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Impact of livelihood diversification of rural households on their ecological footprint in agro-pastoral areas of northern China 被引量:22
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作者 HAO Haiguang ZHANG Jiping +2 位作者 LI Xiubin ZHANG Huiyuan ZHANG Qiang 《Journal of Arid Land》 SCIE CSCD 2015年第5期653-664,共12页
Human-environment relationship is a focus of academic researches and an understanding of the rela- tionship is important for making effective policies and decisions. In this study, based on rural household survey data... Human-environment relationship is a focus of academic researches and an understanding of the rela- tionship is important for making effective policies and decisions. In this study, based on rural household survey data of Taibus Banner, Duolun county and Zhengxiangbai Banner in the Inner Mongolia autonomous region of China, we identified the impact of livelihood diversification on ecosystems in these agro-pastoral areas by using the ecological footprint theory and methodology together with the one-way analysis of variance (ANOVA) and correlation analysis methods. In 2011, the total ecological footprint of consumption (EFC) was 0.665 g hm2, and the total ecological footprint of production (EFP) was 2.045 g hm2, which was more than three times the EFC. The ecological footprint of arable land consumption (EFAC) accounted for a large proportion of the EFC, and the ecological footprint of grassland production (EFGP) occupied a large proportion of the EFP. Both the ecological footprint of grassland consumption (EFGC) and EFGP had a significant positive correlation with the income, indicating that income was mainly depended on livestock production and the households with higher incomes consumed more livestock prod- ucts. The full-time farming households (FTFHs) had the highest EFP, ecological footprint of arable land production (EFAP), EFGP and EFGC, followed by the part-time farming households (PTFHs) and non-farming households (NFHs), which indicated that part-time farming and non-farming employment reduced the occupancy and con- sumption of rural households on local ecosystems and natural resources to some extent. When farming households engaged in livestock rearing, both the EFAP and EFAC became smaller, while the EFP, EFC, EFGC and EFGP increased significantly. The differences in ecological footprints among different household groups should be taken into account when making ecosystem conservation policies. Encouraging the laborers who have the advantages of participating in non-farming employment to move out of the rural areas and increasing the diversification of liveli- hoods of rural households are important in reducing the environmental pressures and improving the welfare of households in the study area. Moreover, grassland should be utilized more effectively in the future. 展开更多
关键词 ecological footprint livelihood diversification livestock rearing non-farming employment rural households agro-pastoral area
