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1.
Soil degradation is a serious problem and an important environmental issue in many ecosystems. Without integrative, interdisciplinary and historical approaches, understanding the effects of long‐term soil degradation is difficult. According to this idea it is hypothesized that in order to study long‐term natural and human‐induced soil degradation, it is necessary to use interdisciplinary and multidisciplinary approaches with respect to temporal and spatial landscape changes. The results of the investigation of colluvial sediments and soils in research area in Schleswig‐Holstein (Germany) with a high resolution in space and time—using the four‐dimensional landscape analysis—indicated the temporal and spatial variation of soils and sediments from the Mesolithic until Modern times. Intensive soil degradation occurred as a result of the land clearance and agricultural land use in the investigation areas since the Neolithic time. The general results of this investigation show that the use of an interdisciplinary and multidisciplinary approach with pedological and geomorphological perspectives for different times and places can help to reconstruct the long‐term natural and human‐induced soil degradation. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

2.
A unique artefact — the fragment of a bow made of yew wood, indicating the hunting activity of prehistoric man — was found within the sediments of the landslide peat bog (at the depth of 330 cm) formed on the Mt. Kamiennik (Polish Flysch Carpathians). The datings of this artefact using 14C method at ca 3790–3380 cal BC indicate its connection with the activity of the Neolithic man, related to the Funnel Beaker Culture. In the sequence of the peat bog deposits formed since the Atlantic Phase, the palaeoclimatic changes of the Middle- and Late Holocene, as well as traces of human impact in these and subsequent periods were recorded and analysed using palynological, macrofossils, lithological methods, and dated with radiocarbon. Palaeoenvironmental changes identified in the peat horizon bearing the artefact were marked by the delivery of minerogenic, “high energy” deposits (with charcoal) to the peat bog, as well as distinct changes of plant communities. These phenomena confirm a significant human impact caused by the Prehistoric man on landslide areas. On the other hand, the study confirms significant importance of climatic condition for human activity and proves that landslide peat bog deposits are very sensitive records of palaeoenvironmental changes. The archaeological artefact essentially supplements the results of our interdisciplinary palaeoenvironmental study. It is one of the rare Neolithic bows found in the area of Europe, till now.  相似文献   

3.
Eurasian Soil Science - Soil-archaeological studies were performed in the area of the Votikeevo archaeological site dating back to the Bakhmutin culture of the early Middle Ages (5th–7th...  相似文献   

4.
Colluvial deposits consisting of silts and loams were detected in several climatologically different areas of NE Tibet (3200–3700 m a.s.l.). Layering, distinct organic content and low content of coarse matter as well as location in the relief revealed an origin from low-energy slope erosion (hillwash). Underlying and intercalated paleosols were classified as Chernozems, Phaeozems, Regosols and Fluvisols. Fifteen radiocarbon datings predominant on charcoal from both colluvial layers and paleosols yielded ages between 8988 ± 66 and 3512 ± 56 uncal BP. Natural or anthropogenic factors could have been the triggers of the erosional processes derived. It remains unclear which reason was mainly responsible, due to controversial paleoclimatic and geomorphic records as well as insufficient archaeological knowledge from this region. Determinations of charcoal and fossil wood revealed the Holocene occurrence of tree species (spruce, juniper) for areas which nowadays have no trees or only few forest islands. Thus large areas of NE Tibet which are at present steppes and alpine pastures were forested in the past.  相似文献   

5.
Background, aim, and scope  The mycological properties of soil can offer information about ancient human–landscape interaction, including urbanization. This preposition has been confirmed in our study of the habitation deposits in the medieval Russian settlements (eighth to fourteenth centuries A.D.). Materials and methods  The mycobiota of profiles of anthropogenically transformed soil of excavated medieval settlements were examined in different climate conditions in the European part of Russia. The fungal biomass and biomass structure were evaluated using luminescent microscopy. The isolation and enumeration of microfungi were performed using the method of serial dilutions of soil samples and plating them out on the number of solid media. The isolation of keratinolytic microfungi was performed by hear-bite technique. Results  It was established that in ancient urban soils, the mycobiota may have properties different from those of zone fungal communities. The examined cultural layers of ancient settlements differ from the horizons of the surrounding natural soils because of a bigger rate of fungal spores in fungal biomass, more mosaic distribution of microfungal communities, different species composition and dominant microfungal species, increased incidence of some ecological, and trophic fungal groups (for example, keratinophilic, potentially pathogenic microfungi). Discussion  The mycological characteristics of anthropogenic deposits in the excavated medieval settlements were found to be mainly similar to mycological properties of modern urban soils. Conclusions  These properties of habitation deposits can be interpreted as a kind of “soil mycological memory” of the ancient urban impact. Recommendations and perspectives  Soil mycological characteristics could be used in paleoecological reconstructions and biomonitoring of urban impacts  相似文献   

