This report reviews recent thinking and debates about physical limits to human activities, and particularly the concept of ‘planetary boundaries’. It looks at the scientific basis of the planetary boundaries concept and its claims for novelty, and the most recent update of the original proposition and analysis. I suggest that geographers can invigorate and inform the science of planetary boundaries by further developing conceptualizations of human-environment relations; by constructing a political ecology of planetary boundaries; by exploring alternative development pathways; and by dissecting the planetary and its relations across scales. These present crucial challenges, necessitating joined-up, dynamic and novel approaches.

Tipping points in complex systems may imply risks of unwanted collapse, but also opportunities for positive change. Our capacity to navigate such risks and opportunities can be boosted by combining emerging insights from two unconnected fields of research. One line of work is revealing fundamental architectural features that may cause ecological networks, financial markets, and other complex systems to have tipping points. Another field of research is uncovering generic empirical indicators of the proximity to such critical thresholds. Although sudden shifts in complex systems will inevitably continue to surprise us, work at the crossroads of these emerging fields offers new approaches for anticipating critical transitions.

This paper outlines scholarship on resistance within geography. Its contention is that conceptualisations of resistance are characterised by a predetermination of form that particular actions or actors must assume to constitute resistance. Asking what we risk ignoring if we only focus on predetermined, recognisable resistant forms, the paper revisits some of the fundamental assumptions (of intention, linearity and opposition) that underpin accounts of resistance. It calls for geographers to engage with resistance in emergence. The paper concludes by detailing what this might look like in practice, including intersections with work on potentiality, incoherent subjects, agentic materiality and speculative futures.

Water resource is an essential element for all lives on this planet, and it is faced with severe scarcity and pollution issues in many parts of the world. Regional water stress assessment becomes a critical part for water resources assessment and management. To better manage and govern water resources under water scarcity conditions, this study reviewed the main approaches for regional water resources stress assessment. The definition and connotation of water resources stress were analyzed, and the common used approaches for water stress assessment were divided into four categories including single indicator, supply-demand ratio, comprehensive assessment and water footprint assessment. Based on the previous studies, the basic theories, data requirements, calculation processes and applications of these approaches were analyzed. It is found that the supply-demand ratio method is the most objective and precise approach for water resources stress analysis. Besides, modified water footprint assessment is also a proper approach since it is simple in calculation and it considers ecological water requirements. Furthermore, this paper also discussed the promising focuses of future researches, including the integrated research of surface water and ground water and the consideration of the seasonal features of water resources.

区域水资源压力分析是区域水资源评价的重要环节和内容。明确水资源压力的概念、梳理水资源压力评价方法,是水资源压力研究及可持续水资源管理的重要前提。论文基于国内外水资源压力理论研究与实践进展,分析了水资源压力的内涵,介绍了水资源压力评价的常用方法,从计算原理、过程以及应用等方面对水资源压力评价方法进行了概述和对比分析。同时,基于国内外相关研究和应用需求,展望了未来水资源压力研究的方向和重点问题,提出应当增加对地表水与地下水耦合、水质与水量耦合以及季节性因素的衡量等。

Uncontrolled and unsustainable urban development has a significant impact on the overall quality of the environment. Contemporary spatial management does not take into account the non-economic conditions of ecosystem functions and their biophysical limits, which results in a deterioration of the environment. Furthermore, urban development continues all over the world, which is associated with a projected population increase, particularly in cities. Therefore, there is need to include analyses in the field of environmental carrying capacity (ECC) for more sustainable spatial management and development. The ECC concept is a tool for sustainable development of human settlements. It could be defined as threshold level of anthropopressure, which the environment is able to balance and withstand without serious degradation and irreversible changes. The use of ECC assessment will help ensure the needs of the city’s residents, which are conditioned by the environment. The paper aims to discuss this issue.

