期刊文献+
共找到615篇文章
< 1 2 31 >
每页显示 20 50 100
Eco-environment Restoration and Regional Differentiation Characteristics Based on “Building Terrace and Returning Slope Farmland to Forests and Grass”
1
作者 Yanhua LIU Yong XU 《Asian Agricultural Research》 2013年第1期41-47,共7页
Based on the scientific and technological achievements in the past decade in the Loess Hilly-gully Region and the successful demonstration experience in Yan'an Yangou watershed, we summarize the characteristics of... Based on the scientific and technological achievements in the past decade in the Loess Hilly-gully Region and the successful demonstration experience in Yan'an Yangou watershed, we summarize the characteristics of eco-environment restoration pattern based on "building terrace and returning slope farmland to forests and grass". According to the data on land use, slope farmland and the agricultural population in 1999, we calculate the area of new terrace that needs to be built, the area of garden plot that needs to be extended, vegetation restoration area and investment demand in counties (cities, districts). Establishing and using some indicators, such as basic farmland extension indicator, garden plot extension indicator, vegetation restoration index and investment demand density, we conduct type classification and analysis of regional differentiation characteristics in 55 counties (cities, districts). The results show that in the Loess Hilly-gully Region, 691 600 hm2 of new terrace needs to be built, 792 000 hm2 of economic forests and orchards need to be extended, 5 410 200 hm2 of vegetation needs to be restored, and the total investment demand is 15.82 billion yuan; in terms of geographical distribution, obviously there are two key areas for eco-environment restoration (one is located in the border area between northern Shaanxi and northwestern Shanxi, and the other is located in the eastern Gansu and southern Ningxia area); the classified regional guidance policies should be formulated as soon as possible, and the limited funds should be concentrated in the key areas. 展开更多
关键词 ECO-ENVIRONMENT restoration "Building TERRACE and
下载PDF
Multi-scales Analysis of Driving Forces on Land Use/Cover Change in China:Taking Farmland Returning to Forest or Grassland as a Case 被引量:1
2
作者 Zhou Hongjian Huang Shuling +2 位作者 Wang Yuanyuan Wang Jing'ai Jia Huicong 《Chinese Journal of Population,Resources and Environment》 北大核心 2006年第3期21-27,共7页