6.
Andreas Lang   《CATENA》2003,51(3-4):209-221
In South Germany, soil erosion is as old as farming and dates back to Early Neolithic times. Its sedimentary products form thick colluvial and alluvial sediment bodies in all drainage basins. Numerous local studies exist but the extrapolation of findings from local case studies to a regional scale has been problematic. Here, a graphical approach is used for frequency analysis of existing data. A frequency distribution for optical dates on colluvial sediments from the beginning of agriculture until 1200 AD was constructed by: (1) representing the optical ages by Gaussian-distributions and (2) summing all the single curves. The resulting graph clearly shows phases of increased colluviation during periods of stronger human impact. A first significant increase occurred during the Bronze Age. During the Iron Age/Roman period and at around 800 AD, distinct maxima appear in the distribution, and highest frequencies are present towards the end of the analysed period at around 1100 AD. Conclusions that can be drawn from such an approach are limited by sampling bias and other factors, but for the analysed period, and on a regional and long-term scale, colluviation seems to have been mainly triggered by intensity of land use. Climatic fluctuations are of only secondary importance. Rainfall events that were sufficiently erosive to produce colluvial sediments occurred throughout the agricultural periods. The limiting factor for colluvium production was sensitivity of the landscape to erosion, and this is a result of land use.  相似文献   

7.
Key catchments of the Roztocze loess area in south-east Poland have a great potential of revealing the history of long-term soil erosion and changes in land use. The knowledge of how and when soil erosion took place in the past helps one understand the impact of land use changes on the landscapes [Bork, H.-R., 1989. Soil erosion during the past Millennium in Central Europe and its significance within the geomorphodynamics of the Holocene. Catena 15, 121–131]. The Jedliczny Dol gully system near the town Zwierzyniec in south-east Poland was investigated by using detailed field stratigraphy and radiocarbon dating of charcoal and wood.In connection with new settlements which were established between the 14th and 16th centuries, arable land was cultivated and forests were used much more intensively. As a consequence, the loess soils were strongly eroded during heavy rainfalls. Up to 4 m of colluvial sediments were deposited in the gully system during the 15th and/or 16th centuries. The thickness of the colluvial sediments indicate severe erosion which might be related to excessive timber exploitation for the local glass and iron production. With the foundation of the so-called Ordinariat Zamoyski at the end of the 16th century, some parts of the area were presumably reforested. High pressure on the land at the beginning of the 19th century enabled a second main phase of gulling before 1900.Since 1890 at the latest, almost the whole catchment is used as a forest, however, concentrated runoff on compacted forest roads can still be high after heavy rainfalls.In loess areas soil erosion caused by intensive land use, triggered by heavy rainfalls, can change the landscape drastically. These changes will continue to influence how catchments react, even if land use gets less intensive again. This knowledge should be considered regarding future, sustainable land use and recent changes in land use in the south-eastern Polish loess regions.  相似文献   

8.
The concentration of heavy metals (Cd, Cu, Pb, Zn) has been analyzed in Holocene slope deposits of the loess agricultural area in the Eastern Poland. Five profiles were examined. In general, low concentrations of the examined metals were determined, on average 50% of the samples exceeded the designated regional, geochemical background. The average concentrations were: cadmium < 0.5 ppm, copper up to 15, and lead up to 20 and zinc up to 70 ppm, showing a vertical diversity in the profile. Higher heavy metal concentrations in Holocene deposits are related to soil formation or accumulation of organic matter. The direct influence of human factors was most visible in recent deposits. It includes the modification of the development conditions of soil-forming processes as well as the influence on the character of the colluvial deposits. Taking into account the 14C datings as well as the archeological and historical data the age and rate of sedimentation of deposits have been calculated. The average rate of the colluvia deposition varied from 1.3 to 7.3 mm/year depending on their age and the character of sedimentation.  相似文献   

9.
崩积层之分类与工程特性研究   总被引:1,自引:0,他引:1  
崩积层堆积之坡地常被列为不可开发区。然因崩积层不易取样以及取样后之代表性不足,造成崩积层工程特性研究之困难。搜集整理多件台湾重要之山崩案例,并按不同山崩机抽进行分类统计,以对于各类型山崩所产生之崩积层产状作一探讨。最后以不同型态之崩积层开发利用实例,对于不同崩塌机制所产生之崩积层之工程特性调查作一探讨。  相似文献   

