Dynamic land use and land cover changes and their effect on forest resources in a coastal village of Matemwe,Zanzibar, Tanzania

Recent land cover change estimates show overall decline of tropical forests at the regional and global scales caused by multiple social, cultural and economic factors. There is an overall concern on the prevailing land use practices, such as shifting cultivation and extraction of forest materials as agents of forests losses, but also new, emerging land uses are threatening tropical forests. Understanding of the long-term development and driving forces of forest changes are needed, especially at local levels where many decisions on forest policies and land uses are made. This paper addresses the importance of such information for improved estimates of forest dynamics by studying local level land cover and land use changes during the last 50–70 years in the Eastern African tropical island of Zanzibar, Tanzania. The paper discusses the role of traditional and new land uses mainly subsistence farming, tourism and government interference through tree planting, in the long-term development of the forests at the village level. The material for the study is gathered from the interpretation of archival maps and aerial photographs combined with contemporary digital aerial photographs. The analyses are based on the mapping, spatial sampling and spatio-temporal change trajectory analysis (LCTA) of forest land cover, forest land uses and settlement patterns with GIS and statistics. Six distinct forest land cover change trajectories were identified and these illustrate dynamic and heterogeneous nature of the forests. Closed forest cover has dominated throughout due to cyclical land use patterns, but over 70% of the land area has been continuously transforming between closed, semi-open and open land cover conditions. Land use turnover rates indicate that hardly any forest areas are left untouched from the forces, which remove and re-establish forest vegetation in the long run. Land cover and land use change trajectories are spatially fragmented in the studied landscape. Majority of forest loss-gain dynamics is caused by shifting cultivation, while forest losses are most dramatic along the coast, where traditional and new land uses meet and land uses pressures are highest. The study suggests that landscape change trajectory analyses, where contemporary and historical information on land uses and land cover changes are spatially linked, can provide valuable aspects into local level forest land use planning and management strategies. For the case study, the findings suggest the following key forest management strategies for consideration: (1) establishment of a protected forest/scrubland in participation with the local stakeholders, especially the farmers, (2) promotion of areas for permanent agricultural practices, while simultaneously introducing management controls in the traditional slash-and-burn farming areas, and (3) promoting new livelihood opportunities for the farmers, who have traditionally been dependent on forest resources, meanwhile introducing alternatives for fuel wood for cooking.     

Dynamics and changes in spatial patterns of land use in Yellow River Basin,China

Rapid land use change has taken place in many arid and semi-arid regions of China over the past decade, such as in Yellow River Basin. In this paper, changes in the land use pattern of the Yellow River Basin were analyzed using Landsat TM data in 1990, 1995 and 2000. The aim was to improve the understanding of changes in land use with a view to identifying potentially more sustainable systems of land use. Firstly, the mathematical methodology was explored and developed for spatial pattern changes of land use, which include the degree index model of land use dynamic, index model of land use degree, mean center model of land use and transformation model of land use. Based on these models, the changing spatial patterns of land use were calculated and analyzed. During the period 1990–2000, the areas of cropland, built-up land and unused land all increased, the area of cropland increased dramatically by 2917 km², while the areas of grassland and woodland decreased by 4668 and 33 km², respectively. Meanwhile, the spatial pattern of land use also experienced a great change. Then the driving factors of land use change were investigated, the governmental policies on eco-environmental protection, population growth and meteorological conditions were the major factors that caused the land use change in the past decade.     

Determinants of Residential Land-Use Conversion and Sprawl at the Rural-Urban Fringe

We estimate a probit model of residential land conversion using parcel-level data from a rural-urban county in Ohio. Spatial landscape pattern metrics are used to quantify land-use patterns and to link patterns of residential sprawl with factors estimated to influence parcel-level land conversion. Findings indicate that the location of new residential development is influenced by preferences for lower density areas that nonetheless are close to existing urban development. Combined, these forces have generated a moderated pattern of residential sprawl. Spatial error autocorrelation is controlled using a spatial sampling technique that enables consistent estimation of the probit model.     