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Livelihood Diversification of Farm Households and Its Impact on Cultivated Land Utilization in Agro-pastoral Ecologically-vulnerable Areas in the Northern China 被引量:4
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作者 LIU Haiyan HAO Haiguang +3 位作者 HU Xujun DU Leshan ZHANG Zhe LI Yuanyuan 《Chinese Geographical Science》 SCIE CSCD 2020年第2期279-293,共15页
The relationship between livelihood diversification of farm households and cultivated land utilization has become a core research topic related to global environmental change.Agro-pastoral ecologically-vulnerable area... The relationship between livelihood diversification of farm households and cultivated land utilization has become a core research topic related to global environmental change.Agro-pastoral ecologically-vulnerable areas face challenges such as insufficient ecosystem conservation,low agricultural production,and weak economies.In this study,215 farm households from Zhengxiangbai Banner,Taibus Banner,and Duolun County of Inner Mongolia were surveyed.The sustainable livelihoods framework of the United Kingdom(UK)Department for International Development(DFID)was used to measure the livelihood capital of these farm households.A one-way analysis of variance(ANOVA)was applied to examine the differences in the livelihood capital of different types households,and a correlation analysis was applied to analyze its impact on cultivated land utilization.Results showed that households with non-farming activities accounted for 64.7%of the total surveyed households,and non-farming employment was becoming more prevalent.Physical and financial capital was the driving factors for livelihood diversity.Each livelihood capital had key factors that affected household farmland use behaviors,such as the age of householder,the labor ratio,proportion of income,farmland scale,number of machines,and these had a significantly positive or negative influence on farmland use.Full-time farming households were more likely to transfer the land into cultivation and invest more labor,while non-farming households with high income were likely to transfer farmland out and invest more money to develop efficient farming or improve the employment skills.The results of this study suggest that policymakers need to fully consider livelihood changes of local households.It is effective to strengthen labor training,create farmland market and improve the efficiency of farmland utilization.We hope to achieve a win-win scenario to improve local economies and ecosystem conservation. 展开更多
关键词 agro-pastoral ecologically-vulnerable areas LIVELIHOOD DIVERSIFICATION CULTIVATED land UTILIZATION ecosystem conservation
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Changes in soil carbon stocks and related soil properties along a 50-year grassland-to-cropland conversion chronosequence in an agro-pastoral ecotone of Inner Mongolia,China 被引量:8
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作者 Yan JIAO Zhu XU +1 位作者 JiaoHong ZHAO WenZhu YANG 《Journal of Arid Land》 SCIE 2012年第4期420-430,共11页
