of broadleaved forests. All traits, except for diameter, decreased along the soil profi le. Fine root numbers and production exhibited a unimodal seasonal pattern with peaks occurring in summer, whereas biomass, necromass and mortality progressivelyincreased over the growing season. The turnover rates of roots < 0.5 mm varied from 0.4 to 1.0 a-1 for the fi ve forest types, 0.5–1.0 a-1 for the soil layers and 0.2–1.1 a-1 for the seasons, with the largest turnover rate at the 0–10 cm depth in summer. The patterns of fi ne root numbers, biomass, necromass, production, mortality, and turnover rates varied with forest types, soil depths, growing season and diameter classes. This study highlights the importance of forest types and diameters in quantifying fi ne root turnover rates.