Human–environment interactions: towards synthesis and simulation ...

Reg Environ Change (2006) 6: 115–123 DOI 10.1007/s10113-005-0012-7

O R I GI N A L P A P E R

J. A. Dearing Æ R. W. Battarbee Æ R. Dikau I. Larocque Æ F. Oldfield

Human–environment interactions: towards synthesis and simulation

Received: 6 July 2005 / Accepted: 15 December 2005 / Published online: 3 February 2006
Springer-Verlag 2006

Abstract Leaders of the PAGES Focus 5 programme ‘Past Ecosystem Processes and Human–Environment Interactions’ identify key issues for research on human– environment interactions for wider discussion. These include the need for long-term perspectives, the opportunities for maximising palaeoenvironmental research, the need for integration and regionalisation and the challenge of developing dynamic simulation models. A new organisational matrix for regional studies is outlined, based on a series of zonal/azonal regions and on the degree of human impact. Future priorities for palaeoenvironmental research include new studies in degraded human-dominated landscapes, highly-valued ecosystems and sites relevant to other IGBP Core Projects. Simulation of future human–environment interactions using modelling approaches that have been tested against long records lags behind global climate modelling, but cellular approaches for biogeophysical and multi-agent systems show promise. Keywords Regionalisation Æ Integration Æ Simulation Æ Palaeoenvironmental studies Æ PAGES Focus 5

J. A. Dearing (&) Æ F. Oldfield Department of Geography, University of Liverpool, L69 7ZT, Liverpool, UK E-mail: [email protected] Tel.: +44-151-7942873 Fax: +44-151-7942866 R. W. Battarbee Environmental Change Research Centre, University College London, WC1 0AP London, UK R. Dikau Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115 Bonn, Germany I. Larocque INRS-ETE, 490 De La Couronne Que´bec, G1K 9A9 Que´bec, Canada

Future world: future needs The threat of an accelerating trend in global warming is now very real. Recent scientific commentators suggest that even climate scenarios made in 2001 are now likely to be underestimations of true temperature rises over the next century (Stainforth et al. 2005). A recent report estimates that severe, if not irreversible, consequences will occur when the mean global temperature rises to 2C above pre-industrial levels, a prospect that could be reached in the next couple of decades (The International Climate Change Taskforce 2005). With population and development pressures continuing to impact on land use and energy resources, some climate research groups (e.g. UKCIP) are even viewing the prospect of limiting CO2 emissions and global warming through international treaty as unlikely. As a result, adaptation and sustainability drive much of the new agenda for the international Earth System Science Partnership and national agencies. Our current predicament focuses attention on the question of how best to anticipate human–environment interactions in the future (Oldfield 2005). To what extent will we be able to anticipate, project, forecast or predict future conditions in human-dominated landscapes and highly valued ecosystems? What is realistic with respect to understanding climate–human activity interactions and defining the needs for sustainable management? What kinds of information would we wish to obtain in order to make good judgements? Here we discuss the importance of different aspects of Focus 5 science that we believe can help answer these questions and contribute to the sustainable management of landscapes and ecosystems.

Improving palaeoenvironmental methodology Linking past and present Realising the full potential of long records requires linking together contemporary and historical perspectives on

