鄂西山地的酸性棕壤和灰棕壤形成条件及理化性质

根据鄂西山地的自然成土条件，分析了酸性棕壤、灰棕壤诊断层和诊断特性，主要理化性质和粘土矿物组成，结果表明：酸性棕壤和灰棕壤同属于亚热带中山上部或亚高山中上部冷湿条件下形成的森林土壤。其理化性质与我国北方同类土壤又有较大差别。     

Composition of the microbial communities in the mineral soil under different types of natural forest

Phospholipid fatty acid (PLFA) patterns were used to describe the composition of the soil microbial communities under 12 natural forest stands including oak and beech, spruce-fir-beech, floodplain and pine forests. In addition to the quantification of total PLFAs, soil microbial biomass was measured by substrate-induced respiration and chloroform fumigation-extraction. The forest stands possess natural vegetation, representing an expression of the natural site factors, and we hypothesised that each forest type would support a specific soil microbial community. Principal component analysis (PCA) of PLFA patterns revealed that the microbial communities were compositionally distinct in the floodplain and pine forests, comprising azonal forest types, and were more similar in the oak, beech and spruce-fir-beech forests, which represent the zonal vegetation types of the region. In the nutrient-rich floodplain forests, the fatty acids 16:1ω5, 17:0cy, a15:0 and a17:0 were the most prevalent and soil pH seemed to be responsible for the discrimination of the soil microbial communities against those of the zonal forest types. The pine forest soils were set apart from the other forest soils by a higher abundance of PLFA 18:2ω6,9, which is typical of fungi and may also indicate ectomycorrhizal fungi associated with pine trees, and high amounts of PLFA 10Me18:0, which is common in actinomycetes. These findings suggest that the occurrence of azonal forest types at sites with specific soil conditions is accompanied by the development of specific soil microbial communities. The study provides information on the microbial communities in undisturbed forest soils which may facilitate interpretation of data derived from managed or even damaged or degraded forests.     

长白山北坡原始林采伐对土壤性质影响的研究

长白山北坡是我国中纬度地区保持得比较完好的著名原始林区。林木组成复杂,成林树种丰富,每公顷蓄积量可达300—600立方米。而适合采伐的成过熟林已占绝大部分。据白河林业局资料:其林分蓄积中成过熟林占90.1%,这些成过熟林的林木生长量已大为减退,平均生长率为3.96%,而自然枯损率却占1.87%。特别是针叶树种平均自然枯损率高达3.79%,几乎与平均生长率相等¹⁾,这表明该局的森林资源应及时开发利用。另一方面,这些可采伐的原始林,地处熔岩高原,是第二松花江的源头,现有森林覆被对于调节气候、涵养水源、保持水土的作用是难于估量的。若采伐方式不当,是否会引起森林立地条件恶化而不利于更新造林,导致生态失去平衡并带来极大的灾难。为此,1982年吉林省林学会联合我院等十多个单位,针对上述问题,从各方面进行考察。笔者等用设立标准地调查对比的方法,于落叶松纯林和阔叶红松林采伐迹地上进行研究,现将初步结果报道如下。     

山地森林土壤枯枝落叶层结构和功能的研究

本试验设置在卧龙自然保护区1200-4300m海拔高度不同生物气候带的森林类型下.五处试验林地是:1.常绿阔叶林下的山地黄壤;2.次生落叶阔叶林下的山地棕壤;3.针阔混交林下的山地暗棕壤;4.暗针叶林下的山地棕色暗针叶林土;5.高山草甸植被下的高山草甸土.通过1981-1984年进行定位观测和试验研究,其结果阐明了该林区森林枯枝落叶层的构型、贮量及其化学、物理性质和灰分元素组成等;并探讨了森林枯枝落叶层在森林土壤生态系统中对水源涵养、养分供应、促进生物活动强度和土壤发育等方面的功能.     

福建东南部山地丘陵土壤的基本特征

福建是我国多山的省份之一.东南部靠山面海,以戴云山为主体的闽中大山带分布于本区西北部,平均高度为海拔800-1000米以上,成东北西南走向,其支脉密布本区,地势由西北向东南倾斜,呈阶梯状下降,由中山过渡到低山、丘陵、台地直至海滨狭小的海积-冲积平原.     

