助手标题  
全文文献 工具书 数字 学术定义 翻译助手 学术趋势 更多
查询帮助
意见反馈
   森林 在 自然地理学和测绘学 分类中 的翻译结果: 查询用时:0.582秒
图标索引 在分类学科中查询
所有学科
自然地理学和测绘学
林业
农业经济
资源科学
旅游
植物保护
环境科学与资源利用
生物学
农业基础科学
更多类别查询

图标索引 历史查询
 

森林     
相关语句
  forest
    Study on Labile Organic Carbon Pool in Forest Soils
    森林土壤活性有机碳库的研究
短句来源
    Dynamic Processes of Forest Landscape and Evaluation of Forest Landscape Ecology in Maoershan Region
    帽儿山地区森林景观动态过程及景观生态评价
短句来源
    A Study on Forest Soil CO_2, N_2O and CH_4 Emission Flux and Dynamics in Xishan Area, Beijing
    北京西山地区森林土壤中CO_2、N_2O和CH_4气体的排放通量及动态研究
短句来源
    Study on Physico-chemical Property and Health Index of Forest Soil on Badaling Mountain in Beijing
    北京八达岭地区森林土壤理化特征及健康指数的研究
短句来源
    Research on Structure and Function of Soil Animals in Forest Ecosystem in Da Xinganling Mountains
    大兴安岭森林生态系统土壤动物结构及其功能研究
短句来源
更多       
  forests
    Soil NH_4~+/ NO_3~- nitrogen characteristics in primary forests and the adaptability of some coniferous species
    原始森林土壤NH_4~+/NO_3~-生境特征与某些针叶树种的适应性
短句来源
    The short-term responses of soil CO_2 emission and CH_4 uptake to simulated N deposition in nursery and forests of Dinghushan in subtropical China
    鼎湖山苗圃和主要森林土壤CO_2排放和CH_4吸收对模拟N沉降的短期响应
短句来源
    Effects of C and N Disturbances on Decomposition of Leaf Litter in Forests
    外源性C、N干扰对森林凋落叶分解的影响
短句来源
    SOIL N_2O EMISSION AND ITS RESPONSE TO SIMULATED N DEPOSITION IN THE MAIN FORESTS OF DINGHUSHAN IN SUBTROPICAL CHINA
    鼎湖山主要森林土壤N_2O排放及其对模拟N沉降的响应
短句来源
    EFFECTS OF SOIL TEMPERATURE AND MOISTURE ON SOIL SURFACE CO_2 FLUX OF FORESTS IN NORTHEASTERN CHINA
    土壤水热条件对东北森林土壤表面CO_2通量的影响
短句来源
更多       
  in forest
    Study on Labile Organic Carbon Pool in Forest Soils
    森林土壤活性有机碳库的研究
短句来源
    Research on Structure and Function of Soil Animals in Forest Ecosystem in Da Xinganling Mountains
    大兴安岭森林生态系统土壤动物结构及其功能研究
短句来源
    The standing stock of litter fall in forest park was 4 317.5 t,and the amount of organic C,N,P,K,Ca and Mg contents were 4 643.51 kg/hm2,108.04 kg/hm2,10.72 kg/hm2,48.26 kg/hm2,156.75 kg/hm2 and 23.96 kg/hm2,respectively,which showed that the litter fall of the forest park was an important nutrient storeroom.
    大蜀山森林凋落物现存量初步估算为4 317.5 t,有机碳、N、P、K、Ca、Mg的含量分别为4 643.51、108.04、10.72、48.26、156.75、23.96 kg/hm2,可见凋落物是森林重要的营养库之一。
短句来源
    STUDIES ON MICROELEMENTS IN FOREST SOIL ECOSYSTEM OF NORTHEASTERN JIANGXI PROVINCE
    赣东北低山区森林土壤生态系统中的微量元素研究
短句来源
    Application of Spatial Analysis in Forest Fireprof GIS
    空间分析在森林防火GIS中的应用
短句来源
更多       
  forested
    Spatial Variability of Characteristic Function of Soil Water Movement on a Forested Hill-slope
    森林流域坡面林地土壤水分运动特征参数空间异质性研究
短句来源
    Recently, rational distribution of forests has been paid much attention, but researches on relationship between forest pattern and erosion and sediment is not much although there are many progresses in studying relations between forested slope and non-forested slope or forested watershed and non-forested watershed.
    (1)以黄委会天水水土保持试验站的吕二沟、罗玉沟、桥子东沟、桥子西沟四个试验流域为研究对象,在收集其多年定位观测的降水、径流、泥沙资料的基础上,结合对流域的实地调查、观测和试验,基于3S技术建立流域空间数据库和属性数据库,为研究流域森林植被格局与侵蚀产沙关系奠定基础。
短句来源
    Soil layer of forested land is a major water storage and adjuster in forest ecological system . Research of permeability and water storage properties about forest soil is the important part of conserving water and soil.
    林地土壤层是森林生态系统中主要的水分蓄存和调节器,森林土壤的透水蓄水性能的研究是森林涵养水源和保持水土研究的重要组成部分,是认识森林水文功能的一个重要环节。
短句来源
    The different distribution patterns of exchangeable cations with soil depth and change between the growing and dormant seasons were very clear,reflecting the nutrient mobility and cycling in the forested peatland ecosystem.
    交换性阳离子的分布随土层深度和森林生长、休眠季节的更替而发生变化,体现了营养元素在森林生态系统中的迁移性和循环性。
短句来源

