Multi-scales Analysis of Driving Forces on Land Use/Cover Change in China:Taking Farmland Returning to Forest or Grassland as a Case

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.

Evaluation of the Land Production Potential in the Context of Returning Farmland to Forest in Karst Region:A Case Study of Guizhou Province

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.

Returning Farmland to Forest, Forest Management and Permanent Forest : Thinking on High-quality Development of Returning Farmland to Forest

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.

Monitoring and Evaluation of Benefits of Project of Returning Farmland to Forests in Henan Province

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.

Effects of Different Modes of Returning Farmland to Forest on Physicochemical Properties of Soil in Bashang Area of Northern Hebei Province

[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.

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

[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.

Eco-environment Restoration and Regional Differentiation Characteristics Based on “Building Terrace and Returning Slope Farmland to Forests and Grass”

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.

Thoughts and Practice of Ecological Protection and Restoration of Mountains, Rivers, Forests, Farmlands, Lakes and Grasslands

The report of the 19th National Congress of the Communist Party of China stated that it was necessary to establish and practice the concept that lucid waters and lush mountains are invaluable assets,treat the ecological environment as life,and coordinate the management of mountains,rivers,forests,farmlands,lakes and grasslands.In recent years,China has organized a series of pilot projects for the ecological protection and restoration of mountains,rivers,forests,farmlands,lakes and grasslands,breaking the boundary between administrative divisions,departmental management and ecological elements,and implementing conservation and restoration oriented towards the improvement of ecosystem services,so as to solve the problem of the lack of overall planning for ecological protection and restoration projects and the separated management of ecological elements.This study systematically elaborated the theoretical basis and connotation characteristics of ecological protection and restoration of mountains,rivers,forests,farmlands,lakes and grasslands.It proposed the implementation path of ecological protection and restoration project of mountains,rivers,forests,farmlands,lakes and grasslands by taking the water source conservation area of Beijing-Tianjin-Hebei as a case,so as to provide reference for the implementation and decision-making management of ecological protection and restoration projects in various regions.

退耕还林地生态环境损害评估案例分析及应用

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。

基于生态韧性的山水林田湖草沙一体化保护修复框架

基于生态韧性内涵的山水林田湖草沙一体化保护修复是提升区域生态系统承载力和风险适应性的创新路径。本文阐述了生态韧性内涵与山水林田湖草沙生命共同体的特征,明确了一体化生态修复同生态韧性内涵关联逻辑,构建了山水林田湖草沙一体化保护修复的韧性作用机制和“问题识别-要素分析-策略制定”研究框架。以石家庄市为例,识别了其水土流失、湿地萎缩等生态问题,明确流域单元关键生态要素,并基于石家庄市生态系统地理空间格局以及面临的生态风险,提出调田节水、生境修复、林草保育等保护策略。以期为推进山水林田湖草沙系统修复工作以及增强生态系统应对干扰的抵抗力和适应力提供支撑。

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

【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。

浙江省钱塘江源区域山水林田湖草生命共同体健康评价

[目的]分析浙江省钱塘江源区域山水林田湖草生命共同体健康状况,为国土空间规划和生态管理提供科学参考。[方法]基于生命共同体理论与活力—组织力—恢复力(vitality-organization-resilience,VOR)生态模型理论,构建生命共同体健康评价指标体系。利用3S技术和社会经济统计资料,以县域为评价单元,对钱江源区域山水林田湖草生命共同体的健康状况进行评价和分级。[结果]①2020年,钱江源区域的淳安县处于生命共同体健康状态,建德市、开化县、常山县生命共同体均为亚健康状态。②2015—2020年4个县(市)生命共同体健康指数总体呈上升趋势,健康指数上升趋势大小依次为:建德市>常山县>淳安县>开化县。③2020年,4县(市)中山水林田湖草子系统健康状态最好的为常山县,最差的为淳安县;生态系统健康状态最好的为淳安县,最差的为常山县。④钱江源区域林、田子系统结构及其生态服务功能有待提升优化。⑤生态修复试点工程对于提升钱江源区域生命共同体健康状态在一定程度上起到了积极的推动作用。[结论]钱江源区域山水林田湖草生态修复工程取得了阶段性成果。4县(市)接下来应针对山、水、林、田、湖等子系统的不同问题开展相关修复工作,同时进行统筹规划与生态整治,实现山水林田湖草生命共同体系统的统筹共治、健康管理与持续经营。