Land use change significantly influences soil properties. There is little information available on the long-term effects of post-reclamation from grassland to cropland on soil properties. We compared soil carbon (C)... Land use change significantly influences soil properties. There is little information available on the long-term effects of post-reclamation from grassland to cropland on soil properties. We compared soil carbon (C) and nitrogen (N) storage and related soil properties in a 50-year cultivation chronosequence of grassland in the agro-pastoral ecotone of Inner Mongolia. Field surveys on land use changes during the period of 1955-2002 were conducted to build a chronosequence of cropland of different ages since the conversion from grassland. The results showed that soil C and N storage, soil texture, and soil nutrient contents varied with land use types and cropland ages (P〈0.01). In the 0-30 cm soil layer, the soil organic carbon (SOC) density was significantly lower in the crop- lands (3.28 kg C/m2 for C50 soil) than in the grasslands (6.32 kg C/m2). After 5, 10, 15, 20, 35, and 50 years of crop planting (years since the onset of cultivation), the SOC losses were 17%, 12%, 19%, 47%, 46%, and 48%, respec- tively, compared with the grasslands. The soil total nitrogen (TN) density of the grasslands was 65 g N/m2, and TN density of the cropland soil was 35 g N/m2 after 50 years of crop planting. Both the SOC and TN densities could be quantitatively determined by a negative exponential function of cropland age (P〈0.0001, R2=0.8528; P〈0.0001, R2=0.9637). The dissolved organic carbon (DOC) content, pH value were decreased; and the soil bulk density and soil available potassium (AK) content, clay content, and sand content were increased since the conversion of grassland into cropland during the 50-year period. Our results show soil nutrients were higher in grassland than in cropland. The conversion of grasslands to croplands induced a loss of soil C storage and changes of related soil properties. The reclamation time of cultivated soil (cropland age) had significant effects on soil properties in the study area. 展开更多
关键词 land use type cropland age GRASSLAND soil physical-chemical properties agro-pastoral ecotone
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Evaluation of Land Reclamation and Implications of Ecological Restoration for Agro-pastoral Ecotone: Case Study of Horqin Left Back Banner in China 被引量:3
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作者 ZHOU Jian ZHANG Fengrong +2 位作者 XU Yan GAO Yang XIE Zhen 《Chinese Geographical Science》 SCIE CSCD 2017年第5期772-783,共12页
The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological res... The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological restoration, is important to ensure food security and environmental improvement in the agro-pastoral ecotone. We selected Horqin Left Back Banner(HLBB) as the subject of our case study. The landscape ecological security pattern of this area was determined using the minimum cumulative resistance model. Over-cultivation, quantity of reserved land resource for cultivation, and changes in landscape indexes before and after