Land use dynamics in the central highlands of Vietnam: a spatial model combining village survey data with satellite imagery interpretation

The paper investigates geo‐physical, agro‐ecological, and socio‐economic determinants of past land use change in two districts of Dak Lak province in the Central Highlands of Vietnam and assesses the influence of rural development policies on land cover change. Landsat satellite images from the years 1975, 1992 and 2000 are interpreted to detect land cover in two time periods. A survey in randomly selected villages provides primary recall data on socio‐economic and policy variables hypothesised to influence land use change. Secondary data on rainfall, soil suitability, and topography was obtained from meteorological stations and from a digital soil map and digital elevation model. All data were spatially referenced using geographic information systems (GIS) software. A reduced‐form, multinomial logit model is used to estimate the influence of hypothesised determinants on land use and the probabilities that a certain pixel has one of five land classes during either of the two periods. Results suggest that the first period from 1975 to 1992 was characterised by land‐intensive agricultural expansion and the conversion of forest into grass and agricultural land. During the second period, since 1992, the rapid, more labour‐ and capital‐intensive growth in the agricultural sector was enabled by the introduction of fertiliser, improved access to rural roads and markets, and expansion of the irrigated area. These policies, combined with the introduction of protected forest areas and policies discouraging shifting cultivation during the second period reduced the pressure on forests while at the same time increasing agricultural productivity and incomes for a growing population. Forest cover during the second period mainly increased due to the regeneration of areas formerly used for shifting cultivation.     

Coupling urban expansion models and hydrological models: How important are spatial patterns?

It is well known that urban expansion has a severe impact on the surface water balance by transforming vegetated covers into sealed surfaces. This transformation causes changing fluxes of evapotranspiration, surface runoff and groundwater recharge. In order to estimate the impact of land cover changes on the surface hydrology, hydrological models are often coupled with different types of land cover change models. It is, however, not clear to what extent spatially-explicit urban expansion scenarios provide an added value in comparison with non-spatial urban expansion models at different scale levels. The objective of this paper is to acquire a better insight in the importance of scale effects involved in the coupling of urban expansion scenarios and hydrological models. The relative importance of using different projections of both (i) quantity and (ii) spatial patterns of urban expansion was analysed at four different scale levels. The highly urbanised Flanders–Brussels region was taken as an example application. Twelve different urban expansion scenarios for 2025 and 2050 were developed and subsequently used as an input in a spatially-distributed water balance model. The results obtained suggest that at the level of the Flanders–Brussels region, an accurate estimation of the quantity of urban expansion should get priority over an accurate projection of the spatial patterns. However, the importance of using accurate projections of the spatial pattern of urban expansion increases systematically at local scale levels. A uniform strategy for coupling urban expansion models and hydrological models thus seems inappropriate. These findings are highly relevant for water management and spatial planning policymakers that typically operate at different administrative levels.     

基于不同Logistic模型的土地利用格局模拟对比研究——以湖北省宣恩县和咸丰县为例

模拟土地利用空间格局分布规律对合理利用土地资源、制定土地利用规划、协调土地与经济、环境的关系具有十分重要的意义。土地利用格局存在空间异质性,对比不同地区格局特征规律对加深土地利用格局的认识具有重要意义。以邻接的湖北省宣恩县和咸丰县为研究对象,通过对比基于局地因子、自相关因子和邻域因子的3种Logistic模型的模拟参数的一致性和异质性来对比研究两地的格局分布规律。实验与分析结果表明,宣恩县和咸丰县的土地利用格局特征存在共同的驱动因子和聚集效应,具有共性;不同模型的模拟结果表明驱动因子在作用方向,大小方面存在差异,邻域因子在邻域尺度上表现出不同特征。研究结果对加深理解不同地区的土地利用分布格局特征的差异性,促进区域土地利用的规划、土地资源的合理开发与可持续发展战略的顺利实施具有一定的参考价值。     