Changes in carbon pool and CO<Subscript>2</Subscript> emission in the course of postagrogenic succession on gray soils (Luvic Phaeozems) in European Russia

An analogous time series of fallow ecosystems (gray soils (Luvic Phaeozems) plowed and fallowed for 2, 7, 20, 60, and more than 120 years) in the broad-leaved forest zone of Orel oblast has been analyzed. Changes in carbon pool and CO2 emission in the course of postagrogenic succession during the vegetation and winter seasons have been estimated. The restoration of ecosystems on Luvic Phaeozems follows regularities revealed in analogous studies of southern taiga Podzols and forest-steppe Chernozems. Analogously to the other studied zonal chronosequences, total annual soil respiration on Luvic Phaeozems reaches the initial level of undisturbed ecosystems simultaneously with the restoration of phytomass reserve, although significantly earlier than the organic carbon reserve in soils is restored. According to regression models, among the zonal fallows in European Russia, including the southern taiga (Podzols), mixed forests (Luvisols), broadleaved forests (Luvic Phaeozems ), forest-steppe (Chernozems) and dry steppe (Calcisol–Solonetz soil complexes), the mean annual soil respiration is maximum in the zone of gray soils and Chernozems. The increase in soil respiration under artificial wetting (Birch effect) on fallows in the broad-leaved forest zone is minimum among the studied zonal chronosequences: 1.1 ± 0.6 (no effect), which corresponds to the optimal hydrothermal conditions in this zone.     

Morphological-genetic characterization of soils on the Enganepe Ridge

Specific features of the soil formation in the Polar Urals related to the slope aspects, parent rocks, and vegetation are considered using the example of the Enganepe Ridge. Soils of the same type (humus-illuvial podburs and podzolized podburs) are formed under the severe climatic conditions of the mountain tundra belt irrespective of the slope aspect. The main differences in the prevalent soils are manifested in the mountain belt of sparse forests. Under the sparse larch forests on the southeast-facing slope, illuvial-humus-iron podzols predominate. On the south-facing slope under the sparse spruce forests, clay-illuviated illuvialhumus-iron podzols alternate with mucky-dark humus soddy lithozems. Burozems are formed in a few ecological niches. The richness of the parent rocks, along with the southern slope aspect and the transitional-accumulative nutrient transfer, is shown to promote the formation of sparse spruce forests under the climatic conditions of the Polar Urals.     

The microbial biomass and its activity and structure in the soils of old forests in the European Russia

The humus-accumulative layer of soils (podzolic, gray, rzhavozem, burozem, and karbolitozem) of old-age forests (>60–450 years old) localized in various vegetation subzones (middle-taiga, southern taiga, subtaiga, dark coniferous forests outside the boreal region, and mountain forests) of the European part of Russia (22 sites of soil sampling of them, 13 in nature reserves and specially protected territories) was studied. The carbon content of the microbial biomass (C_mic) in the soil was determined by the substrate-induced respiration method. The fungal to bacterial ratio was determined by the selective inhibition technique with antibiotics. The basal respiration (BR) was also measured. The BR/C_mic = qCO₂ ratio and the portion of C_mic in the total organic soil carbon was determined. It was shown that the C_mic and BR in the soils of a separate vegetation subzone varied significantly; however, their values increased from the middle-taiga to dark coniferous subzone and decreased in the mountain-forest zone (348 ± 44, 670 ± 66, 1000 ± 86, 1142 ± 49, 789 ± 79 μkg C/g soil and from 0.68 ± 0.23, 1.85 ± 0.10, 2.13 ± 0.15, 1.56 ± 0.14, 0.92 ± 0.07 μkg CO₂-C/soil h, respectively). The fungal component in the humus-accumulative layer of soils is 53–99% of the total Cmic; however, its absolute values increase from the middle subzone to the southern one. The Cmic pool and the total BR in the profile of some soils (mineral horizons and forest litter) were calculated.     

