Core Theme 2

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Introduction

Land-use and -cover change is an important and on-going feature of development in the rural hinterlands of Southeast Asia.  A common pattern of transformation has been, firstly, widespread deforestation, primarily as a result of government policies to obtain logging and timber export revenues, followed by both planned and spontaneous agricultural expansions (Kummer & Turner 1994; Brookfield & Byron 1990) by varying combinations of small-holders and large-scale plantation developers.  In later stages this may then be followed by changes in land use, including abandonment where methods have been inappropriate, and intensification where infrastructure provides the support to market commodities. A special feature of land use in Southeast Asia, not apparent in most national-level statistics, is the prevalence of a wide range of intermediate mixed agro-forestry systems from simultaneous tree-crop systems to agro-forests with only a short inter-cropping phase (e.g. van Noordwijk et al. 1995; Tronkongsin 1987; Colfer et al.1988).

Expansion and intensification of agricultural land uses will continue to grow to meet the food, fibre, and energy needs of growing populations and changing life-styles into at least the middle of the next century.   These transformation in land-use and -cover, while producing increases in productivity and revenues (e.g. from forest harvesting), also have associated environmental costs. In some places such changes are already having significant negative impacts on the rural hinterland environment, to the extent that deforestation, soil degradation and declining water quality are already considered major environmental problems by most Southeast Asian governments (United Nations Environment Programme 1997). The challenge for national governments is to find and then implement, through an appropriate system of incentives, development strategies that limit and begin to reverse some of the adverse environmental impacts of land transformation on biodiversity, soils and water.

A good example of an important land degradation issue is the replacement of moist or monsoonal forests by invasive grassy weeds, especially, Imperata cylindrica.  Garrity et al. (1997) in a preliminary regional assessment estimated that the total area of Imperata grasslands in Asia was about 35 million ha or about 4% of the total land area.  Estimates of the proportion of land cover for countries in Southeast Asia were: Philippines (17%), Vietnam (9%), Laos PDR (4%), Indonesia (4%), Thailand (4%), Myanmar (3%), Cambodia (1%) and Malaysia (<1%). With increasing pressure to develop more land for oil palm, rubber and other agricultural crops as well as to conserve biodiversity and forestry operations in remnant native forests, restoration or intensification of use of Imperata grasslands is becoming a priority policy goal of a number of governments in the region. Developing successful policies and strategies for restoration, however, will require a strong research-based understanding of the many biophysical and socio-economic constraints and dis-incentives to conversion (Tomich et al. 1997; Foresta & Michon 1997; Potter 1997;Magale-Macandog et al. 1998).
Overall, a better understanding of land-use transformations should assist in developing more appropriate land-use systems to sustain growing populations, help improve degraded lands and alleviate deforestation.  This requires a good understanding of what drives land-use and -cover change, its effects, and the social context.  Although land-use and -cover change have a biophysical reality, in practice what constitutes an “environmental problem”, is always in part, culturally and socially determined (Batterbury et al. 1997).

The LUCC Core Project of the IGBP is an interdisciplinary research program leading the international effort aimed at understanding the patterns, causes and implications of land-use and -cover change (Turner 1997; see page 122).  This Core Theme takes as its starting point the LUCC framework (Turner et al. 1995) and applies it to the rural areas in the Southeast Asia region.   Core Themes 1 and 3 extend the framework further to consider in detail the multi-sectoral drivers of land use change including spread of technology, urbanisation, population growth, globalisation of economies, and changes in consumption patterns and life styles. The biophysical implications of land-use and -cover change are addressed in Core Themes 5 and 6 of this Integrated Study.

There are a number of possible perspectives and scales for looking at the drivers of land-use and -cover change (Figure 3.2.1). Agro-ecological knowledge and decision making has different implications at different scales (Fresco 1995). Some studies have focused on decision behaviour of land managers, often the immediate farm owners, but in some cases also key players in national land and agricultural policy processes. Others have examined the relationship between collective decisions as expressed by changes in actual land-use and -cover over time with socio-economic conditions.  These studies explore roles of, for example, population, organisation, technology and labour.  Some of these studies show that increases in population can be associated with economic growth, improved technology, innovation, and thus more sustainable practices (Tiffen & Mortimore 1992; Tiffen 1995). A common goal of such studies is the analysis of the capabilities of local inhabitants to successfully adapt and respond to environmental problems, for example, through application of local knowledge and experience (e.g. Kummer et al. 1994; Brookfield 1995).

