The emergence of land change science for global environmental change and sustainability

Exploring agricultural livelihood transitions with an agent-based virtual laboratory: global forces to local decision-making

Rural populations are undergoing rapid changes in both their livelihoods and land uses, with associated impacts on ecosystems, global biogeochemistry, and climate change. A primary challenge is, thus, to explain these shifts in terms of the actors and processes operating within a variety of land systems in order to understand how land users might respond locally to future changes in broader-scale environmental and economic conditions. Using 'induced intensification' theory as a benchmark, we develop a generalized agent-based model to investigate mechanistic explanations of relationships between agricultural intensity and population density, environmental suitability, and market influence. Land-use and livelihood decisions modeled from basic micro-economic theories generated spatial and temporal patterns of agricultural intensification consistent with predictions of induced intensification theory. Further, agent actions in response to conditions beyond those described by induced intensification theory were explored, revealing that interactions among environmental constraints, population pressure, and market influence may produce transitions to multiple livelihood regimes of varying market integration. The result is new hypotheses that could modify and enrich understanding of the classic relationship between agricultural intensity and population density. The strength of this agent-based model and the experimental results is the generalized form of the decision-making processes underlying land-use and livelihood transitions, creating the prospect of a virtual laboratory for systematically generating hypotheses of how agent decisions and interactions relate to observed land-use and livelihood patterns across diverse land systems.

Assessing spatial uncertainties of land allocation using a scenario approach and sensitivity analysis: a study for land use in Europe

Land change model outcomes are vulnerable to multiple types of uncertainty, including uncertainty in input data, structural uncertainties in the model and uncertainties in model parameters. In coupled model systems the uncertainties propagate between the models. This paper assesses uncertainty of changes in future spatial allocation of agricultural land in Europe as they arise from a general equilibrium model coupled to a spatial land use allocation model. Two contrasting scenarios are used to capture some of the uncertainty in the development of typical combinations of economic, demographic and policy variables. The scenario storylines include different measurable assumptions concerning scenario specific drivers (variables) and parameters. Many of these assumptions are estimations and thus include a certain level of uncertainty regarding their true values. This leads to uncertainty within the scenario outcomes. In this study we have explored how uncertainty in national-level assumptions within the contrasting scenario assumptions translates into uncertainty in the location of changes in agricultural land use in Europe. The results indicate that uncertainty in coarse-scale assumptions does not translate into a homogeneous spread of the uncertainty within Europe. Some regions are more certain than others in facing specific land change trajectories irrespective of the uncertainty in the macro-level assumptions. The spatial spread of certain and more uncertain locations of land change is dependent on location conditions as well as on the overall scenario conditions. Translating macro-level uncertainties to uncertainties in spatial patterns of land change makes it possible to better understand and visualize the land change consequences of uncertainties in model input variables.

Model-based analysis of the environmental impacts of grazing management on Eastern Mediterranean ecosystems in Jordan

Eastern Mediterranean ecosystems are prone to desertification when under grazing pressure. Therefore, management of grazing intensity plays a crucial role to avoid or to diminish land degradation and to sustain both livelihoods and ecosystem functioning. The dynamic land-use model LandSHIFT was applied to a case study on the country level for Jordan. The impacts of different stocking densities on the environment were assessed through a set of simulation experiments for various combinations of climate input and assumptions about the development of livestock numbers. Indicators used for the analysis include a set of landscape metrics to account for habitat fragmentation and the "Human Appropriation of Net Primary Production" (HANPP), i.e., the difference between the amount of net primary production (NPP) that would be available in a natural ecosystem and the amount of NPP that remains under human management. Additionally, the potential of the economic valuation of ecosystem services, including landscape and grazing services, as an analysis concept was explored. We found that lower management intensities had a positive effect on HANPP but at the same time resulted in a strong increase of grazing area. This effect was even more pronounced under climate change due to a predominantly negative effect on the biomass productivity of grazing land. Also Landscape metrics tend to indicate decreasing habitat fragmentation as a consequence of lower grazing pressure. The valuation of ecosystem services revealed that low grazing intensity can lead to a comparatively higher economic value on the country level average. The results from our study underline the importance of considering grazing management as an important factor to manage dry-land ecosystems in a sustainable manner.