Understanding the genesis and evolution of the concept of carrying capacity scientifically is of great scientific value and realistic significance to carry out theoretical investigation and practical research of resources and environmental carrying capacity (RECC). With the perspective of natural resources and environment, in this paper, starting from the terminology of ecological carrying capacity established based on the maximum biomass of individual species, the terminology of resources carrying capacity (RCC) developed based on the relationship of human population and natural resources, to the terminology of environmental carrying capacity formed based on the relationship of human population and environment, and then to the integrated term of RECC oriented to regional sustainable development, the genesis and evolution process of RECC were comprehensively summarized in a longitudinal fashion. This preliminary review paper was typically relied on the currently available historical English literatures (e.g. published papers, books and reports) as well as some literatures in Chinese. This review paper showed that the term of Carrying Capacity originated in the fields of engineering and mechanism which belong to the study of Physics in 1840s. It then achieved continuous but controversial development in Ecology, Geography, Resource Science and Environmental Science. To our knowledge, the concept of RECC can be mirrored in the studies of energy carrying capacity and carrying capacity of animal husbandry in the earlier 1900s. It was not until the late 1940s that the examination of land carrying capacity symbolized the born of RCC. In the late 1990s, a comprehensive concept of carrying capacity or RECC was reported occasionally without gaining too much public attention. However, strictly speaking, the related analysis of RECC in China was just started in the early 2000s. Overall, the RECC related studies in China are currently at their developing stage featured by concept discussion and qualitative analysis, although the concept of RECC has gained much attention from national decision-making departments. In contrast, similar studies of RECC are seldom reported abroad. Entering the 21st century, labelled as an important indicator for describing the restriction degree of development, the practical importance of the RECC related studies is gaining and/or will gain more and more attention from the scientific community of natural resources and environment as well as the central government. For example, there were several projects supported by the National Key Research and Development Program of China during 2016-2018. However, the concept of carrying capacity has seemingly become a ready-made panacea which is widely generalized in many research aspects or has a conceptualization tendency. In terms of these issues, it is necessary to clarify and rectify the genesis and evolution of RECC thoroughly and strengthen continuous studies of RECC from the perspectives of scientific connotation and theoretical basis, technical approaches and model parameters, as well as the standardization for practical utilization.

科学认识承载力概念的源起与发展对于资源环境承载力理论探讨与实践研究具有重要的科学价值和现实意义。论文立足资源环境视角,从基于种群个体最大生物量的生态承载力,到基于人口与资源关系的资源承载力和基于人口与环境关系的环境承载力,再到面向区域可持续发展的资源环境承载力,较为系统地阐释了资源环境承载力的概念源起与发展历程。通过追踪公开发表或可获取的英文文献,同时兼顾中文资料,综述表明：承载力概念最早诞生于1840年代的工程机械领域,之后,在生态学、地理学、资源科学与环境科学领域得到了持续但有争议的发展;资源环境承载力概念最早可见于20世纪初期的能量承载力和畜牧承载力研究,1940年代末期以土地承载力研究为标志的资源承载力研究诞生;直到20世纪末期,具有综合特征的资源环境承载力概念才在中国悄然兴起,严格意义上的资源环境承载力研究则始于21世纪初。目前,我国资源环境承载力研究总体处于发展阶段,以概念探讨和定性研究为主,尽管在政策层面已得到国家有关部门的高度重视。相对而言,国外相关研究却较少使用这一概念,相应研究报道并不多见。2010年以来,作为描述发展限制的一个重要判据,资源环境承载力研究的现实意义在中国越来越受到重视,国家重大研发计划已有多项部署。但承载力概念似乎也成为了“灵丹妙药”,存在研究泛化或概念泛化现象。鉴于此,有必要科学认识资源环境承载力概念的源起与发展,加强资源环境承载力的科学内涵与理论基础、技术方法与模型参数以及模式化、规范化与标准化等方面的研究工作,以求正本清源、学以致用。