116

a particular environmental issue. Within the fields of palaeoecology and palaeohydrology, the closest parallel to this type of productive linkage has been in palaeolimnology. Here, the long-term perspective made possible by sediment studies has been crucial to unravelling the origin of recent problems such as cultural eutrophication and surface water acidification (e.g. Battarbee 1978, 1990; Battarbee et al. 1985; Charles et al. 1990; Smol 2002). Thus there is now wide recognition of the need to place studies of contemporary lake ecosystems into longer-term perspectives by developing the continuum of insight made possible by sediment studies bringing the historical record up to the present day. This is best achieved at sites where both high-quality sediment records and long-term observational records co-exist. These data types are interdependent. Sediment records allow extended time-scales and provide a proxy-monitoring tool for almost all natural (and many artificial) lakes, but are subject to biases arising from differential preservation of fossils (e.g. Battarbee et al. 2005a) and uncertain chronology. Instrumental records on the other hand are highly resolved and accurate in time, but are rare and of limited duration, only very occasionally providing insights into the longer-term variability of ecosystems that is critical for ecological understanding and model development. Combining contemporary and palaeodata has been particularly successful in studies of lake acidification, for example, where long-term data-sets for epilithic diatoms, diatoms in annually exposed sediment traps and diatoms from sediment cores have been used together to indicate changes in lake water pH over the last 200 years (Battarbee et al. 2005b). Increasingly the conceptual gap between palaeolimnology and limnology is being bridged as palaeolimnological techniques improve and as limnologists appreciate the usefulness of the additional time dimension provided by the sediment record (e.g. Jeppesen et al. 2001; Battarbee et al. 2005c). Turning to terrestrial ecosystems, it is hard to escape the view that there is a much greater disjunction between palaeoecology and present day ecology despite recent articles highlighting the convergence in spatial scales of research (Davis 1989), and the crucial role historical information can play in evaluating assertions regarding highly topical issues such as carbon sequestration (Compton et al. 1998; Hooker and Compton 2003; Foster and Aber 2004). The disjunction is methodological rather than simply disciplinary. There is strong interaction between large-scale experiments, coordinated observation campaigns, monitoring and assessment and ecosystem modelling, but most models designed to simulate terrestrial ecosystems pay little regard to the wealth of information present in the palaeorecord. Equally, all too little research in terrestrial palaeoecology is designed with a view to the role it might play in testing ecosystem models. After many meetings and conversations, we conclude that the reasons for this disjunction are many and varied. But, in general, relatively few ‘palaeo’ studies link their temporal record to the contemporary status and dynamics

of particular terrestrial ecosystems. Rather, they are seen as dealing with ‘history’ rather than with processes or dynamics. Examples showing that such links can be made on both small (Oldfield 1970) and large (Foster 2002; Foster et al. 1998, 2002a, b, 2003a) scales seem to have made all too little impact on perceptions on either side of the ‘palaeo’/contemporary divide. But as we have argued in the Introduction paper (Dearing et al. this issue), there is increasing recognition that the functioning of ecosystems and their response to current and future impacts are strongly contingent on the history of environmental change and the way these have interacted with human activities (e.g. Foster et al. 2003a; Foster and Aber 2004). Thus long-term perspectives on ecosystem change are crucial to formulating appropriate sustainable management strategies for modern landscapes and ecosystems. Environmental archives and dating methods that bring the ‘palaeo’ record through to the present day are just as applicable to terrestrial, as they are to limnological, ecosystems. More studies designed to bridge the temporal gap between ‘palaeo’ and contemporary studies would surely help overcome the conceptual disjunction. In some respects, the need is more urgent than it is in the case of climate change. Temporally consistent, widespread and globally comparable records of key aspects of climate span the last century or so, a much longer period than for consistent scientifically useful records of ecosystem characteristics and changes.

Reframing terrestrial, palaeo-environmental proxies The dominant focus on past climate rather than environmental or ecological change in recent years has led to an emphasis on using terrestrial palaeoecological records as climate proxies, rather than as what they primarily are: records of changing ecosystem responses to both climate change and human activities. This can be best illustrated by considering pollen analytical data where the reconstruction of palaeo-climate has involved using skilful statistical filters (e.g. Guiot et al. 1989; Birks 2003). Filtering out non-climate-linked responses in the interests of refining climate proxies does not dispose of the existence of richer and more complex responses to a wider range of influences and interactions. There is, we believe, a strong case now for separating proxies used for climate reconstruction from those used to reconstruct the response of ecosystems to the interacting influences of climate change and human impacts (Ammann 2000; Ammann and Oldfield 2000). The same arguments apply with even greater force to studies that have the potential to set contemporary ecosystems into a dynamic context, which is the only realistic basis for considering their future. That said, it is important to realise that changing terrestrial ecosystems have had significant impacts on climate at least on sub-continental scales, and even possibly at the global scale (Ruddiman 2003), through various types of feedback arising from,