 

查询“森林”译词为其他词的双语例句

     

    查询“森林”译词为用户自定义的双语例句

        我想查看译文中含有:的双语例句
    例句
    为了更好的帮助您理解掌握查询词或其译词在地道英语中的实际用法,我们为您准备了出自英文原文的大量英语例句,供您参考。
      forest
    Moreover, a backward reasoning forest of a reachable marking was generated for explicitly representing reachable paths in RBS.
          
    Growth Model System for National Continuous Forest Inventory
          
    A Growth Model System is developed for data updating and forecasting of the national continuous forest inventory.
          
    Its design is based on the inherent forest growth laws, and its parameters are estimated by modern regression methods.
          
    It is suitable for forest resource information updating and forecasting for a large region, e.g., a province.
          
    更多          
      forests
    The ecological water requirement of forests is defined as the water resources used to maintain and improve the natural balance of forest ecosystems, which can be expressed by evapotranspiration of trees during the growing season.
          
    With geographic information system (GIS), the ecological water requirement for forests in the Jinghe watershed, western China was estimated.
          
    The results revealed that the minimum and suitable ecological water requirements of the forests in the Jinghe watershed were approximately 204×107 and 340×107 m3, respectively.
          
    Although the RENIs of plantations in rehabilitated fields are a little lower than those of natural forests, they are higher than those of cultivated crops.
          
    Comparative Analysis of Plant Diversity of Pinus tabulaeformis Forests in Ten Regions of Beijing Mountainous Areas
          
    更多          
      in forest
    Nitrate has been recognized as the dominant mineral nitrogen form in most agricultural soils and the main nitrogen source for crops, but it is not usually the case in forest ecosystems.
          
    Fine root lifespan and turnover play an important role in carbon allocation and nutrient cycling in forest ecosystems.
          
    Soil properties in forest gaps and under canopy in broad-leaved Pinus koraiensis forests in Changbai Mountainous Region, China
          
    Results showed that compared with farmland watersheds, runoff generation time in forest watersheds was delayed remarkably, and peak flow was reduced greatly, which indicates that vegetation played an important role in holding and absorbing rainfall.
          
    The two forests differ in forest humus layer; it is deep in the Ailao forest while little is present in the Xishuangbanna forest.
          
    更多          
      forested
    In order to accurately estimate the size of the carbon pool and the capacity of the carbon sink in the forested areas of Xiaolong Mountain in Gansu Province, we have established regression equations of organ biomass of eight tree species.
          
