Projecting Large-Scale Area Changes in Land Use and Land Cover for Terrestrial Carbon Analyses

One of the largest changes in US forest type areas over the last half-century has involved pine types in the South. The area of planted pine has increased more than 10-fold since 1950, mostly on private lands. Private landowners have responded to market incentives and government programs, including subsidized afforestation on marginal agricultural land. Timber harvest is a crucial disturbance affecting planted pine area, as other forest types are converted to planted pine after harvest. Conversely, however, many harvested pine plantations revert to other forest types, mainly due to passive regeneration behavior on nonindustrial private timberlands. We model land use and land cover changes as a basis for projecting future changes in planted pine area, to aid policy analysts concerned with mitigation activities for global climate change. Projections are prepared in two stages. Projected land use changes include deforestation due to pressures to develop rural land as the human population expands, which is a larger area than that converted from other rural lands (e.g., agriculture) to forestry. In the second stage, transitions among forest types are projected on land allocated to forestry. We consider reforestation, influences of timber harvest, and natural succession and disturbance processes. Baseline projections indicate a net increase of about 5.6 million ha in planted pine area in the South over the next 50 years, with a notable increase in sequestered carbon. Additional opportunities to expand pine plantation area warrant study of landowner behavior to aid in designing more effective incentives for inducing land use and land cover changes to help mitigate climate change and attain other goals.     

土地使用权出让与土地利用总体规划

本文在论述土地使用权出让和土地利用总体规划内涵的基础上,研究了两者作用和反作用的关系,提出了两者最终目标一致性的观点,并探讨了实践上相关的问题。     

基于因素分析的城市土地集约利用比较研究

构建了一套城市土地集约利用评价的指标体系，利用多元统计分析中的因素分析法，对我国特大城市土地集约利用进行了综合评价，并对我国城市土地集约利用水平进行了比较分析。     

Effects of Land Use Change on Soil Carbon Storage and Water Consumption in an Oasis-Desert Ecotone

Land use and ecosystem services need to be assessed simultaneously to better understand the relevant factors in sustainable land management. This paper analyzed land use changes in the middle reach of the arid Heihe River Basin in northwest China over the last two decades and their impacts on water resources and soil organic carbon (SOC) storage. The results indicated that from 1986 to 2007: (1) cropland and human settlements expanded by 45.0 and 17.6 %, respectively, at the expense of 70.1, 35.7, and 4.1 % shrinkage on woodland, grassland, and semi-shrubby desert; (2) irrigation water use was dominant and increased (with fluctuations) at an average rate of 8.2 %, while basic human water consumption increased monotonically over a longer period from 1981 to 2011 at a rate of 58 %; and (3) cropland expansion or continuous cultivation led to a significant reduction of SOC, while the land use transition from grassland to semi-shrubby desert and the progressive succession of natural ecosystems such as semi-shrubby desert and grassland, in contrast, can bring about significant carbon sequestration benefits. The increased water consumption and decreased SOC pool associated with some observed land use changes may induce and aggravate potential ecological risks for both local and downstream ecosystems, including water resource shortages, soil quality declines, and degeneration of natural vegetation. Therefore, it is necessary to balance socioeconomic wellbeing and ecosystem services in land use planning and management for the sustainability of socio-ecological systems across spatiotemporal scales, especially in resource-poor arid environments.     

Implications of Land Use Changes on Carbon Dynamics and Sequestration—Evaluation from Forestry Datasets, India

