梯田景观的历史分布及典型国际案例分析

梯田是在大面积多山地形和较高人口密度条件下产生的山区土地高效利用方式,广泛分布于世界各地,并且在不同的地理气候条件下产生了不同的类型,具有重要的生态价值和文化价值.梯田作为陡坡耕作区古老的土壤保持措施,有利于农业集约化,一般而言,梯田建设的目的是为了保持水土,减少产流产沙,改善立地环境,便于农业生产.在当前社会经济发展的背景下,大面积的梯田遭到荒废,不仅浪费了土地资源,还易导致严重的土壤侵蚀、坡面坍塌和土地退化.本文综述全球不同地理区域和自然环境条件下梯田的起源、发展以及分布特征,主要选择亚洲、欧洲、美洲和非洲四大重点区域进行系统介绍,并针对每一大洲内的典型国家做了案例剖析.在此基础上,深入探讨梯田建设、利用和荒废过程与气候变化、国家政策、人口变迁等因素的关系,最后针对目前梯田区存在的水资源紧张和梯田荒废退化两个严重问题,提出了尚需开展的研究工作,以期为梯田的可持续利用与管理提供参考依据.     

Ecological succession,patch age and the evolution of social behaviour and terminal investment

Recent years have witnessed a growing interest in understanding the evolution of social behaviour in heterogeneous spatially structured populations. These studies, however, have neglected the impact of extinction–colonisation dynamics and ecological succession on the dynamical expression of social behaviour over time. Here, I present a kin‐selection model in which patches are structured into age‐classes. I show that ecological succession and patch age lead to highly plastic social phenotypes that vary dramatically as societies age since their initial establishment until their ultimate collapse. I find that the mode of colonisation following dispersal strongly influences the patch age‐dependent trajectories of social phenotypes. When patches are colonised by a random collection of immigrants, aggression is favoured during the build‐up of a society, but it slowly subsides until it eventually gives place to cooperation throughout the later stages of a society's lifespan. When newly established societies are formed by collectives of close relatives, cooperation is favoured during the build‐up of the society as well as when the society nears its eventual collapse. At intermediate societal ages, the genetic structure of the society is sufficiently resilient to the influx of immigrants such that cooperation remains relatively high. Moreover, I report a novel form of social terminal investment, whereby cooperative effort rises when patches approach their collapse. When dispersal is allowed to co‐evolve with cooperation, we observe a sudden rise in dispersal phenotypes before a patch's collapse, and the surprising result that clonal colonisation does not yield significantly higher levels of cooperation than the individual mode of colonisation. More generally, my results show that ecological succession strongly determines the dynamics of kin selection after colonisation, and therefore I expect that these findings will be valuable for understanding behavioural syndromes during range expansion or biological invasions.     

闽三角城市群生态环境脆弱性及其驱动力

生态安全是地区社会经济可持续发展的基本前提之一,而生态环境脆弱性会威胁地区的生态安全,进行生态环境脆弱性评价具有重要意义。以闽三角城市群为例,分别选取2000年和2015年的高程、坡度、岩性、土壤类型、NDVI、年均降水量、年均温、人口密度、人均GDP、路网密度、景观多样性、土地利用程度和工业固体废弃物排放量等13个指标,基于空间主成分分析法,并结合全局Moran'I和LISA聚类图,从整体特征、空间差异、空间集聚、地类脆弱性分异以及驱动力5个方面,探讨闽三角城市群的生态环境脆弱性及其驱动力。结果表明:2000—2015年间,闽三角城市群的生态环境脆弱性整体处于中度脆弱,但呈现出由中度脆弱向重度脆弱过渡的趋势;2000—2015年间,生态环境脆弱性呈现出由东南沿海向西北内陆逐渐增强的整体趋势,并存在明显的地带性特征,东南沿海增长不明显,部分地区有所下降,而西北内陆增长明显;生态环境脆弱性存在显著的空间自相关性,且为显著正相关,在西北部山区地带为显著的高高聚集,在东南沿海平原地带为显著的低低聚集,16年间集聚性特征在空间上有所迁移和扩张;2000—2015年间,生态环境脆弱性在各地类存在着一定的异质性,其生态环境脆弱性指数大小顺序始终为:林地未利用地草地耕地水域建设用地,整体由中度脆弱向重度脆弱过渡;2000—2015年间,生态环境脆弱性的驱动力有所变化,但人口密度、景观多样性、岩性和土壤类型一直是闽三角城市群生态环境脆弱性主要的驱动力。     