It is an innovative work of comprehensive deepening reforms of China to establish the mechanism of monitoring and early-warning of carrying capacity. Based on the scientific connotation of the carrying capacity of national resources and environment and oriented to regional sustainable development, this article explores the “pressure-state-response” process of the interaction between the carrying body: the natural foundation (which consists of resources, environment, ecology and disasters) with the carrying object: the human production and life activities, and presents the academic thought that the early-warning of the national resources and environment carrying capacity is an overload early-warning according to the cap of the constraints of resources and environment or the population and economic rational scales or other key thresholds, and also presents a process early-warning in terms of the changes of the natural basic conditions or the tendencies of the impact of resource utilization and environmental changes. According to the exploration on the principles of early-warning carrying capacity, this article constructs the differential indicator system and the overall technical process of early-warning of marine and terrestrial resources and environment carrying capacity. Land resources stress index, water resources use intensity index, environmental stress strength index and vegetation coverage change range index are chosen as basic indicators to conduct an overall regional evaluation, and different specific indicators, such as the pollution level of dust-haze, the increase and decrease of arable land, equilibrium index of grass and livestock and the variation of eco-environmental quality, are chosen to conduct the specific evaluation respectively for the urbanized areas, major grain producing areas, pastoral and semi-pastoral areas and ecological function areas, and then the key thresholds of these indicators are determined to conduct classifying evaluation. Finally, this article integrates all the evaluations and puts forward an evaluation method which shows the differentials in terms of major function oriented zone and evaluation results of consistent expression, and then carries out the process evaluation using two indexes of resource utilization efficiency and environment pollution pressure to reflect auxiliary the early-warning state of China's resources and environment carrying capacity and sustainable development abilities, thus providing a scientific basis for the proposed recommendations for restrictive measures and the improvement of monitoring and early-warning mechanisms.

建立资源环境承载能力监测预警机制,是全面深化改革的一项创新性工作。从资源环境承载能力的科学内涵出发,以区域可持续发展为指向,探究资源、环境等构成的承载体——自然基础同承载对象——人类生产生活活动之间形成的“压力-状态-响应”过程,提出资源环境承载能力预警是从资源环境约束上限或人口经济合理规模等关键阈值开展的超载预警,以及从自然基础条件变化或资源利用和环境影响变化态势开展的过程预警的学术思路。在探讨承载能力预警指标体系选取原则的基础上,构建陆域和海域差异化的预警指标体系和总体技术流程。采用土地资源压力、水资源利用强度、环境胁迫程度、植被盖度变化作为基础指标进行地域全覆盖评价;针对城市化地区、农业地区、牧业地区、生态地区,分别选择灰霾污染程度、耕地面积增减状况、草蓄平衡指数、生态环境质量变化状态作为专项指标,确定各类专项指标的关键阈值并进行分类评价;最后进行复合,形成在鲜明主体功能定位指向下的差别化评价方法、取得具有一致性表达的评价结果,并开展资源利用效率和环境污染压力两方面的过程评价,以辅助反映中国资源环境承载能力和可持续发展能力预警状态,为提出限制性措施建议和完善监测预警机制提供科学依据。

Geography is a subject to explore spatial distribution, time evolution and regional characteristics of geographical elements or geographical complexes. Geography is unique in bridging social sciences and natural sciences, and has characteristics of comprehensiveness, interdisciplinary research and regionalism. With the development of geographical science technology and research methods, geography is in the gorgeous historical process towards geographical science. Research themes of geography are focusing on the comprehensive research on the earth surface. The research paradigms of geography are shifting from geography knowledge description, coupling pattern and process, to the simulation and prediction of complex human and earth system. The development of Chinese geography needs to be rooted in the major needs of national strategy, and plays important roles in the studies of urbanization development, coupling ecological processes and services, water resources management and geopolitics. Under the country's major needs, China's geography tends to achieve the geography theory innovation, new method and technology application and developed disciplinary system with Chinese characteristics, and make more contribution to national and global sustainable development.

地理学是研究地理要素或者地理综合体空间分布规律、时间演变过程和区域特征的一门学科,是自然科学与人文科学的交叉,具有综合性、交叉性和区域性的特点。随着地理信息技术发展与研究方法变革,新时期的地理学正在向地理科学进行华丽转身,研究主题更加强调陆地表层系统的综合研究,研究范式经历着从地理学知识描述、格局与过程耦合,向复杂人地系统的模拟和预测转变。在服务国内重大需求和国际全球战略过程中,地理学正在扮演愈发重要的角色,在新型城镇化、生态环境保护、水土资源管理、地缘政治等领域拥有广阔发展前景。中国地理学正面临前所未有的机遇,需要紧紧围绕国家重大需求,创新发展综合性的理论、方法和技术,逐步形成具有鲜明中国特色、深远国际影响的地理科学体系,为中国和全球的可持续发展服务。

Global environmental change and sustainability science increasingly recognize the need to address the consequences of changes taking place in the structure and function of the biosphere. These changes raise questions such as: Who and what are vulnerable to the multiple environmental changes underway, and where? Research demonstrates that vulnerability is registered not by exposure to hazards (perturbations and stresses) alone but also resides in the sensitivity and resilience of the system experiencing such hazards. This recognition requires revisions and enlargements in the basic design of vulnerability assessments, including the capacity to treat coupled human-environment systems and those linkages within and without the systems that affect their vulnerability. A vulnerability framework for the assessment of coupled human-environment systems is presented.

Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.

In combination with the author's review of frontier issues in human geography in recent years, this paper clarifies that uncovering the spatiotemporal difference rules of human-environment system interaction in the geographic pattern is the highest-level scientific puzzle in modern geography, and is the understanding of key issues which could decide the prospect of future geography. Four practical methods including "process induction, regional comparison, qualitative analysis, logical judgment" until now for integrated human-environment system researches are proposed. Aiming at four frontier fields including regional equilibrium, resources and environment carrying capacity, territorial function, and spatial structure, academic ideas including the driving forces of regional development pattern changes, the impact carrier of natural sphere on human activity sphere, the rules and methods for integrated geographic zoning, and the changing laws of "living-production-ecology" spatial structure, are discussed. Finally, this paper discusses the significance and key issues of regional sustainable development in the framework of "Future Earth", and presents that the integrated method system and basic theoretical system of comprehensive research in complexity science based on "integration of both natural and social sciences" and "interpenetration of both basic researches and decision-making application", will profoundly influence research progress of the process and framework of human-environment system.

本文结合笔者近年来在人文地理学前沿问题探讨的综述,阐释了人—地系统相互作用时空分异规律是现代地理学最高层级的科学难题、也是决定未来地理学前途的关键问题的认识,提出了截至目前开展人地系统综合研究所采用的“过程归纳、区域比较、定性分析、逻辑判断”等4个实用方法,并围绕着区域均衡、资源环境承载能力、地域功能、空间结构等4个前沿领域,讨论了影响区域发展格局变化的驱动力、自然圈对人类活动圈层的作用、综合地理区划原理和方法、以及“生活—生产—生态”空间结构变化规律等研究的学术思想,探讨了“未来地球”框架下区域可持续发展研究的意义和重要命题,认为“自然科学和社会科学交叉”、“基础研究和决策应用贯通”的复杂性科学基础理论体系和综合研究集成方法体系建设,将深刻影响着人地系统过程和格局的研究进展。

As the scientific basis for constructing the basic strategic structures of territorial land space and implementing functional zoning, the "Double Evaluation" (i.e. resources and environmental carrying capacity and territorial development suitability evaluation) provides a series of important parameters for the downscaling of the major function zoning, the optimization of the spatial structure, and the intensity control of the land development. Based on territorial function theory, this paper explores the theoretical connotation of "Double Evaluation" from the evolution of human-land relationship, establishes the scientific logic of "Double Evaluation" to territorial function optimization, and points out that the major function regionalization scheme from "Double Evaluation" comprehensive integration that realizes the comprehensive benefit maximization is the optimal result of territorial function optimization. Taking Fujian province and Liupanshui city as two cases, we transform the rational demand of human production and living activities into the demand control parameters of land use. Combined with the superior planning and the government and expert system, we determine the critical target parameters, including the total control parameters, structural control parameters, spatial structure or strategic pattern control parameters, through the parameter decomposition and measurement of downscaling. By adjusting the indicators, parameters and thresholds, the gird cell territorial function optimization is continuously carried out, and the grid cell territorial function optimization regionalization schemes under different scenarios is obtained. Then continuous evaluation, check and optimization are carried out by the comparison with the planning of major function zones, land use status, neighboring areas, the construction needs of regional development and spatial strategy, as well as the relationship between land and sea. Given the influence of the uncertainty of available data, the adaptability of the data set to the theoretical model, the uncertainty of a usable analytical model and the scale effect, the uncertainty of the major function regionalization scheme and its solution are discussed to enhance the robustness of the optimization results as the scientific basis for territorial planning such as the "Three Zones and Three Lines" (Three Zones represent ecological space, agricultural space, and urban space; Three Lines represent ecological conservation redline, permanent capital farmland, and urban development boundary).