中国集中连片特困区退耕还林还草生态效应评估

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。

对滇池流域山水林田湖草一体化保护和系统治理的思考

滇池是“九五”时期以来我国重点治理的“三河三湖”之一,经过30年治理,水质明显改善,水生态系统演变趋势向好。然而目前,滇池流域“山水林田湖草”系统治理格局还未完全形成,流域生态系统韧性不足,水环境质量正处于进一步改善的瓶颈期。为探索滇池治理的未来发展路径,本文系统总结了前期滇池治理历程与成效,诊断了存在的主要问题,分析了滇池流域自然—社会复合生态系统特征,提出了滇池流域山水林田湖草一体化保护和系统治理的思路、目标、空间布局和重点任务,以期为新时期滇池流域水生态环境保护提供指导,也为其他城市型重污染湖泊流域从水污染防治向水生态保护的转变提供借鉴。

山水林田湖草健康发展时空异质性及其驱动力——以广西北部湾经济区为例

深入评估典型资源要素生态健康的时空异质性及其社会经济自然驱动机理,对实现可持续发展目标具有重要意义。然而,探究区域山水林田湖草(海)健康发展时空异质性及其驱动力的研究案例较少。广西北部湾经济区覆盖内陆与沿海6市,定位为生态环境综合治理先行区。以此为研究区,运用正态云模型、Dagum基尼系数、主成分分析和时空地理加权回归等模型,在综合评价的基础上,分析其2005—2020年山水林田湖草(海)健康发展的时空异质性,并依据系统论深入解析驱动力。结果表明:(1)除北海市的山水林田湖草(海)为亚健康外,其他均为健康状态,经济区内陆3市健康指数的基尼系数(0.095)高于沿海3市(0.016),存在时空非均衡性,超变密度(46.71%)和市域间差异(44.93%)是主要原因;(2)影响健康发展的驱动因子主要为:城镇土地利用率(0.427)>城乡居民可支配收入(0.397)>年均降水量(0.377)>房地产开发投资规模(-0.333)>建成区绿化覆盖度(0.261);(3)影响健康发展的驱动要素表现为:土地投入程度(0.611)>土地利用程度(0.442)>经济城镇化(-0.393)>自然条件(0.23),各因素均存在时空非平稳性。研究表明土地集约利用、城镇化发展和自然环境条件是广西北部湾经济区山水林田湖草(海)健康发展的主要驱动力,表现为自然环境条件起基础保障、土地集约利用起正向促进、经济城镇化起负向抑制的作用机理,提高城镇土地利用率、提升城乡居民可支配收入、扩大建成区绿化覆盖度并控制房地产开发规模是促进健康发展的关键抓手。

新疆退耕还林工程建设存在问题及对策研究

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。

矿山修复为主的山水林田湖草生态修复工程及效益探讨——以大方县煤矿、硫磺矿土地复垦工程安乐F3单元为例

为进一步探索矿山修复为主的山水林田湖草生态修复工程及其产生的效益,以贵州省乌蒙山区山水林田湖草生态保护修复重大工程大方县煤矿、硫磺矿(东关乡片区)土地复垦工程安乐F3单元为例,通过资料收集、现场调查等方法分析矿山存在的生态环境问题与影响。针对主要生态问题,提出以矿山生态修复为主的“土地复垦+污水处理+植被绿化”生态修复措施,同时考虑与矿山生态修复相结合的经济发展,更好地实现矿山生态修复价值最大化,取得良好的生态效益与经济效益,以期为类似矿山的生态修复提供一定的借鉴与参考。

科尔沁地区山水林田湖草沙一体化保护和修复的应用与研究

鉴于科尔沁地区干旱少雨、风沙侵扰的脆弱生态环境特征和半农半牧的社会经济特点,遵循山水林田湖草沙一体化治理理念,坚持保护优先、自然恢复为主,人工辅助的原则,以水资源承载能力为约束条件,突出生态效益并兼顾经济效益。结合工程规模大、管理及协调难度高等特点,探索总结山水林田湖草沙一体化保护和修复工程的实施模式、关键工序、应用技术,对未来生态保护工程EPC模式应用、林草机械融合信息技术升级、“星-空-地”一体化空间发展等发展趋势提出一些建议,以期为后续类似林草生态工程建设提供参考。

山水林田湖草系统治理理论与方法综述

针对不同区域山水林田湖草存在问题,寻求适宜的系统治理方法至关重要。国内外运用最为广泛的山水林田湖草系统治理的理论与方法主要有基于自然的解决方法(NbS)、再野化、景感生态学、生态安全格局和生态系统服务5种,但目前对这些理论与方法的相互联系和区别尚不清晰。从定义及发展、准则、实施方法和典型案例等方面系统梳理了山水林田湖草系统治理的5种理论与方法并进行比较,结果可知,5种理论与方法运用生态系统的恢复力和适应性,通过自然恢复和人为干预等手段,使退化或者破坏的生态系统回归到一种稳定、健康、可持续的发展状态,但它们在人为干预程度、适用范围、与人类关系的密切程度及农业应用等方面有差异。认识到山水林田湖草系统治理不同理论与方法的特点、适用性和局限性,结合治理区域的特点和问题,针对性地选择治理方法,为山水林田湖草系统治理理论和实践提供参考。