    CWD is an important functional and structural component of forested ecosystems and plays an important role in nutrient cycling, long-term carbon storage, tree regeneration, and maintenance of heterogeneous environmental and biological diversity.
          
    Oxidoreductase activity of peat soils as an indicator of the degree of biochemical transformation of drained and forested bogs i
          
    Soil peroxidase activity can be an important indicator of the degree of biochemical transformation of drained and forested bogs.
          
    Consideration is given to uncertainties related to methods for assessing the above and belowground phytomass and primary production of forest stands in test plots, as well as for extrapolating the results to forested areas.
          
    更多          


    A.The Soils Since the goological formation of this mountainous area is quite uniform,a vertical distribution of soils is obviously observed. At the top of the mountain with an elevation of 8,500 feet,the podzolic soil is found. The process of podzolization is clearly shown by the translocation of clays,organic matter, and active aluminum from an upper to lower layer.The gray brown podzolic soil is distributed in areas ranging from 7,000 to 8,500 feet in elevation.It is developed under forest and has a...

    A.The Soils Since the goological formation of this mountainous area is quite uniform,a vertical distribution of soils is obviously observed. At the top of the mountain with an elevation of 8,500 feet,the podzolic soil is found. The process of podzolization is clearly shown by the translocation of clays,organic matter, and active aluminum from an upper to lower layer.The gray brown podzolic soil is distributed in areas ranging from 7,000 to 8,500 feet in elevation.It is developed under forest and has a surface covering of leaf litter and a surface soil with high content of organic matter.In places at an elevatin from 3,900 to 7,000 feet the yellow podzolic soil is dominant.At an elevation below 3,000 foot the red podzolic soil and the sketetal soil are fonnd. The analytical data of the soils of this area may be summarized as follows: 1.pH values of the soils:In the whole area,since the parent rock (gneiss) is poor in basic constituents,soils are all acid in reaction.The pH of the different horizons of the soils ranges from 4.0 to 5.5.The A_0 and A_1 horizons are usually less acid than B horizon,the A and B horizons are much more acid than the parent rock.This shows the leaching process of the soils under such a humid atmosphere. 2.Organic Matter of the soils:The organic matter content of the soils in this area is greatlg influenced by the kind of the vegetation cover.At an elevation of 8,500 feet, the soil developed under forest has 38.92% of organic matter in the A_1,while that under grass has only 11.08% of organic matter in the corresponding horizon.However as the vegetation cover is constant,the dopth of the A_1 and its organic matter content are evidently affected by the elevation.At an elevation of 3,000 feet,the A_1 horizon of the red podzolic soil is only 1 cm.in depth,and it has 3.37% of organic matter.At an elevation of 8,500 feet,howerver,the A_1 horizon of the podzolic soil is 7 cm.in depth, and it has 11.08% of organic matter.In addition,deposition of organic matter in the B horizon is clearly found in the podzolic soil,but it has not been seen in soils found at lower elevation. 3.Active aluminum of the soils:All the soils in this area are high in active aluminum. They contain from 20 to 16 p.p.m.of active aluminum.The content of active aluminum in the different horizons of the same profile has a very close relationship with the pH values of the corresponding horizon.The less acid the reaction the smaller is the amount of acitve aluminum.The active aluminum of the soil is usually higher in amount than that of the parent rock from which the soil is derived. 4.Available calcium magnesium,and potassium of the soils:All the soils are general- ly low in available calcium,magnesium,and potassium.The comparatively high content of these elements in the A horizon is derived from the leaves of the vegetation which are grown on that soil. 5.Available phosphorus of the soils:All the soils of this area are low in available phosphorus. 6.Available nitrate:All soils in this area are very low in nitrate. B.The Vegetation 1.The plants growing on soils of this area are most calcifuge species which are acid- loving (Vaughan and Wishe,1937).As far as the chemical analysis of the soil is concer- ned,those species may be assumed as not only acid-loving,buy also active aluminum- loving (Hutchinson,1943). 2.The distribution of the calcifuge plants In this area is apparently affected by the local climate in terms of elevation.Some of them (temperate plants) are confined to high elevation,others(tropical plants) being limited to low elevation,Two groups of the plants may be given as follows.Many of them are of the same species as those found in southwestern China (Hou,1944). (a) Plants mainly ocurring in areas at elevations from 7,000 to 8,500 foot (temperate plants): Pteridophyta: Destaedtia Scabra (Wall.) Moore Diranopteris linearis Under. Hicrioptris glauea Under. Hymenophyllum crispatum Wall. Hymenophyllum exsertum Wall. Lidsaya cultrata Sw. Lycopodium clavatum L. Plagiogyria pyphylla (Kunze) Mett. Pteridium aquilinum Wightianum Trym Pteris aspericaulis Wall. Flowering Plants: Castanopsis tribuloides A.DC. Lindera pulcherrima Bth. Osbeckia crinata Bth. Rhododendron arboreum Sm. Rhododendron grande Wight Pieris formosana D.Don Vaccinium refersceda HK. Vaccinium serrasum Wight (b) Plants mainly ocurring in areas at elevation from 1,000 to 3,000 feet (tropical plants): Pteridophyta: Adiantum philippense L. Blechnum orientale L. Aglaoorpha coronaus Copel Lycopodium cernum L. Nephrolepsis cordifolia Presl Tectaria spp. Polypodium ucidum Roxb. Flowering plants: Oxyspora paniculate DC. Themeda arundinacea Ridl.