Land use changes and associated environmental impacts on the Mediterranean shallow Lake Stymfalia, Greece

Land cover and land use changes affect ecological landscape functions and processes. Land use changes mainly caused by human activities, is a common reason for wetlands degradation worldwide. Lake Stymfalia, located at Peloponnese, southern Greece, is an ancient wetland with a great ecological value. Lake Stymfalia has been severely degraded and transformed during the past 60 years due to agricultural activities in the surrounding areas and watercourses alterations. In this context, we investigated the land cover/ use changes and the role of the reed beds in the terrestrialization process of this shallow wetland. This particular effort utilized remotely sensed data and Geographical Information Systems (GIS) techniques to estimate land use alterations for the period 1945–1996. Patch related landscape indices were generated to analyze impacts on landscape features. Spatial and thematic information concerning the surface area and the major land cover types of the lake for years 1945, 1960, 1972, 1987, 1992, and 1996 was obtained from aerial photographs and land surveys of the area, and was stored in the GIS database. The 1996 map was ground verified, corrected and updated to 2004 conditions. From the spatio-temporal analysis of the stored data, a permanent decrease of the open water surface has been observed between the years 1945 and 1996. The results indicated that the reed beds expanded dramatically, increasing by 89.3%, and is the predominant aquatic vegetation of the whole wetland. Open water areas and wet meadows decreased by 53.7 and 96.5% respectively. Landscape analyses and, in particular, the use of selected landscape metrics, proved useful for detecting and quantitatively characterising dynamic ecological processes. As land cover/use analysis of the wetland has shown much serious environmental degradation, conservation measures should be undertaken urgently.     

Environment,livelihood and household: The ethno‐history of Rana Tharus Badaghar households

This paper focuses on the changes occurring in households in the indigenous Rana Tharus community. I discuss the household not in terms of physical structure but instead on the social aspects: how people relate to each other through the lens of the household context. I argue that the fluid nature of households makes its flexible to different ecological environments and socio‐economic scenarios. My ethnography of Rana households clearly illustrated that the formation, structure and management of Rana households was fundamentally linked to people's livelihoods. Before 1950s, abundant land resources allowed Ranas to live in joint‐type households. This particular household arrangement not only fulfilled labour needs but also secured the mutual security for every household member. Gradually, undivided and big households (known in Rana as Badaghar) became the ideal model for Ranas as soon as such establishments did not become divided or separated. This household structure also served as an important safety net for most Ranas and fundamental to other social relationships especially Mukhiya (household head system) and Kurmaa (patrilineal kin). However, since the 1950s, new socio‐economic landscapes have significantly challenged the maintenance of traditional Rana households. Within the lifetime of most Ranas, they first experienced household fission and the disappearance of the Mukhiya system. The dynamic relationships between Rana household and new ecological, social and economic landscapes are explored here. It is concluded that the household is a critical institution allowing anthropologists to better understand the long‐term social impacts caused by state policies and ecological changes. This is because people often practice their new household relations in their everyday life as a response to environmental and livelihood changes.     

弘扬生态文明深化学科建设

阐述了"生态"的"耦合关系、整合功能与和谐状态"三大内涵;提出了以气候变化、经济振荡和社会冲突为标志的全球生态安全问题,以资源耗竭、环境污染和生态胁迫为特征的区域生态服务问题,以及以贫穷落后、超常消费和野蛮开发为诱因的人群生态健康和社会生态福祉下降等世界三大生态焦点议题;探讨了生态文明的认知、体制、物态和心态内涵及其研究、发展和管理战略.提出了深化与创新基础生态学和应用生态学研究、献身生态学教育与科普工作、参与生态学决策与管理的对策和倡议.     