Increasing populations are causing an increase in food demands, and the area of cultivated land expands every year. Inappropriate land transition from ecology to production results in the constant decline of the ecolo... Increasing populations are causing an increase in food demands, and the area of cultivated land expands every year. Inappropriate land transition from ecology to production results in the constant decline of the ecological security level and influences the regional sustainable development. Adjusting unreasonable land use mode and reconstructing natural land cover are important ways to maintain and improve the ecological environment. Also reclaiming farmland as areas for forests and grasslands (FRFG) is another way. Successful implementation of FRFG in China is the result of comprehensive effect of the multi-scales driving forces. This paper analyses the driving forces of FRFG in China on a national (country) –regional (province) – local (county) – household (farmer) level scale, and the results are: driving forces at the national scale include ecological and food security and the western development of China; at the regional scale, ecological and economic benefits become the main factors to influence the dimension of FRFG under the same policy. The driving forces can be divided into 6 types: industrial structure adjustment, water source protection, flood prevention, the Three-Gorge Project protection, reduction of the amount of sediment flowing into the Yellow River and wind erosion desertification prevention. The driving forces at the local scale can be divided into 12 types with developing leading industries, increasing farmers’ income and improving agricultural production conditions as the main types; at the household scale, the nationalpolicy meeting farmers’ demands and the optimization of individual interests are all driving forces. 展开更多
关键词 farmland returning to forest or grassland(FRFG) driving forces ecological security different scales China
下载PDF
Importance of Comprehensive Ecological Restoration of Mountains,Rivers,Forests,Farmland,Lakes and Grass:A Case Study of the Shichuan River 被引量:1
3
作者 Shenglan YE 《Asian Agricultural Research》 2020年第7期33-35,共3页
With China's economic development and population growth,China's ecological environment continues to deteriorate.The comprehensive ecosystem restoration of the Shichuan River aims to build an ecosystem containi... With China's economic development and population growth,China's ecological environment continues to deteriorate.The comprehensive ecosystem restoration of the Shichuan River aims to build an ecosystem containing"mountains,rivers,forests,farmland,lakes and grass"by determining scientific and reasonable thickness of foreign soil,pollution restoration,ecological reconstruction,safeguard measures,etc.It brings new vitality to local ecological environment remodeling and economic development. 展开更多
关键词 MOUNTAINS RIVERS forests farmland lakes and grass Ecological restoration Shichuan River
下载PDF
Monitoring and Evaluation of Benefits of Project of Returning Farmland to Forests in Henan Province
4
作者 Lu WANG Weiwei ZHANG +1 位作者 Qianzeng XU Xianwen ZHU 《Asian Agricultural Research》 2022年第11期17-20,共4页
