Leimavo Revisited: Agrarian Land-Use Change in the Highlands of Madagascar

Describing and explaining land-use change is of critical concern in Madagascar, where land transformations such as deforestation and resulting environmental degradation currently capture widespread attention. While the eastern rain forest recedes in the face of swidden cultivators, the highlands demonstrate more constructive transformations. In this paper I present a case study of land-use change in Leimavo, a small village near Ambositra studied in the 1960s by Jean-Pierre Raison. Here, the twentieth century has seen a gradual reduction in irrigated rice cultivation and cattle husbandry, and a boom in market-oriented orange, vegetable, and grain production. In the long term, a historical landscape of grassy hills has been transformed into a productive cultural landscape with woodlots, anti-erosion benching, rice terraces, fruit groves, and diverse crops. Critical factors determining the trajectory of land-use change include regional population pressure, state policies, market incentives, climate variations, and access to land and water resources. These critical factors, or explanations, are linked in the discussion by the use of a simple heuristic device—the range of choice—as a theoretical framework.     

基于遥感影像数据的汉川市土地利用动态变化探讨

以1991~2002年汉川市土地利用遥感数据为基础,选取土地利用变化幅度、动态度、土地利用程度指数及景观生态学指标中的多样性、均衡度和优势度指数,对研究区的土地利用变化状况和驱动力因素进行分析。结果表明:1991年以来,汉川市土地利用结构中,水域、未利用地有所减少,建设用地增加,林地、耕地变化幅度和动态度最大;12年来汉川市土地利用处于调整和发展期,生态景观和均质程度在上升。综合分析表明,人口、经济、政策在土地利用变化中起着主导作用。     

The response of soil erosion and sediment export to land-use change in four areas of Europe: The importance of landscape pattern

The response of erosion and sediment export to past land-use change has been studied in four agricultural areas of Europe. Three of these areas were subject to land abandonment or de-intensification and one to intensification of land-use practices. Erosion and sediment yield were modeled using the WaTEM/SEDEM model, which combines the RUSLE equation with a sediment routing algorithm. Spatial relationships between the RUSLE C-factor (i.e. land-use) and other erosion and sediment export-determining factors (slope, soil erodibility and distance to rivers) were investigated, as these account for non-linearity in the response of erosion and sediment export to land-use change.Erosion and sediment export have decreased enormously in the de-intensified areas, but slightly increased in the intensively cultivated area. The spatial pattern of land-use change in relation to other erosion and sediment export-determining factors appears to have a large impact on the response of soil erosion and sediment export to land-use change. That the drivers of abandonment of arable land and erosion coincide indicates that de-intensification leads to a more favourable landscape pattern with respect to reduction of erosion and sediment export. This mechanism applies not only within the study areas, but also among the European study areas where the process of intensification of some areas and de-intensification of others might result in an overall decrease of erosion and sediment yield through time.     

Globalisation,contest and paradox in a continuing cultural landscape: Land reform in the New Zealand High Country

Geografisk Tidsskrift—Danish Journal of Geography 109(2):161–179, 2009

A key feature of globalization is the way that local landscapes are progressively opened up to the influence of global markets, consumers and capital. The transformations that result are frequently politically contested, and can profoundly and quickly affect cultural landscapes that have evolved slowly over long periods. The contests over policy direction may draw upon long established ideals of occupancy and ownership, and such ‘policy myths’ may paradoxically serve to undermine the very landscapes from which they are drawn. The New Zealand South Island High Country is a distinctive continuing cultural landscape that is currently undergoing radical change as a result of land tenure reform. The unarticle demonstrates the way that cultural and political narratives and ideals are critical factors in mediating the relationship between globalization and local landscape change in this iconic landscape.     

榆林市农业景观格局变化研究

根据1986年和2000年两期TM影像资料和其他辅助资料, 运用人机交互解译方法以及地理信息系统的空间分析和数理统计功能, 分析了榆林市农业景观格局变化, 包括土地利用数量变化、变化速度和区域差异等特征, 以及各景观类型之间的转化情况, 并对景观格局变化进行了定量分析。结果表明: 14a间, 榆林市未利用地减少1305.56km², 其中主要是沙地减少; 耕地、林地、草地分别增加567.11km²、99.6km²和616.79km²; 未利用地和建设用地的变化率最大, 分别为-22.11%和18.18%; 土地利用变化存在明显的区域差异; 各类型间的转化突出表现为未利用地向草地转化, 草地向林地和耕地转化。榆林市近十几年景观类型发生了明显转换, 土地整治取得显著成绩。     

River channel response to short-term human-induced change in landscape connectivity in Andean ecosystems