    1945年10月中旬,作者留印三月另一周,曾作三次野外调查,计包括印缅边区、恒河平原及喜马拉雅山东南麓等三区,茲先将大吉岭区调查结果,草成此文。调查区域大吉岭位于喜马拉雅山东南麓,在我国西藏边境,全区是山地,海拔自1000到9000尺不等,主为酸性的片麻岩地层,在拔海6500尺地点,年平均气温为56.3℉.,年雨量为122寸。土壤灰壤——灰棕壤组合:在拔海8500尺左右的山顶,灰壤见于草地上,而灰棕壤则发育在森林之下。灰棕壤——灰化黄壤组合:在拔海7000—8000尺地带,森林下仍是灰棕壤,而草地上则为灰化黄壤。灰化黄壤——粗骨土组合:在拔海1000—3000尺地带,片麻岩生成灰化红壤,酸性砂岩生成砾质土。全区土壤特征可归纳如下: (1)土壤 pH 值:全区因土壤母质为酸性片麻岩,各类土壤剖面亦为酸性反应;pH 值约自4.0至5.5。A_1层之 pH 值恒较 B 层为大,而土壤剖面内之 A 层及 B 层均较母岩之酸度为高。 (2)土壤有机质:从土壤有机质分析结果观之,显示植物种类对于土壤有机质之含量高低,有密切的关系,在拔海8500尺之地带,发育于森林下的灰棕壤,表土含有机...