“双评价”（资源环境承载能力和国土空间开发适宜性评价）作为构建国土空间的基本战略格局、实施功能分区的科学基础,为主体功能区降尺度传导、国土空间结构优化、国土开发强度管制等提供了一系列重要参数。以地域功能理论为基础,从人地关系演化出发,探索“双评价”的理论内涵,建立“双评价”到地域功能优化分区的科学逻辑,指出“双评价”集成实现综合效益最大化时所形成的主体功能分区方案为地域功能优化分区的最优方案。以福建省、六盘水市为案例,将人类生产生活的合理需求转化为用地需求参数,通过降尺度的参数分解与测算,结合上位规划及政府与专家系统研判,确定总量控制、结构化控制、空间结构或战略格局控制等目标参数,并在“双评价”基础上,通过不断调整指标、参数及阈值,逐步进行格网单元地域功能优化。着重考虑相邻区域功能冲突与协调、差异化的主体功能定位、土地利用现状及规划、区域发展战略格局以及海陆统筹等区域特征,不断校核与优化。从数据的可获取性、数据集满足理论模型及评估方法的适应程度、可使用的分析方法及模型的不确定性以及尺度效应等方面,探讨功能分区方案不确定性及其解决途径,增强优化结果的鲁棒性,以此作为“三区三线”划定等国土空间规划的科学基础。

The imbalance between human activities and Earth's natural surface adversely affects the sustainability of the Earth system. From an understanding of the suitability of surface functions and potential ramifications of policy decisions, this study proposes a sustainable geographical pattern. It introduces a national‐to‐provincial downscaling approach to optimizing a national‐scale zoning scheme that covers 60%–80% of land development and protection functions in China and to creating a major function zoning model. Taking China as the case study area, the following function zones are identified: urbanization zones, food security zones, ecological security zones, and heritage protection zones. This study then proposes a three‐dimensional index system and algorithm, develops individual and integrated assessments for the major functions of the land grid, and produces national‐scale and provincial‐scale major function zoning schemes consisting of county‐level administrative cells, the first schemes to create a blueprint for a sustainable national land pattern in China through optimized convergence. In total, 5% of China's land area is covered by urbanized zones, 28% by food security zones, 55% by ecological security zones, and 12% by heritage protection zones. In the future, there will be 805 urbanization administrative units, 790 food security counties, 780 ecological security counties, and 8,151 heritage protection zones. The scheme created using the model developed in this study is 95% consistent with the final scheme implemented by China's central government, and it has a high degree of robustness and precision. It can serve as a reference for scientific research and decision‐making concerning sustainable development in developing countries.

本文探讨了资源环境承载能力预警机制的设计基点,阐释了资源环境承载能力、承载能力评价和预警的基本概念,创建了资源环境承载能力预警的理论模型,并制定了2016版全国资源环境承载能力预警的技术流程、评价体系、集成方法与类型划分等技术要点,为全国资源环境承载能力预警全面试行提供技术参考。研究表明：增长极限论是资源环境承载能力预警的理论基础;以县级行政区为评价单元的资源环境承载能力预警,分别开展陆域评价和海域评价,二者均包括基础评价和专项评价两部分,基础评价采用统一指标体系对所有县级行政区进行全覆盖评价,专项评价根据主体功能区规划选取特征指标对优化开发、重点开发和限制开发区域进行评价;采取“短板效应”原理确定资源环境超载、临界超载和不超载3种类型,结合资源环境耗损过程评价划分红色(极重警)、橙色(重警)、黄色(中警)、蓝色(轻警)和绿色(无警) 5个预警等级,通过陆海统筹校验确定资源环境承载能力“三类五级”评价方案。

The concept of carrying capacity is related to homeostatic regulation as part of the “new ecology” paradigm. Formulas designed to measure the man‐land balance of tropical horticulturalists reveal two problem areas. Theoretically, the relationship between homeostasis, change, and evolution remains indefinite. Methodologically, there are substantial difficulties in defining cultural and environmental components of the formula and in obtaining diachronic data to test the concept.

