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1.
Changes in the physical, physicochemical, and biological properties of cultivated gray forest soils after their abandoning and overgrowing with meadow and forest vegetation for 8–10 years are clearly seen in the upper part of the former plow layer. The organic matter content and the content of available forms of phosphorus and potassium increase; a significant increase in the root biomass and in the soil biological activity is observed. Changes in the physical properties—an increase in the degree of soil aggregation and a decrease in the bulk density values—are seen in the upper and middle parts of the former plow layer. The biological factor is the major factor of transformation of formerly cultivated gray forest soils upon their abandoning and overgrowing with meadow and forest vegetation. At the same time, a significant role in the improvement of the structural state of the soils belongs to the physical shrink-swell and freezing-thawing processes.  相似文献   

2.
The water-stability of soil and coprolite aggregates in soddy-podzolic soils and the participation of fungi in the formation of water-stable aggregates from earthworm (Aporrectodea caliginosa) coprolites were assessed. The water stability of the soil and coprolite aggregates in the soils increased in the following sequence: potato field—mown meadow—mixed forest. The fungal mycelium reserves increased in the same sequence. The water stability of the coprolite aggregates of Aporrectodea caliginosa inhabiting these soils is 2–2.5 times higher than that of the soil aggregates of the same size (3–5 mm). The inhibition of the growth of fungi by cycloheximide decreased the water stability of the coprolite aggregates, on the average, by 15–20%.  相似文献   

3.
The evolution of automorphic cultivated soils of the Fayette series (the order of Alfisols)—close analogues of gray forest soils in the European part of Russia—was studied by the method of agrosoil chronosequences in the lower reaches of the Iowa River. It was found that the old-arable soils are characterized by an increase in the thickness of humus horizons and better aggregation; they are subjected to active biogenic turbation by rodents; some alkalization of the soil reaction and an increase in the sum of exchangeable bases also take place. These features are developed against the background of active eluvial-illuvial differentiation and gleyzation of the soil profiles under conditions of a relatively wet climate typical of the ecotone between the zones of prairies and broadleaved forests in the northeast Central Plains of the United States.  相似文献   

4.
The plant cover of the Khibiny Mountains is characterized by the well-pronounced altitudinal zonality: high-alpine barrens—lichen, dwarf shrub, and shrub tundra—elfin birch forest—spruce forest. Humic petrozems (Lithic Leptosols) under sparse vegetation are formed on the tops of the mountains. The soils of the tundra zone are represented by podburs on the eluvium of nepheline syenite; smaller areas are occupied by typical cryozems. Humus-illuvial podzols are developed from moraine deposits under elfin birch forests and open spruce woodland. The moraine deposits in the inner valleys of the Khibiny Mountains are enriched in the products of weathering of nepheline syenite. The humus-illuvial podzols developed from them differ from their analogues on plain territories in the higher humus content and less contrasting eluvialilluvial differentiation.  相似文献   

5.
The structure of humic acids (HAs) in zonal soil types—soddy-podzolic soils (two samples), gray forest soil (one sample), and chernozems (two samples)—was quantitatively studied by 13C NMR spectros-copy. In the series considered, the content of unsubstituted carbon in the aromatic fragments of HAs increased, and the fraction of unsubstituted aliphatic structures decreased. HAs of soddy-podzolic soils were found to be enriched with carbohydrate fragments compared to HAs of chernozems and gray forest soil. The carbon skeleton of HAs from typical rich chernozem contained significantly more aliphatic and carbohydrate fragments compared to typical chernozem, which probably reflected the lower degree of HA transformation in rich chernozem.  相似文献   

6.
The effect of two methods for the preparation of soil samples for sorption experiments—hard (dehydration at 105°C) and mild (drying over P2O5 at 20°C in vacuum) drying—on the values of the vaporphase sorption of p-xylene was studied depending on the content of organic matter in the soil. It was shown with dark gray forest and chernozemic soils as examples that the hard drying of soil samples taken from the upper layer of the humus profile with a high content (>4%) of organic carbon decreased their sorption capacity in the range of 0–5% by 7–81%. Therefore, the method is unsuitable for these soils. It was also found that the mild method of soil preparation had obvious analytical advantages.  相似文献   