    1945年10月中旬,作者留印三月另一周,曾作三次野外调查,计包括印缅边区、恒河平原及喜马拉雅山东南麓等三区,茲先将大吉岭区调查结果,草成此文。调查区域大吉岭位于喜马拉雅山东南麓,在我国西藏边境,全区是山地,海拔自1000到9000尺不等,主为酸性的片麻岩地层,在拔海6500尺地点,年平均气温为56.3℉.,年雨量为122寸。土壤灰壤——灰棕壤组合:在拔海8500尺左右的山顶,灰壤见于草地上,而灰棕壤则发育在森林之下。灰棕壤——灰化黄壤组合:在拔海7000—8000尺地带,森林下仍是灰棕壤,而草地上则为灰化黄壤。灰化黄壤——粗骨土组合:在拔海1000—3000尺地带,片麻岩生成灰化红壤,酸性砂岩生成砾质土。全区土壤特征可归纳如下: (1)土壤 pH 值:全区因土壤母质为酸性片麻岩,各类土壤剖面亦为酸性反应;pH 值约自4.0至5.5。A_1层之 pH 值恒较 B 层为大,而土壤剖面内之 A 层及 B 层均较母岩之酸度为高。 (2)土壤有机质:从土壤有机质分析结果观之,显示植物种类对于土壤有机质之含量高低,有密切的关系,在拔海8500尺之地带,发育于森林下的灰棕壤,表土含有机质38.92%,而同处草类和蕨类植物发育下的灰壤的表土,仅含有机质11.08%,但在相同的植物环境下,拔海高度或局部气候,也是支配土壤有机质含量的重要因素,例如在拔海3000尺地带,长有草类的灰化红壤,仅有极薄之有机质层,该层有机质含量为3.37%,而在拔海8500尺地带,长有草类的灰壤,则有较厚层有机质,其含量为11.08%。 (3)可溶性铝质:全区土壤含有高量可溶性铝,大约自20至160 p.p.m.,其含量与 pH 值高低相关,土壤 pH 值愈酸,可溶性铝含量就愈高。 (4)可溶性钙镁及钾质:全区土壤之可溶性钙,镁及钾等之含量均较低,但就同一土壤剖面而言,富于有机质的 A。或 A_1层的钙镁和钾质,常较 B 层为高,此点显示此等成份是来自植物遗体,亦即指示土壤中有机质与肥力之关系。 (5)全区土壤有效磷含量均甚低。 (6)全区土壤硝酸态氮之含量均极低,并有下淋现象。植物本文所论植物,仅以作者所采集而经各专家鉴定为限,其中以蕨类植物为主。本区的土壤都是酸性反应,所见的植物是以嫌钙性者为主,这些嫌钙性植物与拔海高度的关系很显著,兹将常见的植物种类,叙述如下: (一)主分布于拔海7000—8500尺地带的植物: 蕨类植物 Dennstaedtia scabra(Wall.)Moore Dicranopteris linearis Under. Hicriopteris glauca Under. Hymenophyllum crispatum Wall. Hymenophyllum exsertum Wall. Lindsaya cultrata Sw. Lycopodium clavatum L. Plagiogyria pycniphylla(Kunze)Mett. Pteridium aquilinum Wightianum Trym. Pteris aspericaulis Wall.种子植物 Castanopsis tribuloides A.DC. Lindera pulcherrima Bth. Osbeckia crinata Bth. Rhododendron arboreum Sm. Rhododendron grande Wight Pieris formosana D.Don Vaccinium referesceda HK. Vaccinium Serrasm Wight(二)主分布于1000—3000尺地带的植物: 蕨类植物Adiantum philippense L.Blechnum orientale L.Aglaomorpha coron(?)us copelLycopodium cernuum L.Nephrolepsis cordifolia PresslTectaria spp.Polypodium lucidum Roxb.种子植物Oxysoira paniculata DC.Themedra arundinacea Ridl.

    The no staff and self-reducing tacheometer is a new type of surveying instrument designed and constructed by a group of teachers and students of our department. This instrument can be used for topographic and tacheometric measurements with low degree of accuracy for geographic and geological details, and also for land and forest valuations. The most distinguished advantage of this instrument lies in the fact that there is no necessity to place a staff at the point to be sighted, and the horizontal distance...

    The no staff and self-reducing tacheometer is a new type of surveying instrument designed and constructed by a group of teachers and students of our department. This instrument can be used for topographic and tacheometric measurements with low degree of accuracy for geographic and geological details, and also for land and forest valuations. The most distinguished advantage of this instrument lies in the fact that there is no necessity to place a staff at the point to be sighted, and the horizontal distance or vertical height can be read directly from the instrument without the use of stadia slide-rules or stadia-tables, and therefore saves labor and time of computations.

