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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. 相似文献
3.
The close interrelationships between forests and soils and their mutual effects and development are considered. Particular emphasis was given to the positive role of forest in the formation of soil, the actual status of the latter, and its resistance to different natural and anthropogenic impacts. The role of forests in soil formation and the maintenance of natural biodiversity are discussed. The influence of the climate on soils has been studied to some extent. Nowadays, the role of soil in the changes of the climate and biodiversity remains a topical problem, the solution of which is important for the management of the environment. 相似文献
4.
We applied the Revised Soil Loss Equation (RUSLE) to assess levels of soil loss in a Geographic Information System (GIS). In this study, we used the k-NN technique to estimate vegetation cover by integrating Landsat ETM+ scenes and field data with optimal parameters. We evaluated the root mean square errors and significance of biases at the pixel level in order to determine the optimal parameters. The accuracy of vegetation cover estimation by the k-NN technique was compared to that predicted by a regression function using Landsat ETM+ bands and field measurements as well as to that predicted by the Normalized Difference Vegetation Index (NDVI). We used a regression equation to calculate the cover management (C) factor of the RUSLE from vegetation cover data. On the basis of the quantitative model of soil erosion, we explored the relationship between soil loss and its influencing factors, and identified areas at high erosion risk. The results showed that the k-NN method can predict vegetation cover more accurately for image pixels at the landscape level than can the other two methods examined in this study. Of those factors, the C-factor is one of the most important affecting soil erosion in the region. Scenarios with different vegetation cover on high-risk areas showed that greater vegetation cover can considerably reduce the loss of soil erosion. The k-NN technique provides a new method to estimate the C-factor for RUSLE erosion mapping. The quantitative model of different vegetation cover scenarios provides information on how vegetation restoration could reduce erosion. 相似文献
5.
V. A. Rozhkov 《Eurasian Soil Science》2009,42(2):118-128
Soils and the soil cover are witnesses to global changes on the planet; moreover, they play an active role in these changes. Investigations into the role of soils in global processes come to forefront of modern soil science; it is necessary to find appropriate criteria and indicators making it possible to diagnose global environmental changes and to assess their contribution to soil formation. 相似文献
6.
Morphoscopic studies were conducted with the aid of SEM and TEM microscopes, on quartz grains and fractions not exceeding 2 μm, on soil samples from the continental tundra, alpine meadow and arid steppe. The aim of these studies was to define the features and properties of the quartz grains and fractions, produced by the environment of the cryoarid continental climate of Central Asia. It has been established that in cold and humid climates processes of cryogenic and hydrothermic splitting occur on the surface of quartz grains and in cold and dry climates processes of cryothermic scalling. The increase in the surface area of disintegrated minerals under continental climate conditions is accompanied by cryochemical coating by mineral-organic compounds. 相似文献
7.
Because of an increasing world demand for paper and other forest products, the Finnish wood-using industries are expanding rapidly. This has raised serious concern about the future of forest resources. Clearing of land for agriculture has slightly decreased the forest area during recent decades. Today, however, the forest area is increasing, owing to peatland drainage and afforestation of surplus agricultural land. The growing stock of the forests has remained approximately unchanged during all the fifty years covered by repeated national forest inventories. Due to the present expansion of industry, however, intensive silvicultural measures are required to balance the increasing drain from the forests. Calculations show that, with feasible methods, by the year 2000 the annual increment of the forests could be raised by over 50 per cent, and measures have been taken to finance such a programme. Intensive silviculture (artificial reforestation, drainage, fertilization, etc.) will also change the forest scenery. In general, however, the changes will be small, as domestic tree species are favoured and rough terrain, rocky ground, and the Finnish type of forest ownership, prevent the establishment of large uniform monocultures. The biggest change in the scenery will be caused by the large-scale drainage of peat-bogs for forestry. 相似文献
8.
The spatial distribution of major soil horizons and layers of pyroclastic deposits in Kamchatka was analyzed with the use
of GIS technologies. For this purpose, the attribute soil database and the computer-supported cartographic database were developed.
Their analysis with the help of GIS technologies made it possible to study the dependence of the morphology of soil profiles
on the bioclimatic conditions and on the stratification of ash layers in the particular areas of Kamchatka and to develop
the cartographic model of the areas of soil horizons. The concept of tephra stratotypes—the particular combinations of ash
layers in the profiles of volcanic soils—was verified on the basis of factual materials. It was shown that tephra stratotypes
affect many important soil properties and specify the direction of soil formation in Kamchatka. Several major tephra stratotypes
differing in their morphology and environmentally important features were distinguished in Central Kamchatka. The method of
soil mapping on the basis of the concept of tephra stratotypes with due account for the specificity of surface organic horizons
of soils was developed. It is argued that this method makes it possible to reflect the specificity of soil formation in volcanic
regions. 相似文献
9.