7.
Complexes of gray forest soils of different podzolization degrees with the participation of gray forest podzolized soils with the second humus horizon play a noticeable role in the soil cover patterns of Vladimir Opolie. The agronomic homogeneity and agronomic compatibility of gray forest soils in automorphic positions (“plakor” sites) were assessed on the test field of the Vladimir Agricultural Research Institute. The term “soil homogeneity” implies in our study the closeness of crop yield estimates (scores) for the soil polygons; the term “soil compatibility” implies the possibility to apply the same technologies in the same dates for different soil polygons within a field. To assess the agronomic homogeneity and compatibility of soils, the statistical analysis of the yields of test crop (oats) was performed, and the spatial distribution of the particular parameters of soil hydrothermic regime was studied. The analysis of crop yields showed their high variability: the gray forest soils on microhighs showed the minimal potential fertility, and the maximal fertility was typical of the soils with the second humus horizon in microlows. Soils also differed significantly in their hydrothermic regime, as the gray forest soils with the second humus horizon were heated and cooled slower than the background gray forest soils; their temperature had a stronger lag effect and displayed a narrower amplitude in seasonal fluctuations; and these soils were wetter during the first weeks (40 days) of the growing season. Being colder and wetter, the soils with the second humus horizons reached their physical ripeness later than the gray forest soils. Thus, the soil cover of the test plot in the automorphic position is heterogeneous; from the agronomic standpoint, its components are incompatible.  相似文献   

8.
In two layers of the humus horizons in soddy-podzolic soils of different biogeocenoses (Kostroma oblast) representing a succession series, the carbon content in the microbial biomass (Cmic) was determined using the method of substrate-induced respiration and the rate of microbial CO2 production (basal respiration, BR). The Cmic content was from 110 to 755 μg/g soil, and the BR was from 0.40 to 2.52 μg CO2-C/g/h. A gradual increase in the Cmic content and BR was found in the following sequence: cropland—fallow (7-year-old)—young (20- and 45-year-old) forests—secondary and native (primary) forests (90- and 450-year-old, respectively). In the litter, the Cmic content was higher in the 45-year-old forest than in the secondary and native forests: 10423, 6459, and 4258 μg C/g of substrate, respectively. The portion of Cmic in the soil organic carbon content in the upper layer of the soils studied varied from 1.3 to 5.4%; its highest value was in the soils under the secondary and native forests. The pool of microbial biomass carbon and the microbial CO2 production in the upper 25-cm layer of the soils were calculated.  相似文献   

9.
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.  相似文献   

10.
The history of transformation of soils and soil cover in the Tushinskii and Pokrovskoe-Streshnevo forest parks of Moscow is investigated. The peculiarities of the influence of anthropogenic activities on the soil cover and soils are examined with the use of maps and textual materials for a period of more than four centuries. The historical stages of anthropogenic disturbance are established, and different ways of anthropogenic transformation of the soil profiles are described.  相似文献   

11.
Specific features of soil formation and soil cover patterns in mountain forests of the East Khubsugul region are discussed. A scheme of the vertical zonality of soils under mountain forests is given. It is shown that soils of the uppermost forest zone are permafrost-affected. Seasonally freezing soils under forest vegetation predominate at lower heights and in the southern part of the region near the boundary with the steppe zone. The major soil combinations under different types of forest vegetation are described. The morphological, physicochemical, and chemical characteristics of widespread forest soils are given.  相似文献   

12.
The water-physical properties (bulk density, air conductivity, texture, water content, and temperature dynamics) were studied in a chronosequence of soils developing on self-overgrowing quarry-dump complexes in the area of Sokolov, Czechia. The area overgrown for 12 years was covered by a thin grass cover; osiers were observed after 20 years of overgrowth; a broadleaved forest was found on a plot after 45 years of overgrowth. The particle-size distribution in the soil was determined using peptization by pyrophosphate and the FAO method. When the soil was prepared by the FAO method, a predominance of physical clay (62–72%) in the dump material was revealed; at the use of pyrophosphate peptization, the content of this fraction was lower (18–19%). The observed differences can be due to the incomplete degradation of the microaggregates composed of clay particles during the peptization by pyrophosphate. A decrease in the field water content of the soils with the increasing time of the dump’s overgrowth was observed. This could be attributed to the more significant evapotranspiration of the perennial woody vegetation compared to the herbaceous plants, which agreed with the data on the projective cover of plants and their root biomass. A decrease in the soil temperature in the root-inhabited layer (in the diurnal variation) with the age of succession was also observed. The analysis of the data on the field soil water content and their comparison with the results of the laboratory measuring of the wilting points indicated that the development of plants could be restricted by a water deficit at the 20- and 45-year-old stages of the succession.  相似文献   