Use of historical logging patterns to identify disproportionately logged ecosystems within temperate rainforests of southeastern Alaska

The forests of southeastern Alaska remain largely intact and contain a substantial proportion of Earth's remaining old-growth temperate rainforest. Nonetheless, industrial-scale logging has occurred since the 1950s within a relatively narrow range of forest types that has never been quantified at a regional scale. We analyzed historical patterns of logging from 1954 through 2004 and compared the relative rates of change among forest types, landform associations, and biogeographic provinces. We found a consistent pattern of disproportionate logging at multiple scales, including large-tree stands and landscapes with contiguous productive old-growth forests. The highest rates of change were among landform associations and biogeographic provinces that originally contained the largest concentrations of productive old growth (i.e., timber volume >46.6 m³/ha). Although only 11.9% of productive old-growth forests have been logged region wide, large-tree stands have been reduced by at least 28.1%, karst forests by 37%, and landscapes with the highest volume of contiguous old growth by 66.5%. Within some island biogeographic provinces, loss of rare forest types may place local viability of species dependent on old growth at risk of extirpation. Examination of historical patterns of change among ecological forest types can facilitate planning for conservation of biodiversity and sustainable use of forest resources.

Identification of land-cover characteristics using MODIS time series data: an application in the Yangtze river estuary

Land-cover characteristics have been considered in many ecological studies. Methods to identify these characteristics by using remotely sensed time series data have previously been proposed. However, these methods often have a mathematical basis, and more effort is required to better illustrate the ecological meanings of land-cover characteristics. In this study, a method for identifying these characteristics was proposed from the ecological perspective of sustained vegetation growth trend. Improvement was also made in parameter extraction, inspired by a method used for determining the hyperspectral red edge position. Five land-cover types were chosen to represent various ecosystem growth patterns and MODIS time series data were adopted for analysis. The results show that the extracted parameters can reflect ecosystem growth patterns and portray ecosystem traits such as vegetation growth strategy and ecosystem growth situations.

Going beyond the Millennium Ecosystem Assessment: an index system of human dependence on ecosystem services

The Millennium Ecosystem Assessment (MA) estimated that two thirds of ecosystem services on the earth have degraded or are in decline due to the unprecedented scale of human activities during recent decades. These changes will have tremendous consequences for human well-being, and offer both risks and opportunities for a wide range of stakeholders. Yet these risks and opportunities have not been well managed due in part to the lack of quantitative understanding of human dependence on ecosystem services. Here, we propose an index of dependence on ecosystem services (IDES) system to quantify human dependence on ecosystem services. We demonstrate the construction of the IDES system using household survey data. We show that the overall index and sub-indices can reflect the general pattern of households' dependences on ecosystem services, and their variations across time, space, and different forms of capital (i.e., natural, human, financial, manufactured, and social capitals). We support the proposition that the poor are more dependent on ecosystem services and further generalize this proposition by arguing that those disadvantaged groups who possess low levels of any form of capital except for natural capital are more dependent on ecosystem services than those with greater control of capital. The higher value of the overall IDES or sub-index represents the higher dependence on the corresponding ecosystem services, and thus the higher vulnerability to the degradation or decline of corresponding ecosystem services. The IDES system improves our understanding of human dependence on ecosystem services. It also provides insights into strategies for alleviating poverty, for targeting priority groups of conservation programs, and for managing risks and opportunities due to changes of ecosystem services at multiple scales.

Natural and socioeconomic determinants of the embodied human appropriation of net primary production and its relation to other resource use indicators

Indicators of resource use such as material and energy flow accounts, emission data and the ecological footprint inform societies about their performance by evaluating resource use efficiency and the effectiveness of sustainability policies. The human appropriation of net primary production (HANPP) is an indicator of land-use intensity on each nation's territory used in research as well as in environmental reports. 'Embodied HANPP' (eHANPP) measures the HANPP anywhere on earth resulting from a nation's domestic biomass consumption. The objectives of this article are (i) to study the relation between eHANPP and other resource use indicators and (ii) to analyse socioeconomic and natural determinants of global eHANPP patterns in the year 2000. We discuss a statistical analysis of >140 countries aiming to better understand these relationships. We found that indicators of material and energy throughput, fossil-energy related CO₂ emissions as well as the ecological footprint are highly correlated with each other as well as with GDP, while eHANPP is neither correlated with other resource use indicators nor with GDP, despite a strong correlation between final biomass consumption and GDP. This can be explained by improvements in agricultural efficiency associated with GDP growth. Only about half of the variation in eHANPP can be explained by differences in national land-use systems, suggesting a considerable influence of trade on eHANPP patterns. eHANPP related with biomass trade can largely be explained by differences in natural endowment, in particular the availability of productive area. We conclude that eHANPP can deliver important complimentary information to indicators that primarily monitor socioeconomic metabolism.