The project of returning farmland to forest has been implemented and consolidated in Henan Province for 20 years.At present,it is in a critical transition period when the previous round of project of returning farmlan... The project of returning farmland to forest has been implemented and consolidated in Henan Province for 20 years.At present,it is in a critical transition period when the previous round of project of returning farmland to forests has completed and a new round of project of returning farmland to forests has started.Henan Province took counties(cities)with different representations as sample counties for monitoring the benefits of project of returning farmland to forests(key monitoring areas in Henan Province),and monitored social and ecological benefits every year,and has obtained real and scientific monitoring data. 展开更多
关键词 returning farmland to forests Project benefits Monitoring and evaluation
下载PDF
Evaluation of the Land Production Potential in the Context of Returning Farmland to Forest in Karst Region:A Case Study of Guizhou Province 被引量:2
5
作者 Shuang YU Guang LI Ruiping RAN 《Asian Agricultural Research》 2013年第1期21-26,共6页
In this paper, we take Guizhou Province (the heart of southwestern Karst region in China) as the research object. By establishing gray forecasting model and time series forecasting model, we conduct the accuracy test ... In this paper, we take Guizhou Province (the heart of southwestern Karst region in China) as the research object. By establishing gray forecasting model and time series forecasting model, we conduct the accuracy test on the actual production capacity of land and the forecasted production capacity of land in 2007 and 2008, and then conduct comprehensive forecast of the land production potential in Guizhou Province in 2020. On this basis, considering the nutritional standards needed by three kinds of life type (dressing warmly and eating one's fill, well-off life, relatively affluent life), we evaluate the land production potential in Guizhou Province under the project of returning farmland to forest. Based on the evaluation results, we put forth the relevant recommendations for achieving sustainable land use in the context of returning farmland to forest in Guizhou Province. 展开更多
关键词 KARST region Project of returning farmland to fore
下载PDF
Tree Productivity and Water Potential Productivity in Returning Farmland to Forest Project in Datong County, Qinghai Province
6
作者 YinJing LiuChenfeng +1 位作者 ZhaoWanqi HeKangning 《Forestry Studies in China》 CAS 2004年第3期36-42,共7页