Forests and soils are a major sink of carbon, and land use changes can affect the magnitude of above ground and below ground carbon stores and the net flux of carbon between the land and the atmosphere. Studies on methods for examining the future consequences of changes in patterns of land use change and carbon flux gains importance, as they provide different options for CO₂ mitigation strategies. In this study, a simulation approach combining Markov chain processes and carbon pools for forests and soils has been implemented to study the carbon flows over a period of time. Markov chains have been computed by converting the land use change and forestry data of India from 1997 to 1999 into a matrix of conditional probabilities reflecting the changes from one class at time t to another class time t+1. Results from Markov modeling suggested Indian forests as a potential sink for 0.94 Gt carbon, with an increase in dense forest area of about 75.93 Mha and decrease of about 3.4 Mha and 5.0 Mha in open and scrub forests, if similar land use changes that occurred during 1997–1999 would continue. The limiting probabilities suggested 34.27 percent as dense forest, 6.90 as open forest, 0.4 percent mangrove forest, 0.1 percent scrub and 58 percent as non-forest area. Although Indian forests are found to be a potential carbon sink, analysis of results from transition probabilities for different years till 2050 suggests that, the forests will continue to be a source of about 20.59 MtC to the atmosphere. The implications of these results in the context of increasing anthropogenic pressure on open and scrub forests and their contribution to carbon source from land use change and forestry sector are discussed. Some of the mitigation aspects to reduce greenhouse gas emissions from land use change and forestry sector in India are also reviewed in the study.     

Soil Organic Carbon Stock and Distribution in Cultivated Land Converted to Grassland in a Subtropical Region of China

Land-use change from one type to another affects soil carbon (C) stocks which is associated with fluxes of CO₂ to the atmosphere. The 10-years converted land selected from previously cultivated land in hilly areas of Sichuan, China was studied to understand the effects of land-use conversion on soil organic casrbon (SOC) sequestration under landscape position influences in a subtropical region of China. The SOC concentrations of the surface soil were greater (P < 0.001) for converted soils than those for cultivated soils but lower (P < 0.001) than those for original uncultivated soils. The SOC inventories (1.90–1.95 kg m^?2) in the 0–15 cm surface soils were similar among upper, middle, and lower slope positions on the converted land, while the SOC inventories (1.41–1.65 kg m^?2) in this soil layer tended to increase from upper to lower slope positions on the cultivated slope. On the whole, SOC inventories in this soil layer significantly increased following the conversion from cultivated land to grassland (P < 0.001). In the upper slope positions, converted soils (especially in 0–5 cm surface soil) exhibited a higher C/N ratio than cultivated soils (P = 0.012), implying that strong SOC sequestration characteristics exist in upper slope areas where severe soil erosion occurred before land conversion. It is suggested that landscape position impacts on the SOC spatial distribution become insignificant after the conversion of cultivated land to grassland, which is conducive to the immobilization of organic C. We speculate that the conversion of cultivated land to grassland would markedly increase SOC stocks in soil and would especially improve the potential for SOC sequestration in the surface soil over a moderate period of time (10 years).     

中国土地利用和土地覆被变化研究进展

受国际社会影响，中国加强了土地利用／覆盖变化研究的进程，在众多领域取得了瞩目的成就，主要包括动态监测、遥感分类和制图、LUCC驱动力和区域LUCC模型、环境效应等方面，但中国LUCC研究也存在很多突出的问题，包括跨学科、时空尺度、理论体系完善、研究方法、与全球和区域环境变化及可持续发展之间的关系等。为促进中国土地利用／覆盖变化研究的持续、健康发展，提出对中国LUCC研究的建议和展望包括建立LUCC理论体系，深入掌握LUCC动态研究的手段和方法，形成与中国国情密切结合的土地利用和覆被变化综合模型，转变研究重点，更加清晰地认识和把握LUCC有关的可持续发展问题，加强土地利用变化与生态安全机制的研究等。     

城市土地利用评价指标体系构建

在阐述指标体系构建原则的基础上，采用目标法建立了由三大主目标、八大子目标和系列评价指标构成的城市土地利用评价指标体系。其中三大主目标是指城市土地利用的高效化、集约化与协调化；八大子目标是指人地资源关系合理化、土地利用集约化、土地利用结构合理化、土地利用高效化、土地利用与人口发展协调化、土地利用与经济发展协调化、土地利用与环境发展协调化、城郊土地利用协调化。     

土地集约利用潜力测算方法初探

土地集约利用潜力测算研究是充分挖掘城市土地利用潜力的基础。概述了现有土地集约利用潜力测算方法并进行了分析,针对现有测算方法存在的不足提出了改进的正多边形法,运用改进的正多边形法能动态地反映土地集约利用程度、各指标的均衡性与协调性,以及挖潜潜力的方向。土地集约利用潜力测算研究能使土地集约利用评价的成果更好运用于实践。     