13.
The Quaternary deposits on the Tersk coast of the White Sea are represented by marine deposits (the Tersk sands) enriched in the sea-sorted eluvium of the red Tersk sandstone. These deposits and the soils developed from them are characterized by the predominance of the fine sand fraction and the absence of gravel and the coarser fractions. The sediments derived from the red Tersk sandstone have an impoverished chemical composition (the silica content reaches 75–80%). The iron-illuvial podzols developed from them are characterized by the slightly pronounced differentiation of the main oxides and by the eluvial-illuvial redistribution of the amorphous Al and Fe compounds. Sandy soils—psammozems—with undifferentiated soil profiles are developed from windblown sands subjected to afforestation and from coastal marine sands under a relatively thin natural plant cover. Iron-illuvial podzols buried under a thin sand layer preserve the Al-Fe-humus type of the profile differentiation. In the recently deposited sand layer, the eluvial-illuvial redistribution of the chemical elements is absent.  相似文献   

14.
The morphological structure of the soils in the forest areas of European Russia was analyzed. It was shown that most of the soils were formed under the impact of both biotic and anthropogenic factors. Soils with poorly differentiated profiles without podzolization features are typical for the least disturbed forest ecosystems. The presence of an eluvial (EL) horizon is associated with the signs of old plowing and (or) fires. The character and rate of the soil cover transformation under various impacts of the historical land use (felling, plowing, pasturing, burning, etc.) are discussed. The technologies of the main traditional farming systems in the forest zone of European Russia (slash-and-burn, fallow, and shifting farming systems) are considered; their effect on the long-term dynamics of the soil cover is estimated. Farming and the related impacts of historical land use can be a major reason for the formation of degraded soils in the forest zone of European Russia.  相似文献   

15.
Russia has long needed a world-level soil attribute (profile) information database which should become the basis for creating a system of monitoring of the state of soils and for developing measures for their conservation and efficient land use. A unified system of gathering and storing information on soils, which at the same time would be open for general use, is needed. The present work is devoted to problems of the concept and methodology of creating a soil geographic database (SGDB) of Russia. The structure and content of the soil attribute database, underlying which is the concept of representative soils profiles, are given. A list of classifiers for preparing data presentation formats in the SGDB on the basis of existing concepts of soil morphology and classifiers characterizing the main physicochemical properties of soils is developed. The work underlies the creation of an information resource—“Soil-Geographic Database of Russia. Project of the Dokuchaev Soil Science Society”—on the Internet at the address .  相似文献   

16.
The extent of soil degradation and soil pathology in Russia is discussed. The concept of a federal target program “National System of the Chemical and Biological Security of the Russian Federation (2009–2013)” is examined. A definition is given to healthy soil of agrocenoses and its main functional characteristic—ecological stability (including balanced biodiversity, self-cleaning capacity, and suppressive activity of the phytopedocenosis). Urgent applied scientific problems of regional soil sanitation are formulated. Criteria and modern methods of ecological monitoring and assessment of soil quality and health are considered. A systems approach to sanitation of soils infected by highly harmful phytopathogens—the causative agents of root rots of cereal crops—is demonstrated using the induction of soil suppressiveness as an example.  相似文献   

17.
The diversity of soils in the southwestern part of the Pacific coast of Russia (Primorie region) is discussed. Overall, 17 soil types belonging to 8 soil orders have been described in this region, and their morphology and properties have been studied. The diversity of plant communities, geomorphic conditions, and parent materials and relatively mild (as compared with other parts of the Far East region of Russia) specify the great variability of soil cover patterns. Low sea terraces are occupied by various peat, organo-accumulative, and gley soils; poorly drained medium-high terraces are the areas of various dark-humus and darkhumus gleyed soils. Typical and gleyic dark-humus podbels, dark-humus, and dark-humus gleyed soils formed on the high sea terraces. Residual elevations are occupied by brown forest (burozemic) soils, including typical burozems, dark-humus burozems, and gleyic dark-humus burozems and by dark-humus podbels. Various alluvial, gleyic gray-humus, and mucky gley soils are developed on riverine plains. On general, darkhumus soils with the high (>10%) humus content predominate; the area of dark-humus podbels us estimated at about 20%, and the area of dark-humus burozems is about 12%. All the soils in this region are specified by increased acidity values. The exchangeable sodium content is often high in the upper soil horizons with maximum values (0.71–1.19 cmol(c)/kg) in the peat gleyzems, peaty dark-humus soils, mucky-gley soils, and eutrophic peat soils of sea terraces. The grouping of the soils with respect to their physicochemical and agrochemical properties is suggested.  相似文献   