From 2002 to 2003, based on the investigation of sample plots and stem analysis of remained plantation communities in the areas of returning farmland to forest in the 1980s in Datong County, Qinghai Province, this pap... From 2002 to 2003, based on the investigation of sample plots and stem analysis of remained plantation communities in the areas of returning farmland to forest in the 1980s in Datong County, Qinghai Province, this paper studies tree productivity and moisture potential productivity of six types of plantations on the land of returning farmland to forest, such as green poplar (Populus cathayana Rehd.) and shrub mixed forest, Asia white birch (Betula platyphylla) and China spruce (Picea asperata) mixed forest, Dahurian larch (Larix gmelinii) pure forest, China spruce pure forest and Asia white birch pure forest and so on. The results show that: in sub-humid region of Loess Plateau, 3 000 trees per hm2 is a proper standard of planting density. Under current condition, the productivity index of green poplar and shrub mixed forest, Asia white birch pure forest, China spruce pure forest, and Asia white birch and China spruce mixed forest with the density of 2 1003 333 trees per hm2 can serve as potential productivity standard of actual biomass of arbor established forest. In sub-humid area, Thornthwaite Model is adopted to estimate plant climate potential productivity, which is about 8 462 kghm2穉1. The actual potential water productive efficiency of Purplecone spruce (Picea purpurea) and Asia white birch pure established forest are 17.22 and 22.14 kgmm1hm2穉1 respectively, and that of green poplar and shrub mixed established forest, and Asia white birch and China spruce mixed established forest are 21.14 and 19.09 kgmm1hm2穉1 respectively. The potential productivity of green poplar and shrub mixed forest, Asia white birch and China spruce mixed forest, China spruce pure forest and Asia white birch pure forest which have grown into forest with the density of 3 000 trees per hm2 have attained or been close to that of local climax community, which is local maximum tree productivity at present. These types of forestation models are the developing direction of the returning farmland to forest project. 展开更多
关键词 returning farmland to forest tree productivity water potential productivity
下载PDF
Returning Farmland to Forest, Forest Management and Permanent Forest : Thinking on High-quality Development of Returning Farmland to Forest
7
作者 Shiyu GUO Ni ZHOU Han YAN 《Meteorological and Environmental Research》 CAS 2020年第6期82-84,共3页
In the first round of returning farmland to forest,many places in Hubei Province have vigorously developed ecological forests dominated by pine,fir and cypress,to improve the fragile ecological situation as soon as po... In the first round of returning farmland to forest,many places in Hubei Province have vigorously developed ecological forests dominated by pine,fir and cypress,to improve the fragile ecological situation as soon as possible.At present,this kind of ecological forests are facing the dilemma of more pure forests,higher density and less management,with worse economic benefits.To realize high-quality development of these stands,it is necessary to carry out forest management guided by the close-to-nature concept.These stands will be transformed into permanent forests with multi tree species,multi age classes,multi levels and continuous coverage,to realize organic unity of economic,ecological and social benefits. 