This issue of provides an overview of recent advances in Land System Science while at the same time setting the research agenda for the Land System Science community. Land System Science is not just representing land system changes as either a driver or a consequence of global environmental change. Land systems also offer solutions to global change through adaptation and mitigation and can play a key role in achieving a sustainable future earth. The special issue assembles 14 articles that entail different perspectives on land systems and their dynamics, synthesizing current knowledge, highlighting currently under-researched topics, exploring scientific frontiers and suggesting ways ahead, integrating a plethora of scientific disciplines.

土地变化科学是理解人类—自然耦合系统的交叉学科研究方向。多主体模型（ABM）作为过程导向模型,对揭示土地变化驱动力,理解土地变化过程有重要作用。本文从理论、应用与建模框架三方面出发,总结了ABM理论基础和相关概念;阐述了ABM在城市和农业土地系统两方面的应用与发展,进一步介绍了横断山区退耕还林ABM研究案例;在梳理ABM建模协议的基础上,提出了主体视角的土地系统ABM建模框架和实施流程。在城市土地利用方面,ABM研究从最初基于景观研究城市扩张,到研究城市内部居住分隔,规划分区,生态功能等多方面;在农业土地利用方面,ABM应用则呈现出更加多样化和个性化的特征,包括农民行为、农户决策、种植系统、农业政策等。相比于传统模型,ABM因其依靠本地知识与数据而使得其构建更为复杂,且不易推广;但因其独特的自下而上模型构架,在探究土地变化驱动力、刻画人类行为对自然环境影响等方面具有不可或缺的作用。

Land change science has become an interdisciplinary research direction for understanding human-natural coupling systems. As a process-oriented modelling approach, Agent based model (ABM) plays an important role in revealing the driving forces of land change and understanding the process of land change. This paper starts from three aspects: the theory, application and modeling framework of ABM. First, we summarize the theoretical basis of ABM and introduce some related concepts. Then we expound the application and development of ABM in both urban land systems and agricultural land systems, and further introduce the case study of an model on Grain to Green Program in the Hengduan Mountains region, Southwest China. On the basis of combing the ABM modeling protocol, we propose the land system ABM modeling framework and process from the perspective of agents. In terms of urban land use, ABM research initially focused on the study of urban expansion based on landscape, then expanded to issues like urban residential separation, planning and zoning, ecological functions, etc. In terms of agricultural land use, ABM application presents more diverse and individualized features. Research topics include farmers' behavior, farmers' decision-making, planting systems, agricultural policy. Compared to traditional models, ABM is more complex and difficult to generalize beyond specific context since it relies on local knowledge and data. However, due to its unique bottom-up model structure, ABM has an indispensable role in exploring the driving forces of land change as well as the impact of human behavior on the environment.

土地利用/覆被变化是人类活动对地球表层及全球变化影响研究的重要内容。本文基于Landsat 8 OLI、GF-2等遥感图像和人机交互解译方法,获取的土地利用数据实现了中国2010-2015年土地利用变化遥感动态监测。应用土地利用动态度、年变化率等指标,从全国和分区角度揭示了2010-2015年中国土地利用变化的时空特征。结果表明：2010-2015年中国建设用地面积共增加24.6×10³ km²,耕地面积共减少4.9×10³ km²,林草用地面积共减少16.4×10³ km²。2010-2015年与2000-2010年相比,中国土地利用变化的区域空间格局基本一致,但分区变化呈现新的特征。东部建设用地持续扩张和耕地面积减少,变化速率有所下降;中部建设用地扩张和耕地面积减少速度增加;西部建设用地扩张明显加速,耕地面积增速进一步加快,林草面积减少速率增加;东北地区建设用地扩展持续缓慢,耕地面积稳中有升,水旱田转换突出,林草面积略有下降。从“十二五”期间国家实施的主体功能区布局来看,东部地区的土地利用变化特征与优化和重点开发区的国土空间格局管控要求基本吻合;中部和西部地区则面临对重点生态功能区和农产品主产区相关土地利用类型实现有效保护的严峻挑战,必须进一步加大对国土空间开发格局的有效管控。