Figure 3.2.1

Multi-scale driving forces in land-use and land-cover change (after Turner et al. 1995).

 
Another approach focuses on the power-relations between various stakeholders and how these lead to control of land-use by large scale agri-businesses at the expense of small-holders (e.g. Dove 1995; Hirsch 1995). Land degradation and other environmental problems are often associated with marginalisation and lack of empowerment.  Finally, other studies emphasise the biophysical constraints and opportunities of different land units and look to explain deviations between actual land use and best management (e.g. Garrity 1993; Lanh 1994). The insights gained by different approaches are not identical and not easily substitutable; studies are needed from a variety of perspectives.
The purpose of this Core Theme, therefore, is to improve understanding of the drivers of the processes of land-use and -cover transformation, with a focus on those which have recognised environmental impacts, for example, leading to land degradation, restoration and improvements in sustainability or high emissions.

This Core Theme is divided into four activities.  Activity 2.1 documents rates and patterns of change in land-use and -cover. The next two Activities address the processes of transformation, with Activity 2.2 focussing on the role of on-site processes, especially decision making at small scales such as the farm, whereas Activity 2.3 emphasises external drivers of change usually operating at large scales.

The distinction between on-site and external drivers is of course to some extent arbitrary, but does help emphasise that the driving forces of land-use and -cover change are multi-scale. The fourth Activity aims to synthesise this understanding by refining methods to project land-use and -cover changes into the future.

This Core Theme will contribute to the Integrated Study by improving understanding of the processes of environmental change in the inland parts of the catchment.   This knowledge will be integrated with understanding of processes that operate in other parts of the catchment and at the among-catchment scale through the activities in Core Theme 8 and, in turn, contribute to the development of improved landscape management practices (Activity 9.5).

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Activity 2.1 Documentation of Land-Use and –Cover Change Rates and Patterns

Rationale

To get a global or even regional picture of the impacts of land-use and -cover changes, research on the drivers of change must be supported by accurate data on how land-use and -cover has actually changed. This requires the development of efficient and reliable methodologies to document land-use and -cover changes in the coastal zone (cf. Activity 1.4) and rural hinterland. Remote sensing technologies (e.g. satellite imagery and aerial photography) are crucial for land-cover. Information on actual land-uses, however, will usually still require, in addition, farm-level surveys or agricultural census data. Studies of tropical deforestation in the Amazon  (e.g. Skole & Tucker 1993) and Southeast Asia (e.g. McGregor et al. 1996) illustrate the value, and limitations, of remote sensing for describing spatial patterns of land cover change, especially fragmentation, and the implications of regeneration. When these data are combined with land census data and understanding of economic and institutional factors, we can begin to understand the complex interaction of drivers and scales  (Skole et al. 1994; Turner 1997).

Objectives and Questions

The primary objective is to document the rates and spatial patterns of land-use and -cover change in the rural areas of Southeast Asia.

Some questions to be addressed include:

1. What is the rate and spatial extent of deforestation for agriculture and logging?  Does clearing for agriculture and timber extraction have different characteristic patterns of spread across the landscape? What are the transition dynamics for abandonment and regeneration?

2. What is the rate and spatial extent of agricultural intensification?  How are patterns of spread influenced by scale of land holdings?

3.  How does the rate of deforestation and agricultural intensification vary on an inter-annual, inter-decadal basis?

4.  How long does it take to introduce a new land use type?  How does the structure of the landscape evolve as a new land use type goes from rare to common? How does the proximity and quality of roads and markets influence patterns of land-use and -cover change?

5.  How sensitive are rates of deforestation, agricultural expansion and intensification to the scale of measurement?  How do measures of patterns of land-use and -cover change vary with scale?