117

for example, changes in albedo (e.g. Prentice et al. 2000) or the effects of forest fires and biomass burning (e.g. Langenfields et al. 2002). The interactions are not simple and unidirectional. The need to transform palaeodata for terrestrial ecosystem changes into quantitative statements that allow for direct comparison with present day ecosystems poses daunting challenges. These are well illustrated at the landscape level by the combination of observations and modelling used by the POLLANDCAL community (e.g. Brostro¨m et al. 1998; Gaillard et al. 1998; Sugita et al. 1999) to calibrate pollen spectra against contemporary vegetation even at the level of estimating the degree of openness or forest cover. Despite these problems, there are growing number of examples of research comparing pollen-analytical reconstructions of forest history with retrospective scenarios generated by dynamic vegetation models, and using the insights arising from the comparisons (e.g. Bugmann and Pfister 2000; Cowling et al. 2001). Nevertheless, most of the models used by present day ecologists are based solely on linkages and trajectories inferred from short-term observations. In many cases, they are therefore, less likely to serve well as templates for developing future trajectories on decadal or longer timescales. Data from palaeo-research can provide the basis for assessing the skill with which such models capture the nature of change through time (see e.g. Kaplan et al. 2003). Whilst this may lead to improvements in model design, it is also quite likely to reduce the fluency with which scenarios can be generated by models less rigorously constrained by relevant data.

Integrated case-studies and regionalisation Integration and parallel histories There are two dominant models for the integration of human–environment interactions. The first comes from the environmental sciences and emphasises integrative studies across natural systems. This approach moves beyond ‘historical ecology’ (cf. Swetnam et al. 1999) in order to try and encompass the full set of multi-directional interactions between human activities and fluvial, ecological, geomorphic and climatic systems. The objectives seek to find explanations of human actions in terms of the wider political and economic climate, with the emphasis on the description and reconstruction of parallel histories. The Ystad Project (Berglund 1991) exemplified this approach, describing the cultural landscape in southern Sweden over the past 6,000 years through historical and scientific reconstructions at a number of sites (Fig. 1). It attempted to describe changes in society and the landscape in order to better understand human–environment interactions through time and to provide a sound foundation for the management of the natural environment, cultural landscapes and ancient monuments. It posed questions about the

effects and spatial patterns of human influence on vegetation change set within a broad hypothesis that argued for the development of agrarian landscapes driven by technology, population and environmental carrying capacity. The project succeeded in drawing together the expertise of Quaternary geologists, archaeologists, environmental historians, plant ecologists and human geographers to produce detailed reconstructions of social and environmental histories for population, human actions, climate and ecosystem responses (Fig. 1) that represents a unique database on which to evaluate modern resource management and conservation practices. However, this approach raises an issue, that lies at the heart of what is meant by the ‘human dimension’—that is, the way we represent human actions within the environment. The Ystad Project effectively treated human actions, like deforestation and drainage, as stressors on a natural environment, not unlike climate. The objectives sought to find explanations of human actions in terms of the wider political and economic climate, but the emphasis was on the description and reconstruction of parallel histories. Less emphasis was placed on the changing nature of social and political organisation; and the role of distal economic drivers, technology, disease and climate feedback, in the form of drought and extreme cold, were essentially implicit or speculative. All too often, human activities within even the recent past are viewed with a narrow focus on the constraints placed on subsistence agriculture rather than the wider political and economic context. As multi-agent modeling of contemporary land use shows, the reasons for a change in land use are often complex and may be only loosely linked to climate or environmental conditions (Geist and Lambin 2002; Lambin et al. 2001, 2003). Thus, a second type of integration that treats humans in past natural environments, explicitly, as actors rather than stressors may be necessary if we are to learn more about the complexity and underlying drivers of environmental change. This type of integration is implicit within the aims of IGBP Core Projects (e.g. LAND) and the wider Earth System Science Partnership, but entails much more ambitious integration than currently bridges the gaps between world systems, social science, historical ecology and earth system science. A recent conference (World System History and Global Environmental Change http://www.humecol.lu.se/woshglec/) not only showed the scope for achieving this but also the substantial challenges that have to be met (Hornborg et al. in press). In this respect, one recent publication provides an excellent foundation for future studies. The Mappae Mundi project (De Vries and Goudsblom 2003) was developed to place the sustainability of humans and their habitats in a long-term socio-ecological perspective. De Vries (in press) reviews the lessons learned from the Mappae Mundi project, arguing that evolutionary perspectives on socio-ecological change advance new understanding on sustainable human–environmental interactions, allowing in some cases the testing of