    无须跑尺自计视距仪是一种新式的测量仪器,经过研究,我们已初步试制成功。利用它可作地形测量,地理及地质勘测,土地及森林估测等。此仪器的最大特点是无须跑尺和在仪上直接读出平距与高差,故不独可节省人力而且节省计算时间。

    The materials of present report were collected from reconnaissence soil survey of Kwangtung and Kwangsi provinces in 1958—1960. Soils investigated include yellow earths, red earths and lateritic soils. They are developed under natural vegetations of tropic monsoon forest (secondary), subtropic evergreen broadleaf forest, conifer and broadleaf mixed forest, subalpine dwarfing and bamboo ferests, confer forests of Cunninghamia lanceolata and Pinus massoniana, and grass land. A few samples of rice paddy soil were...

    The materials of present report were collected from reconnaissence soil survey of Kwangtung and Kwangsi provinces in 1958—1960. Soils investigated include yellow earths, red earths and lateritic soils. They are developed under natural vegetations of tropic monsoon forest (secondary), subtropic evergreen broadleaf forest, conifer and broadleaf mixed forest, subalpine dwarfing and bamboo ferests, confer forests of Cunninghamia lanceolata and Pinus massoniana, and grass land. A few samples of rice paddy soil were also studied for comparison. Laboratory investigations invplved the determination of chemical composition of forest litters, fraction of soil humus (after Turin and Kononova), and analysis of soil exchangeable bases, active iron and alumina, etc. From the results obtained the writers come to the following conclusions: 1. The ratios of humic acid over fulvic acid under natural vegetations are usually less than 1. Fulvic acid prevails in acid soils of tropic and subtropic regions with the presence of active iron and alumina. On the contrary, intensively cukivated paddy soils of neutral to slightly alkaline reaction in the same areas, after a long-time application of lime and manures, give a humic acid over fulvic acid ratio of about 2. 2. Active soil humus, including humic and fulvic acid extractable by 0.1 N NaOH (Fraction Ⅰ), also predominates in soil organic matter. The ratio of soil humus "Fraction 1" over "Fraction Ⅱ, including humic acid and fulvic acid only soluble through repeatedly extraction by 0.1 N H_2SO_4 and NaOH", ranges from 5:1 to 10:1. 3. Soils developed under natural vegetations contain 20—35% of readily soluble humus {extractable by 0.05 N H_2SO_4) in total organic matter. Rice paddy soils in the same area usually contain readily soluble humus less than 5%. It appears that under present agricultural practices, the more active forms of soil humus undergo rapid decomposition, and the maintenance of soil fertility is largely dependded on manures and nitrogenous fertilizers. 4. Soils of the investigeted areas contain 40—50% humin (residual organic matter resistant 1.0 acid and alkaline extraction) in total organic matter. 5. Soil litters of conifer forest of Cunninghamia lanceolate contain CaO+Mg+K_2O+Na_2O up to 59.51% and SiO_2 10.57% in the ash. Litters of bamboo forest contain CaO+MgO+K_2O+ Na_2O 8.87% and SiO_2 up to 78.21% in the ash. Litters of Pine massoniana contain CaO+MgO + K_2O+Na_2O 11.18% and a very high content of A1_2O_3 (13.91%). The present data, however, give no correlation between the chemical composition of soil litter and that of soil exchangeable bases. Soils under Pine massoniana contain relatively greater amounts of exchangeable alumina (4—16 m.e./100 gm. of soil) and active iron (65—200 m.e./100 gm. of soil) in surface layer.