10.
崩岗崩积体土质疏松,抗侵蚀能力弱,其颗粒组成及分形维数有其自身的特性。采用激光粒度分布仪对花岗岩崩岗崩积体及崩壁土样的颗粒进行测定,对其土壤颗粒组成及分形特征进行比较分析。结果如下:崩积体土壤以砾石、砂粒、粉粒含量为主,黏粒含量极低,土壤质地主要为砾石土;崩积体各层次土壤颗粒分形维数均值为2.61~2.70,分形维数值较低,反映了其细颗粒损失情况;黏粒含量是影响土壤颗粒分形维数的主要因素;崩壁土体的颗粒分形维数大小能够表征土壤的理化特征,而崩积体土壤颗粒分形维数无法真实反映崩积体的理化性质。  相似文献   

11.
Development plans are mainly responsible for population changes and the conversion of forest and rangelands into agricultural lands and human settlements. Qualitative and quantitative analysis of population and land use changes are necessary to assess the impacts of change on hydrological processes. However, such important issues have been less considered worldwide particularly in developing countries. Therefore, we selected the Shazand Watershed (1740 km2) because of rapid industrialization to track the effects of land use and population changes on streamflow and sediment yield. The data were collected from statistical yearbooks and satellite imageries from 1973 to 2008. All available measurements on discharge and suspended sediment concentration at the Pole doab hydrological station were also collected. The study was conducted for the whole period, as well as the pre‐1991 and post‐1991 as a basis for the economic development growth in the region. We found that the land use and population changes have occurred in the Shazand Watershed, especially in the vicinity of industrial zones. The results showed that the cities, industrial zones, roads, and bare lands quickly increased from 58 · 8 to 134 · 3 km2 during post‐1991. The flow durations, sediment rating curves and trend analyses indicated distinct variations in the relationship between streamflow and sediment and also caused changes within different periods. Based on the results, the mean annual flow and sediment yield in post industrialization (1991–2008) were respectively 0 · 84 and 1 · 19 times of those for pre‐industrialization period and the annual sediment yield increased from 25,000 to 29,850 Mg. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

12.
Land‐use and cover changes around Budongo Forest Reserve (BFR) were analysed from multi‐temporal LandSat images (1988 and 2002) and associated field‐based studies in 2003–2004. Three major land‐use and cover classes: forest/woodland, sugarcane plantations and grassland/shifting‐cultivation/settlements were clearly discriminated. The area under sugarcane cultivation increased over 17‐fold, from 690 ha in 1988 to 12729 ha in 2002, with a concomitant loss of about 4680 ha (8·2 per cent) of forest/woodland, mainly on the southern boundary of BFR. Land‐use and cover changes were a result of (a) agricultural expansion, (b) increasing human population, exacerbated by large influxes of refugees, (c) conflicts of interest and political interference in the management of BFR and (d) unclear land tenure. Agriculture is the main land‐use practice and source of income to local people, with commercial sugarcane and tobacco as the primary cash crops. Individual smallholder sugarcane plantations covered distances ranging from 30 to 1440 m along the BFR edge, with no buffer zone, resulting in direct conflicts between farmers and forest wild animals. There is an ever‐increasing need for more land for agricultural expansion, resulting in continued loss of forest/woodland on private/communal lands and encroachment into BFR. This unsustainable agricultural expansion and the local people's perception of BFR as an obstacle to agriculture, threatens the conservation of its threatened wild plants (e.g. Raphia farinifera) and the endangered chimpanzees. Therefore, their sustainable management for both development and conservation will require strong and incorruptible institutions that will seek a balance between resource exploitation and conservation. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

13.
Phaeozems of northeastern Germany and their position in holocene landscape development A typical soil association of NE-German young moraine area (Uckermark-region) including Phaeozems and colluvial deposits (Cumulic Anthrosols) was described macromorphologically using a trench profile and investigated by chemical standard analyses, humic compound analysis, pollen analysis and 14C-radiocarbon dating. Results are discussed in view of pedogenesis of Phaeozems. Conclusions were made concerning the holocene premedieval landscape development. A key position for reconstructing palaeoecological environmental conditions is held by “Black colluvium”. The “Black colluvium” is the relocated humous horizon of former Chernozems influenced by syn- and postsedimentary processes. The specific character of holocene landscape development and pedogenesis of the Uckermark-region is connected with the special natural conditions and history of land-use.  相似文献   