The content and composition of the lignin phenols in plants and soils of vertical natural zones were studied in the Northern
Caucasus region and Northwestern Tien Shan. Three types of lignin transformation were revealed: steppe, forest, and meadow
ones. It was shown that the degree of oxidation of the biopolymer during the transformation of organic matter increased when
going from the living plant tissues to humic acids in surface and buried soils. The portion of lignin fragments remained unchanged
during the biopolymer transformation in the following series: plant tissues-falloff-litter-soil-humic acids-buried humic acids.
It was also shown that the biochemical composition of the plants had a decisive effect on the structure of the humic acids
in the soils. The quantitative analysis of the lignin phenols and the 13C NMR spectroscopy proved that the lignin in higher plants was involved in the formation of specific compounds of soil humus,
including aliphatic and aromatic molecular fragments. The first analysis of the lignin content and composition in buried soils
of different ages was performed, and an increase in the degree of oxidation of the lignin structures was revealed in the soil
chronoseries. It was proposed to use the proportions of lignin phenols in surface and buried soils as diagnostic criteria
of the vegetation types in different epochs. 相似文献
10.
V. E. Prikhod’ko I. V. Ivanov D. V. Manakhov E. V. Manakhova 《Eurasian Soil Science》2012,45(8):725-739
Soils of the Arkaim Reserve in the area around a unique settlement-fortress of the Bronze Age in Chelyabinsk oblast have been studied. These soils are generally typical of the entire Trans-Ural Plateau. The soil properties are characterized in detail on the basis of factual data on 170 soil pits and four soil catenas. The soil cover of the reserve is specified into six geomorphic groups: (a) denudational surfaces of the low mountains, (b) accumulative-denudational surfaces of the low mountains, (c) denudational-accumulative plain surfaces, (d) lacustrine-alluvial plain surfaces, (e) floodplain surfaces, and (f) slopes and bottoms of the local ravines and hollows. Chernozems occupy about 50% of the reserve; solonetzes and saline soils, 32%; meadow chernozems, 7%; and forest soils, 1%. The soils of the reserve are relatively thin; they have a distinct tonguing of the humus horizon and are often saline and solonetzic. The latter properties are inherited from the parent materials and are preserved in the soils for a long time under the conditions of a dry continental climate. The genetic features of the soils differ in dependence on the composition and age of the parent materials. With respect to the thickness of the soil profiles and the reserves of soil humus, the soils can be arranged into the following lithogenic sequence: the soils developed from the eluvium of igneous rocks-redeposited kaolin clay-montmorillonite-hydromica nonsaline and saline loams and clays. The content of Corg in the upper 20 cm varies from 2.5 to 5.6%, and the reserves of Corg in the layers of 0?C0.5 and 0?C1.0 m reach 57?C265 and 234?C375 t/ha, respectively. The soils of pastures subjected to overgrazing occupy two-thirds of the reserve. Their humus content is 10?C16% higher in comparison with that in the analogous plowed soils. Another characteristic feature of the humus in the soils of the pastures is its enrichment in the labile fraction (28?C40% of Corg). 相似文献
11.
The features of ancient periglacial phenomena are widespread in landscapes lying beyond the modern permafrost zone. The specificity of the paleogeographic conditions in the south of the Baikal region resulted in the formation of paleocryogenic landscapes with hummocky-hollow landforms. The paleocryogenic mounds (hummocks) are of rounded or elongated shape, their height is up to 2–3 m, and their width is up to 20–25 m. They are separated by microlows (hollows). This paleocryogenic microtopography favors the differentiation of the pedogenesis on the mounds and in the hollows, so the soil cover pattern becomes more complicated. It is composed of polychronous soils organized in complexes with cyclic patterns. Light gray and gray forest soils and leached and ordinary chernozems are developed on the mounds; gray and dark gray forest soils and chernozems with buried horizons are developed in the hollows. The soils of the paleocryogenic complexes differ from one another in their morphology, physical and chemical properties, elemental composition, and humus composition. For the first time, radiocarbon dates have been obtained for the surface and buried humus horizons in the hollows. The results prove the heterochronous nature of the soils of the paleocryogenic landscapes in the south of the Baikal region. 相似文献
12.