Learning actors' leverage for change along the journey to sustainability requires quantifying the component forces of environmental impact and integrating them. Population, income, consumers' behavior, and producers' efficiency jointly force impact. Here, we renovate the "IPAT Identity" to identify actors with the forces. Forcing impact I are P for population, A for income as gross domestic product (GDP) per capita, C for intensity of use as a good per GDP, and T for efficiency ratios as impact per good. In the "ImPACT Identity," parents modify P, workers modify A, consumers modify C, and producers modify T. Because annual percentage changes in component forces add to a change in national impact, actors' leverage is reflected transparently in consistent units of annual percentage changes that can be compared from force to force. Examples from energy and food, farming and manufacturing, and steel and water show that declining C, called dematerialization, can temper the sustainability challenge of growth (P x A), and that innovation or efficient technology that lowers T can counter rising consumption (P x A x C). Income elasticity can accommodate connections between income and other forces. From rates of change of forces, the identity can forecast impacts. Alternatively, by identifying the necessary change in forces to cause a projected impact, ImPACT can assay the likelihood and practicability of environmental targets and timetables. An annual 2-3% progress in consumption and technology over many decades and sectors provides a benchmark for sustainability.

Ecological footprints and appropriated carrying capacity: what urban economics leaves out uses the concepts of human carrying capacity and natural capital to develop a framework to evaluate each city's \"ecological footprint\". It also argues that prevailing economic assumptions regarding urbanization and the sustainability of cities must be revised in light of global ecological change.

The study of societal transformation in response to environmental change has become established, yet little consensus exists regarding the conceptual basis of transformation. This paper aims to provide structure to the dialog on transformation, and to reflect on the challenges of social research in this area. Concepts of transformation are identified through a literature review, and examined using four analytical criteria. It is found that the term 'transformation' is frequently used merely as a metaphor. When transformation is not used as a metaphor, eight concepts are most frequently employed. They differ with respect to (i) system conceptualization, (ii) notions of social consciousness (deliberate/emergent), and (iii) outcome (prescriptive/descriptive). Problem-based research tends to adopt concepts of deliberate transformation with prescriptive outcome, while concepts of emergent transformation with no prescriptive outcome tend to inform descriptive-analytical research. Dialog around the complementarities of different concepts and their empirical testing are priorities for future research.

The planetary boundary (PB) concept, introduced in 2009, aimed to define the environmental limits within which humanity can safely operate. This approach has proved influential in global sustainability policy development. Steffenet al.provide an updated and extended analysis of the PB framework. Of the original nine proposed boundaries, they identify three (including climate change) that might push the Earth system into a new state if crossed and that also have a pervasive influence on the remaining boundaries. They also develop the PB framework so that it can be applied usefully in a regional context.

A major problem worldwide is the potential loss of fisheries, forests, and water resources. Understanding of the processes that lead to improvements in or deterioration of natural resources is limited, because scientific disciplines use different concepts and languages to describe and explain complex social-ecological systems (SESs). Without a common framework to organize findings, isolated knowledge does not cumulate. Until recently, accepted theory has assumed that resource users will never self-organize to maintain their resources and that governments must impose solutions. Research in multiple disciplines, however, has found that some government policies accelerate resource destruction, whereas some resource users have invested their time and energy to achieve sustainability. A general framework is used to identify 10 subsystem variables that affect the likelihood of self-organization in efforts to achieve a sustainable SES.

Optimizing economic welfare in environmental governance has been criticized for delivering short-term gains at the expense of long-term environmental degradation. Different from economic optimization, the concepts of sustainability and the more recent safe operating space have been used to derive policies in environmental governance. However, a formal comparison between these three policy paradigms is still missing, leaving policy makers uncertain which paradigm to apply. Here, we develop a better understanding of their interrelationships, using a stylized model of human-environment tipping elements. We find that no paradigm guarantees fulfilling requirements imposed by another paradigm and derive simple heuristics for the conditions under which these trade-offs occur. We show that the absence of such a master paradigm is of special relevance for governing real-world tipping systems such as climate, fisheries, and farming, which may reside in a parameter regime where economic optimization is neither sustainable nor safe.

