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In this chapter, we first summarize some of the key findings of the LUCC project on its research questions (see Box 1.1), and then outline some of the elements at the frontier in land-use/cover change research. [ABSTRACT FROM AUTHOR]

Human use of the land and oceans is at the center of some of the most complicated and pressing problems faced by policy makers around the world today (e.g., DeFries et al. 2004b; Platt 2004; Millennium Ecosystem Assessment 2005). For the terrestrial biosphere, our need to balance current human needs and longer-term environmental sustainability often involves consideration of the way we use ecosystem goods and services produced by the land. Land-use is at the center of these trade-offs because changes in land use often enhance the share of energy, water and nutrients devoted to human needs but decrease the share available for other species and ecosystem functions. Problems as far ranging as improving human health or ensuring adequate food production cannot be solved unless policy makers understand how their policies alter land use and how altered land use affects ecosystem functions. For example, public health policy that adequately accounts for the future spread of mosquitoes that carry Plasmodium or malaria in the tropics often requires an understanding of the interplay between land use and climate (Lines 1995) (see Chap. 4). In China, agricultural policy makers are using a recent assessment of cropland area to create policies that ensure there will be enough land to meet China's rapidly growing demand for food, feedgrains, and raw materials that is driven by rapid economic growth (Welch and Pannell 1982; Yang and Li 2000; Ho and Lin 2004; Lin and Ho 2005), although it is not clear that other ecosystem services will be maintained in this process. [ABSTRACT FROM AUTHOR]

Much of the scientific research concerned with land-use and land-cover issues is motivated by questions related to global environmental change. For example, will deforestation continue, and if yes, where, and at what rate? How will demographic changes affect future land use and cover? How will economic growth influence future land use and cover? What will be the magnitude of emissions of greenhouse gases related to land use and cover? A common characteristic of these and other issues related to global environmental change is that they stimulate questions not only about past and present changes in land use and cover but also about their future changes (Brouwer and McCarl 2006). The main objective of this chapter is to summarize the state of understanding about the future of land. What are the range and predominant views of this future? What are the views on the global, continental, regional and local levels? We review what (we think) we know and don't know about the future of land by reviewing published scenarios from the global to local scale. Our aim is to identify the main messages of these scenarios especially relevant to global change issues, and to recommend how scenarios can be improved to better address the outstanding questions about global change and land use/cover. [ABSTRACT FROM AUTHOR]

The decade since the initiation of the Land-Use/Cover Change (LUCC) project in 1995 (see Chap. 1) has witnessed considerable advances in the field of modeling of land-use/cover change. The science plan of the project indicated that the major task would be the development of a new generation of land-use/cover change models capable of simulating the major socioeconomic and biophysical driving forces of land-use and land-cover change. In addition, these models were supposed to be able to handle interactions at several spatial and temporal scales. Recent publications indicate that the LUCC science community has successfully met this challenge and a wide range of advanced models, aiming at different scales and research questions, is now available (Briassoulis 2000; Agarwal et al. 2001; Veldkamp and Lambin 2001; Parker et al. 2003; Nagendra et al. 2004; Veldkamp and Verburg 2004; Verburg et al. 2004b; Verburg and Veldkamp 2005). One of the most important observations that can be made examining the range of available land-use/ cover change models is the wide variety of approaches and concepts underlying the models. This chapter intends to describe the variety of modeling approaches, discuss the strengths and weaknesses of current approaches and indicate the remaining challenges for the land-use science community. Not being able to discuss all individual models and approaches, we will focus on broad distinctions between approaches and discuss how modelers have dealt with a number of important aspects of the functioning of the landuse system. A land-use system is understood here as a type of land use with interrelated determining factors with strong functional relations with each other (see Fig. 1.2). These factors include a wide range of land-use influencing factors than can be biophysical, economic, social, cultural, political, or institutional. The discussion of modeling approaches in this chapter is illustrated with examples of models and results from selected research projects. [ABSTRACT FROM AUTHOR]

Local changes in land-use/cover are so pervasive that, when aggregated globally, they may significantly affect central aspects of the Earth System functioning and thus life support functions and human livelihoods. Estimates of the areal extent, spatial expression or likewise quantitative estimate of the impact of land change more or less converge, while estimates driven by notions of "imprint", "impress", "footprint" or "carrying capacity" are larger, thus appearing more dramatic - see Box 4.1 (and Chap. 2). [ABSTRACT FROM AUTHOR]

One of the key activities of the Land-Use/Cover Change (LUCC) project has been to stimulate the syntheses of knowledge of land-use/cover change processes, and in particular to advance understanding of the causes of land change (see Chap. 1). Such efforts have generally followed one of two approaches: broad scale cross-sectional analyses (cross-national statistical comparisons, mainly); and detailed case studies at the local scale. The LUCC project applied a middle path that combines the richness of indepth case studies with the power of generalization gained from larger samples, thus drawing upon the strengths of both approaches. In particular, systematic comparative analyses of published case studies on landuse dynamics have helped to improve our knowledge about causes of land-use change. Principally, two methods exist for comparative analyses of case studies. These methods are sufficiently broad geographically to support generalization, but at a scale fine enough to capture complexity and variability across space and time. [ABSTRACT FROM AUTHOR]

Since time immemorial, humankind has changed landscapes in attempts to improve the amount, quality, and security of natural resources critical to its well being, such as food, freshwater, fiber, and medicinal products. Through the increased use of innovation, human populations have, slowly at first, and at increasingly rapid pace later on, increased its ability to derive resources from the environment, and expand its territory. Several authors have identified three different phases - the control of fire, domestication of biota, and fossil-fuel use - as being pivotal in enabling increased appropriation of natural resources (Goudsblom and De Vries 2004; Turner II and McCandless 2004). [ABSTRACT FROM AUTHOR]

Concerns about land-use/cover change emerged in the research agenda on global environmental change several decades ago with the realization that land-surface processes influence climate. In the mid-1970s, it was recognized that land-cover change modifies surface albedo and thus surfaceatmosphere energy exchanges, which have an impact on regional climate (Otterman 1974; Charney and Stone 1975; Sagan et al. 1979). In the early 1980s, terrestrial ecosystems as sources and sinks of carbon were highlighted; this underscored the impact of land-use/cover change on global climate via carbon cycle (Woodwell et al. 1983; Houghton et al. 1985). Decreasing the uncertainty of these terrestrial sources and sinks of carbon remains a serious challenge today. Subsequently, the important contribution of local evapotranspiration to the water cycle - that is, precipitation recycling - as a function of land cover highlighted yet another considerable impact of land-use/cover change on climate, at a local to regional scale in this case (Eltahir and Bras 1996). [ABSTRACT FROM AUTHOR]