展开更多
关键词 returning farmland to forest High-quality development Forest management Permanent forest
下载PDF
Effects of Different Modes of Returning Farmland to Forest on Physicochemical Properties of Soil in Bashang Area of Northern Hebei Province
8
作者 Yue YANG Yitian YANG +2 位作者 Zhiyong WU Caiwu WU Yongjiao HAN 《Meteorological and Environmental Research》 CAS 2020年第4期98-102,共5页
[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three differe... [Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best. 展开更多
关键词 returning farmland to forest Physicochemical properties of soil Bashang area of northern Hebei Province
下载PDF
Estimation of Relative Ecological Value of Returning Farmland to Forest & Mountain Enclosure for Grazing Prohibition——A case study in Yongxing Township of Jingyuan County,Gansu Province
9
作者 CHANG Zhao-feng CHEN Bin-pu +2 位作者 QIAO Juan CHANG Fang FAN Bao-li 《Animal Husbandry and Feed Science》 CAS 2013年第4期162-168,171,共8页
[Objective]Returning farmland to forest and mountain enclosure for grazing prohibition ecological effect and economy rationality were explored.[Methods]A case study of returning farmland to forest and barren hills gra... [Objective]Returning farmland to forest and mountain enclosure for grazing prohibition ecological effect and economy rationality were explored.[Methods]A case study of returning farmland to forest and barren hills grazing prohibition in Yongxing Township of Jingyuan County was used to discuss and estimate the relative ecological function and relative ecological value.[Results]1)The ecological value of the forest of returning farmland was far more than the sum of the ecological value of farm crops and the agricultural output,and also more than the national subsidy standard.So the state policy of returning farmland to forests is not only favorable to local eco-environment restoration,but also reasonable in economic development.2)The ecological value of mountain enclosure for grazing prohibition was less than the opportunity cost of prohibiting grazing,also less than the national subsidy standard.The sum of the relative ecological value of prohibiting grazing and the state subsidies was more than the opportunity cost of prohibiting grazing.However,the ecological value of new vegetation through returning farmland to forest project was greater than the China's average ecological value of grassland.[Conclusion]The relative ecological value can be used to solve the problems in the equivalent conversion among various ecological indexes and between ecological indexes and economic indexes. 展开更多