Quantifying and understanding land cover changes by large and small oil palm expansion regimes in the Peruvian Amazon

With rapid increases in global food demand and production, oil palm expansion constitutes a major emerging challenge for forest conservation in Amazonia and other tropical forest regions. This threat is evident in the Peruvian Amazon, where local and national incentives for oil palm cultivation along with growing large-scale investments translate into accelerated oil palm expansion. Environmental sustainability of oil palm cultivation in the Peruvian Amazon is contingent on policy incentives for expansion onto already-cleared lands instead of biodiverse, high carbon primary rainforests. Previous research indicates that while industrial plantations use less land area than local smallholders, companies have a higher tendency to expand into primary rainforests. However, the motivations behind these differing expansion scenarios remain unclear. In this study we combine data from optical and radar satellite sensors with training information, field discussions, and review of public documents to examine the policy incentives and spatial patterns associated with oil palm expansion by smallholders and industries in one of Peru’s most rapidly changing Amazonian landscapes: the Ucayali region of the city of Pucallpa. Based on our satellite-based land cover change analysis, we found that between 2010 and 2016, smallholders utilized 21,070 ha more land area for oil palm than industries but industrial expansion occurred predominantly in old growth forests (70%) in contrast to degraded lands for smallholders (56%). Our analysis of national policies related to oil palm expansion reveal policy loopholes associated with Peru’s “best land use” classification system that allow for standing forests to undergo large-scale agricultural development with little government oversight. We conclude that both sectors will need careful, real-time monitoring and government engagement to reduce old-growth forest loss and develop successful strategies for mitigating future environmental impacts of oil palm expansion.     

Does Spatial Dependence Affect the Intention to Make Land Available for Bioenergy Crops?

We find spatial dependence in landowners’ stated intentions to make land available for bioenergy crops. Our data are generated from a contingent valuation survey of 599 owners of marginal land in southern Michigan. Employing a Bayesian framework and using these spatially explicit data, we estimate and compare non‐spatial probit and spatial Durbin probit models to examine the presence of spatial dependence in land rental intentions. Results show that intentions to rent land for bioenergy crop production are spatially dependent. This spatial dependence arises both from the land supply intentions of nearby landowners and from spatial spillover effects of landowner characteristics and attitudes towards environmental amenities and the disamenities of land rental. We show that ignoring spatial dependence in the intentions of neighbouring landowners to participate in land rental markets for bioenergy feedstocks can lead to distortions that underestimate total effects. Our finding implies that studies of land use and crop supply should test for spatial interactions in order to make accurate inferences.     

The Index of Function Suitability (IFS): A new tool for assessing the capacity of landscapes to provide amenity functions

Integrating social demands into landscape management has been proven difficult because of a lack of suitable measures. In order to address this issue this article describes the development of the Index of Function Suitability (IFS). This offers an integrated conceptual tool for incorporating social demands into landscape management. The IFS links preferences to land cover spatial patterns as it uses quantitative indicators for gauging differences between the preferred landscape patterns by users, for a certain activity related to an amenity function (e.g. hunting), and the land cover patterns of a given rural area (either at the present or from scenarios developed for the future). Introducing the measurement of the difference between the preferred spatial patterns and the landscape patterns occurring in a given landscape is a fundamental conceptual development represented in the IFS. By using the same set of indicators to quantify different land cover patterns, the IFS gauges quantitatively the differences between their spatial patterns, thus providing landscape managers with an indication of the suitability of changing land covers to support the selected amenity functions. In this paper, the conceptual aspects, as well as the methodological steps of the IFS were explained and further applied to one empirical case study in the Alentejo region of Portugal. This paper also examines both the strengths and weaknesses of the IFS approach along with a discussion for improvement.     