Research Strategy

A network of case studies is appropriate.  LUCC Focus 2 (Turner et al. 1995) provides a guide in planning for future work under this Activity. This should be built upon the four SARCS-LUCC watershed case studies in Indonesia, the Philippines, Thailand and Malaysia (SARCS 1998), and be extended to include some of the other parallel initiatives in the region, such as the, the Alternative to Slash and Burn  project in Indonesia (van Noordwijk et al. 1995), and the East-West Centre studies in Northern Thailand (Fox et al. 1995, 1997).  These later studies will be particularly important for understanding of the drivers of land conversion (Activities 2.2 and 2.3).

The SARCS-LUCC case studies aim to develop standard methodology to monitor land-cover change; to understand and describe the processes, factors, and forces that drive the changes; and to evaluate the impacts of the changes on the environment.  The case studies have already made substantial progress in developing national teams competent in carrying out land-cover change studies over 5-10 year time frames with geographic information system and remote sensing technologies. For example, the case study of land-cover changes in Klang-langat basin, Malaysia, document the expansion of human settlements (and industry) around Kuala Lumpur and the continuing conversion of forest for agriculture in more distant areas from the city (Figure 3.2.2).   All four case studies documented declines in forest cover in all sites (Figure 3.2.3, bottom).  Agricultural land cover declined in the Upper Citarum and Magat watersheds, whereas it increased at the other two sites (Figure 3.2.3, top).  The decline in agricultural land in the Upper Citarum watershed in Java, Indonesia, was due largely to conversion to urban settlement, grasslands and barelands.

These studies provide a base within the region for further developing and testing methods to improve the temporal resolution of historical data and distinguishing transitions among a wider range of land use types. They also provide a framework for developing the kinds of standardised protocols and classifications essential for comparing sites and extending the network to include other catchments in the Integrated Study.  The main challenge, however, is to begin linking these observations of changes in land cover with the critical datasets on social and human drivers of change (Activities 2.2, 2.3).

Outputs

· A set of high quality, validated datasets describing the changes in land use and cover in a set of case studies across Southeast Asia useful for developing models to project land-use and -cover changes in the rural hinterland (cf. Activity 2.4).
· Based on the datasets, a series of studies for: (i) developing and testing land surface - atmospheric models (cf. Activity 6.1); (ii) integrated bioregional models (cf. Activity 8.5); and (iii) large-scale models to explore the influence of land-use and –cover change on the regional and global biophysical environments (cf. Activity 8.6), especially, greenhouse gas emissions.
· Some of the expertise needed to develop standardised methods of data collection, interpretation and classification for the development of regional data and information systems (cf. Activity 8.1)

Figure 3.2.2
Land-cover changes in the Klang-langat basin, Malaysia. Areas that changed between 1974 and 1984 are shown with a speckled pattern.  The four other main land-covers are also identified in the image by examples (small areas were also classified as grassland and bareland). A small colour version of this image appears on the cover of this publication. (Source:  Universiti Kebangsaan Malaysia: SARCS/LUCC Case Study).

Figure 3.2.3
Agricultural and forest land-cover changes in the four case studies of the Southeast Asian SARCS-LUCC project.  The periods covered in the four studies were: Chiang Mai (Thailand) 1984-1996; Magat (Philippines) 1974-1990; Klang Langat (Malaysia) 1983-1993; Upper Citarum (Indonesia) 1985-1995. (Re-drawn from data in summary tables in SARCS 1998).

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Activity 2.2 On-site Drivers of Land-Use and -Cover Change

Rationale

At the scale of unit of production, important processes with immediate and direct impacts on land cover are burning and clearing.  More subtle impacts may result from harvesting of timber and non-timber products (e.g. hunting) in forest and complex agro-ecosystems.  Changes in land use and cover result from a wide range of land management practices, including soil improvement methods, choices of crops, and so on.

The on-site social drivers of land-use change decisions include values, the structure and size of families, division of labour, availability and skill of labour, degree of empowerment and wage rates. These drivers, in turn, interact with external socio-economic factors (cf. Activity 2.3) and on-site biophysical processes determining, for example, micro-climate, soil moisture and fertility (cf. Core Theme 5).  Adaptation to recent and expected climate variation may influence land-use decisions decisions although this often will often be compounded by other external economic and social factors (e.g. Smit et al. 1996; Salafsky 1994; cf. Activity 2.3).