land use adjustment were then analyzed. Over-cultivation is a serious problem in the agro-pastoral ecotone. Reserved land resource for cultivation is less than that considered previously, and the area of reserved land resource for cultivation in HLBB only accounts for 11.50% of total uncultivated land. With regard to changes in landscape indexes, the adjusted land use pattern is effective for anti-desertification. The compensation standard for abandoned cultivated land should be improved and the comprehensive results of ‘Grain for Green' should be evaluated to further implement ecological restoration in the agro-pastoral ecotone. 展开更多
关键词 land reclamation ecological restoration minimum cumulative resistance model agro-pastoral ecotone China
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Agricultural Vulnerability to Drought in China's Agro-pastoral Ecotone:A Case Study of Yulin City,Shaanxi Province 被引量:3
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作者 LI Yuheng CHENG Wenjing +1 位作者 ZUO Wenjie ZHANG Lingyue 《Chinese Geographical Science》 SCIE CSCD 2023年第5期934-945,共12页
Agro-pastoral ecotone of northern China is the prominent area for agricultural production,but it is also the most typical ecological fragile area with frequent drought disasters.Taking Yulin City at Shaanxi Province i... Agro-pastoral ecotone of northern China is the prominent area for agricultural production,but it is also the most typical ecological fragile area with frequent drought disasters.Taking Yulin City at Shaanxi Province in China as the case area,the paper aims to investigate the spatio-temporal changes of agricultural vulnerability to drought in China’s agro-pastoral ecotone in the period 2000 to2020.The results show that:1)the agricultural vulnerability to drought in Yulin City has shifted from high vulnerability in the period2000–2010 to low vulnerability in the period 2011–2020.2)There exist obvious spatio-temporal differences of the agricultural vulnerability to drought in Yulin City during the research period.3)Four sensitive events and 14 resilient events were identified in the research and the crops of Yulin had become more resilient to drought.Finally,the paper put forward with policy implications to make adaptive strategies of agriculture to climate change in China’s agro-pastoral ecotone in the future,e.g.,carrying out agricultural zoning based on agricultural production conditions,intensifying the construction of disaster prevention and relief system,and integrating with modern agricultural technology to develop new type agriculture. 展开更多
关键词 climate change agricultural vulnerability DROUGHT agro-pastoral ecotone Yulin City China
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Wavelet analysis of spring climate characteristics in arid aeolian area of agro-pastoral ecotone in China 被引量:2
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作者 Chun-xia ZOU Xiang-dong SHEN +2 位作者 Hong-yun LI Xia-zi LI Zhang-jun LI 《Water Science and Engineering》 EI CAS 2012年第3期269-277,共9页
