Land system science: handling complex series of natural and socio-economic processes

Land system science: handling complex series of natural and socio-economic processes

This special issue of Journal of Land Use Science contains a selection of papers presented at the Third LaSyS Workshop in Tune, October 2007. LaSyS, the Danish Network for Land Systems Research, was formed with the aim of providing a forum for discussion of contemporary research directions in land systems research. It is rooted in research ideas promoted over the past decade by ‘The Global Change and Terrestrial Ecosystem’ and ‘Land Use Land Cover Change’ (GCTE–LUCC) communities under the IGBP and IHDP programmes (Lambin and Geist 2006; Canadell, Pataki and Pitelka 2007; Turner, Lambin and Reenberg 2007). This work is currently being continued and developed into a transdisciplinary approach to the study of coupled human–environmental systems under the auspices of The Global Land Project (GLP 2005). Hence, GLP's ambition is to combine the experience from the ecosystem research and land use system research communities and move towards studying the land system dynamics as a complex interaction between societal, natural and mixed processes at various temporal and spatial scales. Two major future challenges are pointed out by the GLP. One is to deal with the upscaling of local and regional process understanding to achieve global process understanding; the other is to fully integrate the societal and environmental dimensions of the problem (GLP 2005).

The intention in creating the LaSyS network was to facilitate the discussion of the ways in which Danish research environments can best combine efforts and expertise in order to contribute to the international development of an integrated and interdisciplinary analysis of global land system change processes. Although the first efforts mainly concentrated on mapping Danish ideas and results (Reenberg 2006), the third LaSyS workshop focused on discussions of a more fundamental nature, and involved to a large extent research-based international experience and visions.

Overall, the workshop tried to embrace two major themes. On the one hand, a number of speakers were asked to present their visions for contemporary approaches to land systems science. They were asked to share their experience and point to seminal recent developments within land systems science as well as to future challenges. On the other hand, a number of contributions placed emphasis on challenges related to interdisciplinary land systems research. Using examples from their individual disciplinary background, the importance and influence of different disciplinary cultures, success criteria and meanings, for example, in terms of level of documentation and standards to confirm research hypotheses, were addressed.

The papers presented in this issue in no way represent a full record of the discussions or a comprehensive reflection and conclusion related to these two themes. Rather, they constitute a taste of the many important challenges that pave the road towards a common theoretical and methodological platform for land systems science.

Veldkamp (pp. 5–14, this issue) addresses conceptual challenges to be faced by land system modellers. He proposes that a multi-scape system approach might serve as a simple qualitative framework to identify relevant issues and to help bridge the multidisciplinary gap. The basic notion is that land appears in different realities as different phenomena, which are referred to as ‘scapes’ (e.g. geo-scape, bio-scape, econ-scape, mind-scape). Veldkamp argues that, because the land system is a coupled human–environmental system, there is a fundamental need for modelling feedbacks, which allows the system some degree of self-organization. It is specifically stressed that stakeholder perceptions must be included in the modelling in order to advance scenario development. Dealing with land systems is not goal free. It is therefore essential when describing and modelling land dynamics to implicitly address the different goals involved and to pay specific attention to land governance.

The concept of the human appropriation of net primary production (HANPP) has gained attention as an indicator that explicitly links natural and socio-economic processes. Krausmann et al. (pp. 15–33, this issue) illustrate in their paper how HANPP can be employed as a socio-ecological indicator of the intensity of land use. In a number of previous papers, this research group has demonstrated that understanding patterns in HANPP is important for the integrated analysis of the global land system. It is specifically noted that explanations of spatial patterns of HANPP need to take both socio-economic and natural factors as well as their interaction into account. The paper in this issue analyses the global geographical patterns of HANPP by discussing statistical analyses of a global national-level data set that includes data on HANPP and its components as well as selected potential determinants of HANPP. They find that population density emerges as the most powerful determining factor. However, their results also underline that the interrelation between HANPP and economic growth or development is complex. Richer societies are normally associated with consumption preferences that tend to drive up HANPP, such as diets based on animal products, but economic growth is also associated with growing biomass trade as well as technological innovations that can help to reduce the amount of HANPP caused per unit of biomass consumption.