闽南山地3种典型植被类型土壤分形与养分特征

[目的]探索闽南山地不同植被类型土壤分形特征及其与表层土壤颗粒组成、养分含量的相关关系,为评价闽南山地典型植被类型土壤质量,开展土地利用结构调整、土壤侵蚀防治及生态修复等提供参考。[方法]选取土壤颗粒体积分形维数模型对3种典型植被类型林地土壤的分形维数D值进行计算,并与土壤颗粒组成及土壤养分进行相关性分析。[结果]土壤颗粒体积分形维数D值从大到小依次为次生林马尾松林柑橘林;分形维数D值与土壤黏粒和粉粒体积百分数存在显著正相关关系,与砂粒体积百分含量呈显著负相关(p0.05);土壤pH值、全氮、全磷、全钾、水解性氮、有效磷、速效钾和有机碳含量从大到小均为:次生林马尾松林柑橘林;土壤容重为柑橘林马尾松林次生林;分形维数D值与柑橘林的土壤水解性氮含量呈显著正相关,与马尾松林的水解性氮含量、土壤全磷、全钾含量呈显著正相关,与次生林的土壤全磷含量、水解性氮含量呈显著正相关,与有机碳含量均呈显著负相关。[结论]闽南山地不同植被类型会显著影响表层土壤体积分形维数及养分含量,利用土壤体积分形维数可一定程度上反映不同植被类型的土壤颗粒组成及其养分含量。     

Genesis and properties of dark-colored chernozem-like soils of mesodepressions under fallow in the northern Caspian region

Specific features of the most fertile soils in the semidesert zone of the northern Caspian region—dark-colored chernozem-like soils of large mesodepressions—are analyzed. The recent regional rise in the groundwater level and the restoration of steppe vegetation in the fallowed soils of large mesodepressions, especially near forest strips and forest plantations, have led to certain changes in the microfabric and chemical composition of these soils, as well as in the soil organic matter properties.     

祁连山哈溪林区移植前后土壤氮对比研究

研究不同海拔梯度森林土壤氮的分布特征,对于合理利用森林资源、改善森林的生态功能都有重要意义。采用封顶埋管法,对祁连山东段哈溪林区不同海拔梯度和不同植被类型的土壤氮进行了研究。结果表明:(1)海拔2 650m青海云杉林土壤的初始TN,NH_4~+-N和NO_3~--N含量均最低,海拔2 950 m青海云杉林土壤的初始TN,NH_4~+-N和NO_3~--N含量均最高;各海拔梯度青海云杉林土壤经培养后,其TN,NH_4~+-N和NO_3~--N含量均减小。(2)就不同植被类型而言,青海云杉林土壤TN,NH_4~+-N和NO_3~--N含量均最高,草地和灌丛土壤TN,NH_4~+-N和NO_3~--N含量较低,且二者差异不大。草地和灌丛土壤培养后TN和NH_4~+-N含量显著升高,NO_3~--N含量变化不大。(3)某一海拔青海云杉林土壤移植到其他海拔青海云杉林培养后,土壤TN,NH_4~+-N和NO_3~--N含量变化不大;不同植被类型之间土壤相互移植培养后,土壤TN,NH_4~+-N和NO_3~--N含量变化明显,不同植被类型对土壤氮的含量差异显著。     

Soil organic carbon stocks of conifers, broadleaf and evergreen broadleaf forests of Spain

Forests represent an important resource for mitigating the greenhouse effect, but which is the contributions of the different forest types in sequestering and keeping soil C for a longer time is still uncertain, particularly in the Mediterranean area. The aim of this work is to quantify the soil organic C (SOC) stock in the 0–30 and 0–100?cm depths of mineral soil, according to the main forest types—conifers, broadleaf and evergreen broadleaf—and the different climatic zones of Spain, using a database comprising records of 1,974 pedons. Conifers and broadleaf forests show a trend in SOC stock distribution, with the stocks decreasing with increasing Mediterranean conditions. On average, in the 0–30?cm depth, the soils under broadleaf store the highest amount of SOC (5.9?±?0.1?kg?m^?2), followed by conifers (5.6?±?0.1?kg?m^?2) and evergreen broadleaf soils with an amount always lower (3.4?±?0.2?kg?m^?2). Climate and forest cover are the principal factors in determining the amount of SOC stored in Spanish forests. The significantly higher amount of SOC found in conifers and broadleaf forests than the evergreen broadleaf forests leads us to hypothesize a decrease in the SOC if climate change will increase drought periods with a consequent expansion of this latter forest type. Correlations between the SOC stocks under the different forest types, climate and soil features support the major role of climate and vegetation in controlling SOC sequestration in the Mediterranean area, while the effect of texture is less pronounced. Assigning a precise SOC stock to the different forest types, according to each climatic zone, would notably help to obtain an accurate SOC estimate at national level and for future assessments of the status of this large C reservoir.     