18.
The aim of this study was to determine the effect of land‐use and forest cover depletion on the distribution of soil organic carbon (SOC) within particle‐size fractions in a volcanic soil. Emphasis was given to the thermal properties of soils. Six representative sites in Mexico were selected in an area dominated by Andosols: a grassland site, four forested sites with different levels of degradation and an agricultural site. Soils were fractionated using ultrasonic energy until complete dispersion was achieved. The particle‐size fractions were coarse sand, fine sand, silt, clay and particulate organic matter from the coarse sand sized fraction (POM‐CS) and fine sand (POM‐FS). Soil organic carbon decreased by 70% after forest conversion to cropland and long‐term cultivation; forest cover loss resulted in a decrease in SOC of up to 60%. The grassland soil contained 45% more SOC than the cropland one. Soil organic carbon was mainly associated with the silt‐size fraction; the most sensitive fractions to land‐use change and forest cover depletion were POM followed by SOC associated with the silt and clay‐sized fractions. Particulate organic matter can be used as an early indicator of SOC loss. The C lost from the clay and silt‐sized fractions was thermally labile; therefore, the SOC stored in the more degraded forest soils was more recalcitrant (thermally resistant). Only the transformation of forest to agricultural land produced a similar loss of thermally stable C associated with the silt‐sized fraction.  相似文献   

19.
This study was carried out to evaluate the effects of deforestation on physical and chemical properties of soils under native forest in the Mediterranean region of northwestern Jordan. Land use/cover maps of 1953, 1978 and 2002 were interpreted and analysed within GIS to quantify the shift from forest to rainfed cultivation. Six sites were sampled in a non‐changed forest and in cultivated fields, three for each. Different soil properties of texture, bulk density, organic matter, total nitrogen, pH, cation exchange capacity (CEC), phosphorous and potassium were analysed. Results showed that many forests were changed into cultivated lands at a rate more than the reforestation. Subsequently, adverse effects on the studied physical and chemical properties were observed. The most affected properties were particle size distribution, bulk density of surface soil and subsoil. Organic matter and CEC decreased in cultivated soil as compared to the forest soil. Cultivated soils were found to exhibit a significantly lower status in physical and chemical soil properties as compared to forest soils. This general decline in the soil physical and chemical properties, in turn, contributed to soil erosion, reduction of soil fertility and land degradation. There is an urgent need to improve soil quality by developing sustainable land use practices to reduce the rate of soil degradation and to ensure long‐term sustainability of the farming system in the study area and in similar biophysical settings. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