随着经济社会发展,由耕地利用类型结构、投入结构和种植结构决定的区域耕地利用功能究竟如何转型,至今悬而未决。通过分析诱致性生产替代与3种结构演变的内在联系,构建耕地利用功能转型综合解释框架及量化方法,选取广东省为典型地区,研究区域耕地利用功能转型。结果表明：① 广东省耕地利用功能处于从经济社会型转向生态经济型转型的过渡期,但区域差异明显。其中,珠江三角洲耕地利用功能实现了从经济社会型向生态经济型的转型,东翼、西翼、山区实现了从社会生态型向经济社会型的转型;② 广东省耕地利用功能转型的人文驱动机理表现为,经济—社会和社会—体制两方面的驱动力沿“城镇化发展—经济发展水平提高—诱致性生产替代—耕地利用结构演变—耕地利用功能形态转变”的级联驱动效应;③ 耕地利用结构演变分析是耕地利用功能转型研究的有效视角。随着经济社会从初级发展阶段经历中高级到高级阶段,在诱致性生产替代作用下,耕地利用类型结构、投入结构和种植结构演变将决定耕地利用功能从社会生态型向经济社会型、生态经济型转型;④ 对土地利用转型中“型”的内涵做出了新的阐释。在诱致性生产替代理论认知基础上,对耕地利用功能“型”之转变的深层机理进行了新的探索。这对缩小学术界与公众、决策层在耕地利用转型方面的认知鸿沟,以及推动土地利用转型深入研究具有重要意义。此外,提出了中国“旱改水”及耕地利用功能转型的社会生态效应管控建议。

长期以来乡村土地利用功能的供需不平衡是造成乡村问题的主要原因之一。论文基于土地利用多功能性视角,以“供给—需求”“要素—结构—功能”为主线,阐释了农村土地整治与乡村振兴的互馈关系,探讨了如何通过农村土地整治实现乡村土地利用功能的供需平衡,进而促进乡村振兴。研究结果如下：① 综合土地整治是一种多功能的土地利用方式,是当前解决乡村问题、促进乡村振兴的重要手段,其本质是从以经济效益为主的生产主义向兼顾社会、经济、环境等的非生产主义的转变。② 乡村土地利用具有生产、生活、生态、文化等4种主要功能,满足乡村振兴在经济、社会、环境、文化等方面的需求,其中生产功能分为农业、商业、工业生产功能,生活功能分为居住、就业和公共服务功能。③ 农村土地整治沿整合土地利用要素、重组土地利用结构、优化土地利用功能的路径,从供给侧因地制宜地平衡乡村发展对土地利用多功能的需求。④ 今后,农村土地整治与乡村振兴的研究应该考虑不同空间尺度下土地整治对于乡村振兴的作用机制与模式,定量分析土地整治影响下土地利用的多功能供给以及不同类型乡村发展对土地利用功能的需求,从而为土地利用和乡村振兴规划的制定和实施提供科学依据。

The long-term supply-demand imbalance of rural land use functions (RLUFs) is one of the main reasons for rural issues in China. Based on the multifunctionality theory, this study explained the mutual relationship between rural land consolidation (RLC) and rural vitalization with a focus on supply-demand and element-structure-function relationships, and then discussed how to realize the supply-demand balance of RLUFs through RLC so as to promote sustainable rural development. The results show that: 1) Comprehensive rural land consolidation is a multifunctional land use method and an important means to solve rural issues for promoting rural vitalization. In essence, it is the transition from productivism that focuses on economic benefits to non-productivism that takes social, economic, and environmental benefits as a whole. 2) RLUFs include production, living, ecological, and cultural functions, corresponding to the economic, social, enviromental, and cultural demands of rural vitalization. The production functions are divided into agricultural, commercial, and industrial functions, and living functions include residential, employment, and public service functions. 3) Along the path of integrating land use elements, restructuring land use structures, and optimizing land use functions, RLC promotes the supply-demand balance of RLUFs from the supply side according to local conditions. 4) In future research, the mechanisms and modes of RLC impact on rural vitalization at different spatial scales, as well as quantitative analysis of the functional supply of land use and the functional demand of rural vitalization under the influence of RLC should be given more attention, thus laying a scientific foundation for the formulation and implementation of land use and rural vitalization planning.