Vegetation dynamics, and land use and land cover change in the Bale Mountains, Ethiopia

Shifts in biological communities are occurring at rapid rates as human activities induced global climate change increases. Understanding the effects of the change on biodiversity is important to reduce loss of biodiversity and mass extinction, and to insure the long-term persistence of natural resources and natures' services. Especially in remote landscapes of developing countries, precise knowledge about on-going processes is scarce. Here we apply satellite imagery to assess spatio-temporal land use and land cover change (LULCC) in the Bale Mountains for a period of four decades. This study aims to identify the main drivers of change in vegetation patterns and to discuss the implications of LULCC on spatial arrangements and trajectories of floral communities. Remote sensing data acquired from Landsat MSS, Landsat ETM + and SPOT for four time steps (1973, 1987, 2000, and 2008) were analyzed using 11 LULC units defined based on the dominant plant taxa and cover types of the habitat. Change detection matrices revealed that over the last 40 years, the area has changed from a quite natural to a more cultural landscape. Within a representative subset of the study area (7,957.5 km(-2)), agricultural fields have increased from 1.71% to 9.34% of the total study area since 1973. Natural habitats such as upper montane forest, afroalpine grasslands, afromontane dwarf shrubs and herbaceous formations, and water bodies also increased. Conversely, afromontane grasslands have decreased in size by more than half (going from 19.3% to 8.77%). Closed Erica forest also shrank from 15.0% to 12.37%, and isolated Erica shrubs have decreased from 6.86% to 5.55%, and afroalpine dwarf shrubs and herbaceous formations reduced from 5.2% to 1.56%. Despite fluctuations the afromontane rainforest (Harenna forest), located south of the Bale Mountains, has remained relatively stable. In conclusion this study documents a rapid and ecosystem-specific change of this biodiversity hotspot due to intensified human activities (e.g., deforestation, agriculture, infrastructure expansion). Specifically, the ecotone between the afromontane and the afroalpine area represent a "hotspot of biodiversity loss" today. Taking into consideration the projections of regional climate warming and modified precipitation regimes, LULCC can be expected to become even more intensive in the near future. This is likely to impose unprecedented pressures on the largely endemic biota of the area.

Assessment of global carbon dioxide concentration using MODIS and GOSAT data

Carbon dioxide (CO₂) is the most important greenhouse gas (GHG) in the atmosphere and is the greatest contributor to global warming. CO₂ concentration data are usually obtained from ground observation stations or from a small number of satellites. Because of the limited number of observations and the short time series of satellite data, it is difficult to monitor CO₂ concentrations on regional or global scales for a long time. The use of the remote sensing data such as the Advanced Very High Resolution Radiometer (AVHRR) or Moderate Resolution Imaging Spectroradiometer (MODIS) data can overcome these problems, particularly in areas with low densities of CO₂ concentration watch stations. A model based on temperature (MOD11C3), vegetation cover (MOD13C2 and MOD15A2) and productivity (MOD17A2) of MODIS (which we have named the TVP model) was developed in the current study to assess CO₂ concentrations on a global scale. We assumed that CO₂ concentration from the Thermal And Near infrared Sensor for carbon Observation (TANSO) aboard the Greenhouse gases Observing SATellite (GOSAT) are the true values and we used these values to check the TVP model accuracy. The results indicate that the accuracy of the TVP model is different in different continents: the greatest Pearson’s correlation coefficient (R²) was 0.75 in Eurasia (RMSE = 1.16) and South America (RMSE = 1.17); the lowest R² was 0.57 in Australia (RMSE = 0.73). Compared with the TANSO-observed CO₂ concentration (XCO₂), we found that the accuracy throughout the World is between −2.56∼3.14 ppm. Potential sources of TVP model uncertainties were also analyzed and identified.

Regional land salinization assessment and simulation through cellular automaton-Markov modeling and spatial pattern analysis

Land salinization and desalinization are complex processes affected by both biophysical and human-induced driving factors. Conventional approaches of land salinization assessment and simulation are either too time consuming or focus only on biophysical factors. The cellular automaton (CA)-Markov model, when coupled with spatial pattern analysis, is well suited for regional assessments and simulations of salt-affected landscapes since both biophysical and socioeconomic data can be efficiently incorporated into a geographic information system framework. Our hypothesis set forth that the CA-Markov model can serve as an alternative tool for regional assessment and simulation of land salinization or desalinization. Our results suggest that the CA-Markov model, when incorporating biophysical and human-induced factors, performs better than the model which did not account for these factors when simulating the salt-affected landscape of the Yinchuan Plain (China) in 2009. In general, the CA-Markov model is best suited for short-term simulations and the performance of the CA-Markov model is largely determined by the availability of high-quality, high-resolution socioeconomic data. The coupling of the CA-Markov model with spatial pattern analysis provides an improved understanding of spatial and temporal variations of salt-affected landscape changes and an option to test different soil management scenarios for salinity management.