118

Fig. 1 Reconstructed histories of population, human actions, climate, ecological change and environmental responses in southern Sweden during the last 6,000 years produced as part of the Ystad Project (after Berglund 1991)

119

hypotheses about their socio-cultural dynamics, and helping to develop and test new theory. For example, De Vries (in press) argues for (amongst others) the development of ‘ecocultural’ dynamical theory along the lines of Ostrom’s view (1990) that sustainable societies in the past have always had ‘common property regimes’. Where palaeoenvironmentalists have worked together with environmental historians (e.g. Berglund 1991; Elvin et al. 2003; Crook et al. 2004), the potential to support or refute conjectures about the causes of environmental change by recourse to documentary information on political, economic, and demographic social drivers, both proximal and distal, is clear. At the very least, reconstructing ‘parallel histories’ of social, climate and natural environmental change provides a methodology in which circular argument and inference of causative links are minimised, and deductive hypothesis-testing maximised. It follows that major priorities for future research should be to develop and apply more detailed and imaginative theories for human–environment interactions at different spatio-temporal scales, using palaeoenvironmental and socioeconomic histories for both inspiration and as mutually independent records that can be used to test inferences from each type of study. Along with the IGBP mission, a major objective of Focus 5 is to provide scientific

information for sustainable or harmonious human– environment interactions. Therefore, an issue for the Focus 5 community is the extent to which it continues with the more familiar type of integration across natural systems, or seeks novel approaches with social scientists and environmental historians in order to develop theory. Both the Ystad and Mappae Mundi projects represent significant advances in interdisciplinary integration in terms of problem-solving across disciplinary boundaries, albeit at quite different spatial scales. But neither study is avowedly forward-looking in a directly prescriptive or explicit sense; rather, each is justified more in terms of how ‘a thorough understanding of the past (is necessary) in order to be able to say something sensible about the future’ (De Vries and Goudsblom 2003, p11). In response, we would make three points. First, integrated studies of past human–environment interactions can engage with contemporary issues in several additional ways—as outlined in the introductory paper (Dearing et al. this issue)—where the past is used to inform about the present and future. Second, integrated studies can provide further forward-thinking through generating new theory and, as we discuss below, dynamic modelling of human–environment interactions. Third, the Ystad and Mappae Mundi projects show that the power of integration, attempted with humans represented as ei-

Fig. 2 An example of an organisational matrix for the regionalisation of zonal and azonal global palaeoenvironmental case-studies according to the intensity of human pressure through land use, pollution, etc. Each labelled cell represents a region for which high quality (well-dated, high resolution) multi- and inter-disciplinary palaeoenvironmental data (including sedimentary, archaeological, instrument and documentary data as appropriate/available) already exist and where synthesis of information for different

environmental systems (e.g. lakes, fluvial) and/or at different scales is feasible. Cells with diagonal lines signify combinations of ecosystem and impact history that may not exist. Blank shaded cells could be targeted for new studies, with priorities set by criteria such as: high biodiversity status; fragile and/or degraded regions; projected climate and /or human impacts; and regions coincident with other IGBP Core Projects

120

ther actors or stressors, comes mainly from successful regional syntheses of environmental archival data.