To study the human drivers of change it is worth distinguishing at least two broad types of units of production in the rural hinterland: smallholders and agribusiness. Most studies to date have focussed on smallholders, both long-term and recent occupants, many of whom practice various forms of shifting cultivation. Studies of shifting cultivation and complex agro-ecosystems reveal a wide variety of practices having very different implications for biodiversity and sustainability (van Noordwijk et al. 1995; Ramakrishnan 1996).

Smallholder systems, however, are not necessarily the most important in terms of regional rates of change or environmental impacts.  Large-scale agribusiness operations in Malaysia, Indonesia and Thailand have rapidly transformed vast areas of native forests, and sometimes traditional smallholder agricultural areas, into monoculture plantations of rubber, oil palm and tree plantations (e.g. Figure 3.2.3; Activity 2.1). Large-scale plantation development although often driven to meet domestic and foreign market demand (cf. Activity 2.3 and 3.1) may also be promoted to restore degraded lands.

The social and economic drivers of land-use change by smallholder and agribusiness operations are likely to be very different so both need to be considered in this study. In addition, in the centrally planned economies, like Laos and Vietnam, as well as some other traditional cultures it may be valuable to distinguish larger scale collective or shared farming systems.

Objectives & Questions

The objective of this activity is to understand the proximate causes of land-cover conversion and subsequent land-use change in the rural areas of Southeast Asia..
Key questions to be addressed are:
1.  How does knowledge, attitude and practices of land managers influence decisions about crops and land management practices? Does the number of family members, especially farm labourers, in a household influence the choice of crops? What is the role of age and gender in such decisions? What is the role of cultural conditioning in the choice of crops and land-use practices?
2.  How are land-use decisions made in response to variability in environmental (e.g. climate) and social conditions (e.g. markets and availability of labour)?   How does the process differ between large-scale agribusiness operations and smallholders?
3.  How do ecological constraints, such as steep gradients, degraded soils, and rainfall patterns interact with cultural attitudes, business and agricultural practices?
4.  What strategies do traditional societies and agricultural businesses use to deal with problems of land degradation? What are the main on-site social and economic barriers to effective rehabilitation or regeneration of degraded uplands?

Figure 3.2.4
Land use change in Sabah 1965-1992 illustrating the rapid expansion of private commercial oil-palm and cocoa plantation estates (Figure prepared from data in Sutton & McMorrow 1998).

Research Strategy

This Activity will require studies of the knowledge, attitude and practices of land managers and decision-making processes. The area of potentially relevant research is very broad, with work being done in many government agricultural departments, research institutions and extension services.  Most of the existing body of work, however, is not conducted in the context of large-scale environmental change (regional and global). Therefore, an important first step should be the preparation of a synthesis of existing research on the on-site social drivers of land-use and -cover change in Southeast Asia.

Sites should be selected for inclusion in the study based on their ability to contribute to an overall understanding of the variability and magnitude of on-site social drivers in the network of sites of the Integrated Study.  This means considering both the kinds of land-use and -cover transformations as well as the nature of the local drivers. A possible strategy for more in-depth study would be to develop two networks of case studies, one focussing on smallholder-dominated landscapes and another for areas in which large-scale business is becoming or is already important.  Alternatively, sites could be selected to represent a range of positions along this spectrum, which essentially corresponds to a segment of the “land-use intensity” gradient proposed as an integration tool (see page 96).  The sites which have already been documented as part of the SARCS-LUCC case studies and the Alternative to Slash and Burn Project in Jambi province would provide an initial core around which to build up the networks.

The insights from this Activity will need to be reconciled with the work on the external drivers of change (Activity 2.3), for example, through the use of multi-scale models (Activity 2.4), to obtain an aggregated picture of the human driving forces of environmental change at the larger regional scales.

The work in this Activity also needs to coordinated with on-site studies of biogeochemical systems (Activity 5.1) so that sustainable land-use systems can be developed. For example, the integration of the results from the individual case studies would benefit from selection of sites which create a conceptual gradient of land-use intensity.