Soils and the soil cover of mountainous tundra and forest landscapes in the Central Khangai of Mongolia

Specific features of the soil formation and soil cover patterns in the mountainous alpine tundra and forest landscapes of the Central Khangai Range are analyzed. It is shown that the specific mucky grayhumus permafrost-affected soils are only formed under larch forests within the tundra-alpine and forest zones. Other soils have a wider geographic area. The morphological, physicochemical, and chemical characteristics of the widespread soils are given. A medium-scale map of the soil cover patterns—soil complexes, combinations, and mosaics—has been developed for the studied area.     

Soils of mountainous forest-steppe in the southwestern part of Khentei Ridge (Mongolia)

The study of soil cover in the mountainous forest-steppe on the southwestern macroslope of Khentei Ridge has shown that the spatial distribution of soils is controlled by the ruggedness of topography, slope aspects, geocryological conditions, and the thickness of loose deposits. The soils belong to the orders of lithozems and organo-accumulative soils (Mollic Leptosols) of the postlithogenic trunk of pedogenesis. Dark-humus and mucky–dark-humus horizons of the organic matter accumulation are characteristic features of these soils. The investigated area is differentiated according to the soil moistening conditions on the slopes of different aspects. Favorable growth conditions for dwarf birch and Siberian larch at the southern boundary of the boreal forests in Mongolia are explained by the relatively high moistening of mucky–darkhumus lithozems and mucky–dark-humus soils developed on windward northern slopes and on mountain terraces in places of the local snow accumulation by wind. An important role in preservation of forest vegetation belongs to permafrost in small cirque-like depressions.     

太行山区不同土地利用方式保水防蚀能力研究

从植被和土壤状况两个方面对太行山区常见的不同土地利用方式的保水防蚀能力进行了研究。研究表明,栓皮栎林、刺槐林和矮刺槐林具有较好的层次结构、较大的枯落物积累量及根系数量,保水防蚀能力较强;板栗林因为人为干扰较为强烈,层次结构单一,保水防蚀能力弱于另外3种林地;撂荒地具有较高的植被盖度和数量较多的草本植物根系以及枯落物的积累,其保水防蚀能力优于农田。农田层次结构单一,枯落物的积累和根系数量少,保水防蚀能力最弱。该地区大部分土壤都具有较大的非毛管孔隙度和较好的渗透性,但抗蚀性较差,植被有提高土壤抗蚀性的作用。     

Soil characteristics in teak plantations and natural forests in Ashanti Region,Ghana

Abstract

The goal of this study to was compare soils of natural forests converted to teak (Tectona grandis Linn. F) plantations (21.3±5.1 years) in the Offinso and Juaso Forest Districts in the Ashanti region, Ghana. Sites selected for this study were in the moist semi‐deciduous forest zone and had nearly identical physiographic characteristics. In each of three natural forest stands and three teak plantations, 16 soil pits were examined and soil samples from the 0–20 (major rooting zone) and 20–40 cm depths were analyzed for selected chemical and physical properties. In the 0–20 cm depths bulk density significantly increased (1.17 to 1.30 g cm^‐3), but soil organic matter (OM) content (13 to 11%), total nitrogen (0.3 to 0.2 %), available phosphorus (4.2 to 1.2 mg kg^‐1), and exchangeable potassium (0.4 to 0.3 cmol(+)kg^‐1), calcium (17.0 to 12.4 cmol(+)kg^‐1), and magnesium (3.8 to 3.2 cmol(+)kg^‐1) significantly decreased in soils where natural forests were replaced with teak plantations. Similar results also were found for the 20–40 cm soil depths. The higher nutrient contents in soils under the natural forest may have been due to more litter contributions from understorey vegetation observed there. In the teak plantations nutrient leaching losses may have accelerated due to increased mineralization and the inability of teak to use the increase in available nutrient.     