A Land System representation for global assessments and land-use modeling

Current global scale land-change models used for integrated assessments and climate modeling are based on classifications of land cover. However, land-use management intensity and livestock keeping are also important aspects of land use, and are an integrated part of land systems. This article aims to classify, map, and to characterize Land Systems (LS) at a global scale and analyze the spatial determinants of these systems. Besides proposing such a classification, the article tests if global assessments can be based on globally uniform allocation rules. Land cover, livestock, and agricultural intensity data are used to map LS using a hierarchical classification method. Logistic regressions are used to analyze variation in spatial determinants of LS. The analysis of the spatial determinants of LS indicates strong associations between LS and a range of socioeconomic and biophysical indicators of human-environment interactions. The set of identified spatial determinants of a LS differs among regions and scales, especially for (mosaic) cropland systems, grassland systems with livestock, and settlements. (Semi-)Natural LS have more similar spatial determinants across regions and scales. Using LS in global models is expected to result in a more accurate representation of land use capturing important aspects of land systems and land architecture: the variation in land cover and the link between land-use intensity and landscape composition. Because the set of most important spatial determinants of LS varies among regions and scales, land-change models that include the human drivers of land change are best parameterized at sub-global level, where similar biophysical, socioeconomic and cultural conditions prevail in the specific regions.

The macroecology of sustainability

Global consumption rates of vital resources suggest that we have surpassed the capacity of the Earth to sustain current levels, much less future trajectories of growth in human population and economy.

The discipline of sustainability science has emerged in response to concerns of natural and social scientists, policymakers, and lay people about whether the Earth can continue to support human population growth and economic prosperity. Yet, sustainability science has developed largely independently from and with little reference to key ecological principles that govern life on Earth. A macroecological perspective highlights three principles that should be integral to sustainability science: 1) physical conservation laws govern the flows of energy and materials between human systems and the environment, 2) smaller systems are connected by these flows to larger systems in which they are embedded, and 3) global constraints ultimately limit flows at smaller scales. Over the past few decades, decreasing per capita rates of consumption of petroleum, phosphate, agricultural land, fresh water, fish, and wood indicate that the growing human population has surpassed the capacity of the Earth to supply enough of these essential resources to sustain even the current population and level of socioeconomic development.

Urban land teleconnections and sustainability

This paper introduces urban land teleconnections as a conceptual framework that explicitly links land changes to underlying urbanization dynamics. We illustrate how three key themes that are currently addressed separately in the urban sustainability and land change literatures can lead to incorrect conclusions and misleading results when they are not examined jointly: the traditional system of land classification that is based on discrete categories and reinforces the false idea of a rural-urban dichotomy; the spatial quantification of land change that is based on place-based relationships, ignoring the connections between distant places, especially between urban functions and rural land uses; and the implicit assumptions about path dependency and sequential land changes that underlie current conceptualizations of land transitions. We then examine several environmental "grand challenges" and discuss how urban land teleconnections could help research communities frame scientific inquiries. Finally, we point to existing analytical approaches that can be used to advance development and application of the concept.

Economic-based projections of future land use in the conterminous United States under alternative policy scenarios

Land-use change significantly contributes to biodiversity loss, invasive species spread, changes in biogeochemical cycles, and the loss of ecosystem services. Planning for a sustainable future requires a thorough understanding of expected land use at the fine spatial scales relevant for modeling many ecological processes and at dimensions appropriate for regional or national-level policy making. Our goal was to construct and parameterize an econometric model of land-use change to project future land use to the year 2051 at a fine spatial scale across the conterminous United States under several alternative land-use policy scenarios. We parameterized the econometric model of land-use change with the National Resource Inventory (NRI) 1992 and 1997 land-use data for 844 000 sample points. Land-use transitions were estimated for five land-use classes (cropland, pasture, range, forest, and urban). We predicted land-use change under four scenarios: business-as-usual, afforestation, removal of agricultural subsidies, and increased urban rents. Our results for the business-as-usual scenario showed widespread changes in land use, affecting 36% of the land area of the conterminous United States, with large increases in urban land (79%) and forest (7%), and declines in cropland (-16%) and pasture (-13%). Areas with particularly high rates of land-use change included the larger Chicago area, parts of the Pacific Northwest, and the Central Valley of California. However, while land-use change was substantial, differences in results among the four scenarios were relatively minor. The only scenario that was markedly different was the afforestation scenario, which resulted in an increase of forest area that was twice as high as the business-as-usual scenario. Land-use policies can affect trends, but only so much. The basic economic and demographic factors shaping land-use changes in the United States are powerful, and even fairly dramatic policy changes, showed only moderate deviations from the business-as-usual scenario. Given the magnitude of predicted land-use change, any attempts to identify a sustainable future or to predict the effects of climate change will have to take likely land-use changes into account. Econometric models that can simulate land-use change for broad areas with fine resolution are necessary to predict trends in ecosystem service provision and biodiversity persistence.