Outputs

· An improved understanding of land-use decisions at the farm level by smallholders and larger-scale agribusiness. This understanding of the constraints — economic, ecological and social —  should help improve conceptual models of decision behaviour.
· Contributions, in collaboration with the studies on off-site drivers (cf. Activity 2.3), to the effort to develop strategies to promote sustainable agricultural practices (cf. Activity 9.3) and improve landscape and regional land management and planning (cf. Activity 9.5), by identifying key constraints that influence decision making.

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Activity 2.3 External Drivers of Land-Use and -Cover Change

Rationale

Land-use changes are not just driven by proximate ecological and socio-economic factors influencing land-use decisions at the scale of the unit of production (see Figure 3.2.2).  The external, or off-site drivers can often be even more important. They are distant, do not experience close feedback with local environmental mismanagement, and usually allow land managers little or no control over them.

External drivers include processes such as industrialisation, urbanisation, transport infrastructure development, population growth and migration and the globalisation of markets and economies.  Changing consumption patterns in urban centres may be particularly important in expanding the overall ecological footprint of cities on the rural hinterland and creating demand for new agricultural products and faster rates of extraction of natural resources.

The development strategy followed by most Southeast Asian governments, especially in the 1950s and 1960’s, emphasised industrialisation as a key to rapid growth with policies that often discriminated against agricultural development (Than 1998). Since then most governments have acknowledged the critical role played by the agricultural sector in supporting overall development and economic growth (Baliscan 1998; Rahman 1998; Tambunan 1998).
National governments facilitate changes in land use through incentive systems to change the product mix, favouring certain crops over others in different places and times (e.g. through fertiliser subsidies, controlling commodity prices and so on).  Governments also use various instruments (e.g. land zoning, property rights) to discourage particular land uses, sometimes with the stated aim of protecting the environment and conserving biodiversity.

Laos, Vietnam and Thailand, for example, have numerous policies directed at ethnic minority groups practicing shifting cultivation in upland areas.  A number of commentators have pointed out that some of these policies, such as fruit growing and terracing for vegetables, if implemented where there is no infrastructure to take products to markets, may create more problems than they solve (e.g. Fujisaka 1991; Rerkasem & Rerksasem 1995; Fox et al. 1994). Inadequate property rights and lack of political power of ethnic minorities and smallholders are often key issues in determining land-use decisions (cf Activity 3.2).

The emphasis within the forestry sector in Southeast Asia, has been on production of wood and wood products (including plywood and pulp and paper) rather than sustainable use of forest resources ( Lohmann 1996; Thompson & Duggie 1996). As a consequence, deforestation has been a prominent feature of agricultural and industrial development in Southeast Asia over the past several decades ( Hirsch 1987).

Objectives & Questions

The objective is to understand the external drivers of land-cover conversion and subsequent land-use change in the rural areas of Southeast Asia.

Key questions to be addressed are:
1.  How do changes in demand for agricultural commodities as a result of lifestyle changes in urban areas influence land-use change? What are the effects of national economic growth on land use in the rural hinterland?  What are the effects of urbanisation and transmigration programmes on land-use and -cover changes? How do the energy demands associated with  industrialisation impact on land use and cover in the rural hinterland?
2.  How does the development of rural infrastructure, in particular, the provision of roads, influence land-use decisions in remote areas where access to markets is a key constraint on earning an income from agriculture?
3.  To what extent do centralised policy decisions on agricultural development and land use over-ride local drivers of land-use change? How do national agricultural, timber and general market policies hinder or promote land conversion? What is the influence of within country and international trade on land-use practices? How do regional trade agreements influence market prices of key commodities in the rural hinterland?
4.  How does the degree to which a nations’ economy is centrally-planned, or conversely, market-driven, affect rates and patterns of land-use change?  Does centralised land-use planning produce more homogeneous landscapes?
5.  How do external drivers influence changes in landscape structure in areas dominated by smallholders versus those controlled by large agri-businesses? Under what environmental conditions and socio-political contexts do large-scale agri-business operations perform better — economically, ecologically and socially — then smallholder land-use systems, and vice-versa?   What is the relationship between large-scale agribusiness, smallholders and government?  What is the system of land tenure for agribusinesses?  What obligations must agribusiness meet under regional environmental laws?