基于土地适宜性评价的区域碳排放权分配研究

资源环境与经济发展的矛盾日益突出,严格控制碳排放是增强可持续性发展的根本途径.研究参考已有文献,将碳平衡引入土地适宜性评价研究,分别从经济、生态、社会角度建立了基于碳平衡的城市圈土地适宜性评价指标体系,具体包括碳源适宜性评价和碳汇适宜性评价.运用基于蚁群算法的投影寻踪模型得到两类适宜性综合评价值.碳平衡适宜性评价结果显示,各城市适宜性差异显著,存在较大的区域内协调潜力.运用多目标规划模型在适宜性评价的基础上对城市圈的碳排放权进行优化配置.碳排放权配置研究可促进低碳经济发展,是生态文明建设的目标之一,对城市圈可持续发展具有重要的指导意义.     

城市土地利用绩效动态评价研究

在界定城市土地利用绩效内涵的基础上,构建了城市土地利用绩效评价指标体系,采用加权函数法和障碍度模型对我国城市土地利用绩效水平进行了评价.研究结果表明:①我国1995-2008年城市土地利用绩效水平总体不断提高,综合指数从0.0658增加到0.7773,绩效水平经历了“低级水平-中级水平一良好水平”的演变历程;②投入水平和利用程度指数上升幅度较小,利用效益和利用可持续性提高幅度较大;③投入水平和利用程度的障碍度分别以年均4.83％和15.37％的速度增加,利用程度是影响城市土地利用绩效水平的首要因素;④影响城市土地利用绩效水平的主要障碍因子包括地均从业人数、人均建设用地、综合容积率、建成区人口密度和建成区绿化覆盖率等.因此,应进一步转变经济发展方式,加强土地利用监督管理,改善城市生态环境,不断提高城市土地利用绩效水平.     

Assessment of Economic and Water Quality Impacts of Land Use Change Using a Simple Bioeconomic Model

The objective of this study is to assess the economic and water quality impact of land use change in a small watershed in the Wiregrass region of Alabama. The study compares changes in water quality and revenue from agricultural and timber production due to changes in land use between years 1992 and 2001. The study was completed in two stages. In the first stage, a biophysical model was used to estimate the effect of land use change on nitrogen and phosphorus runoff and sediment deposition in the main channel; in the second stage, farm enterprise budgeting tools were used to estimate the economic returns for the changes in land use condition. Both biophysical and economic results are discussed, and a case for complex optimization to develop a decision support system is presented.     

土地利用规划战略环境影响评价浅探

本文在介绍国内外规划环境影响评价发展概况的基础上，提出了土地利用规划环境影响评价的重要意义。初步探讨了土地利用规划战略环境影响评价的范畴、体系、指标体系与评价方法，并建议应深入开展土地利用规划战略环境影响评价理论研究，健全相关制度，尽快出台相关技术规程。     

The Impact of Land Use/Land Cover Changes on Land Degradation Dynamics: A Mediterranean Case Study

In the last decades, due to climate changes, soil deterioration, and Land Use/Land Cover Changes (LULCCs), land degradation risk has become one of the most important ecological issues at the global level. Land degradation involves two interlocking systems: the natural ecosystem and the socio-economic system. The complexity of land degradation processes should be addressed using a multidisciplinary approach. Therefore, the aim of this work is to assess diachronically land degradation dynamics under changing land covers. This paper analyzes LULCCs and the parallel increase in the level of land sensitivity to degradation along the coastal belt of Sardinia (Italy), a typical Mediterranean region where human pressure affects the landscape characteristics through fires, intensive agricultural practices, land abandonment, urban sprawl, and tourism concentration. Results reveal that two factors mainly affect the level of land sensitivity to degradation in the study area: (i) land abandonment and (ii) unsustainable use of rural and peri-urban areas. Taken together, these factors represent the primary cause of the LULCCs observed in coastal Sardinia. By linking the structural features of the Mediterranean landscape with its functional land degradation dynamics over time, these results contribute to orienting policies for sustainable land management in Mediterranean coastal areas.     

