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1.
    
Rapid development and associated land‐use change have resulted in increased soil erosion and widespread land degradation in tropical ecosystems. Precipitation‐induced soil erosion causes the export of soil organic carbon (SOC) and the associated bacterial community affecting soil quality and functioning. We assessed the transfer of SOC and soil bacterial diversity and functions in surface water runoff from different land uses: Teak with and without understory (TW and TWO, respectively) and upland rice (UR) in a tropical, upland catchment during a simulated rain event. Total suspended sediment (TSS) concentration was higher in TWO (1.23 ± 0.21 g L−1) than in TW (0.37 ± 0.16 g L−1) and UR (0.44 ± 0.2 g L−1), whereas dissolved organic carbon (DOC) concentration was lower under TWO (3.8 ± 0.7 mg L−1) than under TW or UR (13.4 ± 7.5 and 9.57 ± 4.8 mg L−1, respectively). Runoff from TWO harboured the highest proportion of bacterial taxa common to soil (27% and 29.5%) as compared with TW (22.8% and 13%) and UR (17.3% and 7%) for both particle attached and free‐living fractions, respectively. Bacterial community export in surface runoff was driven by changes in DOC and TSS, suggesting that eroded soil particles simultaneously carry organic carbon and attached bacterial taxa in surface runoff. Consequently, the export of soil functional groups relating to organic carbon degradation and nitrogen cycle was higher under TWO than in TW or UR. Our results underline that teak plantations with unsustainable practices such as the removal of understory degrades soil functions and accelerates land degradation through soil erosion and surface runoff on the long term.  相似文献   

2.
农牧交错带土地利用的土壤侵蚀状况分析   总被引:7,自引:0,他引:7       下载免费PDF全文
土地是人类赖以生存的根本。土壤侵蚀会导致土地资源的退化,造成环境恶化。农牧交错带是我国一个独特的地理景观,对它的研究在生态、区域发展上有重要意义。在定义土壤侵蚀指数的基础上.以土地资源类型为单元,以遥感与GIS为技术支撑,分析不同土地资源类型下土壤侵蚀类型与强度.阐明土地资源的土壤侵蚀背景,揭示出两之间的关系,并作了区域上的分析。结果认为在我国农牧交错带的东部草地退化,西部沙化严重,亟需治理。  相似文献   

3.
    
Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production. With the ongoing intensification of agricultural practices and negative natural factors, black soils are confronting enhanced degradation. The holistic overview of black soil degradation and the underlying mechanisms for soil health improvement will be key for agricultural sustainability and food security. In this review, the current status and driving factors of soil degradation in the four major black soil regions of the world are summarized, and effective measures for black soil conservation are proposed. The Northeast Plain of China is the research hotspot with 41.5% of the published studies related to black soil degradation, despite its relatively short history of agricultural reclamation, followed by the East European Plain (28.3%), the Great Plains of North America (20.7%), and the Pampas of South American (7.9%). Among the main types of soil degradation, soil erosion and soil fertility decline (especially organic matter loss) have been reported as the most common problems, with 27.6% and 39.4% of the published studies, respectively. In addition to the natural influences of climate and topography, human activities have been reported to have great influences on the degradation of black soils globally. Unsustainable farming practices and excess in agrochemical applications are common factors reported to accelerate the degradation process and threaten the sustainable use of black soils. Global efforts for black soil conservation and utilization should focus on standardizing evaluation criteria including real-time monitoring and the measures of prevention and restoration for sustainable management. International cooperation in technology and policy is crucial for overcoming the challenges and thus achieving the protection, sustainable use, and management of global black soil resources.  相似文献   

4.
为研究退耕还林工程建设对吴起县土地利用/覆被变化及其土壤侵蚀的影响,基于3S技术与RUSLE土壤侵蚀模型,分析评价了该县退耕还林前后土地利用/覆被、土壤侵蚀的时空变化。结果表明:吴起县实施退耕还林后10 a来,各种土地利用类型之间发生了较为复杂的转化,耕地面积比退耕前减少66.51%,林地面积比退耕前增加了212.61%;水土流失控制效果明显,全县平均土壤侵蚀模数由退耕还林前的9 779 t/(km2·a)减少为退耕还林后的5 285 t/(km2·a),减少了45.96%,退耕还林后全县每年可减少土壤侵蚀量约1 704万t;土壤侵蚀与土地利用类型关系密切,未利用地的侵蚀最严重,其平均土壤侵蚀模数为19 513 t/(km2·a),为林地土壤侵蚀模数平均值856 t/(km2·a)的22.79倍;研究结果将对该区域水土流失控制及其土地资源的合理利用提供参考依据。  相似文献   

5.
    