城市综合生态风险评价——以淮北市城区为例

城市面临复杂的生态风险,为了保障城市安全,需要对单一灾害或污染源的生态风险评估结果进行整合。基于城市复合生态系统特性,将当前城市地域常见的生态风险区分为自然灾害、环境污染及生态退化等3种主要类型,以土地利用单元作为风险受体,整合自然、人文、景观及环境因子,在现有生态风险评价研究方法基础上,构建了城市综合生态风险评价的空间分析框架。研究中选择淮北市城区作为研究区,针对研究区内存在的洪涝、干旱、水污染、大气污染、采煤塌陷及生态服务降低等生态风险类型,定量评价其空间差异,并提出相应的风险防范措施。案例分析结果表明,研究区综合生态风险较高的区域包括龙河、岱河、龙岱河与闸河等过境河流流经塌陷密集带的河段,北湖、东湖、中湖及南湖等人工湖泊沿岸,化家湖湖岸,及土型、新蔡、北杨新杨煤矿及其外围地区。由降低生态风险保障城市生态安全角度,在未来城市的整体规划中,建议结合城市外围绿地与城市内部的高风险区域,划设禁建或限建区域,共同构建淮北城市生态风险防范的空间结构。     

Let the earth forever remain! Landscape legacies and the materiality of history in the northern Basin of Mexico

This article examines the landscape as an enduring protagonist in the northern Basin of Mexico over the past 1,000 years in communities north of Mexico City. Viewing materiality as the mutual constitution between social and physical worlds, I discuss the production and inheritance of landscape legacies. The manner in which legacies are inherited is tied to changing political, economic, and social conditions. This project integrates multiple sources of information (archaeological, ethnographic, historical, and ecological) to understand transforming connections between people and the landscape in this region, from the ancient state of Xaltocan to the Aztec and Spanish empires, continuing into the struggle for a modern nation. It reveals relationships that are apparent only via a perspective in dialogue with the landscape's materiality over time. In so doing, this article asserts archaeologists' unique contribution to the study of not only long‐term change but also historical processes inherited by and relevant to the contemporary world.     

Efficacy of Integrating Herder Knowledge and Ecological Methods for Monitoring Rangeland Degradation in Northern Kenya

The world-wide debate on land degradation in arid lands, usually linked to local land use practices, does not reflect methodological advancements in terms of assessments and monitoring that integrate local communities’ knowledge with ecological methods. In this paper, we evaluated the efficacy of three different methods related to herder assessments and monitoring of land degradation; herder knowledge and ecological methods of assessing impacts of livestock grazing along gradients of land use from settlement and joint monitoring of selected marked transects to understand long-term vegetation changes in southwestern Marsabit northern Kenya. The performance of each method was carefully evaluated and interpreted in terms of the indicators used by herders and ecologists. Herder interpretations were then related to ecologists’ empirical analysis of land degradation. The Rendille nomads have a complex understanding of land degradation which combines environmental and livestock productivity indicators, compared to conventional scientific approaches that use plant-based indicators alone. According to the herders, the grazing preference of various livestock species (e.g., grazers versus browsers) influences perceptions of land degradation, suggesting degradation is a relative term. The herders distinguished short-term changes in vegetation cover from long-term changes associated with over-exploitation. They attributed current environmental degradation around pastoral camps, which shift land use between the alternating wet and dry seasons, to year-round grazing. We deduced from long-term observation that herders interpret vegetation changes in terms of rainfall variability, utilitarian values and intensification of land use. Long-term empirical data (23 years) from repeated sampling corroborated herder interpretations. Land degradation was mostly expressed in terms of declines in woody plant species, while spatial and temporal dynamics of herbaceous species reflected the effects of seasonality. The efficacy of the three methods were inferred using explanatory strengths of ecological theory; insightfulness of the methods for describing land degradation and the likelihood of using the methods for promoting local community participation in the implementation of the UN Convention on Combating Desertification (CCD) and the Convention on Biological Diversity (CBD).     