Research Strategy

The potential scope of this Activity is very large and overlaps substantially with other parts of the Integrated Study.   In many ways it is one of the central themes of the overall Study.  For this reason, this Activity will need to draw on the results and findings of various other parts of the study to a greater extent then most other Activities in Core Themes 1 through 7. For example, understanding of on-site drivers (Activity 2.2), and insights from the analysis of property rights systems (Activity 3.2), investment and trade (Activity 3.1), environmental agreements (Activity 3.3) and urban footprints (Activity 1.3) will be valuable.  Statistical analysis of the relationships of key drivers with actual land-use made at multiple scales will be an important implementation tool.   An excellent and highly relevant example of such an analysis is the investigation by (Veldkamp & Fresco 1997) for Costa Rica using multiple regression models at different levels of aggregation of the basic gridded data (see Activity 2.4).  An early step in this activity should be the extension of such analyses to the existing Southeast Asian case studies.

A case study approach is appropriate and should build on existing projects. For example, current research by organisations like International Centre for Research in Agroforestry (see page 127) through the Alternative to Slash-and-Burn Project (van Noordwijk et al. 1995) is an excellent model for building the necessary network of case studies. Also, commencing an analysis of the implications of the major external drivers for the four SARCS-LUCC Southeast Asian case studies should be a high priority.  In selecting additional sites for comparison, consideration should be given not only to the on-site characteristics (e.g. covers) and drivers, but also their socio-economic contexts to capture a wide variety of potential external drivers.  Adding a case-study from Vietnam, which is undergoing rather different process of institutional and organisational reform than its’ neighbours (e.g. Que 1998), would, thus, be highly desirable.
In terms of strategies for analysis, one possible approach might be to arrange case studies along a conceptual axes of degree of government control vs. free-market or smallholder vs. agribusiness. Also sites could be organised along a conceptual gradient of land-use intensity (cf. Activity 8.4, see page  95) which would facilitate linkage to the biophysical work in Core Themes 5 and 6.

Outputs

· This Activity will make a major contribution to the overall synthesis of human driving forces (Activity 8.2).
· An improved understanding of how external drivers, operating at multiple scales, such as markets, population policy, lifestyle changes, and industrialisation, influence land-use changes in the rural hinterland.
· Together with the analysis of ecological footprints of cities (cf. Activity 1.3), quantification of the magnitude of the inter-dependence between industrial/urban centres and the rural hinterland.
· Insights into how policies directed at other sectors, in particular, economic growth, trade  and industrial development, have unintended side-effects on rural development. This information will be crucial to the multi-sector assessment of sustainable development strategies (cf. Core Theme 9).
· Together with the on-site research (cf. Activity 2.2), the conceptual framework and some of quantitative relations needed to construct models of land-use and -cover change in the rural hinterland that go beyond the immediate drivers (cf. Activity 2.4).  This is a critical step on the way towards fully integrated bioregional models of land-use and -cover change and its effects (cf. Activity 8.5).

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Activity 2.4 Projecting Land-Use and -Cover Change into the Future

Rationale

To project rates and patterns of land-use and –cover change there is a need to develop modelling systems capable of representing the proximate and external driving forces. This, in turn, requires the understanding and datasets developed through Activities 2.1, 2.2 and 2.3, and approaches capable of handling, in a spatially explicit way, drivers that operate at different scales.

There is now substantial international effort under LUCC and related programs to develop integrated models of the drivers of change. These vary widely from, normative approaches that seek economically or ecologically efficient solutions, to empirical approaches that stress observed relations between land-use and drivers (Turner et al. 1995).
In agricultural land use studies planning options are often been explored using land evaluation methods combined with multi-criteria models.  These are typically driven by yield-potential which is a poor descriptor of actual yields and land-uses (Veldkamp & Fresco 1997). More realistic scenarios of land use can be achieved by incorporating the empirical relations between actual land use and the biophysical and human drivers at multiple scales (Veldkamp & Fresco 1996).  Such models can often capture more realistically the dynamics of competition among land-use types.