Regional syntheses A considerable amount of palaeoenvironmental and historical information already exists for many parts of the world, yet rarely is it compiled and analysed in a form that maximises our learning beyond the level of the case study. One major task is therefore to produce syntheses at either national levels or for common ecosystems and landscapes that capture the current understanding of long-term (101–103 years) ecosystem dynamics and contemporary forcings. In many regions, it is feasible to compile evidence from published multiple case-studies that together include analyses of instrumental data, documented histories, archaeological records, lake sediments, fluvial sediments, peat, soils and geomorphology. Thus is any particular zone, we might deduce the type of land use that has had the greatest historical impact on the fluvial and sediment regime, or the nature of thresholds for landsliding. We might infer the time when aquatic communities started to shift in terms of their form as a result of inadequate sewage disposal, and define target conditions for ecological rehabilitation. Attempts to ‘regionalise’ palaeodata (e.g. Chiverrell this volume; English Lake District) show the scope and the difficulties. Focus 5 is thus encouraging HITE, LIMPACS and LUCIFS communities to interact more effectively in order to provide a fuller understanding of landscapes and environmental systems. These integrative syntheses will act as inventories of information that can help inform contemporary studies of these ecosystems (ideally linked to other IGBP Core Projects, such as LAND, or the Long-Term Ecological Research Network), enable the testing and evaluation of impact assessment models, identify research priorities and, in their communication (e.g. web-sites, reports and journal articles), satisfy the strong needs for education and informational outreach. A draft scheme for organising regional syntheses (Fig. 2) shows a two-dimensional matrix defined by zonal and azonal geographical regions, and simple measures of the intensity and duration of past human impact. Such a scheme would allow us to catalogue regions where sufficient information and data already exist, and to prioritise new regions where records are required. The definitions arising from the matrix are neither narrowly prescriptive nor complete. For example, in the case of lakes, the dimension of human impact can include atmospheric or catchment sources of pollution. Regions that can be included now will already have critical masses of research groups and published datasets. For prioritising new research or syntheses in zonal/azonal regions, there are many criteria that can be defined, but following recent discussions these would include: • ‘Fragile human landscapes’ where there is already evidence for rapid deterioration in processes and

ecosystem services and where there may be significant difficulties in formulating appropriate sustainable management strategies (e.g. some intensively managed agroecosystems or lakes strongly threatened by pollution). • ‘Threatened human landscapes’ where climate and/or demographic projections indicate that there may be significant future environmental changes, including extreme events (e.g. flooding, fire) driven by a combination of human activities and/or climate (e.g. mountain agroecosystems; sub-Saharan Africa; Mediterranean zones). • ‘Highly valued ecosystems’ where the goal is conservation, preservation or rehabilitation of biodiversity and/or ecological services in the face of projected human and/or climate impacts or regulation (e.g. lake amenity, biodiversity hotspots, wetlands and ancient woodlands). Two further aspects of international environmental change research would be addressed by these syntheses. First, for most administrative regions there is only a weak scientific basis on which to judge the relative sensitivities of different processes, ecosystems or landscapes to projected impacts. As a result, prioritisation for environmental protection or investment at the local or regional level is often poorly justified, piecemeal or misplaced. A full inventory of past environmental processes and human–environment interactions could make major contributions towards ranking sub-system sensitivities to particular combinations of past climate and human impact. For example, it would be possible to discriminate between landscapes/processes, which have been significantly modified by past climate and can be expected to be sensitive to future changes, from those, which are presently expressing themselves in terms of long-term and destructive trends, or identify those which appear to be virtually insensitive to change. Such qualitative descriptions of sub-systems would certainly provide a focus for prioritising predictive modelling studies and adaptive strategies. Success in this may require new methods for ranking the sensitivities of modern ecosystems based on long-term histories, utilising, for example, system energetics, ‘distances’ from pre-impact states and rates of change in key process variables (e.g. Dodson and Mooney 2002). Second, the issue of spatio-temporal scaling that is key to developing a full understanding of environmental behaviour. At a single site, explanations of environmental change made at one level of temporal resolution are usually different from those made at another. For example, Foster et al. (2003b) show that the impact of land use on hydrological and sediment delivery processes in the French Alps dominates over the effects of meteorological events as the timescale of observation is lengthened from years to centuries. For spatial scales too, whether the process of interest is erosion, water quality, or inter-species competition, the transfer of results obtained at one scale to another is rarely additive