A. I. Kliment’ev V. M. Pavleichik A. A. Chibilev I. V. Groshev I. V. Lozhkin Yu. M. Nesterenko 《Eurasian Soil Science》2007,40(1):7-17
The specificity of soil and landscape conditions in the area of the Kzyladyr karst field in the western folding zone of the Southern Urals is discussed. Unique karst landscapes and soils developing from hard gypsum rocks, gypsiferous weathered mantles, and gypsiferous saline rocks are characterized. These soils strongly differ from the background soils on silicate rocks in their morphology and physicochemical properties. At present, the territory under study is subjected to considerable anthropogenic loads and requires special protection measures. It is suggested that it should be included in the system of specially protected territories. The relic, rare, and unique soils of the karst field should be included in the Red Data soil book. 相似文献
13.
Based on the analysis of the relationships between the plant biomass and the different soil properties, a summary table for the biological, water-physical, thermophysical, agrochemical, and mechanical indices of the environmental degradation risk for the tundra soil-plant cover was compiled. Among the indices convenient for the assessment of the soil-plant cover status, the changes in the plant coverage, the depth of the soil thawing, and the humus content in the 0- to 20-cm-thick layer were distinguished. Empirical equations for their quantification are presented. Simple equations for estimating the dynamics of the tundra soilplant cover and the time of its self-regeneration on drained and undrained areas were obtained. The set of equations suggested is a model for the assessment and forecasting of the stability; degradation; dynamics; time of self-regeneration; and, in general, the status of the tundra soil-plant cover taking into account the changes in the topography and hydrothermal conditions after mechanical impacts with corresponding adverse processes. 相似文献
14.
Özlem Karadeniz 《Archives of Agronomy and Soil Science》2017,63(4):586-597
Due to the paucity of data on separate spatial distribution of cosmogenic 7Be radionuclide activities in forest soil layers, a spatial study was performed in Mount Ida (Kazdagi)/Edremit, Turkey. In this study, it was aimed to examine the 7Be spatial variability and depth distribution in the surface soil layers. The 7Be activity concentrations were determined by HPGe gamma spectrometry system and the distributions of 7Be activities in the OL and OF + OH horizons throughout the region were mapped separately. Activity concentrations of 7Be in OL horizons and OF+OH horizons varied as 35 ± 23–701 ± 40 Bq kg?1 and 0.96 ± 0.63–197 ± 11 Bq kg?1, respectively. 7Be inventories (0.20 ± 0.06–5.69 ± 0.75 kBq m?2) in the study area were relatively higher when compared with the other regions of the world. 7Be inventories increased with altitude, slope and the thickness of the humus layer in some of the investigated area. Average 7Be activity level in deciduous forest stand type was significantly higher than that for coniferous and mixed stand types. Our limited data could not provide a latitudinal distribution pattern of 7Be soil inventory or precipitation dependence and further investigation is needed. 相似文献
15.
The territory in the upper reaches of the Pechora River is characterized by the predominance of Al-Fe-humus and metamorphic soils with gley features developing under the middle taiga fir-spruce forests rather than gley-podzolic soils as had been considered before. Some of the described soil profiles represent intergrades between brown taiga soils (burozems) and gleysols; these soils are absent in the new Russian soil classification system. General regularities of the soil cover are controlled by the geomorphic position of the soils on slopes and by the conditions of ground moistening and lateral soil water flows. The development of modern soil cover patterns is determined by the impact of herbaceous and woody vegetation, bioturbation of the soils by windfalls, the presence of dead tree trunks on the soil surface, and other factors. 相似文献
16.
J.C.Z. Woinarski 《Biological conservation》2010,143(10):2385-2394
The fragmented island realm of Oceania includes a relatively small proportion of the world’s tropical forests, but those forests support unusual richness of narrowly endemic species. In common with tropical forests across most of the world, tropical forests in Oceania are declining due to factors associated with increasing human population size, economic drivers and more intensive exploitation. In parts of Oceania, forests are being cleared at unsustainable rates, and replaced with far simpler ecosystems of timber or food crops. To a small degree, the present-day biodiversity of tropical forests in some parts of Oceania may be predisposed to such disturbance, given a history of natural disturbance (particularly through cyclones), and of smaller-scale slash-and-burn agriculture or landscape-scale burning. But, in most places, the current intensity, scale and/or rate of modification far surpass their precedents, and biodiversity is consequently diminishing. Tropical forests in Australia may be an exception to this trend, with now reasonably effective protection. However, more so than for tropical forests in most other continents, the major biodiversity conservation challenges for tropical forests in Oceania are extrinsic. Introduced plants, animals and diseases have collapsed ecological communities through much of Oceania, homogenising the biota from a series of highly distinctive and localised species assemblages to a more impoverished set of ubiquitous disturbance-tolerant exotic species. In many islands, this simplification has occurred regardless of the extent of native forest remaining, such that retention and reservation of primary forest is an insufficient conservation action. The fate of biodiversity in Oceania is also likely to be much affected by climate change, an unbalanced consequence given the region’s relatively small contribution to greenhouse gas emissions. Future hope for biodiversity conservation in tropical forests of Oceania lies in the renewed application of some traditional management constraints, the appropriate delivery of international support (such as may be available through carbon markets), improved quarantine processes, and through some protection naturally offered by the remote scattering of the islands that comprise Oceania. 相似文献
17.