Monitoring land use and land cover changes in the mountainous cities of Oman using GIS and CA-Markov modelling techniques

As a result of the socioeconomic transformation, the rapid urban expansion of cities and towns in the Gulf Cooperation Council (GCC) states has predominately led to tremendous pressure on the limited natural resources and loss of productive lands. Indeed, the spatial patterns of urbanisation and their impacts on mountain resources and environment have received little attention, particularly in Oman. Predicting urban growth in the mountainous cities has the potential to better understand the interaction between the spatial growth patterns and the mountain topography. This study aims to analyse spatiotemporal dynamics of land use/land cover (LULC) (2008–2018) and simulate urban expansion (2008–2038) in Nizwa city, Al Dakhliyah governorate, Oman. Cellular Automata (CA)-Markov and geospatial techniques were utilised to assess and project urban growth and land cover changes. The analysis was based on three maps of LULC at equal intervals derived from satellite imageries: Landsat TM for 1998, 2008 and 2018, along with topographic spatial layers (elevation, aspects, and terrain slopes) derived from the ASTER digital elevation model. In addition, other spatial parameters (population density, proximity to urban centres, and proximity to major roads,) were incorporated in the simulation process. The findings revealed that the actual LULC change during 2008–2018 was 12,014 ha of net urban growth (418.5 % change), while the simulated change was expected to be 14,985 ha by 2028, with a total of 37,465 ha increase in the built-up area and urban growth by 2038. Although the topographic variability will control LULC changes, the urban expansion overly will occupy the arable land across the valleys along with the flat areas. During the next two decades, the built-up areas will dominant, with a large percentage of vacant land (net loss 12,813 ha) and vegetation cover (net loss 35 ha) will be gradually converted into residential land use. The output of the simulations in this research could serve not only as spatial guidelines for monitoring future trends of LULC dynamics, but also address the threats and deteriorates of urban sustainability in the Omani mountainous cities. Furthermore, identifying bare soils and vegetation areas that are susceptible to urbanisation is of value for the national strategy of future urban planning in Oman.     

An interactive land use transition agent-based model (ILUTABM): Endogenizing human-environment interactions in the Western Missisquoi Watershed

Forest Transition Theory (FTT) suggests that reforestation may follow deforestation as a result of and interplay between changing social, economic and ecological conditions. We develop a simplistic but empirically data driven land use transition agent-based modeling platform, interactive land use transition agent-based model (ILUTABM), that is able to reproduce the observed land use patterns and link the forest transition to parcel-level heuristic-based land use decisions and ecosystem service (ES). The ILUTABM endogenously links landowners’ land use decisions with ecosystem services (ES) provided by the lands by treating both lands and landowners as interacting agents. The ILUTABM simulates both the land use changes resulting from farmers’ decision behaviors as well as the recursive effects of changing land uses on farmers’ decision behaviors. The ILUTABM is calibrated and validated at 30 m × 30 m spatial resolution using National Land Cover Data (NLCD) 1992, 2001 and 2006 across the western Missisquoi watershed, which is located in the north-eastern US with an estimated area of 283 square kilometers and 312 farmers farming on 16% of the total Missisquoi watershed area. This study hypothesizes that farmers’ land use decisions are made primarily based on their summed expected utilities and that impacts of exogenous socio-economic factors, such as natural disasters, public policies and institutional/social reforms, on farmers’ expected utilities can significantly influence the land use transitions between agricultural and forested lands. Monte Carlo experiments under six various socio-economic conditions combined with different ES valuation schemes are used to assess the sensitivities of the ILUTABM. Goodness-of-fit measures confirm that the ILUTABM is able to reproduce 62% of the observed land use transitions. However, the spatial patterns of the observed land used transitions are more clustered than the simulated counterparts. We find that, when farmers value food provisioning Ecosystem Services (ES) more than other ES (e.g., soil and water regulation), deforestation is observed. However, when farmers value less food provisioning than other ES or they value food provisioning and other ES equally, the forest transition is observed. The ILUTABM advances the Forest Transition Theory (FTT) framework by endogenizing the interactions of socio-ecological feedbacks and socio-economic factors in a generalizable model that can be calibrated with empirical data.     