121

and linear (e.g. Dearing and Jones 2003). An improved ability to scale-up local case-studies through coordinated regionalisation will allow generalisation or transfer of findings across larger geographical areas and ecosystems, giving compatibility with the scale of real and modelled environmental drivers (e.g. administrative areas, downscaled GCM outputs). An example of where this has already been attempted is the biomisation of pollen diagrams (Prentice et al. 1996) in order to produce global vegetation/biomass maps for chosen time periods (e.g. BIOME 6000). For some processes, it may provide the means to upscale to the global scale in order to compute new global process records, such as a Holocene record of sediment flux to the global coastline.

Dynamic simulation modelling Where the concern about environmental change extends into future decades, rather than years, past records are a key resource for basing judgements about how the future socio-environmental system will evolve. But how do we make those judgements? Narrative descriptions of all analysed past records, however, detailed and penetrating, will not be able to generate alternative and testable strategies for sustainable management. The power of environmental reconstruction and history can only be utilised fully to inform alternative views of the future through simulation modelling. Climate scenarios produced by global climate models are at the forefront of all scientific and political agenda engaged with global warming. They provide the impetus for scientific debate about the mechanisms of climate change and the basis on which to design mitigative and adaptive strategies. While the models typically deliver scenarios at global and sub-continental scales, recent downscaling at a national level (UK) has achieved a 50 km grid spatial resolution for the 21st century (Hulme et al. 2002). In contrast, simulations of interactions between future climate, human activities and terrestrial systems are far less developed. In a growing number of palaeoenvironmental studies, the view provided by detailed and rigorously reconstructed histories points to non-linear and complex system behaviour where emergent phenomena are the norm. The complexity of the whole system, particularly cascading systems such as river and lake catchments, exists across a wide range of spatial and temporal scales. Thus, ideally, simulation models of human–environment interactions should allow complex and macroscale emergent phenomena to arise from microscale interactions. Such models would be run forwards from the past and validated against palaeoenvironmental time series before simulating future systems under different scenarios of climate, environmental and societal change: a methodology utilised in disentangling the individual and combined roles of alternative climate drivers of 20th century global warming.