以黑龙江省巴彦县为研究区,基于研究区DEM数据,运用土地利用类型的分布指数、土地利用结构的信息熵、均衡度和优势度,明确研究区土地利用空间格局的地形梯度特征及地形因子对土地利用空间格局的影响。结果表明：① 研究区土地利用空间格局在地形因子的作用下存在明显的梯度特征,旱地、水田、草地、水域、建设用地及其他用地主要分布在较低地形级别区,林地主要分布在较高地形级别区。② 除林地以外,其他土地利用类型分布的优势地形位均位于较低地形级别区,林地分布的优势地形位位于较高地形级别区,各土地利用类型分布的优势区域不尽相同。③ 研究区土地利用结构的信息熵及均衡度变化趋势相同,优势度的变化趋势与信息熵、均衡度的变化趋势相反,土地利用空间格局与地形因子具有显著的相关性。

The purpose of this article is to explore the relationship between spatial distribution of land use and topographic factors and provide new ideas for regional land use planning. The study area of this study is Bayan County, Heilongjiang Province, in Northeast China. Three kind of topographic factors are extracted, which are elevation, slope and aspect, based on the DEM data of research area by the utilizing of GIS. The distribution characteristics of different kind of land use type among different topographic factors are identified after the classification of the three topographic factors which were extracted. Based on that, distribution index of land use type among different topographic factors are calculated, including the information entropy, equilibrium degree, dominance degree of land use structure and the correlation coefficient between different land use style and topographic factors. So that, the relationship between spatial distribution of land use and topographic factors could be identified. The results show that: 1) The spatial distribution of land use in research area shows gradient feature due to the impact of topographic factors. There are more dry land, paddy field, grassland, water area, construction land and other land in the region of low level of terrain, but more forest land in the region of high level of terrain. 2) Except forest land, the dominant landforms of other land use types are located at lower levels, and the predominant terrain of forest land distributed in the area of high level of topographic factors. The dominance regions of different land use types are different. The dominant region of dry land is the central and northwest region of the study area, the dominant region of paddy field is the southern edge of the study area, the dominant area of forest land is the northeast and southeast of the study area, the dominant region of construction land is the south of the study area, the dominant area of grassland is the northwest and the southern edge of the study area, the dominant region of water area is the southern edge of the study area and the dominant area of other land is in the south of the study area. 3) The degree of order, equilibrium and dominance of land use structure in the study area have a certain gradient under the function of topographic factors. The information entropy and equilibrium degree of the land use structure show the same changing trend, the values of information entropy and equilibrium degree of the land use structure are larger in the area of low level of elevation and slope. The trend of dominance is opposite to the information entropy and equilibrium, the dominance value of single land use type is higher in the area of high level of elevation and slope. Thus, the distribution of land use types are significantly correlated with topographic factors.

FLUS模型是一种新型的土地利用变化模拟模型,应用前景广阔。本文通过在FLUS模型的人工神经网络（Artificial Neural Network,ANN）训练模块中引入空间自相关因子来改进模型,以珠江三角洲地区为例,基于2009年、2015年土地利用数据和一系列驱动因子对改进的模型进行了验证,并利用该改进的FLUS模型模拟了2035年研究区在3种情景下土地利用变化格局。结果表明：① 引入空间自相关因子后各地类发生概率分布的预测精度更高,耕地、林地、建设用地、水体和未利用土地的拟合优度ROC值分别从0.819、0.928、0.885、0.855和0.861提高到0.857、0.934、0.890、0.863和0.978;② 改进的FLUS模型的模拟精度有一定的提高,Kappa系数从0.732提高到0.744,FOM系数从0.077升到0.106;③ 情景模拟表明,3种情景下珠江三角洲建设用地和林地均将增加、而耕地均呈减少趋势。但不同情景下模拟的土地利用格局也存在显著差异: 基准情景下,建设用地明显扩张且大幅侵占耕地。耕地保护情景下,耕地面积保持在合理水平,建设用地蔓延扩张趋势得到遏制,土地利用布局总体趋向合理。生态保护情景下,耕地、林地和水体得到较好保护,建设用地布局更为合理,土地利用可持续性明显提高。