基于生态系统服务价值与粮食安全的生态安全底线核算

河北省沿海经济的快速发展导致滨海土地利用结构快速转变,威胁土地生态安全.针对性核算滨海土地生态系统服务价值并测算生态安全底线可为区域生态保护和修复提供依据.本文以河北省东南部黄骅市为研究区,科学地选择生态安全与粮食安全的结合点、设计结合通道并创建结合方式,利用生态系统服务价值和粮食安全标准进行生态安全底线测算.结果表明： 2011年,研究区各地类单位面积生态系统服务价值大小依次为： 湿地＞水域＞园地＞耕地＞草地＞其他土地＞盐田＞盐碱地＞建设用地;各单项生态系统服务价值贡献率从大到小依次为： 养分循环＞水源涵养＞娱乐文化＞物质生产＞生物多样性维持＞气体调节＞气候调节＞净化环境;单位面积耕地粮食产量底线为0.21 kg·m^-2,粮食产值底线为0.41 元·m^-2,单位面积土地生态系统服务价值底线为21.58 元·m^-2,研究区土地生态服务总价值底线值为42.44亿元;2081年研究区生态安全达到底线,以人为主体的生态系统将濒临崩溃.根据生态安全状况,黄骅市可分为生态核心保护区、生态缓冲区、生态恢复区和人类活动核心区.     

Assessing the efficiency and effectiveness of rangeland restoration in Namaqualand,South Africa

South Africa’s Succulent Karoo is home to unmatched numbers of dryland plant species. Unfortunately, decades of overstocking these rangelands with small livestock and historical ploughing for fodder have led to extensive degradation. Some areas are severely degraded, negatively affecting both agricultural livestock productivity and ecosystem health. Land degradation reduces land use options and leaves land users, and the ecosystems on which they depend, more vulnerable to environmental and economic stressors. Ecological restoration is promoted as an effective and cost-efficient option for building the resilience of local and regional ecosystems. However, dryland restoration confronts many environmental challenges that have limited its success to date. Here, we present the results of a local-scale participatory restoration trial and an assessment of the costs of regional-scale ecological restoration in the Nama Khoi area in Namaqualand, South Africa. In combination, these analyses are useful for identifying opportunities and barriers for the improved efficiency and effectiveness of dryland restoration. In Namaqualand, we find that ecological restoration is difficult and expensive. The expected impacts of climate change will only exacerbate these challenges. However, we argue that a holistic suite of land management actions that include sound management, the prevention of further degradation, and prudent investments in restoration even where costs are high is likely to be the only real option for sustaining land-based livelihoods in this region over the longer term.     

旅游生态安全约束下张家界市土地利用优化

土地利用多以经济、社会和生态效益最大化为目标进行数量结构优化,很少对旅游生态安全约束下的土地利用进行空间结构优化,鉴于此,为提高旅游城市土地利用综合效益和改善生态环境,在旅游生态安全约束下,不仅对土地利用数量结构进行优化,而且实现了土地利用空间结构优化。以典型旅游城市张家界为例,构建旅游生态安全评价指标体系,运用灰色线性规划法中的Lingo模型求取旅游生态安全约束下的最优土地利用结构,并根据分布规则把优化后的数量结构配置在空间上,借助CLUE-S模型进行土地利用空间优化。结果表明:(1)2015年旅游生态安全综合指数为0.7394,旅游环境状况和旅游人文社会响应的安全度均比旅游资源环境压力低。(2)在数量结构优化下,林地、水域、建设用地面积增幅明显,耕地、草地和未利用地的面积有所减少,2025年旅游生态安全综合指数为0.8196,比2015年提高了0.0802,处于安全的状态。(3)在空间结构优化下,林地主要分布在桑植县和慈利县的山地丘陵区、武陵源区以及永定区南部;建设用地主要集中在慈利县、桑植县及永定区城区;草地主要位于桑植县和慈利县的山区以及武陵源区;耕地主要分布在慈利县和永定区的平原和丘陵地区;未利用地零星分布在慈利县、桑植县及永定区。研究结果可为张家界市土地资源永续利用和旅游生态安全建设提供规划指导和技术借鉴。     

基于遥感的煤炭型矿业城市土地利用与生态承载力时空变化分析

运用遥感和社会经济系统发展指数修正生态足迹模型,开展淮南市土地利用与生态承载力时空演化分析。结果表明:1987—2012年,淮南市人均生态承载力总体呈现缓慢降低后略微升高的趋势,2009年是人均生态承载力提升的拐点,表明经济科技因子的提升作用;淮南市生态承载力时空差异显著,总体呈现东南和北部高、西部低的格局,而且区域破碎化加剧的趋势。矿区占用大量耕地以及积水塌陷区的形成,是生态承载力的下降和空间格局分异的主要原因;土地利用转移以耕地、建筑用地为主,水域对土地利用格局的影响日益增强,开展塌陷区整治,将塌陷区形成的水域转换成耕地或建设用地,将是提高淮南市生态承载力的最有效途径之一。     