The drainage basin of the Deleg River (88 km²), located in the southern Ecuadorian Andes, was studied to assess the geomorphic and hydrologic response of a fluvial system to human-induced environmental change in its contributing area. Historical data on land use, channel morphology and sedimentology were collected, based on a spatial analysis of aerial photographs (1963–1995) and a field survey (2002). Analysis of channel cross-sectional profiles and sedimentological data revealed a major change in morphology and sedimentology of the Deleg River during the past four decades: (i) the active river channel narrowed by over 45%, (ii) the riverbed incised on average by over 1.0 m and (iii) the median grain size of the bed surface decreased from 13.2 cm to 4.7 cm. The spatial pattern of land cover within the Deleg catchment also changed considerably: highly degraded agricultural land in the low-lying areas was abandoned and partially afforested for timber and wood production, whereas secondary upland forest was increasingly cleared for expansion of cropland and pastures. Notwithstanding large changes in the spatial organization of land use within the catchment, the overall land use did not change significantly during the past four decades. This suggests that the response of the Deleg River to land-use change not only depends on the overall land-use change, but also on the spatial pattern of land-use/cover change within the catchment. Although forestation and regeneration of bare gully slopes and floors throughout the catchment only represented a minor part of the total land-use change, these land-use/cover changes had a major impact on the hydrological and sediment connectivity in the landscape.     

北京市土地利用空间格局演化模拟及预测

土地利用空间格局的演化模拟可定量地从空间尺度揭示区域土地利用变化的驱动因素,是厘清未来时期内土地变化的重要途径。基于CLUE-S模型,以北京市为研究案例,结合1985、2000和2010年三期土地利用数据,运用Logistic逐步回归方法识别了北京市各种土地利用类型演化的驱动因素,对北京市土地利用空间格局进行模拟。在此基础上,基于北京市社会经济发展、土地利用规划、资源禀赋及生态保护等不同情景,对北京市2020年土地利用空间分布格局进行模拟及预测。结果表明：①不同的时期内,驱动因子对不同土地利用类型的影响呈现差异性,其中交通因素及社会经济因素对土地利用类型的转化率影响较显著,坡度对各个土地利用类型的影响较大。②通过对2010年北京市土地利用变化的模拟结果来看,Kappa指数为87.03%,说明预测结果与实际土地利用情况有较好的一致性。③预测结果显示,北京市的城市发展均表现为继续向外扩展,且以东南、东北为主要扩展方向,但扩张的程度存在差异。     

The interpretation of culture in nature: Landscape transformation and vegetation change during two centuries at Hystad,SW Norway

In Norway, on-site biological surveys precede the designation of nature reserves. Although many nature conservation areas have been affected by past human use (e.g. cattle grazing, timber harvesting), a typical biological survey may fail to portray the extent of human influence on biodiversity and vegetation dynamics. In 1984, Hystad forest (western Norway) was made a nature reserve after botanists interpreted the ecosystem 'close to untouched'. It was thought best to leave the forest alone, so no management plan was developed. It was later realized that the vegetation was changing, but the reason was not obvious. I gathered and analyzed further biological data plus information on land-use history from varied sources (e.g. cadastral maps, archive material and oral histories). The area has undergone a series of transformations since the 17th century. The present forest is no more than 100 years old, and extensive parts are much younger. The initial survey underestimated the extent of cultural impact and failed to predict vegetation change subsequent to reserve establishment, whereas a historical-geographical approach reveals that the vegetation is in a state of transition, driven primarily by a change from active farming to farm abandonment. Planning for conservation must recognize past as well as present human use of the landscape to anticipate consequent land cover responses.     

An interdisciplinary approach to depict landscape change drivers: A case study of the Ticuiz agrarian community in Michoacan, Mexico

Landscape changes are driven by a combination of physical, ecological and socio-cultural factors. Hence, a large amount of information is necessary to monitor these changes and to develop effective strategies for management and conservation. For this, novel strategies for combining social and environmental data need to be developed. The purpose of this study is to demonstrate the value of an innovative interdisciplinary approach to help in explaining landscape change. We integrated three main sources of information: biophysical landscape attributes, land-use/cover change analysis and social perceptions of land-use change, institutional and policy factors and environmental services. Multivariate statistical analysis was used to develop a weight for each variable described or quantified. Finally we identified proximate causes and underlying driving forces of land transformation in the study area. The study was undertaken in a typical community in Mexico.     

Landscape position and spatial patterns in the distribution of land use within the southern Appalachian Mountains

Understanding the forces that influence the distribution of land use and land-use change (LUC) is an essential step in developing effective strategies for managing these issues. We examined the influence of landscape position on spatial patterns in land-use distribution within the Little Tennessee River Basin (LTRB) of the southern Appalachian Mountains. We show that landscape position, defined with respect to both natural and anthropogenic spatial variables, provides for the identification of statistically significant differences in the distribution of common forms of land use in the study region. Using the same variables, significant differences in the landscape positions subject to land-use change in the LTRB are also examined. These results suggest landscape position exerts a strong influence on the distribution of different forms of land use and the likeliness of given area undergoing LUC. The approach presented here, of considering land use as a function of landscape position that responds to both natural and anthropogenic forces, may prove useful in aiding the development of future strategies to address the consequences of land use in many regions.     