    本文对华南地区不同植被下的土壤有机貭、土壤活性矿物貭組成及枯枝落叶层进行了研究,企图探求植被类型对于土壤腐殖貭組成以及肥力变化的影响。供試土壤包括山地草甸土、黃壤、紅壤及砖紅壤性紅壤,由不同母貭发育而成。植被类型包括常綠闊叶林、針叶闊叶混交林、高山矮林及竹林、杉木林、馬尾松灌丛、草坡等。此外,还选了三个珠江三角洲地区不同肥力的水稻土,以比較自然植被下土壤性貭和农田土壤性貭的异同。根据初步研究結果,获得下列几点认識。 1.土壤活性腐殖质的变化两广地区自然植被下的土壤,其活性腐殖貭占土壤有机貭总量的百分比显然高于农田土壤。森林及以禾本科为主的中生性草地下的土壤,表土有机貭中合有約20—35%的活性腐殖貭(为0.1 N NaOH所能提取),但是水稻土中,通常只占6%以下。这点說明了在热带和亚热带地区的生物气候条件下,一年2—3造的耕作制度,可使結构比較簡单的活性腐殖貭很快的被矿化,而土壤肥力的維持在很大程度上依賴于有机肥料和化学肥料的逐年补給。 2.土壤中胡敏酸与富里酸的比率华南自然植被下的土壤有机貭中,胡敏酸与富里酸的比率通常小于1,紅壤地区土壤中富里酸比胡敏酸高的特点,是由于富里酸能在酸性溶液中和活...