土地利用可持续性评价是土地系统科学与可持续发展交叉学科研究中一个重要内容,对识别区域土地利用与管理问题,制定可持续土地管理决策具有重要意义。本文从土地利用可持续内涵解析出发,提出了一种基于土地系统冲突与适配视角、适用于不同区域与时段的土地利用可持续评价框架,并以2000—2015年长三角地区为例进行实证分析。结果显示：① 基于土地系统外部发展施压及土地系统内部支撑角度,可以构建由“资源子系统冲突”“功能子系统冲突”“承载子系统冲突”“资源—功能适配性”“功能—承载适配性”组成的土地系统结构。并基于静力学平衡方程,通过计算结构支撑性与平衡性得到土地利用可持续性;② 长三角地区各项土地冲突适配指标中,土地系统功能冲突改善程度最高,但土地功能与承载适配程度最低。各项冲突适配指标具有显著的城乡、纬度、海陆空间分异特征;③ 长三角地区包含17种土地系统构型,呈现最稳定与最不稳定构型两极分布多、中间构型数量少的特征。长三角地区土地利用可持续性结果范围是0.20~1.58,其中浙江>安徽>长三角地区均值>江苏>上海,浙江诸暨市、安吉县等实施绿色发展战略地区显著高于江苏连云港市、如东县等实施传统经济主导型发展战略地区。本文可以为分析区域土地系统可持续性、设置土地可持续发展规划目标、探索土地系统转型方向提供思路与方法借鉴。

土地利用转型正表现为城乡地域系统演变的重要特征,土地利用转型分析的意义在于发现土地利用形态转变指示的土地利用问题。本文尝试解析了区域人地耦合关系下的土地利用形态转型逻辑,系统阐释了区域土地利用转型的诊断分析路径,重点探讨了乡村土地利用转型问题诊断与调控途径。研究指出：① 区域土地利用转型侧重考察土地变化趋势性转折对应的土地利用方式的转变要求,阐释转型分析所指示的土地利用问题及其表现特征,以此找寻转型调控的应对策略。② 应依据尺度和梯度分异方式揭示区域土地利用转型特征,理解不同尺度上转型调控的融合过程,研判区域土地利用转型调控措施。③ 土地服务供给变化是引发乡村土地利用显性形态和隐性形态转型发生错位的关键原因,土地利用显性形态与隐性形态之间的互适关系,则反映了土地利用形态空间关系构成的问题特征。④ 基于乡村地域尺度和梯度分异原则、基于城乡融合发展背景、重构农村土地权利体系和开展国土空间规划是探索乡村土地利用转型调控的四个重要分析路径。⑤ 不同尺度区域土地利用转型认知与转型调控对策的融合仍需要进一步拓展,而激活乡村土地资源要素是调控乡村土地利用转型的关键途径。

Land use transition is an important feature of urban and rural regional system evolution. The significance of land use transition analysis is to find the land use problems indicated by land use form change. This paper attempts to analyze the transition logic of land use form under the coupling relationship between human and land, explains the diagnostic analysis path of regional land use transition systematically, and focuses on the diagnosis and regulation of rural land use transition. The research points out that: (1) The study of regional land use transition should explore the changing requirements of land use form corresponding to the trend of land use change, and resolve the land use problems and explain their performance characteristics indicated by the transition analysis, so as to figure out the coping strategies of land use transition regulation. (2) Scale selection and gradient differentiation are the basic premise of regional land use transition research. We should reveal the characteristics of regional land use transition according to scale and gradient differentiation, understand the integration process of transition regulation on different scales, and study the regulation and control measures of regional land use transition. (3) The change of land service supply is the key reason for the dislocation of the dominant and recessive forms of rural land use, and it is the key point to diagnose the transition of land use forms. The mutual adaptability between the dominant and recessive forms of land use reflects the problem characteristics of the spatial relationship of land use forms, which is the main body of land use to provide land services response results. (4) Based on the principle of rural regional scale and gradient differentiation, and under the background of urban-rural integration, the reconstruction of rural land right system and the development of land spatial planning are four important analysis paths to explore the transition and regulation of rural land use. (5) The integration of cognition of land use transition in different scale regions and the regulation measures of transition still needs to be further expanded, and activating rural land resource elements is the key way to regulate rural land use transition.