However, the relative tractability of the fluid dynamics of climate systems contrasts sharply with the intrinsically more complex nature of socio-environmental systems, particularly in terms of cross-scale process interaction, and the nature and timelines of emergent phenomena. Socio-environmental systems are characterised by the growth of far longer-lived emergent phenomena at all scales: social institutions, social structures, ecosystems and geomorphic forms (Dearing in press). One promising approach would be to build on recent developments in spatially explicit cellular automata-type models. These models can be classified according to the level of functional rules used, the means by which and the timescales over which the model is validated, and the extent to which the activities of human agents and decision-making are made explicit. As with integration of case-studies there is a logical dichotomy of approaches depending on how human actions are captured. For example, Tucker and Slingerland (1997) and Coulthard et al. (2002) have pioneered the use of mathematical biophysical cellular models in catchment hydrology with low-level rules, long-timescales ranging from decades to millennia, but with limited inclusion of agents. Environmental changes are expressed as sequential maps or as time-series of outputs from the whole catchment. A simulation of sediment generation over the last 10,000 years for an upland catchment in the UK shows a curve that captures the same trend and frequency-magnitude behaviour that is seen in an aggregated time-series of alluvial activity produced from dated stratigraphic sections in UK river catchments (Coulthard et al. 2002). In such examples, human agents are brought into play mainly as stressors in order to set future scenarios for hard engineering options or land use change: the models are essentially low-level rule-based biophysical models. In contrast, the inclusion of humans as agents makes use of high-level rules and often a restricted history. Torrens and O’Sullivan (2001) in a review of the limitations of cellular automata modelling of urban systems point to the constraints imposed by the simplicity of cellular models and how this simplicity has to be compromised to accommodate action-at-a-distance processes. But such problems apart, there are ongoing developments that are likely to see improved cellularbased modelling, through integration with GIS, macrolevel models and, in ecology, developing individualbased approaches (e.g. Gimblett 2002). Perhaps most headway towards the development of integrated socioenvironmental models has been gained through the development of agent-based models (ABMs), particularly amongst the international community (e.g. Parker et al. 2001) attempting to model changes in land cover and land use [IGBP-IHDP Programme ‘Land Use and Cover Change’ (LUCC)]. However, validation has largely come through comparison with sequential maps of land cover derived from satellite imagery since the 1960s and these approaches have yet to exploit the full

122

reconstructed history of process-responses and human– environment interactions that is often available.

Concluding points

• The functioning of the majority of modern ecosystems is contingent on a significant history of human impact, demanding that integrated strategies for preservation, conservation or sustainable management of ecosystems incorporate an understanding of long-term responses to climate and human activities. • Palaeoenvironmental studies can be profitably extended to include information from instrumental and documentary archives. Sets of parallel histories derived from reconstructed biophysical records, instrument data and documents provide a sound basis for studying the long-term dynamics of past socio-environmental systems, and validating dynamic simulation models. • Integration and regionalisation of case-studies are seen as necessary developments in the process of presenting and promoting the value of long-term perspectives to the widest scientific and political communities. An organisational scheme for regionalisation is presented based on the type of zonal/azonal region and the degree of historical human impact. Future regional priorities include: fragile or degraded landscapes/systems; landscapes threatened by climate or demographic projections; and highly valued ecosystems. • Dynamic modelling of human–environment interactions lags behind climate modelling, but is viewed as essential to the creation of sustainable management strategies. In this sense, biogeophysical cellular models that allow continuous feedback show great promise. Additionally, there is scope for multi-agent models to utilise longer records of human–environment interactions than are represented by satellite images and documentary information.

Acknowledgements The authors wish to acknowledge discussions at a recent (2005) PAGES Focus 5 meeting held in California, particularly with Prof Neil Roberts regarding regionalisation matrices.

References Ammann B (2000) Biotic responses to rapid climatic changes. Introduction to a multidisciplinary study of the Younger Dryas and minor oscillations on an altitudinal transcet in the Swiss Alps. Palaeogeogr Palaeoclimatol Palaeoecol 159:191–201 Amman B, Oldfield F (2000) Preface. Rapid warming project. Palaeogeogr Palaeoclimatol Palaeoecol 159:v–vii Battarbee RW (1978) Observations on the recent history of Lough Neagh and its drainage basin. Philos Trans R Soc B 281:303–345