Environmentally-Displaced Peoples and the Cascade Effect: Lessons from Tanzania

This paper investigates the links between migration and ecological change by focusing on environmentally-displaced populations. The discussion is based on a case study from the Usangu Plains, Tanzania, a receiving area for displaced herders and cultivators from elsewhere in Tanzania. I focus on two of these groups—the Nyakyusa and the Sukuma—in analyzing the ecological causes and consequences of rural–rural migration. The spread of cash crop production, leading to degradation and resource scarcity, was a key factor underlying displacement from both locations. I emphasize social and cultural variables influencing resource use and management in assessing the ecological impact of migration on the Usangu Plains. Migration is not always ecologically destructive; this paper indicates some of the conditions under which it can have this outcome. In this case study, environmental displacement caused environmental problems to be transferred elsewhere, to be translated into new forms, and to increase in complexity, a phenomenon I call the cascade effect.     

Future eating and country keeping: what role has environmental history in the management of biodiversity?

In order to understand and moderate the effects of the accelerating rate of global environmental change land managers and ecologists must not only think beyond their local environment but also put their problems into a historical context. It is intuitively obvious that historians should be natural allies of ecologists and land managers as they struggle to maintain biodiversity and landscape health. Indeed, ‘environmental history’ is an emerging field where the previously disparate intellectual traditions of ecology and history intersect to create a new and fundamentally interdisciplinary field of inquiry. Environmental history is rapidly becoming an important field displacing many older environmentally focused academic disciplines as well as capturing the public imagination. By drawing on Australian experience I explore the role of ‘environmental history’ in managing biodiversity. First I consider some of the similarities and differences of the ecological and historical approaches to the history of the environment. Then I review two central questions in Australian environment history: landscape‐scale changes in woody vegetation cover since European settlement and the extinction of the marsupials in both historical and pre‐historical time. These case studies demonstrate that environmental historians can reach conflicting interpretations despite using essentially the same data. The popular success of some environmental histories hinges on the fact that they narrate a compelling story concerning human relationships and human value judgements about landscape change. Ecologists must learn to harness the power of environmental history narratives to bolster land management practices designed to conserve biological heritage. They can do this by using various currently popular environmental histories as a point of departure for future research, for instance by testing the veracity of competing interpretations of landscape‐scale change in woody vegetation cover. They also need to learn how to write parables that communicate their research findings to land managers and the general public. However, no matter how sociologically or psychologically satisfying a particular environmental historical narrative might be, it must be willing to be superseded with new stories that incorporate the latest research discoveries and that reflects changing social values of nature. It is contrary to a rational and publicly acceptable approach to land management to read a particular story as revealing the absolute truth.     

Natural regeneration in the context of large‐scale forest and landscape restoration in the tropics

Large‐scale and long‐term restoration efforts are urgently needed to reverse historical global trends of deforestation and forest degradation in the tropics. Restoration of forests within landscapes offers multiple social, economic, and environmental benefits that enhance lives of local people, mitigate effects of climate change, increase food security, and safeguard soil and water resources. Despite rapidly growing knowledge regarding the extent and feasibility of natural regeneration and the environmental and economic benefits of naturally regenerating forests in the tropics, tree planting remains the major focus of restoration programs. Natural regeneration is often ignored as a viable land‐use option. Here, we assemble a set of 16 original papers that provide an overview of the ecological, economic, and social dimensions of forest and landscape restoration (FLR), a relatively new approach to forest restoration that aims to regain ecological integrity and enhance human well‐being in deforested or degraded forest landscapes. The papers describe how spontaneous (passive) and assisted natural regeneration can contribute to achieving multiple social and ecological benefits. Forest and landscape restoration is centered on the people who live and work in the landscape and whose livelihoods will benefit and diversify through restoration activities inside and outside of farms. Given the scale of degraded forestland and the need to mitigate climate change and meet human development needs in the tropics, harnessing the potential of natural regeneration will play an essential role in achieving the ambitious goals that motivate global restoration initiatives.     