    本文对华南地区不同植被下的土壤有机貭、土壤活性矿物貭組成及枯枝落叶层进行了研究,企图探求植被类型对于土壤腐殖貭組成以及肥力变化的影响。供試土壤包括山地草甸土、黃壤、紅壤及砖紅壤性紅壤,由不同母貭发育而成。植被类型包括常綠闊叶林、針叶闊叶混交林、高山矮林及竹林、杉木林、馬尾松灌丛、草坡等。此外,还选了三个珠江三角洲地区不同肥力的水稻土,以比較自然植被下土壤性貭和农田土壤性貭的异同。根据初步研究結果,获得下列几点认識。 1.土壤活性腐殖质的变化两广地区自然植被下的土壤,其活性腐殖貭占土壤有机貭总量的百分比显然高于农田土壤。森林及以禾本科为主的中生性草地下的土壤,表土有机貭中合有約20—35%的活性腐殖貭(为0.1 N NaOH所能提取),但是水稻土中,通常只占6%以下。这点說明了在热带和亚热带地区的生物气候条件下,一年2—3造的耕作制度,可使結构比較簡单的活性腐殖貭很快的被矿化,而土壤肥力的維持在很大程度上依賴于有机肥料和化学肥料的逐年补給。 2.土壤中胡敏酸与富里酸的比率华南自然植被下的土壤有机貭中,胡敏酸与富里酸的比率通常小于1,紅壤地区土壤中富里酸比胡敏酸高的特点,是由于富里酸能在酸性溶液中和活性R_2O_3相結合(特別是活性鉄),这項特性在邱林、科諾諾娃、波諾馬列娃等人的研究中早已証明了。珠江三角洲上的高度熟化水稻土(土壤pH7.8),由于长期施用有机肥料及石灰的影响,有机貭中胡敏酸的数量高出富里酸一倍,胡敏酸与富里酸的比率为1.95。但是在新垦的紅壤性水稻土中(土壤pH4.5),这項比率是0.39,这点也可以証明有机貭分解过程和富里酸的形成是和土壤酸度及活性鉄、鋁有关的。 3.活性铁和鋁与腐殖质組成的关系本区一般森林及草本植被下的土壤,表土活性鋁的合量通常为每百克土4—10毫克当量,活性鉄为20—100毫克当量;馬尾松灌丛下的紅壤,活性鋁的含量每百克土可达20毫克当量左右。这些土壤的盐基飽和度一般在20—30%之間,每百克土的代換性鈣通常仅在1—2毫克当量上下,但是土壤有机貭分組分析結果,第一組腐殖貭(包括活性較強的胡敏酸和富里酸)的含量远远超过了第二組腐殖貭(指由酸液和碱液反复提取以后能溶解的部分),它們的比率为5:1和10:1(只有一个例外)。这項結果說明土壤中大量活性鋁离子和鉄离子的存在,使腐殖貭的活度增強。在珠江三角洲水稻土中,第一組腐殖貭和第二組腐殖貭的比例也在这个范围內。 4.土壤腐殖貭中的不溶性殘渣(胡敏素)的含量在表土中所有供試土壤都很一致,約占土壤腐殖貭总量的40—50%上下。植被类型、海拔高度、耕作过程、成土母质等对于胡敏素的合量,均沒有明显的影响。这样在热带和亚热带土壤的腐殖貭中,似乎有一半是胡敏素,它在短期內是不能矿化的。 5.土壤腐殖貭中的碳氮比率(C/N) 森林及草本植被下的表土腐殖貭中,其C/N比率通常在10—15左右,只有馬尾松灌丛下的紅壤,C/N比率为19.6。在这个地区的水稻土中C/N比率一般为9—11。耕作縮小了C/N比率,但是自然植被下有机貭中活性腐殖貭的含量,都远远地超过农田土壤,因此,碳氮比率的縮小,很难认为土壤有机貭中氮素有效性的提高。这在国內外的研究材料中也指出过,例如合胡敏素极高的泥炭和褐煤,其C/N比率可以在10以下。 6.不同植被下殘落物的灰分組成杉木林的殘落物合有最高的基性物貭,CaO+MgO+K_2O+Na_2O的总量占灰分的59.51%;竹林和馬尾松灌丛的殘落物合基性物貭最低,前者为8.87%,后者为11.18%(都是CaO、MgO、K_2O、Na_2O的总量)。竹林殘落物的灰分中含SiO_2高达78.21%,而杉木林的殘落物灰分中含SiO_2量最低,为10.57%。馬尾松灌丛及亚热带針闊叶混交林下的殘落物灰分中含Al_2O_3高于其他植被的殘落物,为13.91%5及12.86%。其他一般的常綠闊叶林、針闊叶混交林和亚高山矮林等殘落物灰分中的基性物貭总量均在30%左右。虽然不同植被类型地表殘落物的矿貭組成有明显的差异,但就現在的初步材料,远远不足以闡明这項差异在生物物貭循环过程中的作用。这些成分上的变化,对于土壤活性矿物貭很少有直接的相关性。只有馬尾松灌丛下的紅壤,其活性鋁含量高于一般土壤,这点可能是受了殘落物貭腐解体的影响。我們初步接触了华南地区的植被类型、土壤腐殖貭組成和活性矿物貭間相互关系的問題以后,觉得波雷諾夫所启示我們的生物地球化学的研究方向,在这一地区中有許多工作可以推进。这項研究方法如果进一步地应用于农田土壤中的輪作方式及耕作措施对于土壤肥力消长关系的研究,便可以把森林和草地土壤以及农田土壤的生成发育方向做出具体的比較。此外,我們感到,尽管邱林、科諾諾娃和瓦克斯曼(Waksman,S.A.)等近三十年来在土壤有机貭的研究上做了很多工作,但是目下的有机貭分級方法应用于热带及亚热带的土壤(特别是水稻土)的适应性还值得研究。至于胡敏酸、富里酸等在土壤中与活性矿物貭的結合情况,以及各种腐殖貭物貭对于土壤肥力及植物营养上的作用,更是一个急待进一步研究的問題。

     
    << 更多相关文摘    
    图标索引 相关查询

     


     
    CNKI小工具
    在英文学术搜索中查有关森林的内容
    在知识搜索中查有关森林的内容
    在数字搜索中查有关森林的内容
    在概念知识元中查有关森林的内容
    在学术趋势中查有关森林的内容
     
     

    CNKI主页设CNKI翻译助手为主页 | 收藏CNKI翻译助手 | 广告服务 | 英文学术搜索
    版权图标  2008 CNKI-中国知网
    京ICP证040431号 互联网出版许可证 新出网证(京)字008号
    北京市公安局海淀分局 备案号:110 1081725
    版权图标 2008中国知网(cnki) 中国学术期刊(光盘版)电子杂志社