Space versus Place in Complex Human-Natural Systems: Spatial and Multi-level Models of Tropical Land Use and Cover Change (LUCC) in Guatemala

The relative role of space and place has long been debated in geography. Yet modeling efforts applied to coupled human-natural systems seemingly favor models assuming continuous spatial relationships. We examine the relative importance of placebased hierarchical versus spatial clustering influences in tropical land use/cover change (LUCC). Guatemala was chosen as our study site given its high rural population growth and deforestation in recent decades. We test predictors of 2009 forest cover and forest cover change from 2001-2009 across Guatemala's 331 municipalities and 22 departments using spatial and multi-level statistical models. Our results indicate the emergence of several socio-economic predictors of LUCC regardless of model choice. Hierarchical model results suggest that significant differences exist at the municipal and departmental levels but largely maintain the magnitude and direction of single-level model coefficient estimates. They are also intervention-relevant since policies tend to be applicable to distinct political units rather than to continuous space. Spatial models complement hierarchical approaches by indicating where and to what magnitude significant negative and positive clustering associations emerge. Appreciating the comparative advantages and limitations of spatial and nested models enhances a holistic approach to geographical analysis of tropical LUCC and human-environment interactions.

Elementary processes governing the evolution of road networks

Urbanisation is a fundamental phenomenon whose quantitative characterisation is still inadequate. We report here the empirical analysis of a unique data set regarding almost 200 years of evolution of the road network in a large area located north of Milan (Italy). We find that urbanisation is characterised by the homogenisation of cell shapes, and by the stability throughout time of high–centrality roads which constitute the backbone of the urban structure, confirming the importance of historical paths. We show quantitatively that the growth of the network is governed by two elementary processes: (i) ‘densification’, corresponding to an increase in the local density of roads around existing urban centres and (ii) ‘exploration’, whereby new roads trigger the spatial evolution of the urbanisation front. The empirical identification of such simple elementary mechanisms suggests the existence of general, simple properties of urbanisation and opens new directions for its modelling and quantitative description.

Critical perspectives on historical collapse

Historical collapse of ancient states or civilizations has raised new awareness about its possible relevance to current issues of sustainability, in the context of global change. This Special Feature examines 12 case studies of societies under stress, of which seven suffered severe transformation. Outcomes were complex and unpredictable. Five others overcame breakdown through environmental, political, or socio-cultural resilience, which deserves as much attention as the identification of stressors. Response to environmental crises of the last millennium varied greatly according to place and time but drew from traditional knowledge to evaluate new information or experiment with increasing flexibility, even if modernization or intensification were decentralized and protracted. Longer-term diachronic experience offers insight into how societies have dealt with acute stress, a more instructive perspective for the future than is offered by apocalyptic scenarios.

An assessment of landscape characteristics affecting estuarine nitrogen loading in an urban watershed

Exploring the quantitative association between landscape characteristics and the ecological conditions of receiving waters has recently become an emerging area for eco-environmental research. While the landscape-water relationship research has largely targeted on inland aquatic systems, there has been an increasing need to develop methods and techniques that can better work with coastal and estuarine ecosystems. In this paper, we present a geospatial approach to examine the quantitative relationship between landscape characteristics and estuarine nitrogen loading in an urban watershed. The case study site is in the Pensacola estuarine drainage area, home of the city of Pensacola, Florida, USA, where vigorous urban sprawling has prompted growing concerns on the estuarine ecological health. Central to this research is a remote sensor image that has been used to extract land use/cover information and derive landscape metrics. Several significant landscape metrics are selected and spatially linked with the nitrogen loading data for the Pensacola bay area. Landscape metrics and nitrogen loading are summarized by equal overland flow-length rings, and their association is examined by using multivariate statistical analysis. And a stepwise model-building protocol is used for regression designs to help identify significant variables that can explain much of the variance in the nitrogen loading dataset. It is found that using landscape composition or spatial configuration alone can explain most of the nitrogen loading variability. Of all the regression models using metrics derived from a single land use/cover class as the independent variables, the one from the low density urban gives the highest adjusted R-square score, suggesting the impact of the watershed-wide urban sprawl upon this sensitive estuarine ecosystem. Measures towards the reduction of non-point source pollution from urban development are necessary in the area to protect the Pensacola bay ecosystem and its ecosystem services.