关键词 returning farmland to forest Mountain enclosure for grazing prohibition Relative ecological function Relative ecological value Jingyuan County
下载PDF
The Regional Climate Effects of Replacing Farmland and Re-greening the Desertification Lands with Forest or Grass in West China 被引量:5
10
作者 施伟来 王汉杰 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第1期45-54,共10页
The West Development Policy being implemented in China causes significant land use and land cover (LULC) changes in West China, of which the two most important types of LULC change are replacing farmland and re-greeni... The West Development Policy being implemented in China causes significant land use and land cover (LULC) changes in West China, of which the two most important types of LULC change are replacing farmland and re-greening the desertification land with forest or grass. This paper modifies the prevailing regional climate model (RCM) by updating its lower boundary conditions with the up-to-date satellite database of the Global Land Cover Characteristics Database (GLCCD) created by the United States Geological Survey and the University of Nebraska-Lincoln. The modified RCM is used to simulate the possible regional climate changes due to the LULC variations. The preliminary results can be summarized as that the two main types of LULC variation, replacing farmland and greening the desertification lands with forest or grass in west China, will affect the regional climate mostly in northwest and north China, where the surface temperature will decrease and the precipitation will increase. The regional climate adjustments in South, Southwest China and on the Tibet Plateau are uncertain. 展开更多
关键词 West Development Policy replacing farmland with forest/grass regional climate modeling and virtual simulation
下载PDF
中国式现代化视域下习近平生态文明思想整体系统观及其方法论 被引量:4
11
作者 李勇强 《西南大学学报(社会科学版)》 CSSCI 北大核心 2024年第2期1-16,共16页
党的十八大以来,在推进中国式现代化建设的伟大征程中,以习近平同志为核心的党中央坚持系统观念,基于对西方现代化道路的深刻反思和对自然界作为有机系统整体的精准认识,赓续与拓新马克思主义和中华优秀传统文化关于人与自然真实图景的... 党的十八大以来,在推进中国式现代化建设的伟大征程中,以习近平同志为核心的党中央坚持系统观念,基于对西方现代化道路的深刻反思和对自然界作为有机系统整体的精准认识,赓续与拓新马克思主义和中华优秀传统文化关于人与自然真实图景的系统辩证思想,形成和确立了丰富完备、逻辑严密的习近平生态文明思想整体系统观。秉持山水林田湖草沙是生命共同体的系统理念,这一整体系统观锚定生态文明建设和环境治理的目标任务,坚持推进中国式现代化生态文明建设与环境治理的系统层级观,坚持共同体构架的国内外合作治理的系统联动机制,对其内核“是什么”的问题作了精要而又深邃的回答。习近平生态文明思想层层追问中国式现代化生态文明建设之道,彰显了其整体系统思维在回答生态文明建设根本性问题上的强大方法论功能;以系统工程方式“全方位全地域全过程”推进生态文明建设与环境治理的全面系统展开,立体呈现了习近平生态文明思想整体系统观鲜明的方法论特质,为中国式现代化新征程上全面推进美丽中国建设提供了科学思想方法,开拓了中国式现代化恢宏壮丽的生态篇章。 展开更多
关键词 中国式现代化 习近平生态文明思想 整体系统观 生态困局 环境治理 山水林田湖草沙
下载PDF
退耕还林地生态环境损害评估案例分析及应用 被引量:1
12
作者 周海兰 姜苹红 +1 位作者 唐彬 赵文涛 《环境科技》 2024年第1期40-46,共7页