The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time s... The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time series of temperature and precipitation in spring when sandstorms often occur in the area. Based on meteorological data for a 46-year period from 1959 to 2004, multi-scale variations and abrupt changes in temperature and precipitation were analyzed with the Mexican hat function (MHF) wavelet method, showing the multi-scale variation characteristics of temperature and precipitation, as well as the periods and change points at different time scales. The relationship between temperature and precipitation was obtained using the wavelet analysis method. Obvious staggered features of the variations of spring temperature and precipitation were observed in this agro-pastoral ecotone. The strongest oscillation periods of spring temperature variations were 1 and 22 years, while for precipitation, the strongest oscillation periods of variations were 2, 8, and 22 years. In addition, lower spring temperature corresponded to lower precipitation, whereas higher temperature yielded higher precipitation rate. 展开更多
关键词 spring temperature spring precipitation climate characteristics MHF waveletmethod arid aeolian area agro-pastoral ecotone
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Wind Tunnel Study of Multiple Factors Affecting Wind Erosion from Cropland in Agro-pastoral Area of Inner Mongolia,China 被引量:4
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作者 HE Ji-jun CAI Qiang-guo CAO Wen-qing 《Journal of Mountain Science》 SCIE CSCD 2013年第1期68-74,共7页
In this paper,the process of wind erosion on two kinds of soil from the agro-pastoral area of Inner Mongolia are studied using wind tunnel experiments,considering the wind speed,blown angle of wind and soil moisture c... In this paper,the process of wind erosion on two kinds of soil from the agro-pastoral area of Inner Mongolia are studied using wind tunnel experiments,considering the wind speed,blown angle of wind and soil moisture content.The results showed that the modulus of soil wind erosion increases with an increase of wind speed.When the wind speed exceeds a critical value,the soil wind erosion suddenly increases.The critical speed for both kinds of soil is within the range of 7-8m·s-1.For a constant wind speed,the rate of soil wind erosion changes from increasing to falling at a critical soil slope.The critical slope of loam soil and sandy loam soil is 20° and 10°,respectively.Soil moisture content has a significant effect on wind erosion.Soil wind erosion of both soils decreases with an increase of the soil water content in two treatments,however,for treatment two,the increasing trends of wind erosion for two soils with the falling of soil water content are no significant,especially for the loam soil,and in the same soil water content,the wind erosion of two soils in treatment one is significantly higher than treatment two,this indicates reducing the disturbance of soil surface can evidently control the soil wind erosion. 展开更多
关键词 agro-pastoral area Soil wind erosion Critical slope Wind tunnel experiment