Twenty-three years of forest cover change in protected areas under different governance strategies: A case study from Ethiopia’s southern highlands

Tropical deforestation has heightened the need for effective governance of protected areas aimed at conserving natural resources, biodiversity, and ecosystem services. The southern highlands of Ethiopia hold some of the largest expanses of contiguous tropical forest in Ethiopia. This area also is undergoing rapid land conversion. Multiple protected areas with different management strategies and objectives have been established, in part, to conserve forests and the ecosystem services they provide. We examined four types of protected areas; a national park, a state-run forest enterprise, two occupied privately leased hunting concessions, and two unoccupied hunting concessions, to evaluate their effectiveness at protecting forest cover. We used 1509 field plots with medium-resolution Landsat imagery from 1987 to 2015 to develop models of forest cover at approximately five-year time intervals. We found protected areas that were actively managed for timber production or hunting were more effective at conserving forest cover than the national park and the unoccupied hunting concessions. Over the study period, net forest cover change was −7.8% for the national park, 12.9% for the state-run forest enterprise, −0.2% and 13.3% for the occupied hunting concessions and −14.0% and −13.0% for the unoccupied hunting concessions. We also discuss how the change in forest cover relates to historic political events. In places like Ethiopia where the federal resources needed to conserve forests are limited, promoting a network that includes both federally and non-federally managed protected areas can result in more area and forests under protection.     

Climate change versus land-use change—What affects the mountain landscapes more?

Land use and climate change are both strong drivers of landscape transformation. Using a representative valley of the Central Alps (Stubai Valley, Tyrol, Austria) we assess (1) the historical and likely future spatial patterns of land use/land cover (LULC), (2) the influence of temperature increase on the LULC distribution, and (3) the speed at which these changes will occur. Based on the historical landscape development and spatially explicit models, the effects of various land use and climate scenarios were modelled. Employing a pan-Alpine model, we were able to detect the temporal trajectory of spatial reforestation. The results show that land-use changes that already occurred during the last decades are responsible for the main future LULC changes (by secondary succession). Only an extreme land abandonment scenario and extreme climate scenarios (5 K temperature increase) would bring about similar changes in LULC distribution and expansion of the forested areas. While alpine grasslands, alpine pioneer formation and glaciers would shrink drastically, especially deciduous forests would spread. To a considerable degree, such changes might take place over the next 300 years. By contrast, the increase in forest areas triggered by temperature changes would be slower and longer termed (up to 700–800 years).The effects and intensity of land-use change in the investigated valley, that is comparable to many regions in the Alps, will be at least equally severe and responsible for transformation of the landscape as those of a projected temperature increase.     

Spatially explicit micro-level modelling of land use change at the rural–urban interface

This paper describes micro‐economic models of land use change applicable to the rural‐urban interface in the US. Use of a spatially explicit micro‐level modelling approach permits the analysis of regional patterns of land use as the aggregate outcomes of many, disparate individual land use decisions distributed across space. In contrast to the models featured by Nelson and Geoghegan, we focus on models that require spatially articulated data on parcel‐level land use changes through time. In characterising the spatially disaggregated models, we highlight issues uniquely related to the management and generation of spatial data and the estimation of micro‐level spatial models.     