Landscape urbanization and economic growth in China: positive feedbacks and sustainability dilemmas

Accelerating urbanization has been viewed as an important instrument for economic development and reducing regional income disparity in some developing countries, including China. Recent studies (Bloom et al. 2008) indicate that demographic urbanization level has no causal effect on economic growth. However, due to the varying and changing definition of urban population, the use of demographic indicators as a sole representing indicator for urbanization might be misleading. Here, we re-examine the causal relationship between urbanization and economic growth in Chinese cities and provinces in recent decades, using built-up areas as a landscape urbanization indicator. Our analysis shows that (1) larger cities, both in terms of population size and built-up area, and richer cities tend to gain more income, have larger built-up area expansion, and attract more population, than poorer cities or smaller cities; and (2) that there is a long-term bidirectional causality between urban built-up area expansion and GDP per capita at both city and provincial level, and a short-term bidirectional causality at provincial level, revealing a positive feedback between landscape urbanization and urban and regional economic growth in China. Our results suggest that urbanization, if measured by a landscape indicator, does have causal effect on economic growth in China, both within the city and with spillover effect to the region, and that urban land expansion is not only the consequences of economic growth in cities, but also drivers of such growth. The results also suggest that under its current economic growth model, it might be difficult for China to control urban expansion without sacrificing economic growth, and China's policy to stop the loss of agricultural land, for food security, might be challenged by its policy to promote economic growth through urbanization.

Global bioenergy potentials from agricultural land in 2050: Sensitivity to climate change, diets and yields

There is a growing recognition that the interrelations between agriculture, food, bioenergy, and climate change have to be better understood in order to derive more realistic estimates of future bioenergy potentials. This article estimates global bioenergy potentials in the year 2050, following a "food first" approach. It presents integrated food, livestock, agriculture, and bioenergy scenarios for the year 2050 based on a consistent representation of FAO projections of future agricultural development in a global biomass balance model. The model discerns 11 regions, 10 crop aggregates, 2 livestock aggregates, and 10 food aggregates. It incorporates detailed accounts of land use, global net primary production (NPP) and its human appropriation as well as socioeconomic biomass flow balances for the year 2000 that are modified according to a set of scenario assumptions to derive the biomass potential for 2050. We calculate the amount of biomass required to feed humans and livestock, considering losses between biomass supply and provision of final products. Based on this biomass balance as well as on global land-use data, we evaluate the potential to grow bioenergy crops and estimate the residue potentials from cropland (forestry is outside the scope of this study). We assess the sensitivity of the biomass potential to assumptions on diets, agricultural yields, cropland expansion and climate change. We use the dynamic global vegetation model LPJmL to evaluate possible impacts of changes in temperature, precipitation, and elevated CO(2) on agricultural yields. We find that the gross (primary) bioenergy potential ranges from 64 to 161 EJ y(-1), depending on climate impact, yields and diet, while the dependency on cropland expansion is weak. We conclude that food requirements for a growing world population, in particular feed required for livestock, strongly influence bioenergy potentials, and that integrated approaches are needed to optimize food and bioenergy supply.

Historical reconstruction reveals recovery in Hawaiian coral reefs

Coral reef ecosystems are declining worldwide, yet regional differences in the trajectories, timing and extent of degradation highlight the need for in-depth regional case studies to understand the factors that contribute to either ecosystem sustainability or decline. We reconstructed social-ecological interactions in Hawaiian coral reef environments over 700 years using detailed datasets on ecological conditions, proximate anthropogenic stressor regimes and social change. Here we report previously undetected recovery periods in Hawaiian coral reefs, including a historical recovery in the MHI (~AD 1400-1820) and an ongoing recovery in the NWHI (~AD 1950-2009+). These recovery periods appear to be attributed to a complex set of changes in underlying social systems, which served to release reefs from direct anthropogenic stressor regimes. Recovery at the ecosystem level is associated with reductions in stressors over long time periods (decades+) and large spatial scales (>10(3) km(2)). Our results challenge conventional assumptions and reported findings that human impacts to ecosystems are cumulative and lead only to long-term trajectories of environmental decline. In contrast, recovery periods reveal that human societies have interacted sustainably with coral reef environments over long time periods, and that degraded ecosystems may still retain the adaptive capacity and resilience to recover from human impacts.