\n Background: The Planetary Boundaries concept (PBc) has emerged as a key global sustainability concept in international sustainable development arenas. Initially presented as an agenda for global sustainability research, it now shows potential for sustainability governance. We use the fact that it is widely cited in scientific literature (>3500 citations) and an extensively studied concept to analyse how it has been used and developed since its first publication. Design: From the literature that cites the PBc, we select those articles that have the terms ‘planetary boundaries’ or ‘safe operating space’ in either title, abstract or keywords. We assume that this literature substantively engages with and develops the PBc. Results: We find that 6% of the citing literature engages with the concept. Within this fraction of the literature we distinguish commentaries—that discuss the context and challenges to implementing the PBc, articles that develop the core biogeophysical concept and articles that apply the concept by translating to sub-global scales and by adding a human component to it. Applied literature adds to the concept by explicitly including society through perspectives of impacts, needs, aspirations and behaviours. Discussion: Literature applying the concept does not yet include the more complex, diverse, cultural and behavioural facet of humanity that is implied in commentary literature. We suggest there is need for a positive framing of sustainability goals—as a Safe Operating Space rather than boundaries. Key scientific challenges include distinguishing generalised from context-specific knowledge, clarifying which processes are generalizable and which are scalable, and explicitly applying complex systems’ knowledge in the application and development of the PBc. We envisage that opportunities to address these challenges will arise when more human social dimensions are integrated, as we learn to feed the global sustainability vision with a plurality of bottom-up realisations of sustainability.

INTRODUCTION-- Tlie abovo subjoct is ohosen on the ground that it is a se1f'concerned prob1em in the sense of both its building up and its so1ution, as wellas in the sharing of its effeot, good or bad.

作者声明选择这个题目的原因有四:(一)为这个问题与我们个个都有直接利害的关系。(二)关於这个问题的酿成我们各位都负有不能逃脱的责任。(三)这个问题的解决我们每人皆有应尽而且能尽的义务。(四)关於这个问题的严重最低限度国人有明了的必须。以下所论系根据近来关於中国人口问题各方面的研究,作一比较综合的解释并分下列四点来研究其相互的影响,供读者一识。

Introduction Economic reconstruction is generally admitted to be one of the major and urgentproblems China has to deal with at the present time.

Major Function Oriented Zoning (MFOZ) is the blueprint for the future developmnt and protection pattern of China's territory, and has been raised to from major function zones planning to major function zoning strategy and major function zoning institution. From 2004 to 2014, the author organized a series of research projects to compose MFOZ for the country, studied basic theory of regional function and MFOZ technical process, and proposed that space controlling zones of national and provincial scales can be divided into four types: urbanized zones, foodstuff-security zones, ecological safety zones, cultural and natural heritage zones. On this basis, major function zones of county scale should be transferred to optimized, prioritized, restricted, and prohibited zones. In this paper, a regional function identification index system comprising nine quantitative indicators (including water resources, land resources, ecological importance, ecological fragility, environment capacity, disaster risk, economic development level, population concentration and transport superiority) and one qualitative indicator of strategic choice is developed. Based on the single index evaluation, comprehensive evaluation using regional function suitability evaluation index is conducted, aiming at testing several key parameters including lower limit of protection zones and upper limit of development zones at the provincial level. In addition, a planning-oriented zoning method of major function zones is also discussed, which has brought the first MFOZ planning in China. According to the MFOZ caliber, it is forecasted that national spatial development intensity will rise from 3.48% in 2010 to 3.91% in 2020. Furthermore, according to caliber of the provincial integrated MFOZ planning, the area of optimized, prioritized and restricted zones accounts for 1.48%, 13.60% and 84.92%, respectively, and that of urbanized, foodstuff-security and ecological safety zones accounts for 15.08%, 26.11% and 58.81%, respectively. In combination of analyses of development level, resources and environmental carrying status and quality of the people's livelihood, the main characteristics of MFOZ were identified. Through verification, MFOZ draft of national and provincial scales, which is interactively accomplished with "MFOZ Technical Process" put forward by the author, is mostly above 80% identical with what have been forecasted.