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Determinants of Food Security in Selected Agro-pastoral Communities of Somali and Oromia Regions, Ethiopia 被引量:1
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作者 Kwadwo Asenso-Okyere Daniel Ayalew Mekonnen Elias Zerfu 《Journal of Food Science and Engineering》 2013年第9期453-471,共19页
In spite of receiving a significant amount of food aid, achieving food security has been a major problem in Ethiopia. The claim is evidenced from the 2010 Global Hunger Index where the country fared dismally, coming o... In spite of receiving a significant amount of food aid, achieving food security has been a major problem in Ethiopia. The claim is evidenced from the 2010 Global Hunger Index where the country fared dismally, coming only fourth from the bottom. There are several factors attributing to this problem of food insecurity in a country like Ethiopia which depends highly on agriculture and allied activities. Some of the factors can be linked to low food production and productivity thereby leading to pervasive poverty. In order to assess these factors, the study was conducted on some selected members of agro-pastoral communities of Somali and Oromia regions in Ethiopia. Using availability of food in the household for the last one month as a proxy for food security, the estimated results of a logistic regression model indicated that the most significant factors affecting household food security are educational level of the spouse and that of the household head, size of farm land, availability of household assets including livestock, peace and security. The paper suggests some leads to how these amenities and resources can be provided to household members as they endeavor to reduce food insecurity. 展开更多
关键词 Household food security HUNGER food availability agro-pastoral Ethiopia.
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西藏色季拉山林线冷杉种群结构与动态 被引量:73
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作者 任青山 杨小林 +4 位作者 崔国发 王景升 黄瑜 WEI Xiao hua LI Qinglin 《生态学报》 CAS CSCD 北大核心 2007年第7期2669-2677,共9页
急尖长苞冷杉(Abies georgei var.smithii)是西藏东南部地区高山林线森林群落的主要建群树种,主要分布在色季拉山海拔3600~4400m区域,并成为阴坡高山林线的优势树种。通过对色季拉山林线群落交错区域的定位调查,分析了急尖长苞冷杉的... 急尖长苞冷杉(Abies georgei var.smithii)是西藏东南部地区高山林线森林群落的主要建群树种,主要分布在色季拉山海拔3600~4400m区域,并成为阴坡高山林线的优势树种。通过对色季拉山林线群落交错区域的定位调查,分析了急尖长苞冷杉的个体生长、种群结构与动态以及林线特征。分析结果表明:(1)西藏色季拉山海拔4320m处为森林郁闭上限,该区域存在两种类型的高山林线,阳坡为渐变型林线,林线树种为方枝柏(Sabina saltuaria);阴坡为急变型林线,林线树种为急尖长苞冷杉。阳坡与阴坡林线分布海拔上限分别为4570m和4390m,阳坡高于阴坡180m;阳坡与阴坡林线群落交错区垂直宽度分别为250m和70m,阳坡比阴坡宽180m。(2)阴坡海拔3700~3800m属急尖长苞冷杉分布的最适范围,种群径级结构表现为典型的反"J"型,种群密度约380株/hm2;种群年龄结构表现为"金字塔"型,属于扩展型种群。(3)静态生命表和种群存活曲线反映了急尖长苞冷杉种群在形成初期的20a和生长发育的60~160a分别经历了强烈的环境筛选和竞争自疏,以及后期与环境变化相关的死亡波动,200a左右为急尖长苞冷杉的生理寿命,种群后期基本稳定,400a左右为极限寿命。 展开更多
关键词 西藏 急尖长苞冷杉 林线 种群结构 动态
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麦薯带状间作农田地表土壤抗风蚀效应研究 被引量:33
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作者 陈智 麻硕士 +1 位作者 范贵生 赵永来 《农业工程学报》 EI CAS CSCD 北大核心 2007年第3期51-54,共4页
该文探讨了阴山北麓农牧交错区麦薯带状间作农田土壤的抗风蚀效果.研究表明,有88.46%~98.56%的翻耕带土壤风蚀物能够被保护性耕作带截留,是一种既可以保护间作翻耕带,又能满足地区种植结构要求的防风抗蚀的种植方式.在定量研究的基础上... 该文探讨了阴山北麓农牧交错区麦薯带状间作农田土壤的抗风蚀效果.研究表明,有88.46%~98.56%的翻耕带土壤风蚀物能够被保护性耕作带截留,是一种既可以保护间作翻耕带,又能满足地区种植结构要求的防风抗蚀的种植方式.在定量研究的基础上,提出了保护性耕作带截留风蚀物的标准留茬高度和植被覆盖度分别为30 cm和50%. 展开更多