Representations of Nature on the Mongolian Steppe: An Investigation of Scientific Knowledge Construction

Extensive land degradation across the Mongolian steppe has prompted a variety of multinational and multidisciplinary research projects over recent years. The situation provides an important opportunity to investigate and illuminate some of the international, national, and local dimensions of scientific practice that critically condition the production of environmental knowledge. In this article I juxtapose the competing knowledge bases and assumptions of various relevant groups (including natural vs. social scientists, nationalist Chinese vs. ethnic Mongolians, and urban intellectuals vs. indigenous herders) to develop the argument that multiple ideological and institutional boundaries work together to circumscribe scientific inquiry and data collection. The situated construction of knowledge undermines prospects for improving incremental objectivity and impedes more comprehensive understanding of serious environmental problems. [Chinese grasslands, land degradation, indigenous knowledge, sociology of science, interdisciplinary research]     

我国大型煤炭基地建设的生态恢复技术研究综述

煤炭能源是我国的主体能源,在我国经济社会发展中具有重要的战略地位。煤炭工业是关系我国经济发展和能源供应安全的重要基础产业。由于受传统发展观的影响,煤炭工业一直存在生产粗放、安全事故频发、资源浪费严重、环境治理和管理滞后等问题。我国大型煤炭基地的建设对提高煤炭供应保障能力起到了关键支撑作用。因此,从区域可持续发展的角度出发,加强矿区的生态恢复,深化煤炭资源的开发利用和环境保护,对促进国家和区域生态环境与社会经济的可持续发展,构建和谐矿区,确保区域乃至全国的生态安全特别是能源安全具有重要的意义。介绍了国家大型煤炭基地的发展历程、分布和开发现状,以及煤炭开采利用带来的一系列生态环境问题,重点阐述了当前我国煤炭基地建设的关键生态恢复技术体系,并从生态恢复与环境管理的角度提出我国大型煤炭基地的可持续发展建议。     

A review of spatial-explicit factors determining spatial distribution of land use/land-use change

Land development is necessary for human progress, but its impact has resulted in the degradation of ecosystem services not only locally and regionally, but globally as well. Human behavior toward land use/land-use change (LULUC) must be examined and fully understood in order to achieve better land management. Several studies were recently conducted on LULUC patterns, suggesting a relationship between spatial distribution of LULUC and land attributes. We reviewed these studies and listed the factors determining spatial distribution of LULUC, and then we categorized them into: (1) socioeconomic factors, subcategorized into accessibility, local community development, spatial configuration, and political restrictions; and (2) natural environmental factors, subcategorized into topography and productivity. Here, we discuss the effects of these factors, especially road construction as a socioeconomic, accessibility factor, and slope as a natural environmental, topography factor. We also discuss the future work required to provide the tools for better land management.     

1988-2013年重庆市主城九区生态用地空间结构及其生态系统服务价值变化

在当前快速城市化的背景下,理解和把握城市生态系统服务功能退化原因及规律的最有效手段是对其生态用地结构及其生态系统服务价值进行准确的评估。采用RS、GIS技术以及生态系统服务价值评估等方法,对重庆市主城九区1988、1996、2004、2013年4个时段遥感影像进行解译及比较分析,结果表明：1988-2013年间,重庆市主城九区城市化水平经历了加速阶段、减速阶段及饱和阶段,城市化水平的提高对城市建设用地增长的影响显著;重庆市主城九区生态用地主要为城市提供了食物生产、提供原材料、废物处理、土壤形成与保护、气候调节、气体调节、生物多样性以及水源涵养等生态系统服务,在结构变化上呈现出“二减三增”的结构变化特点;25年间重庆市主城九区共减少生态系统服务价值260.60×10⁶元,整体处于下降趋势,其中农地的生态系统服务价值损失最大,共减少24.50%;在空间分布上,随着城市建设用地向“南-北-西”方向扩展,生态系统服务价值以中梁山与铜锣山之间的区域减少最为严重,整个研究区生态系统服务价值下降的主要原因来自于农地的大量减少以及城市建设用地扩张所带来的生态负影响。研究结果表明在重庆市主城九区生态用地空间格局与生态系统服务变化之间存在密切相关性,在城市化率达到饱和阶段后应严格控制建设用地增长,促进建设用地集约节约利用,加大农地的保护力度以及对林地、水体、草地的维护,维持整个区域的生态平衡。研究可为科学合理布局和保护城市生态用地提供信息资料和决策参考。