当前,土地变化研究尚缺乏统一的理论指导。探索土地利用转型理论对构建土地变化研究的理论基础具有重要意义。本文试图梳理土地利用转型研究的缘起、拓展及启示,辨析土地利用转型与土地利用变化的内涵差异,构建土地利用转型的研究框架。结果表明：① 耕地及城乡建设用地利用转型研究对构建土地利用转型的研究框架具有重要价值;② 土地利用转型与土地利用变化在基本类型、时间尺度、空间尺度、价值主体、驱动因素、轨迹特征和结果/影响方面存在显著差异;③ 土地利用转型的研究框架涵盖转型诊断、机制研究和效应研究。其中,转型诊断的关键在于,从数量变化视角、景观格局变化视角和经营格局变化视角,以及外部性视角和政策发展视角,构建土地利用空间形态及功能形态的分析指标和转型的诊断准则;转型机制表现为人口、经济、技术、制度、文化和区位因素等土地利用变化深层驱动因素的级联驱动效应。转型机制研究应当着重探讨土地利用空间转型与功能转型的互动机制环;土地利用转型效应包括社会、经济、环境3个方面;④ 1961-2011年法国耕地利用转型能够支撑本文提出的研究框架及中国耕地保护创新。

Land change has been a hot topic in geographical research. The overarching and convincing theories of land change science, however, have not emerged. Establishment of land use transition theory is of significance for the theory basis of land change science. This paper attempts to establish a research framework of land use transition based on summarizing the development and implications of land use transition research and clarifying the differences between land use transition and land use change. Results show that transition research of artificial ecosystems, such as cultivated land, rural housing land and urban land, is of significance. Land use transition is distinguished from land use change on several aspects, such as fundamental types, temporal scale, spatial scale, agents, driving forces, trajectory, and results or effects. Research framework of land use transition covers transition diagnosis, mechanism research and effects research. Key issues of transition diagnosis are the establishment of measuring indices and diagnosis principles of land use spatial and functional morphologies from the perspectives of quantity change, landscape pattern change and management pattern change, and of land use externality and land use policy development. Mechanism of land use transition behaves as cascading effects of underlying driving factors of land use change, including demographic, economic, technological, institutional, cultural, and location factors. Mechanism research should place emphasis on interaction between land use spatial transition and functional transition. Effects of land use transition covers at least 17 themes relating to social, economic and environmental dimensions. Cultivated land use transition in France in 1961-2011 confirms the research framework of land use transition and is beneficial to the innovation of cultivated land protection in China.

伴随着快速城镇化,生态环境剧烈变化与社会经济结构深刻转变使中国城乡发展问题愈发突出,城乡治理面临新挑战。社会—生态韧性理论与城乡治理实践存在紧密关联,但对两者关系的研究欠缺。论文以中国城乡发展问题为导向,厘清社会—生态韧性与城乡发展的关系,构建社会—生态韧性视角下城乡治理的逻辑框架。将社会—生态韧性的核心理念(耦合、自组织和学习)引入城乡规划、个体参与和政策制定,将促进城乡融合和可持续发展。在未来的城乡治理中,需要将社会与生态问题统筹考虑,贯彻人地耦合的理念,形成多层级的城乡协同治理网络,促进适应性治理,培育不同尺度城乡治理主体的合作和创新,尤其要重视城乡社区的学习、适应能力构建。实践中需要充分利用空间规划工具,将生态系统服务纳入城乡空间治理范畴,协调城乡生态系统服务与居民福祉的关系,增强城乡对不确定性的缓冲和应对能力。