14.
This study presents a Holocene sediment budget for the upland catchment of the Speyerbach in the Palatinate Forest, southwestern Germany. The influences of both, data availability and the choice of an appropriate soilscape model on the sediment budget calculations are investigated. For budget calculations the spatial distribution of soils was derived from the soil map 1:50,000. Thickness values of soil truncation and colluvial burial were extracted from two soil data sets with varying information content. Data processing contained a disaggregation of the soil map with the help of land use data. In order to model the sediment budget a reference soil thickness (a so-called soilscape model), which represents the initial conditions is necessary. As upland soils are developed in periglacial solifluction sheets, the main solifluction sheet (MSS, “Hauptlage”) showing a constant thickness and being affected by soil forming processes was chosen.  相似文献   

15.
北京市平谷区农村居民点内部用地结构差异分析   总被引:4,自引:1,他引:3  
研究微观尺度农村居民点内部用地结构差异有利于因地制宜、差异化开展农村居民点内部用地结构调整,分类指导农村居民点用地科学规划与管理,提高农村居民点内部土地利用效率。本文以北京市平谷区为例,利用基于功能的农村居民点内部用地分类体系,调查了5个不同发展类型农村居民点内部用地结构差异,对比分析了其用地微观结构特点。研究发现:生活功能用地为农村居民点内部用地的基本结构,生产功能用地为衍生结构,生态功能用地为辅助结构,潜在功能用地为可变结构。受自然条件、区位条件、经济水平、产业结构与生计类型及政策条件等5维驱动因素共同作用,不同发展类型农村居民点内部用地数量结构、类型结构及信息熵差异显著,空间结构则呈现趋同性。随着社会经济发展水平提高,农村居民点用地结构表现出生活功能用地稳定、生产功能用地增加、生态功能用地减少的趋势。村庄规划应在把握其内部用地结构演变规律的基础上,注重可变影响因素调整,促进用地结构与其发展条件和谐统一。  相似文献   

16.
Soil carbon stock change between two major land uses in New Zealand was measured by sampling paired plots across the boundaries of low productivity grassland and forest planted pre‐1990. The national soil carbon monitoring system uses low productivity grassland as a benchmark to evaluate soil carbon stock change for other land uses. The goal was to validate earlier estimates of the effect of pre‐1990 afforestation and to reduce their level of uncertainty. We selected a set of sites to represent the national stocks of forests planted pre‐1990. Previous studies derived estimates of the land‐use effect on soil carbon for afforestation ranging from +1.6 to ?8.5 t/ha to 30 cm depth. For all estimates, the 95% confidence interval spanned zero. Our study used nine of the previous paired‐plot sites and sampled and analysed 21 new sites. The land‐use effect of change from grassland to forest planted pre‐1990 was estimated at ?17.4 t/ha. The 95% confidence interval ranged from ?10.1 to ?24.6 t/ha and did not include zero change. The result supported the soil carbon monitoring system assumption that forests planted pre‐1990 have significantly lower soil carbon stocks than the low‐productivity‐grassland standard. Evidence of stock change occurred in depth increments to 0.2 m but with no significant change for the 0.2–0.3 m increment. This suggests that the sampling depth of 0.3 m was adequate for the estimation of soil carbon stock change.  相似文献   

17.
土地用途管制既是现阶段国土空间规划的核心,也是乡村聚落演变的外源性关键因素。明晰土地用途管制下乡村聚落时空演变特征,对完善国土空间规划编制方法具有重要意义。运用ArcGIS空间分析法、统计分析法,探究了土地用途管制下长株潭生态绿心地区乡村聚落的时空演变特征及规律。结果表明:(1)土地用途管制下,长株潭生态绿心地区乡村聚落数量和面积呈现先增加-后减少-再增加的变化趋势,转折点分别为2013年和2016年;集聚模式在空间分布上由均匀式低密度核心向集中式高密度核心突变,聚集核心由禁止开发区和限制开发区向协调建设区迅速迁移。(2)土地用途管制对乡村聚落演变的交通指向性和沿乡镇点聚集性干预程度不显著。2018年禁止开发区、限制开发区和协调建设区内乡村聚落数量较2016年增幅为11.35%,16.74%和53.36%,乡村聚落面积增幅为35.67%,30.93%和13.35%,随着土地用途管制年限的增长,禁止开发区内乡村聚落突破管制目标,形成小规模集聚。(3)新时期空间管制规划方法更利于土地利用的统筹、优化,但仍需在相应配套政策的保障下实施。研究结果可为完善该地区国土空间用途管制方案、统筹推进生态环境保护与经济高质量发展提供一定的数据参考。  相似文献   