伊犁河谷土地利用/土地覆盖遥感调查分析研究

伊犁河谷水土资源开发使得土地利用/土地覆盖类型这一区域生态环境演变的重要因素处在变化之中,由此产生的生态环境问题还没有得到有效控制。在解析2000和2005年伊犁河谷的Landsat TM遥感影像基础上,分析、探讨土地利用/土地覆盖现状和动态变化及其特征,揭示生态环境问题。为了防止生态环境问题进一步恶化,使生态环境效益与经济效益同步协调发展,提出调整产业结构、建设草业、设计生态用水、实行环境保护工作“一把手”负责制的建议。     

The Influence of Knowledge and Motivation on Sustainable Label Use

Sustainable labels are considered the best way for consumers to identify brands with environmental or social attributes on the shelves, and therefore promoted as a means to develop the so-called “ethical markets”. However, little is known about how consumers use these brands. This paper tries to offer complementary theoretical insights on the determinants of sustainable label use by drawing on the economic model of information search; in particular, it examines the influence of two factors on the purchase of such labels: motivation and knowledge. Information was gathered through a structured questionnaire in personal interviews with 289 primary buyers. The study found that education influences directly knowledge, while Motivation influences Label use both directly and indirectly, via Label knowledge. This study concludes that Motivation is the most powerful factor to explain Label use; knowledge is a necessary but not sufficient condition. Even more, consumers may not have a good understanding of sustainable labels and still use them in their purchasing decisions. This suggests that there is a dual processing mode of sustainable labels, both systematic and heuristic.     

Land Use and Climate Variability Amplify Carbon,Nutrient, and Contaminant Pulses: A Review with Management Implications

Nonpoint source pollution from agriculture and urbanization is increasing globally at the same time climate extremes have increased in frequency and intensity. We review >200 studies of hydrologic and gaseous fluxes and show how the interaction between land use and climate variability alters magnitude and frequency of carbon, nutrient, and greenhouse gas pulses in watersheds. Agricultural and urban watersheds respond similarly to climate variability due to headwater alteration and loss of ecosystem services to buffer runoff and temperature changes. Organic carbon concentrations/exports increase and organic carbon quality changes with runoff. Nitrogen and phosphorus exports increase during floods (sometimes by an order of magnitude) and decrease during droughts. Relationships between annual runoff and nitrogen and phosphorus exports differ across land use. CH₄ and N₂O pulses in riparian zones/floodplains predominantly increase with: flooding, warming, low oxygen, nutrient enrichment, and organic carbon. CH₄, N₂O, and CO₂ pulses in streams/rivers increase due to similar factors but effects of floods are less known compared to base flow/droughts. Emerging questions include: (1) What factors influence lag times of contaminant pulses in response to extreme events? (2) What drives resistance/resilience to hydrologic and gaseous pulses? We conclude with eight recommendations for managing watershed pulses in response to interactive effects of land use and climate change.     

Optimal Land Use Management for Soil Erosion Control by Using an Interval-Parameter Fuzzy Two-Stage Stochastic Programming Approach

Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China’s Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10⁹ $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.     

衡阳市城市土地集约利用研究

随着衡阳市工业化、城市化和现代化的迅速发展,土地问题已成为制约衡阳市经济发展的关键因素.对城市土地集约利用进行了研究,不断提高城市土地利用效率,有利于城市土地资源的优化配置和合理利用.在介绍衡阳市土地概况的基础上,采用层次分析法,从影响城市土地利用的因素出发,选择土地投入水平、土地利用程度、土地经济产出、社会生态效益四个准则层建立了适合衡阳市城市土地集约利用的评价指标体系.对衡阳市2000-2006年的土地集约利用分值进行了计算,结果表明衡阳市处于基本集约利用的状态,集约利用水平呈曲线上升趋势,并在分析评价结果的基础上提出了实现衡阳市城市土地集约利用的建议.     

对于土地使用权升值问题的探讨

基于经济和社会等方面的原因,土地所有权的价格一般会不断上涨,固定年期土地使用权价格也会随之上升。但受让土地使用权价格存在类似折旧的现象。投资人能否从地价普遍上涨中获得增值收益,取决于土地所有权增值比率、土地还原利率、剩余使用年期等多种因素。