关键词 农牧交错区 土壤风蚀 保护性耕作 带状间作
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扬子板块中部南山坪背斜的形成与演化 被引量:14
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作者 戴俊生 马占荣 +1 位作者 冀国盛 田海芹 《中国地质》 CAS CSCD 2003年第4期367-371,共5页
南山坪背斜位于扬子板块中部,核部上震旦统含有大量沥青,是一个被破坏的古油藏。笔者通过建造分析认为震旦纪至中三叠世属于古隆起发育阶段,进一步划分出震旦纪古隆起雏形期、早古生代古隆起保持期和晚古生代—中三叠世古隆起发展期。... 南山坪背斜位于扬子板块中部,核部上震旦统含有大量沥青,是一个被破坏的古油藏。笔者通过建造分析认为震旦纪至中三叠世属于古隆起发育阶段,进一步划分出震旦纪古隆起雏形期、早古生代古隆起保持期和晚古生代—中三叠世古隆起发展期。晚三叠世至新生代属于断裂褶皱发育阶段,进一步划分出晚三叠世-中侏罗世宽缓背斜发育期、燕山运动Ⅱ幕断展背斜发育期、燕山晚期和喜玛拉雅期背斜改造期。南山坪古油藏以上震旦统灯影组白云岩为储层,以上覆下寒武统牛蹄塘组黑色碳质泥岩和石煤为烃源岩,志留纪至中三叠世古隆起聚集油气,晚三叠世至中侏罗世是油气再分配和南山坪古油藏形成时期,之后是古油藏被破坏时期。 展开更多
关键词 灯影组 古油藏 构造演化 南山坪
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低孔渗油气富集区优质储层形成条件及相关问题 被引量:77
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作者 王多云 郑希民 +4 位作者 李风杰 王峰 刘自亮 王志坤 李树同 《天然气地球科学》 EI CAS CSCD 2003年第2期87-91,共5页
低孔低渗 (孔隙度一般小于 1 2 % ,渗透率大多在 1× 1 0 - 3μm2左右 )性质的碎屑岩作为储层的油气藏是我国中西部地区稳定克拉通盆地或者叠合盆地中最主要的油气藏类型。但是 ,通过近几年的勘探实践发现 ,在低孔低渗含油气区中 ,... 低孔低渗 (孔隙度一般小于 1 2 % ,渗透率大多在 1× 1 0 - 3μm2左右 )性质的碎屑岩作为储层的油气藏是我国中西部地区稳定克拉通盆地或者叠合盆地中最主要的油气藏类型。但是 ,通过近几年的勘探实践发现 ,在低孔低渗含油气区中 ,仍有具优质储集层的高产油气藏存在。从优质储层的构造、沉积和成岩等几个方面讨论了这些优质储层的形成条件、阐述了描述和识别优势储层的原则和方法基础。认为储层的原始物质组成和结构是影响其物性特征的最关键因素、先天母质条件是优质储层之本源 。 展开更多
关键词 渗透率 孔隙度 碎屑岩 储层 油气藏 形成条件 沉积环境
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黄土丘陵区纸坊沟流域植被特点与生态交错带效应 被引量:15
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作者 王国梁 刘国彬 刘芳 《西北植物学报》 CAS CSCD 2002年第5期1102-1108,共7页
通过对纸坊沟流域植被特点的分析 ,阐述了森林草原交错带的边缘效应现象、形成机理和边缘效应的通道作用 ,并指出将交错带作为一个独立的分类单元不仅有助于解决黄土高原森林与草原的边界问题而且有助于对该区更进一步的深入研究。
关键词 黄土丘陵区 纸坊沟流域 植被特点 生态交错带效应
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农牧交错带(武川县)生态系统功能的变化 被引量:3
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作者 潘志华 安萍莉 +2 位作者 刘亚玲 郑大玮 妥德宝 《中国农业大学学报》 CAS CSCD 北大核心 2004年第1期37-40,共4页
随着北方农牧交错带生态系统结构的退化 ,生态系统的功能相应退化。以内蒙古武川县为例研究表明 :194 9— 1995年间 ,粮食单产与农作物光能利用率一直维持在 730kg·hm-2 和 0 0 8%的较低水平 ,天然牧草产量及其光能利用率则不断下... 随着北方农牧交错带生态系统结构的退化 ,生态系统的功能相应退化。以内蒙古武川县为例研究表明 :194 9— 1995年间 ,粮食单产与农作物光能利用率一直维持在 730kg·hm-2 和 0 0 8%的较低水平 ,天然牧草产量及其光能利用率则不断下降 ,分别由 82 5kg·hm-2 和 0 0 5 %下降到 375kg·hm-2 和 0 0 2 % ,农田养分输出大于输入 ,生态系统趋于退化。 1996年后这种状况有所缓解 ,粮食产量、农作物光能利用率转向上升 ,农田养分输入转向大于输出 ,农田生态系统开始得到恢复 ,但天然牧草的情况仍不容乐观。 展开更多
关键词 农牧交错带 武川县 生态系统功能 生态退化 生物生产 物质循环 能量流动 光能利用率
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桐柏─大别山西段的伸展构造 被引量:17
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作者 金维浚 宋鸿林 马文璞 《地质科学》 CAS CSCD 北大核心 1997年第2期156-164,共9页
桐柏─大别造山带经历了两阶段的伸展作用。早阶段伸展形成了局限海,并且形成了桐柏─大别山变质核杂岩的雏形。二郎坪岩群、龟山岩组、南湾岩组沉积在局限海中,沉积层序表现为从北向南的迁移。宽坪岩群和二郎坪岩群以低压高温的拉张... 桐柏─大别造山带经历了两阶段的伸展作用。早阶段伸展形成了局限海,并且形成了桐柏─大别山变质核杂岩的雏形。二郎坪岩群、龟山岩组、南湾岩组沉积在局限海中,沉积层序表现为从北向南的迁移。宽坪岩群和二郎坪岩群以低压高温的拉张变质作用为特征。晚期伸展对桐柏─大别山变质核杂岩的最后成型起着重要作用,并产生了中生代的花岗岩侵入和混合岩化。 展开更多
关键词 桐柏山 大别山 变质核杂岩 伸展构造 造山带
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农牧交错带不同土地利用方式土壤水分利用效益的比较 被引量:7
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作者 孙泽强 李子忠 龚元石 《中国农业大学学报》 CAS CSCD 北大核心 2003年第1期43-46,共4页