中国主体功能区划方案是刻画未来中国国土空间开发与保护格局的规划蓝图,主体功能区规划已上升为主体功能区战略和主体功能区制度。2004-2014年,笔者组织系列研究项目,配合国家编制主体功能区规划,研究地域功能基础理论和功能区划技术流程,提出国家和省区尺度进行空间管制的地域功能区域类型为城市化区域、粮食安全区域、生态安全区域、文化和自然遗产区域等4类,在此基础上转化为以县级行政区划为单元的优化开发、重点开发、限制开发和禁止开发4类主体功能区。研制了由水资源、土地资源,生态重要性、生态脆弱性、环境容量、灾害危险性、经济发展水平、人口集聚度和交通优势度等9类可定量指标及战略选择为1项定性指标构成的地域功能识别指标体系,进行了单项指标评价,开发并运用地域功能适宜程度综合评价指数进行了综合评价,测算了各省区保护类区域下限、开发类区域上限以及开发强度等关键参数;研讨了以规划为应用指向的主体功能区划分方法,形成中国首部主体功能区划方案,按照全国主体功能区规划口径,2020年与2010年相比,全国国土空间开发强度从3.48%增加到3.91%;按照省区集成的主体功能区规划口径,优化、重点、限制开发区域的土地面积比重分别为1.48%、13.60%、84.92%,城市化、粮食安全、生态安全区域的土地面积比重分别为15.08%、26.11%、58.81%。结合区域发展水平、资源环境承载状态、民生质量等相关分析,给出了主体功能区的主要特征。通过区划方案校验,国家和省区分两级采用笔者主持制定的《主体功能区划技术规程》互动完成的全国主体功能区划方案,同预判的吻合程度多为80%以上。

Ecological regime shifts are large, abrupt, long-lasting changes in ecosystems that often have considerable impacts on human economies and societies. Avoiding unintentional regime shifts is widely regarded as desirable, but prediction of ecological regime shifts is notoriously difficult. Recent research indicates that changes in ecological time series (e.g., increased variability and autocorrelation) could potentially serve as early warning indicators of impending shifts. A critical question, however, is whether such indicators provide sufficient warning to adapt management to avert regime shifts. We examine this question using a fisheries model, with regime shifts driven by angling (amenable to rapid reduction) or shoreline development (only gradual restoration is possible). The model represents key features of a broad class of ecological regime shifts. We find that if drivers can only be manipulated gradually management action is needed substantially before a regime shift to avert it; if drivers can be rapidly altered aversive action may be delayed until a shift is underway. Large increases in the indicators only occur once a regime shift is initiated, often too late for management to avert a shift. To improve usefulness in averting regime shifts, we suggest that research focus on defining critical indicator levels rather than detecting change in the indicators. Ideally, critical indicator levels should be related to switches in ecosystem attractors; we present a new spectral density ratio indicator to this end. Averting ecological regime shifts is also dependent on developing policy processes that enable society to respond more rapidly to information about impending regime shifts.

Catastrophic ecological regime shifts may be announced in advance by statistical early warning signals such as slowing return rates from perturbation and rising variance. The theoretical background for these indicators is rich, but real-world tests are rare, especially for whole ecosystems. We tested the hypothesis that these statistics would be early warning signals for an experimentally induced regime shift in an aquatic food web. We gradually added top predators to a lake over 3 years to destabilize its food web. An adjacent lake was monitored simultaneously as a reference ecosystem. Warning signals of a regime shift were evident in the manipulated lake during reorganization of the food web more than a year before the food web transition was complete, corroborating theory for leading indicators of ecological regime shifts.

Very precise data on the dynamics of a competitive system of two species of Drosophila have been obtained. By a curvilinear regression approach, analytical models of competition have been fitted. By statistical and biological criteria of simplicity, reality, generality, and accuracy, the best of these models has been chosen. This model represents an extension of the Lotka-Volterra model of competition; it adds a fourth parameter that controls the degree of nonlinearity in intraspecific growth regulation. It represents a similar extension of the logistic model of population growth.

Enhancing the resilience of ecosystem services (ES) that underpin human well-being is critical for meeting current and future societal needs, and requires specific governance and management policies. Using the literature, we identify seven generic policy-relevant principles for enhancing the resilience of desired ES in the face of disturbance and ongoing change in social-ecological systems (SES). These principles are (P1) maintain diversity and redundancy, (P2) manage connectivity, (P3) manage slow variables and feedbacks, (P4) foster an understanding of SES as complex adaptive systems (CAS), (P5) encourage learning and experimentation, (P6) broaden participation, and (P7) promote polycentric governance systems. We briefly define each principle, review how and when it enhances the resilience of ES, and conclude with major research gaps. In practice, the principles often co-occur and are highly interdependent. Key future needs are to better understand these interdependencies and to operationalize and apply the principles in different policy and management contexts.