Soils of the subtaiga landscapes on the northern spurs of the Tsagan-Daban Ridge in the Selenga Mountains

The soil cover patterns in the subtaiga landscapes on the northern spurs of the Tsagan-Daban Ridge in the Selenga Mountains have been studied. Gray-humus lithozems and bedrock outcrops are typical of the steep south-facing slopes under herbaceous pine forests. Soddy iron-illuvial podburs are formed under forest vegetation on gentle slopes of northern and western aspects with a thick mantle of loose colluvial deposits. Dark-humus metamorphic soils occur on the slopes of western and northwestern aspects below 700 m a.s.l. under secondary forb-grassy communities that replaced the initial herbaceous pine forests. Windblown hollows (yardangs) are occupied by humus psammozems under steppe pine forests. The morphological and physicochemical characteristics of these soils are discussed in the paper.     

太行山区主要森林生态系统水源涵养能力

森林生态系统水源涵养功能是林冠层、枯落物层和土壤层对大气降水进行再分配的过程。本文通过文献收集整理太行山地区森林植被林冠一次降水截留量、枯落物层持水量和土壤层贮水量数据,分析该地区主要森林植被对降水的截留和贮蓄能力,采用综合蓄水能力法对森林植被的综合涵养水源能力进行评价,旨在为合理经营和管理森林生态系统提供依据。结果表明:1)土壤非毛管孔隙度与生态系统综合持水量呈正相关,且最大持水量占整个森林生态系统综合持水量的90%以上,表明土壤层作为森林生态系统水文效应最重要的一层,是整个森林系统水分循环的主要贮蓄库和调节器;2)针叶林中油松和侧柏的冠层一次降水截留量显著高于其他林型,其林冠结构更加适应该地区气象条件,林冠层降水再分配能力也优于其他林型;3)混交林郁闭度低,有利于林下灌、草丛的生长,其枯落物现存量比纯林和人工林更高,虽然林冠一次截留量低但林下具有丰富的枯落物层而更易涵养水源;4)天然林综合蓄水能力整体高于人工林,侧柏人工林和油松人工林综合蓄水能力仅次于刺槐、侧柏和油松天然林。综上可见,合理利用森林资源防止水土流失、天然林长期封育和合理控制优势树种密度及增加植被覆盖率对太行山地区植被恢复和生态建设具有重要意义。为提高该区综合水源涵养能力,可增加乡土树种油松和侧柏人工林的种植面积。     

Soil cover patterns and land assessment in the Baikal region of Buryatia using the example of the Kabansk district

The soil cover patterns in the Kabansk district (the Baikal region of the Buryat Republic), including the Selenga River delta, are analyzed. A soil map of this area has been developed on a scale of 1 : 500000. Stony organic soils are widespread in the tundra zone. Mountain-meadow soddy soils and tundra podburs (under dwarf pine) are formed at lower heights around lakes and in glacial valleys. Kabansk district includes taiga landscapes on the northern slopes of the Khamar-Daban Ridge with the predominance of podburs, podzols, soddy-taiga soils, and burozems. Agrolandscapes occur in the Nizhneselenginsk meadow-bog and forest-steppe natural region with a predominance of soddy forest, soddy gray forest, meadow, alluvial, meadow-bog, and bog soils. Data on the land evaluation in the agricultural part of the studied region are given.     

三峡库区森林土壤优先流染色特征

森林土壤优先流在涵养水源和调节径流过程中起着重要作用,林地优先流特征研究对分析森林土壤水分入渗特征和探讨森林对流域水文过程的调节机制具有重要意义。使用染色示踪法在三峡库区不同垂直带内进行森林土壤优先流染色试验,研究不同山地森林土壤的染色特征。结果表明:不同森林土壤的表层(0-10cm)染色比例和染色剂入渗深度差异较大,土壤染色垂直变化趋势也不相同。中山常绿和落叶阔叶混交林表层土壤染色比例最高,染色剂入渗最浅,土壤染色比例随深度变化呈连续下降趋势。中山常绿针叶林表层土壤染色比例和染色剂入渗深度在不同样地间存在着变异,土壤染色垂直分异特征存在一定的差异。低山常绿针叶林表层土壤染色比例最低,染色剂入渗最深,土壤染色比例随深度变化呈波动下降趋势。不同森林土壤中优先流路径数量和分布不同是导致染色特征存在差异的主要原因,而森林土壤中的根系、裂隙以及土壤物理性质等都会影响到优先流的形成。