Spatial covariation between freshwater and terrestrial ecosystem services

To inform the design and implementation of land-use policies that consider the variety of goods and services people derive from ecosystems, it is essential to understand spatial patterns of individual services, how multiple services relate to each other, and how these relationships vary across spatial scales and localities. Despite the importance of freshwater as a determinant of regional economic and human demographic patterns, there are surprisingly few studies that map the provision of a range of services associated with the quality of the aquatic environment. Here we examine relationships between indicators of riverine water and associated habitat quality, freshwater biodiversity, three terrestrial ecosystem services, and terrestrial biodiversity across England and Wales. The results indicate strong associations between our indicators of freshwater services. However, a comparison of these indicators of freshwater services with other ecosystem services (carbon storage, agricultural production, recreation) and biodiversity of species of conservation concern in the surrounding terrestrial landscape shows no clear relationships. While there are potential policy "win-wins" for the protection of multiple services shown by associations between indicators of freshwater services and carbon storage in upland areas of Britain, the other ecosystem services showed either negative or no relationships with the indicators of freshwater services. We also consider the influence that spatial scale has on these relationships using River Basin Districts. Our results indicate that relationships between indicators of services can change dramatically depending on the societal pressures and other regional conditions. Thus, the delivery of multiple ecosystem services requires the development of regional strategies, or of national strategies that take account of regional variation.

Land-use poverty traps identified in shifting cultivation systems shape long-term tropical forest cover

In this article we illustrate how fine-grained longitudinal analyses of land holding and land use among forest peasant households in an Amazonian village can enrich our understanding of the poverty/land cover nexus. We examine the dynamic links in shifting cultivation systems among asset poverty, land use, and land cover in a community where poverty is persistent and primary forests have been replaced over time--with community enclosure--by secondary forests (i.e., fallows), orchards, and crop land. Land cover change is assessed using aerial photographs/satellite imagery from 1965 to 2007. Household and plot level data are used to track land holding, portfolios, and use as well as land cover over the past 30 y, with particular attention to forest status (type and age). Our analyses find evidence for two important types of "land-use" poverty traps--a "subsistence crop" trap and a "short fallow" trap--and indicate that the initial conditions of land holding by forest peasants have long-term effects on future forest cover and household welfare. These findings suggest a new mechanism driving poverty traps: insufficient initial land holdings induce land use patterns that trap households in low agricultural productivity. Path dependency in the evolution of household land portfolios and land use strategies strongly influences not only the wellbeing of forest people but also the dynamics of tropical deforestation and secondary forest regrowth.

Spatio-temporal pattern and rationality of land reclamation and cropland abandonment in mid-eastern Inner Mongolia of China in 1990-2005

The Mid-eastern Inner Mongolia of China, a typical agro-pastoral transitional zone, has undergone rapid agricultural land use changes including land reclamation and cropland abandonment in past decades due to growing population and food demand, climatic variability, and land use policy such as the "Grain for Green" Project (GFG Project). It is significant to the regional ecology and sustainability to examine the pattern and its rationality of land use change. The processes of land reclamation and cropland abandonment were accessed by using land use change dataset for four periods of 1990, 1995, 2000, and 2005, derived from the interpretation of Landsat TM images. And then the rationality of land reclamation and cropland abandonment was analyzed based on the habitat suitability for cultivation. The results indicated that: (1) land reclamation was the dominant form of agricultural land use change from 1990 to 2005, the total cropland area increased from 64,954.64 km(2) in 1990 to 76,258.51 km(2) in 2005; However, the speed of land reclamation decreased while cropland abandonment increased around 2000. The Land Reclamation Degree decreased from 1995-2000 to 2000-2005, meanwhile, Cropland Abandonment Degree increased. (2) As for the habitat suitability levels, moderately and marginally suitable levels had largest areas where cropland was widespread. Pattern of agricultural land use trended to become more rational due to the decrease of land reclamation area in low suitable levels and the increase of cropland abandonment in unsuitable area after 2000. (3) The habitat suitability-based rationality analysis of agricultural land use implicated that the GFG Project should take cultivation habitat suitability assessment into account.