退耕还林过程中旱地—林地景观梯度时空变化分析——以西北旱区陕西耀州为例

[目的]研究掌握退耕还林政策实施过程中的土地动态变化程度和景观梯度空间分布,促进区域土地政策优化调整,实现土地资源可持续和集约化利用。[方法]文章以西北旱区关中平原典型县域陕西耀州为研究区域,采用土地利用动态度模型、土地利用扩展程度综合指数和土地景观梯度模型,充分利用土地景观空间信息,研究分析2000—2015年陕西耀州主要地类旱地、林地动态变化程度和景观梯度空间信息。[结果]退耕还林政策实施效果明显。该政策直接影响研究区域旱地和林地的数量和空间分布,林地和旱地在2000—2008年间的动态变化程度较2008—2015年均表现更为剧烈,2000—2015年间旱地景观梯度空间分布为西北向东南方向递增和聚集,即东南区域以旱地景观聚集区为主,林地景观梯度空间分布为南部向北部方向递增和聚集,即中部和北部以林地景观聚集区为主,旱地退化过程也是向东南方向逐渐推进,旱地和林地景观经历了2000—2008年急速变化期和2008—2015年持续稳定期两个阶段。[结论]提出的分析方法能快速、客观反映研究区域旱地和林地的动态变化程度和景观变化空间信息,为土地政策调控和优化土地利用结构提供科学的参考依据。     

基于土地利用变化的辉南县生态脆弱性时空变化分析

山区平原过渡地带因其地质、地貌的特殊性而担负着自然地域界面的作用,并表现出更高的生态环境脆弱性,研究其脆弱性变化对山区平原生态安全预警非常重要。特别是从土地利用方式改变评价其生态脆弱性,对于土地利用方式调整和规划具有重要指导意义。本文以地处山区平原过渡区的辉南县为例,在分析其土地利用变化基础上,参照生态价值评估体系并结合周围生态环境敏感因子,建立生态脆弱性综合评价指标,对研究区1986年以来环境脆弱性的时空变化进行评价和分析。评价结果如下：（1）从不同用地类型看,生态综合指数大小顺序依次为林地、草地、水域、未利用地,其次是耕地和建设用地。（2）脆弱性时间变化特征：由于土地利用变化,特别是林地减少和耕地、建设用地增加,导致生态贡献指数、生态稳定性指数和生态综合指数显著下降,分别由1986年的2.999、3.324和6.322减小为2006年的2.828、3.032和5.861。（3）空间变化特征：全区范围内生态环境综合指数下降显著,表现为低值区域范围扩大,高值区域范围明显减小。高值区范围由1986年的33217.95ha缩小为2006年的1283.40ha,而低值区的范围则由1986年的86550.87ha扩大为2006年的98084.83 ha。（4）地区差异性：虽然三个生态指数在整体上呈现下降,但是不同子流域其变化表现出显著的差异性,总体上呈现东南山区减小,而西北平原区呈现不明显的增加特点。本文研究结果表明,导致研究区生态脆弱性的主要原因为林地减少和耕地增加。从保护生态环境角度,控制耕地增加和林地减少是有效防范措施。     

Policy lessons from spatiotemporal enrollment patterns of payment for ecosystem service programs in Argentina

Payment for ecosystem services schemes (PES) are lauded as a market-based solution to curtail deforestation and restore degraded ecosystems. However, PES programs often fail to conserve sites under strong long-term deforestation pressures. Underperformance, in part, is likely due to adverse selection. Spatial adverse selection occurs when landowners are more likely to enroll parcels with low deforestation pressure than parcels with high deforestation pressure. Temporal adverse selection arises when parcels are enrolled for short time periods. In both cases, financial resources are allocated without having a sizeable impact on long-term land use change. Improving program performance to overcome these shortcomings requires understanding attributes of landowners and their parcels across large scales to identify spatial and temporal enrollment patterns that drive adverse selection. In this paper, we examine these patterns in Argentina’s PES program in Chaco forest, a global deforestation hotspot. Our study area covers 252,319 km². Results from multinomial logistic regression models showed that large parcels of enrolled land and parcels owned by absentee landowners exhibit greater evidence of spatiotemporal adverse selection than smaller parcels or parcels owned by local landowners. Furthermore, parcels managed under land use plans for conservation and restoration are more likely to be associated with adverse selection than parcels managed for financial returns such as harvest of non-timber forest products, silviculture, and silvopasture. However, prior to recommending that PES programs focus on land uses with higher potential earnings, a greater understanding is needed of the degree to which these land uses meet ecological and biodiversity goals of PES programs. We suggest that increased spatial targeting of enrollment, along with enrollment of local landowners and further incentives for land uses that support conservation and restoration, could promote long-term conservation of forest lands.     