近年来,随着我国经济的高速发展,林地生态环境损害事件日益增加。不同类型的生态系统或同一生态系统在不同区域所提供的生态服务功能侧重均不同,鉴定评估林地生态系统的环境损害价值时应选用不同的测算方法。通过阐述理论公式法和实际... 近年来,随着我国经济的高速发展,林地生态环境损害事件日益增加。不同类型的生态系统或同一生态系统在不同区域所提供的生态服务功能侧重均不同,鉴定评估林地生态系统的环境损害价值时应选用不同的测算方法。通过阐述理论公式法和实际监测法的原理和适用范围及其在生态环境损害评估中的应用,并对量化过程中参数的选取原则与方法进行说明。结合案例分析非法占用退耕还林地导致的生态环境损害范围和程度,计算出2012年~2019年的生态环境损害价值量为205万元。研究退耕还林地生态环境损害典型案例,并将其推广应用于小规模普通林地,对林地生态环境损害案件的鉴定评估环节具有重要引领作用。 展开更多
关键词 生态环境损害 退耕还林地 理论公式法 生态服务功能价值 鉴定评估
下载PDF
山水林田湖草沙系统治理与水土保持高质量发展
13
作者 胡春宏 张晓明 《水土保持通报》 CSCD 北大核心 2024年第4期441-447,共7页
[目的]中国水土流失治理已由“全面治理,重点治理”迈向“系统治理,攻坚克难”的新阶段。分析山水林田湖草沙系统治理的内涵、准则及其与水土保持的关系,旨在丰富新时代水土保持理论体系,引领水土保持高质量发展。[方法]在长期理论探索... [目的]中国水土流失治理已由“全面治理,重点治理”迈向“系统治理,攻坚克难”的新阶段。分析山水林田湖草沙系统治理的内涵、准则及其与水土保持的关系,旨在丰富新时代水土保持理论体系,引领水土保持高质量发展。[方法]在长期理论探索和实践验证的基础上,梳理山水林田湖草沙系统治理理念的发展过程,阐明其内涵、目标与实践准则。[结果]水土流失长期治理实践总结提升形成的以小流域为单元的综合治理技术路线是山水林田湖草沙生命共同体系统思想最朴素的实践体现。小流域综合治理的系统性主要体现为治理对象的系统协调,总体布局的系统统筹,治理措施的系统考量,治理成效的多效益兼顾,实施和管理的多部门协同和多主体参与的共治共享6个方面。水土保持高质量发展实践需要遵循的基于系统治理理念的具体举措包括:利用系统思维理解水土保持高质量发展的内涵和要求,精准诊断山水林田湖草沙系统短板及其控制性要素,构建山水林田湖草沙多层次全方位立体化防控体系,构筑完备的水土保持管理与技术保障体系。[结论]在新的历史时期,应该完整准确理解并全面贯彻落实山水林田湖草沙系统治理的理念,探索整体提升水土保持学术研究水平和治理效能的新路径、新模式、新机制。同时应结合区域或流域实际,对农田、水利、牧业、林业及生产建设活动进行全面综合系统的规划和治理,推动水土保持高质量发展。 展开更多
关键词 山水林田湖草沙 系统治理 生命共同体 水土保持 理论体系 小流域综合治理 高质量发展
下载PDF
塔河胡杨林核心区退耕地初始年土壤及植被养分特征数值分析
14
作者 张优 刘茂秀 +3 位作者 史军辉 王新英 艾吉尔·阿不拉 张炎 《新疆农业科学》 CAS CSCD 北大核心 2024年第3期699-707,共9页
【目的】研究塔河中下游胡杨林核心区退耕地初始年土壤和植被的养分特征,为胡杨林公益林核心区退耕地生态恢复提供基础支撑数据。【方法】以塔河中下游胡杨林核心区退耕地初始年的土壤和植被为研究对象,运用“S”形布点法、野外标准木... 【目的】研究塔河中下游胡杨林核心区退耕地初始年土壤和植被的养分特征,为胡杨林公益林核心区退耕地生态恢复提供基础支撑数据。【方法】以塔河中下游胡杨林核心区退耕地初始年的土壤和植被为研究对象,运用“S”形布点法、野外标准木全株收割法、多点混合方法分别采集植被和土壤样品,结合室内测定植被和土壤养分特征数值进行分析。【结果】(1)土壤养分含量和植被营养成分积累量均集中分布在Ⅳ区和Ⅴ区。(2)土壤垂直深度上,养分集中在表层土壤,且随着土层深度增加,土壤养分含量依次递减,但是在60~100 cm土层处,呈现小幅增加。不同样地与不同土层深度之间土壤养分含量差异显著(P<0.05)。(3)不同样地中残存棉花(棉秆、根系)及草本植物中全N、全P、全K、有机碳含量均有显著差异(P<0.05)。【结论】胡杨林自然保护区核心区退耕地初始年土壤养分含量较高,有利于荒漠植被群落的生长和发育,提高群落演替速率,有利于塔河胡杨林退耕地植被恢复与环境变化及其相互作用、生态过渡带植被恢复与区域生态稳定。 展开更多
关键词 胡杨林 退耕地 初始年 养分特征
下载PDF
中国集中连片特困区退耕还林还草生态效应评估
15
作者 刘亦文 邓楠 +1 位作者 颜建军 胡宗义 《生态学报》 CAS CSCD 北大核心 2024年第11期4719-4732,共14页
集中连片特困地区作为我国生态环境脆弱区是退耕还林还草的主战场,其退耕成效直接反映了退耕还林还草工程的整体实施效果,为新征程中巩固和拓展退耕还林还草成果提供经验镜鉴。以《中国农村扶贫开发纲要(2011—2020年)》文件明确的14个... 集中连片特困地区作为我国生态环境脆弱区是退耕还林还草的主战场,其退耕成效直接反映了退耕还林还草工程的整体实施效果,为新征程中巩固和拓展退耕还林还草成果提供经验镜鉴。以《中国农村扶贫开发纲要(2011—2020年)》文件明确的14个集中连片特困地区作为研究区域,基于2000—2020年生态系统年总初级生产力(AGPP)数据集和归一化植被指数(NDVI)数据集,对比分析集中连片特困区的退耕区和未退耕区AGPP和NDVI的年际变化差异,以此来评估集中连片特困地区实施退耕还林还草工程的生态效应。研究发现:(1)2000—2020年,集中连片特困区退耕还林还草面积为178554km2,占2000年耕地总面积的44.71%;(2)研究期内,退耕区与未退耕区AGPP和NDVI整体表现出增长趋势,其中退耕区AGPP和NDVI呈现极显著和显著上升趋势的面积分别占总面积的69.07%和86.51%,未退耕区的占比分别为65.88%和72.61%,且退耕区AGPP和NDVI的年均值和相对变化率均高于未退耕区;(3)2000—2020年整个区域、退耕区以及未退耕区AGPP和NDVI年际变化趋势大体一致,均表现出线性递增态势,且退耕区AGPP和NDVI的增长始终高于整个集中连片特困区和未退耕区。因此,研究通过探讨原集中连片特困区退耕还林还草对AGPP和NDVI的影响,为进一步调整和优化退耕还林还草政策提供了参考依据。 展开更多
关键词 集中连片特困区 退耕还林还草 生态效应
下载PDF
黄土高原退耕还林区典型植被大型土壤动物群落特征
16
作者 史嘉豪 闫慧玲 +2 位作者 王思艺 刘长海 赖善梅 《延安大学学报(自然科学版)》 2024年第3期68-75,共8页