Spatial analysis of long-term land-use development in regard to physiotopes: case studies from the Carpathians

Abstract

The influence of abiotic conditions on land-use development since the nineteenth century is assessed in case studies from the Czech and Slovak Carpathians. Hypotheses claim that significant land-use changes have occurred, but without pronounced differences because of similar abiotic conditions in the case studies. Abiotic conditions are expressed by physiotopes, which contain information on georelief, lithology, and soil. Our results indicate a high rate of land-use change in both case studies, and a detailed analysis of changes in two sequential periods reveals significant differences in five of the six periods compared in these case studies. Areas along state border seem to be more affected by anthropogenic changes as the proportion of plots with stable land use was only 25.7% in the Czech area (Starý Hrozenkov, Vápenice, and Vy?kovec) compared to 47.6% in the Slovak area (Lietavská Svinná-Babkov). Repeated land-use changes occurred mostly in valley floors and adjacent slopes. Land-use changes in the study areas are only partly explained by the abiotic conditions in physiotope and morphometric attributes, as shown by multiple correspondence analysis. The crucial difference in land use is in different settlement structures, which reflect differences in historical development.     

局地土地利用变化现实情景研究

局地土地利用变化表现为时序短、空间倾向性强且多为人类强制干扰, 其变化过程与结果 是区域尺度响应与反馈国家尺度、全球尺度最有效的途径。城市化、农业结构调整和土地整理是 目前我国局地土地利用变化的几种主要利用方式。城市化是一个不可逆过程, 农村景观转为城市 景观, 改变了诸如地表反照率、粗糙度等下垫面特征, 局地生境与物种的数量与种类发生改变, 逐 步形成以人类为主的均质化景观格局; 农户微观土地利用选择行为是局地农业产业结构调整的 原动力, 不同类型农户在投资、生产与经营等经济活动的差异将导致局地土壤结构、水分、养分等 土壤条件及环境改变; 土地整理是一个复杂的系统工程, 在一定程度上改变了局地土壤性状与土 壤生物, 更甚的是改变了局地斑块- 廊道- 基质模式的景观格局。因此, 为进一步加深局地土地利 用变化情景的理解, 厘定“人- 地协调系统”的理论框架, 进行局地土地利用变化的情景模拟和生 态环境效应研究将是未来局地土地利用变化的研究方向。     

伊洛河流域森林景观变化驱动因素

1 Introduction Landscapes are the outcome of the interaction between socio-economic and natural forces (Wrbka et al., 2004). During the evolution of cultural landscapes throughout the world, human activities have become dominant factors shaping most lands…     

Modeling the effects of land-use optimization on the soil organic carbon sequestration potential

Increasing soil organic carbon (SOC) sequestration is not only an efficient method to address climate change problems but also a useful way to improve land productivity. It has been reported by many studies that land-use changes can significantly influence the sequestration of SOC. However, the SOC sequestration potential (SOCP, the difference between the saturation and the existing content of SOC) caused by land-use change, and the effects of land-use optimization on the SOCP are still not well understood. In this research, we modeled the effects of land-use optimization on SOCP in Beijing. We simulated three land-use optimization scenarios (uncontrolled scenario, scale control scenario, and spatial restriction scenario) and assessed their effects on SOCP. The total SOCP (0–20 cm) in Beijing in 2010 was estimated as 23.82 Tg C or 18.27 t C/ha. In the uncontrolled scenario, the built-up land area of Beijing would increase by 951 km² from 2010 to 2030, and the SOCP would decrease by 1.73 Tg C. In the scale control scenario, the built-up land area would decrease by 25 km² and the SOCP would increase by 0.07 Tg C from 2010 to 2030. Compared to the uncontrolled scenario, the SOCP in 2030 of Beijing would increase by 0.77 Tg C or 0.64 t C/ha in the spatial restriction scenario. This research provides evidence to guide planning authorities in conducting land-use optimization strategies and estimating their effects on the carbon sequestration function of land-use systems.     