《Soil Use and Management》2018,34(1):147-153
As in many areas of the developing world, intensification of agriculture in Tonga, and other Pacific Islands, has put increased pressure on the soil resource. Two experiments were conducted to evaluate the effect of mulch on the growth and yield of two important food and fibre crops. The first was conducted on sloping land to evaluate the effect of guinea grass (Megathyrsus maximus ) mulch and hedgerows on taro [Colocasia esculenta (L.) Schott] yield, and in controlling soil erosion. The second compared the response of paper mulberry [Broussonetia papyrifera (L) Ventenot] to different management regimes of a grass fallow. Thick vegetative mulch increased taro corm yield by 81% and reduced soil loss by 50% compared to local farmer practice, and the soil loss from taro with mulch was comparable to the perennial cash hedgerow treatment. Mulch increased paper mulberry bark yield by 30% compared to the non‐mulch control. Comparative economic analysis showed that increased net profit in the mulched treatments compared to the non‐mulched control was T$2660/ha for taro and T$12 108/ha for paper mulberry. Considering that mulch is readily available to many farmers throughout the Pacific Islands and elsewhere in the tropics, it is recommended as a sustainable practice for crop production.  相似文献   

6.
应用TM遥感影像,提取土地利用和土壤侵蚀的相关信息。采用叠加分析的方法,对黑龙江省克山县1995-2000年的土地利用变化和土壤侵蚀变化的关系进行了分析。结果表明:黑龙江省克山县土地利用的变化不利于水土保持、土壤侵蚀面积的减少以及土壤侵蚀强度的降低,影响土壤侵蚀的主要土地利用变化发生在微丘平原区旱地。  相似文献   

7.
四川省土壤侵蚀与土地退化研究   总被引:1,自引:0,他引:1  
四川省的土壤侵蚀是造成土地退化的主要原因,全省水土流失面积20.0万km~2,以水力侵蚀为主.土地退化的主要类型有土壤退化、土地石质化、土地沙质化和土地沙石化,全省沙质荒漠化面积达95.14万hm~2.毁林垦殖、滥伐森林、工矿生产污染是造成土壤侵蚀、土地退化加剧的主要原因.  相似文献   

8.
    
Large areas of traditional slope cropland were recently converted to other land‐use types in the semiarid Loess Plateau of China. In this study, we selected four representative conversion options of slope croplands, i.e., pastureland rotated with cropland (cultivated with Medicago sativa L. and rotated with Triticum aestivum L.), shrubland and woodland (afforested with Hippophae rhamnoides L. and Pinus tabulaeformis), and grassland (native herbage Stipa breviflora) to study the effect of land‐use conversion by comparing with traditional cropland. Compared with slope cropland, the relative effects of different conversion options on surface runoff and soil erosion were assessed over a 14‐year measurement period. Observations showed that distinct features and consequences of vegetation succession were found among the conversion options. Plots of shrubland had the highest vegetation coverage with dense undergrowth; natural herbaceous and subshrub species gradually spread into plots of grassland resulting in higher vegetation cover. Neither bushes nor herbs colonized the plots of Pinus tabulaeformis, which resulted in a higher percentage of bare soil. Significant differences in runoff generation, sediment yield and conservation efficiencies among the selected conversion options were detected through an analyses of variance (ANOVA). Compared with cropland, total runoff and sediment decreased by 65 per cent and 95 per cent in shrubland, 41 per cent and 92·5 per cent in grassland, 18 per cent and 77 per cent in woodland, and 12 per cent and 58 per cent in pastureland, respectively. The ranking of soil and water conservation efficiencies was shrubland > grassland > woodland > pastureland > cropland. Based on the effectiveness of soil and water conservation, shrubland and grassland are highly recommended as promising options for cropland conversion projects. However, pastureland and woodland are not suggested as potential options for slope‐cropland conversion because of low soil and water conservation in the long term. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

9.
黄土高原丘陵沟壑区的土壤侵蚀与土地利用   总被引:7,自引:0,他引:7  
黄土高原丘陵沟壑区生态农业建设的目标是调和自然和人类的关系,不合理的土地利用是导致土壤侵蚀的主要因素,控制严重的土壤侵蚀并改善提高当地人民的生活水平,合理利用土地资源调整土地利用结构是建设秀美山川的根本出路。  相似文献   

10.
    