根据在农牧交错带典型地段河北坝上地区田间定位实测的土壤水分、作物和降水资料 ,运用水分平衡原理 ,研究了相同降水条件下天然草地、人工草地和农田等 3种土地利用方式的耗水规律 ,分析了水分利用效率、经济效益和生态效益。结果表明 ... 根据在农牧交错带典型地段河北坝上地区田间定位实测的土壤水分、作物和降水资料 ,运用水分平衡原理 ,研究了相同降水条件下天然草地、人工草地和农田等 3种土地利用方式的耗水规律 ,分析了水分利用效率、经济效益和生态效益。结果表明 ,在当地 ,作物耗水集中于 6和 7月 ,约占生育期总耗水量的 6 5 %以上 ;人工草地耗水量为 2 13.2mm ,比天然草地少 14mm ;人工草地水分利用效率最高为 0 .78kg·m-3 ,是农田的 1.7倍 ;人工草地的济效益较好 ,达到 2 388.4元·hm-2 ,产投比是农田的 4 .6倍 ;人工草地的风蚀模数小于农田 ,生态效益优于农田。因此 ,从可持续发展的角度考虑 ,在农牧交错带现有条件下 ,人工草地是较好的土地利用方式。 展开更多
关键词 农牧交错带 土地利用方式 土壤水分 水分利用效率 经济效益 生态效益 可持续发展 人工草地
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大洋洲地区大地构造格架与优势矿产资源 被引量:4
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作者 姚仲友 王天刚 +6 位作者 傅朝义 马春 齐立平 孔红杰 汪传胜 李文光 陈刚 《地质通报》 CAS CSCD 北大核心 2014年第2期143-158,共16页
大洋洲横跨印澳板块、太平洋板块和欧亚板块三大板块,区内从太古宙至今经历了漫长的构造演化历史。根据区域地质特征,该区可划分为3个一级构造单元,即澳大利亚中西部前寒武纪克拉通、澳大利亚东部古生代造山带和环太平洋中新生代岛弧区... 大洋洲横跨印澳板块、太平洋板块和欧亚板块三大板块,区内从太古宙至今经历了漫长的构造演化历史。根据区域地质特征,该区可划分为3个一级构造单元,即澳大利亚中西部前寒武纪克拉通、澳大利亚东部古生代造山带和环太平洋中新生代岛弧区,12个二级构造单元和40个三级构造单元。3个一级构造单元由于经历了不同的构造演化过程,各自发育了不同的岩石组合和矿化作用。在研究区域构造演化与成矿作用耦合关系的基础上,总结出3个构造单元的成矿特征:澳大利亚中西部前寒武纪克拉通成矿过程与克拉通的生长有关,成矿时代主要为太古宙和元古宙,优势矿种为金、铜、镍、锰、铁、铀、稀土、铅锌、铝土等;东部古生代造山带成矿多和古太平洋与古冈瓦纳板块的相互作用有关,成矿时代为古生代,优势矿种为铜、金、铅锌和钨锡;环太平洋中新生代岛弧区的成矿作用多与印澳板块、欧亚板块与太平洋板块的相互作用有关,成矿时代多集中在中—更新世,优势矿种为铜、金、镍、钴等。对大洋洲地区矿产资源潜力进行了评估,认为大洋洲地区的铁、锰、铜、铝、镍、金、铀、稀土等矿产资源均具有较好的潜力。 展开更多
关键词 构造单元 优势矿产资源 构造事件 成矿作用 成矿系列 找矿远景
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城乡交错带河流表层沉积物重金属污染及潜在生态风险评价 被引量:2
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作者 彭越 刘国东 +2 位作者 骆斌 叶伦文 吴永康 《水土保持研究》 CSCD 北大核心 2013年第6期173-176,共4页
针对城乡交错带河流表层沉积物重金属污染问题,以成都市江安河为例进行污染分析和潜在生态风险评价。选取何家湾、马家市、金花桥、凉港大桥4个断面进行沉积物取样,测定其Cu、Pb、Cr、Ni、Mn、Zn、Cd共7种重金属元素的含量,并采用地积... 针对城乡交错带河流表层沉积物重金属污染问题,以成都市江安河为例进行污染分析和潜在生态风险评价。选取何家湾、马家市、金花桥、凉港大桥4个断面进行沉积物取样,测定其Cu、Pb、Cr、Ni、Mn、Zn、Cd共7种重金属元素的含量,并采用地积累指数法和Hakanson指数法进行重金属污染级数分析及潜在生态风险评价。研究表明:何家湾受到Zn中度污染,马家市、金花桥、凉港大桥受到Zn轻度污染,何家湾、金花桥和凉港大桥受到Cu和Cr轻度污染。潜在生态风险指数由大到小为何家湾>凉港大桥>金花桥>马家市,均小于40,属轻微生态风险。城市化所带来的重金属污染初见端倪,污染分布和生态风险与沿岸工农业生产分布和城市化进程相关。城乡交错带在城市化进程中应开展环境整治并加强环境管理。 展开更多
关键词 城乡交错带 沉积物 重金属污染 生态风险
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宗务隆构造带西段物质组成及演化特征 被引量:3
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作者 许海全 严玉峰 +2 位作者 屈光菊 袁锦鹏 王钦元 《青海大学学报(自然科学版)》 2019年第3期87-93,共7页
为查明宗务隆构造带西段物质组成、变形特征及演化特征,运用野外地质剖面测制、岩石组合分析、LA-ICP-MS锆石U-Pb同位素定年等手段进行了调查研究,认为宗务隆裂谷带是在初始小洋盆或有限小洋盆的基础上发展起来的,是基于南祁连陆块与欧... 为查明宗务隆构造带西段物质组成、变形特征及演化特征,运用野外地质剖面测制、岩石组合分析、LA-ICP-MS锆石U-Pb同位素定年等手段进行了调查研究,认为宗务隆裂谷带是在初始小洋盆或有限小洋盆的基础上发展起来的,是基于南祁连陆块与欧龙布鲁克陆块之间的前寒武纪结晶基底和早古生代加里东褶皱基底的基础上经历了陆内拉张、有限洋盆发育、俯冲-碰撞和碰撞后推覆造山等过程演化而发展起来的华力西-印支期造山带。研究结果为宗务隆构造带西段物质组成及演化特征提供了理论依据。 展开更多
关键词 宗务隆构造带 物质组成 演化特征 青海省
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北淮阳东段“小溪河组”的解体与构造环境分析 被引量:10
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作者 张鹏 《安徽地质》 1992年第3期11-19,共9页
基于大量的1:5万区调资料,通过对北淮阳东部"小溪河组"的岩石组成、各种界面关系和岩石化学等特征的研究认为"小溪河组"变质岩原岩主要由一套产于大陆裂谷环境且具有完整演化特征的A型花岗岩组成,不具有地层意义;... 基于大量的1:5万区调资料,通过对北淮阳东部"小溪河组"的岩石组成、各种界面关系和岩石化学等特征的研究认为"小溪河组"变质岩原岩主要由一套产于大陆裂谷环境且具有完整演化特征的A型花岗岩组成,不具有地层意义;另一部分为构成其围岩的火山-沉积的表壳岩。建议废除"小溪河组"一词,将变形变质侵入岩改称小溪河片麻岩套;表壳岩部分单独建组。同位素年龄资料表明该套片麻岩形成于晚元古代。大别山地块于晚元古代因北淮阳裂谷作用从华北地块分出。可能的裂谷南北边界分别为桐柏-磨子潭断裂和金寨-韩摆渡断裂。 展开更多
关键词 小溪河组 片麻岩套 构造环境 北淮阳裂谷
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