Global land use changes are frequently the result of complex patterns of spatial linkages in which local land uses are spatially disjoined from the corresponding product demand and consumption. Life cycle impact assessment (LCIA) models can serve as a useful tool to analyse such perspectives of land occupation and land transformation. Schmidt et al. (pp. 35–52, this issue) demonstrate the application of LCIA in their study of the land use impact of increasing demand for biodiesel. They compare the impacts of rapeseed oil production in the EU and palm oil production in Southeast Asia and assess the land occupation and land transformation for the two alternative vegetable oils. Based on the models, a number of scenarios are developed. The scenarios, in turn, enable a comparison of different strategies for biodiesel provision for the European market which take into account the global land use footprints (in e.g. Southeast Asia or Canada) as well as the possible impact on biodiversity.

The impact of land use on biogeochemical cycles is a key issue in land systems science, and has a prominent position in the GLP science plan. One theme of importance is how land use change influences the hydrological processes and water quality, for example, as a result of changes in agricultural runoff. Jensen and Veihe (pp. 53–72) employ a classical dynamic agro-ecosystem model (Daisy) to examine the potential effect of land use and climate change on nitrate leaching rates. They present the results of a case study from Denmark and show how scenario analysis can provide a useful point of departure for in-depth assessment of land management scenarios, specifically with regard to the correspondence between land use and nitrate leaching at the regional scale.

The last three papers have an empirical focus on Eastern Europe, and hence address land use systems which have experienced a very radical and rapid change in their social, economic and political conditions. This makes them particularly interesting laboratories for studies of the dynamics of change in coupled human–environmental systems. Kuemmerle et al. (a, pp. 73–83) focus on the dynamics of forest cover with specific attention to how harvesting rates differ among different landownership types in times of radical change. They investigate the rates and spatial patterns of forest disturbance in private forests, state forests and a National Park in the Polish Carpathians before and after the collapse of socialism using Landsat TM images and a landownership map. They find that disturbance rates in private forests are higher than on public lands, and that private forests are more fragmented than state and National Park forests. Their case reveals that hierarchical and multi-scale controls are affecting land cover change, ranging from e.g. national political and legal structures to local ownership conditions. Kuemmerle et al. (b, pp. 85–107) present a new approach suited to analyse land use changes in post-socialist landscapes where large fields are fragmented into smaller ones. Their method is based on image texture based on Landsat data. They demonstrate that field size is highly correlated with image texture. Hence, image texture is demonstrated to have a significant potential for mapping land use patterns and may contribute to a better understanding of land cover modifications in Eastern Europe and elsewhere.

Finally, Müller et al. (pp. 109–129) focus on cropland abandonment in Eastern Europe. They derive the documentation of land use changes from satellite images, which enable them to monitor 15 years of change. The process of change is expected to be caused by socio-economic as well as biophysical factors, such as market access, local population changes, plot fragmentation or topography. Spatially explicit statistical modelling is employed to identify the direction and strength of the causal influences that led to cropland abandonment. The integrated modelling approach enables them to document the dynamic trends of the land system, i.e. a spatial reorganization of the landscape towards a more homogenous cropland use, notably in the hilly areas that are well connected with the main employment centre.

As evident from the introduction above, the papers differ in many respects: disciplinary emphasis, methodological approach, empirical focus, levels of temporal and spatial scales dealt with, etc. They represent, each in their own fashion, conceptual, methodological or empirical contributions to land systems science. They provide, however, in no way a systematic or exhaustive treatment of the challenges faced by the land systems researchers; nor are they meant to. The workshop identified and discussed a number of other areas that will need considerable attention in the future development of a land systems science capable of dealing with the dynamics of coupled human–environmental systems. Prominent among these challenges are, for example (1) transdisciplinary barriers for the land system science research community, created by firmly rooted, disciplinary differences in research cultures, agendas, success criteria, mutual interactions and meaning, and (2) the temporal complexity of land systems, which calls for conceptual models that go beyond ‘history matters’ and take path dependency and adaptive cycles into account.

Acknowledgements

The Danish Network for Land System Science (LaSyS) is supported by a grant from the Danish Council for Agricultural and Veterinary Research (SJVF), which has made the LaSyS Workshop possible. The event was co-organized with the GLP.

Lars Jorgensen from the GLP's International Project Office at the University of Copenhagen has provided invaluable support for the organization and practical implementation of the workshop and during the editorial process.

We extend our thanks to all participants in the workshop for their valuable contributions and to the Journal of Land Use Science for making space available for this special issue. Last but not least, we would like to thank the anonymous referees who have kindly assisted us with assessing the quality of the submitted papers and made useful and much appreciated suggestions for improvements.