人地关系地域系统理论系统提出30 a来,对促进地理学综合研究、学科建设和服务国家重大战略决策发挥了重要的科学支撑与导向作用。深入解析了人地关系地域系统理论的科学内涵及时代价值,诠释了现代人地系统的类型与环境,提出了“人地圈”与人地系统科学研究的主要内容和前沿领域。初步研究表明：① 现代人地系统具有复杂性、地域性和动态性特征,人?地交互作用过程、格局及其综合效应正在发生深刻变化,地球表层人地系统成为现代地学综合研究的核心内容和重要主题。② 科学认知和有效协调人地关系,亟需深入探究人地系统耦合格局与机理,探明人地关系地域系统类型、结构及其动力机制。依据城乡关系将人地关系地域类型划分为城市地域系统、城乡融合系统、乡村地域系统。乡村地域系统可细分为农业系统、村庄系统、乡域系统、城镇系统等子系统,分别对应于作土关系、人居关系、居业关系、产城关系。③ 现代人类活动强烈地作用于地球表层人地系统,形成了人地系统耦合与交互作用的地表圈层——“人地圈”,其实质是现代人类活动与地表环境相互联系、耦合渗透而形成的自然–经济–技术综合体或人地协同体。④ 人地系统科学或人地科学是研究人地系统耦合机理、演变过程及其复杂交互效应的新型交叉学科。它是现代地理科学与地球系统科学的深度交叉和聚焦,以现代人地圈系统为对象,致力于探究人类活动改造和影响地表环境系统的状态,以及人地系统交互作用与耦合规律、人地协同体形成机理与演化过程。人地系统耦合与可持续发展是人地系统科学的研究核心。传承创新人地关系地域系统理论和发展人地系统科学,更能凸显地球表层人类的主体性、人地协同的过程性和可持续发展的战略性,为人地系统协调与可持续发展决策提供科学指导。

In the past 30 years, the theory of human-earth areal system has played an important support and guidance role in promoting the comprehensive research, disciplinary development and serving national strategic decision of geography. This study analyzes the scientific connotation and era value of human-earth areal system, explores the types and environment of modern human-earth system, and puts forward 'human-earth sphere' and the main contents and frontier fields of human-earth system science. The results show that: 1) The modern human-earth system is characterized by complexity, regionalism and dynamicity. The processes, pattern and comprehensive effect of human-earth interaction are undergoing profound changes, and the human-earth system on the surface of the earth has become the critical content and important theme of modern geosciences. 2) To scientifically understand and effectively coordinate the human-earth relationship, it is urgent to explore the coupling pattern and mechanism of human-earth relationship and to analyze the type, structure and dynamic mechanism of human-earth areal system. Based on the urban-rural relationship, the human-earth areal system can be divided into urban regional system, urban-rural integration system and rural regional system. Furthermore, the rural regional system is subdivided into agricultural system, village system, rural system and township system. 3) Modern human activities strongly affect the human-earth system on the surface of the earth, forming a new surface with the coupling and interaction between human and earth. In essence, it is a natural-economic-technological synthesis or human-earth coordination. They are also the main contents of deepening the researches on the coupling of human-earth system and supporting decision-making for coordinated development of human-earth system. 4) Human-earth system science or human-earth science is a new interdisciplinary subject which studies the coupling mechanism, evolution process and complex interaction effect of man earth system. It is the deep intersection and focus of modern geographic science and earth system science. Taking the modern human-earth sphere system as the research object, it is committed to exploring the state of human activities transforming and affecting the surface environment system, the interaction and coupling law of human-earth system, the formation mechanism and evolution process of human-earth coordination.Human-earth system coupling and sustainable development is the core of human-earth system science. Inheriting and innovating the theory of human-earth areal system and developing the human-earth system science will highlight the subjectivity of human on the earth surface, the process of human-earth coordination and the strategy of sustainable development, thus providing scientific guidance for the coordination of human-earth system and sustainable development decision-making.