Alternate land uses that restore ecological balance with economic viability are desirable. Alternate land uses, that is, horti‐pasture systems (HPSs) with Emblica officinalis and Psidium guajava trees and pasture (Cenchrus ciliaris + Stylosanthes seabrana), were introduced with different soil moisture conservation measures (staggered contour trenches [T1], continuous contour trenches [T2], stone mulch [T3], vegetative barriers [T4], and control [T5]) for reclamation of degraded land and to test their capacity to perform ecological functions and provide economic return to the farmers. After 10 years, T1 increased soil organic carbon by ~58% and 15% over control in Emblica‐ and Psidium‐based HPS, respectively. T1 stipulated fruit and pasture yield by ~45% and 90% and 32% and 22% over control plots, in those HPS, respectively; T1 also improved fodder and fruit quality. Changing climates significantly affected the fruit and pasture yield. Despite this, T1 assured a benefit–cost ratio of 3.78 and 4.23 in those HPSs, respectively. The sustainable yield index for fruit and pasture in T1 were approximately (a) 1.85 and 1.68 and (b) 1.33 and 1.25 times higher than control, for Emblica‐ and Psidium‐based HPS, respectively. Soil moisture conservation could enhance profit by ~30% and 20% in those HPSs, respectively over control. T1 can potentially recycle approximately (a) 83%, 77%, and 71% and (b) 62%, 122%, and 81% higher N, P, and K than control in those HPSs, respectively. Thus, Emblica‐ and Psidium‐based HPS with staggered trenching could be replicated on a wide scale to enhance income, ensure fodder supply, and improve degraded land.  相似文献   

11.
研究延怀盆地典型土地利用类型地表土壤风蚀物分布特征,可为了解该区域风蚀过程、改善生态环境提供数据支撑。以怀来县为研究对象,采用野外监测和室内分析相结合的方法,分析了葡萄、果桑、欧李、玉米免耕、玉米翻耕5种土地利用类型在冬季休耕期(上年11月—次年2月)和春季备耕期(3—5月)风蚀物质量、粒径及碳氮含量随高度的变化特征。结果表明:(1)欧李与玉米翻耕地土壤风蚀物质量分数垂向分布遵循幂函数递减规律; 果桑、葡萄与玉米免耕地土壤风蚀物质量分数在监测高度范围内随高度增加无规律性变化。(2)春季备耕期5种土地利用类型输沙通量均高于冬季休耕期。(3)冬季休耕期5种土地利用类型风蚀物的粒径范围集中分布在500~2 μm; 春季休耕期5种土地利用类型风蚀物的粒径范围集中分布在250~2 μm。(4)5种土地利用类型冬季休耕期风蚀物碳氮含量高于春季备耕期。风蚀物质量、碳氮含量及粒径的垂直分布受土地利用类型和人为活动的影响,其中人为活动对输沙通量影响较大,因此在该区域土壤风蚀防治过程中可以采用构建防风草篱、合理调整土地利用布局的方式,达到降低近地表风速、拦截风沙的作用。  相似文献   

12.
[目的] 现场调查三江源区土壤侵蚀状况,旨在为该区域今后水土流失防治提供参考。[方法] 调查组在2023年7月25日至8月20日,分3组分别前往青海省的果洛州、玉树州、海南州和黄南州,对上述区域的林地、草地、农田、裸地、道路、河流岸坡、山区沟谷进行了调查和分析。[结果] 草地的土壤侵蚀类型最为复杂,受到风蚀、水蚀、冻融侵蚀和重力侵蚀等多营力侵蚀的共同作用,造成了其水土流失严重。此外,高原鼠害对草地破坏可能是草地侵蚀发生另一重要因素;乔木林地常在林下出现侵蚀细沟,但是由于工程护坡的作用下,发生侵蚀风险整体偏小;灌木林地所在坡面的坡脚处,受到水力侵蚀和重力侵蚀的影响较大,侵蚀风险较大;农田虽然分布面积较少,但是在田埂部分发生轻度的水蚀;对于裸地,细沟侵蚀较为剧烈,水土流失严重;值得注意的是,在道路两侧,边坡侵蚀较为严重,工程开挖导致草皮破坏,在重力的作用下发生滑塌,出现较大的裸露面,为水蚀的发生提供了条件,导致部分区域已经形成了较大的侵蚀沟网。[结论] 青海省三江源区域土壤侵蚀类型复杂多样,随着人类活动的加剧,局部区域水土流失有进一步加剧的风险,亟需开展新时期的水土保持工作,需要在该区域加强土壤侵蚀基础研究,加强水土保持监测站网的布设,智能化管理等。  相似文献   