Objectives & Questions

The primary objective of this Activity is to project land-use and -cover changes in the rural hinterland into the future based on an improved understanding of local and external drivers.
Some of the key questions to be addressed are:
1.  How might the rate and spatial extent of deforestation for agriculture expansion progress over the next 10, 20 and 50 years?
2.  How might the spatial extent of land use by large-scale agribusiness for mono-specific plantations change with respect to land use by smallholders for complex agroecosystems and other cropping systems?
3. How have general economic conditions and the commodity markets for export-oriented crops, like tea, coffee, sugar, palm oil and rubber, affected land-use changes historically?  Given plausible scenarios for how such markets might evolve in the future, what are the likely dynamics of  agricultural land-use?
4.  Are there any important interactions in land-use patterns between countries within the Southeast Asian region?  For example, how does the rapid growth in area of oil palm plantations in Indonesia influence further land use conversion to plantation in Malaysia or elsewhere in the region?
5.  How does economic growth and urbanisation influence surrounding land use? What are the potential impacts of fluctuations in the size of the rural workforce and technological change on large-scale patterns of land use?
6.  How do the dynamic relationships between social drivers and land use/cover change vary with spatial scale? Conversely, what relationships are largely scale-independent?

Research Strategy

Parts of LUCC Focus 3 (Turner et al. 1995) provide a suitable framework for this Activity within the Southeast Asia region.  The key element of this strategy is to adopt a two-track approach: extending existing modelling approaches, and developing new modelling frameworks. The appropriateness of  methods will depend on the time scale of interest and the availability and resolution of data.  For short time scales, say less than 10 years, projections from state-and-transition models may be appropriate. However, as the time-scales increase, 10-40 years, a greater emphasis on spatial dynamic modelling and plausible land development scenarios becomes more important.  These models will need to go beyond proximate drivers and consider the external drivers of land-use and -cover change.  An economic-sector modelling framework may be appropriate (e.g. Darwin et al. 1996). Policy analysis matrices can help explore the consequence of plausible government interventions on future land-use mixtures, for example, conversions between rice, mung bean and soybeans in Northeast Thailand (e.g. Yao 1997). At decade-to-century time scales, increasing the spatial scale and incorporating successional processes and climate sensitivity analyses will also be required (Rotmans et al. 1994).   Spatial dynamic models will be valuable in exploring the interactions between on-site and external drivers of change, which often work at disparate spatial and temporal scales.

A network of modelling groups is needed to synthesis the understanding from the previous three Activities in Core Theme 2.  A major effort should be made to formalise the procedures for validation and independent testing of models. One possible strategy would be to bring together in a single network the new modelling studies in the Asian region adopting CLUE-like modelling frameworks (Veldkamp & Fresco 1996), and the Impacts Centre for Southeast Asia Landscape Modelling Network (Lebel 1997), with the existing SARCS-LUCC and Alternative to Slash and Burn projects. With this approach it may be worthwhile extending the areal extent of the case studies to address more fully the interaction between, for example, urban centres (cf. Activity 1.3) and changes in the rural hinterland.
A new initiative will be required to bring together researchers working on economic and social futures with those studying land-use and -cover dynamics to prepare a set of working scenarios of future land development in the rural hinterland for each of the sites in the case study network.  These scenarios will be important for exploring the sensitivity of models.

Outputs

· Models with a vastly improved capability to develop scenarios of land-use and -cover changes in the rural hinterland over the next several decades. These models will provide a  research tool to explore the sensitivity of overall rates and patterns of land-use change to various postulated drivers of change (cf. Activity 2.3), which can be tested against observations (cf. Activity 2.1).
· Land-use and –cover change projections, and their sensitivity to assumptions about agricultural land development policies, for use by natural resource managers and regional planners.
· Model-derived scenarios which contribute to, and are influenced by, the development of long-term futures scenarios for Southeast Asia (cf.Activity 8.7).
· Models which, together with biochemical process models (cf. Activity 6.1), contribute the rural component of integrated models of bioregional development (cf. Activity 8.5) and greenhouse gas emissions (cf. Activity 8.6).

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