近40年来广西耕地非农化的时空演变特征、成因与对策

目的 掌握耕地非农化的时空演变特征及原因是保护耕地和保障粮食安全的重要基础。方法 文章运用耕地非农化重心转移模型、空间自相关分析等方法探究广西近40年来111个县级评价单元耕地非农化的时空演变特征,分析其原因并提出对策。结果 （1）广西耕地面积由1980年的517.72万hm²持续减少到2020年的507.68万hm²,连片耕地主要集中在中南部地区。（2）耕地转为林地是广西耕地非农化的主要模式,占各时段耕地非农化面积的60.00%以上;建设占用耕地面积明显增多;耕地撂荒现象趋于严重;因石漠化、水土流失等原因灾毁的耕地面积逐渐扩大;耕地转为水域对广西耕地非农化的影响逐渐减弱。（3）广西耕地非农化空间不均衡性不断减弱,耕地非农化空间格局趋于稳定,总体趋势向东。耕地非农化重心先向西南转移192.72km、再向东北转移198.88 km,最终在广西中东部地区趋于平稳。（4）广西耕地非农化空间分布格局由空间离散转为空间集聚,空间集聚程度越来越强烈;耕地非农化的连片带动作用逐渐增强。结论 近40年来,广西耕地非农化面积持续上升,大量耕地转为林地和建设用地等地类,耕地非农化重心向东部转移并有连片带动效应。应严格限制耕地转为林地和建设用地,提高农民耕地保护动力,遏制耕地撂荒,同时加强耕地治理,严防耕地灾毁,提高桂东南地区耕地保护力度。     

Projecting future crop productivity for global economic modeling

Assessments of climate change impacts on agricultural markets and land‐use patterns rely on quantification of climate change impacts on the spatial patterns of land productivity. We supply a set of climate impact scenarios on agricultural land productivity derived from two climate models and two biophysical crop growth models to account for some of the uncertainty inherent in climate and impact models. Aggregation in space and time leads to information losses that can determine climate change impacts on agricultural markets and land‐use patterns because often aggregation is across steep gradients from low to high impacts or from increases to decreases. The four climate change impact scenarios supplied here were designed to represent the most significant impacts (high emission scenario only, assumed ineffectiveness of carbon dioxide fertilization on agricultural yields, no adjustments in management) but are consistent with the assumption that changes in agricultural practices are covered in the economic models. Globally, production of individual crops decrease by 10–38% under these climate change scenarios, with large uncertainties in spatial patterns that are determined by both the uncertainty in climate projections and the choice of impact model. This uncertainty in climate impact on crop productivity needs to be considered by economic assessments of climate change.     

A century of change in coastal sedimentary landscapes in the Canary Islands (Spain) — Change,processes, and driving forces

A global understanding of landscape dynamics, through local case studies, is a prime topic in land change science. Consequently, this approach should be urgently applied to changing and heavily transformed environments, such as coastal areas. The aim of this work is to study landscape changes, comparatively, by focusing on three coastal sedimentary landscapes in the Canary Islands (Spain). We examine changes in main land cover types and identify their driving forces, actors and institutions, analyze their inter-relationships, and match each case to a case-specific development model. The three landscapes reveal very different change processes with regard to population density, land cover, and major land change processes (i.e., resource extraction, urbanization, tourism, and nature protection). We found that socioeconomic, political, and natural/spatial driving force types are of highest importance, while the local level is dominant in all three cases. The findings of this study can be used to interpret other similar landscapes worldwide. Driving-force and organizational-level patterns may be expressed in a synthesized manner as we demonstrate in this paper.