为了解黄土高原退耕还林区典型植被类型土壤动物群落特征及其影响因子,选取“退耕还林第一县”延安市吴起县内的金佛坪小流域退耕后形成的典型乔木(刺槐)、灌木(沙棘)、混交林(山杏×沙棘)、草地4种生境中的大型土壤动物进行研究。... 为了解黄土高原退耕还林区典型植被类型土壤动物群落特征及其影响因子,选取“退耕还林第一县”延安市吴起县内的金佛坪小流域退耕后形成的典型乔木(刺槐)、灌木(沙棘)、混交林(山杏×沙棘)、草地4种生境中的大型土壤动物进行研究。于2021年春、夏、秋、冬四个季节使用手拣法收集,进行大型土壤动物采样,通过对研究区内植被、林下草本以及耦合土壤因子对土壤动物群落特征的影响进行分析,结果表明:刺槐乔木林中捕捉650只土壤动物共57个类群,沙棘灌木林中捕获472只土壤动物共37个类群,山杏沙棘混交林中共捕获491只土壤动物46个类群,撂荒草地共捕获315只土壤动物29个类群,不同生境土壤动物群落组成结构差异显著;刺槐乔木中土壤动物群落多样性最高;生境、林下草本群落、土壤因子与土壤动物群落密切相关;根据RDA-VPA分析,不同土壤动物群落组成结构主要受到林下草本植被群落的影响,进一步分析表明土壤速效钾、碱解氮、非毛管孔隙度、和地下草本生物量是影响土壤动物群落组成的主要影响因子。 展开更多
关键词 土壤动物 不同生境 群落特征 黄土高原 吴起县 植被类型 退耕还林
下载PDF
退耕还林工程对缩小农户收入差距的影响——基于3231个农户样本的实证分析
17
作者 孔凡斌 王永成 +2 位作者 陆雨 徐彩瑶 翟郡 《林业经济问题》 北大核心 2024年第3期225-238,共14页
基于2011—2020年中国健康与养老追踪调查数据库中25个省份3231个农户样本的大型微观样本数据,采用再中心化影响函数(RIF)模型,分析退耕还林工程对农户收入差距的影响及其多维异质性特征。研究发现:(1)退耕还林工程能够显著缩小农户收... 基于2011—2020年中国健康与养老追踪调查数据库中25个省份3231个农户样本的大型微观样本数据,采用再中心化影响函数(RIF)模型,分析退耕还林工程对农户收入差距的影响及其多维异质性特征。研究发现:(1)退耕还林工程能够显著缩小农户收入差距,退耕补助每多发放1%,基尼系数下降0.078,这一结果在替换被解释变量与解释变量后依然稳健;(2)从退耕农户收入差距与非退耕农户收入差距的差异分析结果来看,相较于非退耕农户,退耕农户收入差距更小,其收入分位距与基尼系数均显著低于非退耕农户;(3)从连续退耕与非连续退耕农户的异质性分析结果来看,退耕还林工程对连续退耕农户收入差距的缩小作用强于非连续退耕农户;(4)从异质性分析结果来看,退耕还林工程对农户收入差距的缩小效应在不同受教育程度农户中存在异质性,对受教育程度低的农户影响更明显。 展开更多
关键词 退耕还林 农户 收入差距 影响函数
下载PDF
黄河中游不同地貌条件下植被干旱时空特征及影响因素
18
作者 郭宇星 孙从建 +1 位作者 陈伟 张齐飞 《地理科学》 CSSCI CSCD 北大核心 2024年第9期1676-1683,共8页
利用归一化植被指数、地表温度和降水数据构建温度植被降水干旱指数(TVPDI)分析黄河中游2000—2021年植被干旱时空特征及影响因素,论证了黄河中游退耕还林还草工程实施与区域植被干旱特征间的关系。结果表明:①黄河中游2000—2021年多... 利用归一化植被指数、地表温度和降水数据构建温度植被降水干旱指数(TVPDI)分析黄河中游2000—2021年植被干旱时空特征及影响因素,论证了黄河中游退耕还林还草工程实施与区域植被干旱特征间的关系。结果表明:①黄河中游2000—2021年多年平均TVPDI值呈不显著上升趋势,TVPDI多年均值为0.708,对应干旱等级为轻旱。②黄河中游2000—2021年TVPDI有较强的空间分异性,呈现“东北、西南部地区旱情较轻,西北、东南部地区旱情较重”的空间分布格局;从各地貌分区来看,黄土高塬沟壑区旱情较轻,风沙区与河谷平原区旱情较重。③黄河中游TVPDI空间分异的主要影响因子为气温、蒸散发和降雨量,且与TVPDI存在显著线性关系。黄河中游2000—2021年植被覆盖度与蒸散发量均呈增加趋势,土壤水分呈下降趋势。 展开更多
关键词 退耕还林还草工程 黄河中游 植被干旱 TVPDI
原文传递
新疆退耕还林工程建设存在问题及对策研究
19
作者 丽娜·阿斯勒汗 《园艺与种苗》 CAS 2024年第6期105-107,共3页
退耕还林是我国生态文明建设的重要举措之一,也是解决生态环境问题的有效途径。新疆作为我国重要的生态屏障和生态功能区,退耕还林工作具有重要意义。然而,新疆在退耕还林过程中面临着一系列问题,如地方政府重视程度不够、技术保障力量... 退耕还林是我国生态文明建设的重要举措之一,也是解决生态环境问题的有效途径。新疆作为我国重要的生态屏障和生态功能区,退耕还林工作具有重要意义。然而,新疆在退耕还林过程中面临着一系列问题,如地方政府重视程度不够、技术保障力量普遍薄弱、土地利用冲突、生态补偿机制不完善等。该文通过对新疆新一轮退耕还林存在的问题进行研究,分析了问题的原因,并提出了相应对策,旨在为新疆的退耕还林工作提供参考。 展开更多
关键词 新疆 退耕还林 问题 对策
下载PDF
立地类型划分对威宁自治县新一轮退耕还林工程中华山松造林效果的影响
20
作者 赵大燕 《林业科技情报》 2024年第4期125-127,共3页
威宁自治县自2014年实施“新一轮”退耕还林工程以来,陆续种植用材林华山松,于2020年8月9月组织相关人员,针对不同海拔高度下不同坡度的华山松造林效果进行调查分析。根据调查结果可知:高中山海拔区斜坡的成活率稍高于陡坡,但陡坡的成... 威宁自治县自2014年实施“新一轮”退耕还林工程以来,陆续种植用材林华山松,于2020年8月9月组织相关人员,针对不同海拔高度下不同坡度的华山松造林效果进行调查分析。根据调查结果可知:高中山海拔区斜坡的成活率稍高于陡坡,但陡坡的成活率也达到了理想的标准。中山海拔区域斜坡的成活率是43%,中山海拔区陡坡成活率是41%,和陡坡对比,斜坡成活率稍高,但无明显差距。高中山区域陡坡病害率稍高于斜坡,但整体无明显差距,说明高中山区域在斜坡种植华山松切实可行。中山海拔区陡坡病害情况稍微明显,但整体而言,无较大差距,说明斜坡陡坡均可种植。结果证实立地类型划分是营林和造林设计中最重要的工作,通过立地研究可选择最有生产力的造林树种,提出合适的育林措施,从而达到持续高效发展林业的目的。 展开更多
关键词 立地类型 退耕还林 华山松 造林效果
下载PDF
上一页 1 2 31 下一页 到第
使用帮助 返回顶部