I. N. Bezkorovainaya 《Eurasian Soil Science》2011,44(2):186-193
The biomass of large invertebrates was studied in the soils of forest ecosystems in the forest-tundra and southern taiga of Central Siberia. Its formation is shown to be controlled by the integrated effect of the soil and climatic conditions. The distribution of the zoomass according to the main taxonomic groups testifies to the higher functional significance of the large saprophagous invertebrates in the ecosystems of the southern taiga compared to those of the forest-tundra. The quantitative contribution of the invertebrates-destroyers to the organic matter decomposition was assessed on the basis of field experiments; it was shown to be determined by the quality of the material decomposed irrespective of the conditions and time of its exposition. Every year, soil saprophages decompose 0.5–2.0% of the total phytodetritus reserves in the forest-tundra and 3–14% in the southern taiga amounting to 12–54% of its losses upon decomposition. 相似文献
18.
《Soil Use and Management》2018,34(1):60-71
Lynchets represent a traditional landscape element in agricultural landscapes having multiple functions in soil material redistribution, water retention, biodiversity and landscape character. They act as a barrier to translocated soil matter, and they can store a significant amount of soil material and soil organic carbon. Lynchets developed in many regions during formation of agriculture landscape as field boundaries or path networks. Further management led to unleveling of the fields and development of lynchets. During the 20th century, a large number of lynchets disappeared in Central and Western Europe due to land consolidation, intensification and industrialization of agriculture. This study was performed at a large agricultural study plot with dissected relief (Central Czechia) with the aim of assessing the influence of former but now completely levelled lynchets on actual soil stratigraphy, depth, soil organic carbon stocks and structure of soil units. The soil profiles in 20‐m‐long transects perpendicular to former lynchets were analysed, and statistical relationships between the positions above, in and below the former lynchets were assessed. The results showed high variability of studied soil characteristics in the areas of former lynchets. Statistically significant greater A horizon thickness (50–100 cm) and SOC stock (12.7 kg/m2) were observed in the location of a former lynchet, where colluvial soils were identified. Other areas of accumulation were identified below a lynchet, at the former break‐in‐slope. The strip above a lynchet was identified as a sediment delivery area, having a partly truncated soil profile. SOC concentration and SOC stock in A horizon did not differ significantly in the positions in, above or below a lynchet. 相似文献
19.
Gravelly clay loamy and clayey soils developed from the derivatives of ultramafic rocks of the dunite-harzburgite complex
of the Rai-Iz massif in the Polar Urals have been studied. They are represented by raw-humus pelozems (weakly developed clayey
soils) under conditions of perfect drainage on steep slopes and by the gleyzems (Gleysols) with vivid gley color patterns
in the eluvial positions on leveled elements of the relief. The magnesium released from the silicates with the high content
of this element (mainly from olivine) specifies the neutral-alkaline reaction in these soils. Cryoturbation, the accumulation
of raw humus, the impregnation of the soil mass with humic substances, gleyzation, and the ferrugination of the gleyed horizons
are also clearly pronounced in the studied soils. Despite the high pH values, the destruction of supergene smectites in the
upper horizons and ferrugination (the accumulation of iron hydroxides) in the microfissures dissecting the grains of olivine,
pyroxene, and serpentine, and in decomposing plant tissues take place. The development of these processes may be related to
the local acidification (neutralization) of the soil medium under the impact of biota and carbonic acids. The specificity
of gleyzation in the soils developing from ultramafic rocks is shown in the absence of iron depletion from the fine earth
material against the background of the greenish blue gley color pattern. 相似文献
20.
This paper discusses the quantitative characteristics of the intrabiogeocenotic variability of litter carbon reserves, carbon
content and reserves in the upper mineral layer of sod-podzol soils in forest biogeocenoses of the southern taiga of European
Russia. Their dependence on forest type, parcel type, position in a tessera, and moisture degree is studied. 相似文献