20.
Background, aim, and scope  Exploited gas fields and underground gasholders are specific sources of increasing methane concentration. Methane migrates into the soils by diffusion and convection through natural and technogenic cracks in geological structures and influences the function of the soils. Soil cover of gas-bearing area functions as a specific, bilateral, periodically penetrating, geomembrane. Soils shield, transform, and differentiate migrating fluxes of technogenic-allochthonous methane, preventing its emission to the atmosphere. Problems of methane’s emission are rather current at the present, as methane is the second in importance after CO2 greenhouse gas, since its concentration in the atmosphere annually grows by approximately 1%. By global estimations, methane emissions in the gas industry make about 8% of annual receipt to the atmosphere, equal on the average to 500 Тg per a year (Cicerone and Oremland, Global Biogeochem Cy 2:299–327, 1988). But these calculations are based on the account of the technological losses making 3–12% from the mining of natural gas. The contribution of migratory methane fluxes to the atmosphere, as a rule, is not considered. The need for research of soil cover functioning on gas-bearing areas is explained by the fact that processes of methane oxidation, its transformation in soils, and emission to the atmosphere at these objects are now practically not being studied. The aim of our study was to reveal specific processes of soil function and formation on gas-bearing areas by an example of underground gasholder. Materials and methods  The material was sampled in 1998–2003 at the territory of underground gasholder located in Albeluvisol’s zone in Russia. According to the comparative-geographical method, 51 soil profiles have been studied in similar litologically geomorphological conditions in various geochemical zones: in the industrial zone, in the zone of gas dissipation, and at the regional background. The total square of investigated territory is about 60 km2. Six soil profiles were investigated in seasonal dynamics. Samples of soils for physical, chemical, and microbiological analyses were taken from each horizon of soil profiles (202 samples). Samples of soil air for a definition of methane concentration were taken from depths of 20, 40, and 60 cm. Methane emission to the atmosphere was measured near soil’s cuts and, in addition, on all area of the investigated territory at knots of squares network through 700–1,000 m, in total at 32–42 points in May, July, and November. Years of investigation have been split by technological and hydrothermal conditions. The periods with the normal and lowered compression of gas in gasholder, dry and warm, and damp and cool years have been allocated. It has influenced the soil function processes and considered an interpretation of the data received. Results  The changes of functional parameters of soils at a gas-bearing area influenced by methane fluxes migrating from gas deposits, in comparison with background soils, are revealed. Such functional parameters are methane concentration in the soils, activity of its bacterial oxidation, methane emission to the atmosphere, and oxidation–reduction potential. Spatial and temporary dynamics of these parameters at gas-bearing and background territory are investigated. Discussion  Methane interaction with soil’s air is in its ascending (descending) and lateral diffusion and convection in soils. Methane fluxes dissipate in porous space of soils forming gas anomalies. The technogenic-allochthonous methane concentration strongly varies in soil’s air on gas-bearing area (1–10,500 ppm) and, on average, exceeds the autochthonous, microbiologically produced methane at background territories. Migratory methane is deposited on diffusion and sorption barriers. The capacity of diffusion barrier depends on effective coefficient of diffusion, the attitude of air and general porosity, and granulometric composition and sharply differs in auto-, semi-hydro-, and hydromorphic soils reaching maximum in hydromorphicity and among the soils with identical water content—in heavy soils. The capacity of the sorption barrier is defined by abiotic methane absorption and a specific surface of soils and grows with their increasing intensity in soils to a heavier granulometric composition or into soils with peat and gleyic horizons. The low sorption capacity leads to an increase of methane concentration in the soil’s air and decreases its utilization by microorganisms, in which its quantity depends on sorption properties. The central component of functioning that promotes a number of essential transformations in soils on gas-bearing areas is methane interaction with the biotic phase. The periods of methane deposition by diffusion and sorption barriers are used for biological methane oxidation and formation of biogeochemical barriers in soils. The activity of bacterial methane oxidation is characterized by spatial variability and depends on the entrance of methane, defined by granulometric composition, soil moisture, the attitude of air and general porosity, Eh, organic matter content, and salinization. During interaction between technogenic-allochthonous methane and soil on diffusion, sorption, and biogeochemical barriers, its transformation occurs, accompanied by a strengthening of variability of oxidation–reduction potential and formation of pedogenic, bacteriomorphic, and nanodispersic magnetic oxides of iron. Conclusions and perspectives  Specificity of soil functioning on a gas-bearing area is in interaction of technogenic-allochtonous methane with solid, liquid, gaseous, and living substance of the soil system. Spatial laws of soils functioning on gas-bearing area in the Albeluvisol’s zone are revealed. Distinctions of soil functions depending on litologically geomorphological conditions are shown. The greatest changes of parameters of functioning under the influence of technogenic-allochthonous methane occur in automorphic soils, and it is less in semi-hydromorphic soils. Activity of bacterial methane oxidation in soils, emission, and consumption from the atmosphere and their spatial laws are characterized by the time dynamics depending on hydrothermal and technological conditions of seasons and years. During oxidation in soils of gas-bearing areas, carbon of methane is concentrated on a biogeochemical barrier that is shown in the increase of methylotrophic microorganisms’ biomass and leads to a high variability and decrease of Eh and to the formation of magnetic oxides of iron. Recommendations  Results of research can be used for carrying out ecological monitoring and an estimation of tightness of objects of the gas industry. Activity of bacterial methane oxidation, Eh, and magnetic oxides of iron can be used as diagnostic parameters of soils on gas-bearing areas. This paper has been developed from a presentation at the conference SUITMA-4 (Soils in Urban, Industrial, Traffic, Mining and Military Areas) Nanjing, China, 2007  相似文献   

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