Impacts of surface gold mining on land use systems in Western Ghana

Land use conflicts are becoming increasingly apparent from local to global scales. Surface gold mining is an extreme source of such a conflict, but mining impacts on local livelihoods often remain unclear. Our goal here was to assess land cover change due to gold surface mining in Western Ghana, one of the world's leading gold mining regions, and to study how these changes affected land use systems. We used Landsat satellite images from 1986-2002 to map land cover change and field interviews with farmers to understand the livelihood implications of mining-related land cover change. Our results showed that surface mining resulted in deforestation (58%), a substantial loss of farmland (45%) within mining concessions, and widespread spill-over effects as relocated farmers expand farmland into forests. This points to rapidly eroding livelihood foundations, suggesting that the environmental and social costs of Ghana's gold boom may be much higher than previously thought.

Major ecosystems in China: dynamics and challenges for sustainable management

Ecosystems, though impacted by global environmental change, can also contribute to the adaptation and mitigation of such large scale changes. Therefore, sustainable ecosystem management is crucial in reaching a sustainable future for the biosphere. Based on the published literature and publicly accessible data, this paper discussed the status and trends of forest, grassland, and wetland ecosystems in China that play important roles in the ecological integrity and human welfare of the nation. Ecological degradation has been observed in these ecosystems at various levels and geographic locations. Biophysical (e.g., climate change) and socioeconomic factors (e.g., intensive human use) are the main reasons for ecosystem degradation with the latter factors serving as the dominant driving forces. The three broad categories of ecosystems in China have partially recovered from degradation thanks to large scale ecological restoration projects implemented in the last few decades. China, as the largest and most populated developing nation, still faces huge challenges regarding ecosystem management in a changing and globalizing world. To further improve ecosystem management in China, four recommendations were proposed, including: (1) advance ecosystem management towards an application-oriented, multidisciplinary science; (2) establish a well-functioning national ecological monitoring and data sharing mechanism; (3) develop impact and effectiveness assessment approaches for policies, plans, and ecological restoration projects; and (4) promote legal and institutional innovations to balance the intrinsic needs of ecological and socioeconomic systems. Any change in China's ecosystem management approach towards a more sustainable one will benefit the whole world. Therefore, international collaborations on ecological and environmental issues need to be expanded.

Integrated management of heterogeneous landscape—Mediterranean Israel as a study case

Natural and semi-natural landscapes usually serve varied land uses, including grazing, forestry, recreation, and nature or biodiversity protection. In most cases areas with differing land uses are managed by different agencies, with differing perspectives, goals, and operating methodologies. In his teaching, Imanuel Noy-Meir emphasized the ecological basis of the management of principal land-use practices (forests, rangelands, nature reserves) in Mediterranean Israel, and advocated ecological thinking to achieve better management and to minimize inter-agency conflicts. We propose a broader framework for integrated management of multiple uses by adoption of a landscape perspective that cuts across administrative lines. The reasoning for taking such an approach is based on the newly developing understanding of the impact of dynamic processes that occur spontaneously on a large scale in Mediterranean Israel. Landscape-scale interactions—oak woodland succession and pine colonization—may interfere or even conflict with some management goals set by the agencies involved. Attempts to mitigate these interactions may be very costly or ineffective. We propose coordinated management, planning, and implementation, based on common ecological criteria. We base this paper on observations and on perceptions gained from analyzing landscape dynamics of the predominant ecosystems in Mediterranean Israel: dense oak woodland and planted pine forests. The small size of Israel and the consequently small size of different land-use units, as well as their close proximity to each other, call for coordination of the organizational perspectives that relate at present independently to the various units. The new perspective should be broader, regional, landscape-oriented, and should take into consideration ecological processes that integrate neighboring units. As a first step, all agencies involved should accept the pine-oak interaction and dynamics as part of the local succession and should adapt their management schemes accordingly.

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.

Global land use change, economic globalization, and the looming land scarcity

A central challenge for sustainability is how to preserve forest ecosystems and the services that they provide us while enhancing food production. This challenge for developing countries confronts the force of economic globalization, which seeks cropland that is shrinking in availability and triggers deforestation. Four mechanisms-the displacement, rebound, cascade, and remittance effects-that are amplified by economic globalization accelerate land conversion. A few developing countries have managed a land use transition over the recent decades that simultaneously increased their forest cover and agricultural production. These countries have relied on various mixes of agricultural intensification, land use zoning, forest protection, increased reliance on imported food and wood products, the creation of off-farm jobs, foreign capital investments, and remittances. Sound policies and innovations can therefore reconcile forest preservation with food production. Globalization can be harnessed to increase land use efficiency rather than leading to uncontrolled land use expansion. To do so, land systems should be understood and modeled as open systems with large flows of goods, people, and capital that connect local land use with global-scale factors.