13.
河北坝上地区处于中国北方农牧交错带,由于长期大规模高强度地滥垦滥牧,在近100年的时间里,该区生态环境遭受了空前的破坏;而该区域居民粮食不足和收入低的事实又使其经济发展显得尤为重要。因此,该区的土地利用模式必须走生态、经济兼顾型道路。该文依据国家旱农张北试验区多年田间试验结果和作者的调查,提出了以“乔灌成网、少耕留茬、高效集约、草畜一体”为内容的生态经济型土地利用模式与技术体系。  相似文献   

14.
不同区域土地利用与土壤侵蚀空间关系研究   总被引:2,自引:2,他引:2  
在总结土地利用与土壤侵蚀空间关系一般研究方法的基础上,引入并修正了土壤侵蚀强度综合指数和区域土壤侵蚀强度综合指数,对整个中国境内、辽河中下游地区、南水北调丹江口水库水源区湖北部分和广东省惠东县4个区域土地利用类型与土壤侵蚀强度空间关系进行了定量比较分析。结果表明:不同区域土地利用类型的土壤侵蚀序列各不相同,而同一区域不同时期土地利用类型的土壤侵蚀序列不确定;新出现的难利用地比长期闲置的难利用地土壤侵蚀发生率高;草地土壤侵蚀发生率偏高;耕地中旱地的土壤侵蚀发生率高;建设用地建设时土壤侵蚀强度大,而建成后土壤侵蚀强度小。  相似文献   

15.
    
Soil degradation threatens sustainable food production and accelerates global warming. Poorer countries, whose agricultural sectors are highly dependent on their natural resource bases, are hit particularly hard by declining soil productivity. Calls for soil‐quality monitoring are therefore, justified and this could inform decision‐makers on the preparation of appropriate interventions. However, the provision of monitoring methodologies is not an easy task. Soil degradation affects several soil characteristics that at larger scales cannot be evaluated with models or remote‐sensing techniques. Therefore, this study focuses on investigating the use of field‐based soil assessment methodologies to differentiate degrees of soil degradation. Specifically, we test the Visual Soil Field Assessment Tool (VS‐Fast) for detecting and monitoring soil degradation using a cross‐section of 71 sites in Senegal, the soil quality of which were classed by local experts. We found low correlation between VS‐Fast classes and expert assessments. By using an ordered logit model to quantify class boundaries, we show that experts categorized areas as ‘degraded’ for a wider range and higher VS‐Fast scores than the corresponding VS‐Fast class. Yet, from general linear models and analysis of variance procedures we found that areas classed by experts as ‘degraded’ had statistically significant lower VS‐Fast scores compared to those that were judged as ‘normal’ and ‘good’, while differences of the VS‐Fast scores between the latter two were negligible. It is remarkable that the visual assessment, the cheaper component of the VS‐Fast score, performs better in differentiating degradation status than its measured counterpart. The results support the need to investigate the applicability of other VSA methodologies that only use field observations and tactile methods.  相似文献   

16.
不同土地利用方式下赤红壤坡面土壤侵蚀特征   总被引:6,自引:2,他引:6  
为探究降雨和土地利用对南方赤红壤坡面侵蚀特征的影响,通过天然降雨观测试验,定量分析不同土地利用方式(坡耕地、果园、人工草地和撂荒地)下坡面径流和侵蚀泥沙特征,探讨降雨类型及土地利用对坡面侵蚀产沙的影响以及降雨特征参数与坡面水沙指标间的关系。结果表明:(1)2018年研究区降雨主要集中在5—9月,且每月降雨量主要由一场或几场暴雨及大暴雨组成;(2)坡耕地坡面年径流量和年侵蚀量均最大,分别是果园、人工草地以及撂荒地处理下的3.4,8.0,6.0倍和340.5,1605.3,1720.3倍;(2)次降雨下,坡面径流量在年内表现为前期平稳,后期波动增加,侵蚀量表现为前期波动较大,后期变化相对平稳,且侵蚀产沙主要集中在前期;(3)不同土地利用方式下,暴雨及大暴雨产生的径流量均占年径流量的75%以上,坡耕地、果园、人工草地以及撂荒地处理下由暴雨和大暴雨产生的侵蚀量分别占年侵蚀量的99.1%,71.8%,52.3%和51.6%;(4)降雨量和最大30min降雨强度是影响赤红壤坡面侵蚀最重要的降雨特征参数,降雨历时和植被覆盖度均显著影响果园、人工草地及撂荒地坡面径流量。研究结果有助于明晰南方赤红壤区不同土地利用现状土壤侵蚀特征,为区域水土保持提供参考依据。  相似文献   

17.
    