北京丰台区土地利用变化及其经济驱动力分析

采用GIS技术和统计分析技术,基于1984、1992和1995～2001年土地利用图件和数据,分析了1984年以来北京丰台区土地利用变化历史过程及其空间分异特征。土地利用变化的基本特点是农业用地面积大幅度下降,非农用地面积快速增加,且随着时间的推移,变化高峰地域在由内向外传递。对1999年土地利用类型数据与经济产值数据匹配结果表明:土地经济产出效益巨大差异的存在是驱动丰台区土地利用从农业用地,尤其是耕地向非农业用地转化的最大动力所在。利用1992～2001年的非农业用地与固定资产投资、人口,二、三产业增加值进行的相关分析显示,固定资产投资、人口增长和第二产业的发展对非农业用地扩展有着显著的作用。     

全球变化背景下景观生态适应性特征

全球变化包含气候变化、经济发展、土地利用变化等自然、人为及共同作用下引发的转变,是当前景观结构与功能保障面临的主要挑战。景观生态适应性是指景观这一地表镶嵌体吸纳上述影响并维持主要功能的特性,涉及不同景观类型、组成单元及层级在不同时空尺度中的不同程度转变。本文从景观生态学视角切入,以景观系统作为缓解与适应全球变化冲击的主体,整合农业景观、城市景观等相关研究案例,凝练当前景观系统适应全球变化过程的特征为：①由部分因子的绝对主导转向复合因子共同作用;②景观类型内部趋同,景观多样性及独特性降低;③同类景观间功能等级分明、分工明确,跨区域时空联系增强;④不同景观类型间空间边界清晰,过渡带景观功能退化。就当前全球变化议题,建议后续研究应加强：不同景观类型或组成单元的适应能力对比及其不确定性分析;基于景观系统整体健康的适应途径尺度联系解析;多学科、多部门研究在全球变化情景下的有效整合;景观系统适应性或适应能力量化分析方法的深化。     

Political Ecology and Cultural Change: Impacts on Swidden-fallow Agroforestry Practices among the Mopan Maya in Southern Belize

Little agroecological research examines indigenous agroforestry practices that appear to be unsustainable, and how such practices devolved from more environmentally sound land use strategies that have been documented by geographers and others. This paper discusses the political ecological factors that led the Mopan Maya to reject a diverse swidden-fallow management strategy for a system where an abandoned milpa provides few forest products. In doing so, this paper explains the process whereby cultural change, in this case rejection of certain agricultural traditions, leads to a less diverse agricultural landscape and ultimately a less diverse biological landscape.     

江汉平原土地利用的时空变化及其驱动因素分析

采用遥感、GIS一体化技术,利用1989～1990、1995～1996和1999～2000年获取的三期陆地资源卫星图像,对江汉平原土地利用10年变化和以1995～1996年为界的前后两个5年变化的时空特征进行了分析,并探讨了变化的驱动因素。结果表明,该区的土地利用在不同的时间及空间尺度上有明显不同的特点。10年间,耕地减少近5万hm²,其中,前5年的减少量占多数,达6783%。各类建设用地总计增加了156万hm²,其中,前5年的增加量是后5年的2倍。水域面积在10年间增加了达到354万hm²,后5年的增幅不到前期的1/2。土地利用变化最快的区域均处于工业经济较发达、城市化较快的地区如武汉、仙桃,变化最慢的区域在监利、松滋、天门等地。政策、社会经济与科技因素对土地利用随时间尺度的变化有决定性的影响。     

Soil CO2 flux trends with differences in soil moisture among four types of land use in an Ecuadorian páramo landscape

Abstract

Páramo grasslands are important carbon sinks in the Ecuadorian Andes. Although carbon content of páramo Andisols is correlated with high water retention, the effects of differences in soil moisture under different types of land use on soil carbon processes have not been explicitly tested in the Ecuadorian Andes. This study assessed the relationship between soil moisture and soil CO₂ flux among a mature páramo grassland, recently burned páramo grassland, native montane forest, and pine plantation in an Ecuadorian páramo landscape. Soil CO₂ flux was greater in the forest sites compared to the grassland sites. Thus, a shift from grassland to forest cover may have significant implications for soil carbon loss via CO₂ flux. Our results suggest that although soil moisture plays a significant role in differences of soil CO₂ flux rates among land-use types, more investigation into mechanisms for soil carbon loss and how they are driven by land-use change is needed. To our knowledge, these are the first soil CO₂ flux rates reported for the Ecuadorian páramo.     

近30年玉门市土地利用与景观格局变化及其驱动力

干旱内陆河流域生态环境非常脆弱,是土地利用和景观格局变化的敏感区域,也是全球环境变化响应比较突出的区域。采用1976年、1989年、2000年和2010年的Landsat遥感影像,利用GIS技术和景观格局分析方法,系统地分析了疏勒河中游玉门市的土地利用和景观格局变化的时空特征,为研究区土地可持续利用政策的制定提供参考和依据。研究结果显示:近34a来,玉门市土地利用和景观格局发生了剧烈变化,土地利用变化经历了"缓慢变化—急剧变化—显著变化"的过程。研究区景观密度增大,多样性和均匀度先减小,后增加;不同斑块间的分离度减小。农业人口增长和经济发展是玉门市土地利用景观格局变化的最直接驱动力,同时还受气候因素和政策因素的影响。