18.
基于土地功能的农村居民点内部用地结构分类   总被引:2,自引:4,他引:2  
科学合理的农村居民点内部用地功能结构分类是提升农村土地利用效率、实现用地结构优化配置的重要前提。该文在梳理农村居民点用地分类现状的基础上,从土地利用的功能角度出发,构建了涵盖农村居民点用地生产功能、生活功能、生态功能和潜在功能的分类体系,其中包含4个一级类、10个二级类和37个三级类;并以该分类方法为基础,通过实地调查典型农村居民点内部用地结构现状,从微观视角揭示内部用地结构。基于新的分类体系,大兴庄村用地类型可分为28种,农村居民点内部生产用地、生活用地和生态用地的比例分别为34.73%、53.53%和4.06%,可挖潜面积比例为占农村居民点总面积的13.09%。研究结果为中国农村居民点用地分类体系构建提供了基本思路和工作框架。  相似文献   

19.
There is considerable interest in the computation of national and regional soil carbon stocks, largely as the result of the provisions of the Kyoto Protocol. Such stocks are often calculated and compared without proper reference to the uncertainties induced by different analytical methodologies. We illustrate the nature and magnitude of these uncertainties with the present soil organic carbon (SOC) study in Belgium. The SOC recovery of the Walkley‐Black method was investigated based on a database of 475 samples of silt loam and sandy soils, which cover different soil depths and vegetation types in northern Belgium. The organic carbon content of the soil samples was measured by the original Walkley‐Black method and by a total organic carbon analyser. The recovery was computed as the ratio of these two results per soil sample. Land use, texture and soil sampling depth had a significant influence on the recovery as well as their three‐way interaction term (land use × texture × sampling depth). The impact of a land use, texture and sampling depth dependent Walkley‐Black correction on the year 2000 SOC inventory of Belgium was determined by regression analysis. Based on new correction factors, the national SOC stocks increased by 22% for the whole country, ranging from 18% for cropland to 31% for mixed forest relative to the standard corrected SOC inventory. The new recovery values influenced therefore not only C stocks in the year 2000, but also the expected SOC change following land use change. Adequate correction of Walkley‐Black measurements is therefore crucial for the absolute and comparative SOC assessments that are required for Kyoto reporting and must be computed to take into account the regional status of soil and land use. ‘Universal’ corrections are probably an unrealistic expectation.  相似文献   

20.
Hettwer  K.  Deicke  M.  Ruppert  H. 《Water, air, and soil pollution》2003,149(1-4):363-384
Fens in karst sinkholes are excellent archives for the reconstruction of vegetation, land use and emission rates over millennia. The reasons are the usually good preservation of pollen, the high portion of low density organic material with very low background concentrations of heavy metals, and the circum-neutral pH-values in most of these mires preventing migration of heavy metals. Immissions of dust and of harmful elements can easily be correlated with changes in vegetation (`immission' is a synonym for the deposition or impact of pollutants from the atmosphere on a receptor surface).One 13 m core from a ~5000 yr old karst sinkhole fen (Silberhohl, western margin of the Harz Mountains, central Germany) was investigated by geochemical analysis, pollen analysis and dated by 14C and palynological data. The core consists of organic material with a few percent of CaCO3 precipitated from groundwater and a small amount of atmospheric detritus. As early as the Iron Age (first pre-Christian millennium), slight but significant enrichments of Pb, Zn, Cu and Cd are observed. After 400 AD stronger enrichments occurred culminating in the High Middle Ages (~1200–1300 AD). Maximum values are 1250 μg g-1 Pb, 214 μg g-1 Cu, 740 μg g-1 Zn, and 3.8 μg g-1 Cd. The enrichments are caused by emissions during smelting of sulfidic lead-zinc ores from the adjacent Hercynian deposits to extract Ag and Cu. Except for cadmium, these values were never exceeded in modern times. Since the Iron Age 23 g technogenic Pb, 5.3 g Cu, 27 g Zn and 0.2 g Cd have been deposited per square meter.Palynological investigations show a strong correlation between decreasing red beech pollens (Fagus sylvatica) and increasing demand on woodfor smelting in the Middle Ages. Simultaneously, the pollen share of pioneer trees such as birch (Betula pubescens) and of cereal grains (e.g. Secale) increases. Since the beginning of the 14th century, the decline of agriculture and population is reflected in the decreasing contents of Secale and heavy metals in the fen deposits.  相似文献   

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