The implementation of soil and water conservation (SWC) measures in the Ethiopian Highlands is a top priority to reduce soil erosion rates. However, the effectiveness of these measures for different hillslope gradients and land use conditions remains poorly understood. This study addresses this knowledge gap by determining support practice (P) and cover‐management (C) factors of the Revised Universal Soil Loss Equation for commonly used SWC structures in semi‐arid environments. The factor values were calculated on the basis of soil loss data collected with 21 large runoff plots installed in rangeland and cropland sites. The P‐ and C‐factors were calculated following the recommended procedures. Results show P‐factors ranging from 0.32 to 0.74 for stone bunds, from 0.07 to 0.65 for trenches, and from 0.03 to 0.22 for stone bunds with trenches. Reduced storage capacities due to sediment deposition resulted in significant declines of the effectiveness of SWC structures over time. For example, the average P‐factor value for trenches increased from 0.1 in the first year after installation to 0.51 after 3 years. C‐factor values ranged from 0.23 to 0.82 in rangeland and from 0.03 to 0.35 in cropland. For rangeland, this large variability is due to vegetation cover changes caused by grazing. In cropland, C‐factors vary with crop types and tillage practices. The results of this study not only aid in modelling and quantifying the short‐term impacts of SWC structures on soil erosion rates but also highlight the importance of considering temporal variations of the effectiveness of SWC measures.  相似文献   

18.
 研究不同土地利用类型土壤侵蚀量的坡度效应,以便为退耕还林及坡耕地水保措施提供依据。根据上舍河小流域2000年55场有效降雨资料,对不同土地利用类型(坡耕地、杉木林地)次降雨地表径流量、径流侵蚀模数与坡度、降雨量、降雨强度、植被盖度等影响因子进行相关分析。结果表明:坡耕地、杉木林地的次降雨地表径流量、地表径流侵蚀模数与坡度、降雨量、降雨强度、植被盖度等相关显著。在一定坡度范围内,坡耕地的次降雨地表径流量和径流侵蚀模数,随着坡度的增大而增加,而杉木林分的次降雨地表径流量和径流侵蚀模数,随着坡度的增加而降低。  相似文献   

19.
云蒙湖流域不同土地利用类型的土壤侵蚀特征分析   总被引:2,自引:0,他引:2  
在RS与GIS支持下,获取云蒙湖流域土地利用空间数据,选用RUSLE模型估算土壤侵蚀量,对云蒙湖流域不同土地利用类型的土壤侵蚀特征进行分析。结果表明:1986—2010年间,土壤年总侵蚀量由647万t降至630万t,水土保持生态恢复工程取得了一定的成效;云蒙湖流域耕地土壤侵蚀最为严重,1986年和2010年土壤侵蚀模数高达5 325t/(km2·a)和5 504t/(km2·a),分别占土壤侵蚀总量的85.8%和84.7%;草地是重点治理的另一对象,强度以上等级侵蚀都分别占总侵蚀面积的40%和44%;随着耕地和草地类型的转入,居民用地侵蚀面积由1986年的1 010hm2增至2010年的2 608hm2,土壤侵蚀总量由5.4万t增至14.2万t,是变化较为明显的土地利用类型。  相似文献   

20.
川中不同类型小流域土壤侵蚀特征分析   总被引:1,自引:0,他引:1  
以川中小流域为研究对象,2004年第5期小流域竣工验收报告为基础数据,以流域土地利用方式面积比例为指标进行聚类,将小流域分为不同类型,然后分别建立以不同类型小流域的土壤侵蚀量为因变量,用地面积为自变量的多元线性回归方程。从而比较区域内部小流域之间的差异,分析不同类型小流域的土壤侵蚀特征,以期更有针对性地为小流域综合治理提供理论和实际依据。研究表明:(1)根据其主要土地利用方式,研究区小流域分为4类;(2)不同类型小流域,水土流失主要及最大来源、侵蚀模数等特征有显著差异。  相似文献   

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