Battarbee RW (1990) The causes of lake acidification with special reference to the role of acid deposition. Philos Trans R Soc Lond Ser B 327:339–347 Battarbee RW, Flower RJ, Stevenson AC, Rippey B (1985) Lake acidification in Galloway: a palaeoecological test of competing hypotheses. Nature 314:350–352 Battarbee RW, Mackay AW, Jewson DH, Ryves DB, Sturm M (2005a) Differential dissolution of Lake Baikal diatoms: correction factors and implications for palaeoclimatic reconstruction. Glob Planetary Change 46:75–86 Battarbee RW, Monteith DT, Juggins S, Evans CD, Jenkins A, Simpson GL (2005b) Reconstructing pre-acidification pH for an acidified Scottish loch: a comparison of palaeolimnological and modelling approaches. Environ Pollut 137:135–149 Battarbee RW, Anderson NJ, Jeppesen E, Leavitt PR (2005c) Combining palaeolimnological and imnological approaches in assessing lake ecosystem response to nutrient reduction. Freshw Biol 50:1772–1780 Berglund BE (ed) (1991) The cultural landscape during 6000 years in southern Sweden (ecological bulletin 41). Blackwell, Oxford, pp 495 Birks HJB (2003) Quantitative palaeoenvironmental reconstructions from Holocene biological data. In: Mackay AW, Battarbee RW, Birks HJB, Oldfield F (eds) Global change in the Holocene. Arnold, London, p 528 Brostro¨m A, Gaillard M-J, Ihse M, Odgaard B (1998) Pollenlandscape relationships in modern analogues of ancient cultural landscapes in southern Sweden—a first step towards quantifying vegetation openness in the past. Vegetation Hist Archaeobot 7:189–201 Bugmann H, Pfister C (2000) Impacts of interannual climate variability on past and future forest composition. Regional Environ Change 1:1–19 Charles DF, Binford MW, Furlong ET, Hites RA, Mitchell MJ, Norton SA, Oldfield F, Paterson MJ, Smol JP, Uutala AJ, White JR, Whitehead DR, Wise RJ (1990) Paleoecological investigation of recent lake acidification in the Adirondack Mountains NY. J Paleolimnol 3:195–241 Chiverrell R (in press) Past and future perspectives upon landscape instability in Cumbria, nowthwest England. Regional Environ Change Compton JE, Boone RD, Motzkin G, Foster DR (1998) Soil carbon and nitrogen in a pine-oak sand plain in central Massachusetts: role of vegetation and land-use history. Oecologia 116:536–542 Coulthard TJ, Macklin MG, Kirby MJ (2002) Simulating upland river catchment and alluvial fan evolution. Earth Surf Process Landforms 27:269–288 Cowling SA, Sykes MT, Bradshaw RHW (2001) Palaeovegetationmodel comparisons climate change and tree succession in Scandinavia over the past 1500 years. J Ecol 89:227–236 Crook DS, Siddle DJ, Dearing JA, Thompson R (2004) Human impact on the environment in the Annecy Petit lac catchment Haute-Savoie: a documentary approach. Environ Hist 10:247–284 Davis MB (1989) Insights from paleoecology on global change. Ecol Soc Am Bullet 70:220–228 Dearing JA (in press) Integration of world and earth systems: heritage and foresight. In: Hornborg A et al (eds) World system history and global environmental change. Left Coast Books, Santa Barbara Dearing JA, Battarbee RW, Dikau R, Larocque I, Oldfield F (2006) Human-environment interactions: learning from the past. Reg Environ Change 6:10.1007/s10113-005-0011-8 (this issue) Dearing JA, Jones RT (2003) Coupling temporal and spatial dimensions of global sediment flux through lake and marine sediment records. Glob Planet Change 39:147–168 De Vries B (in press) In search of sustainability: what can we learn from the past? In: Hornborg A et al (eds) World system history and global environmental change. Left Coast Books, Santa Barbara

123 De Vries B, Goudsblom J (eds) 2003 Mappae mundi: humans and their habitats in a long term socio-ecological perspective. Amsterdam University Press, Amsterdam, p 470 Dodson JR, Mooney SD (2002) An assessment of historic human impact on south-eastern Australian environmental systems using late Holocene rates of environmental change. Aus J Bot 50:455–464 Elvin M, Crook DS, Shen JI, Jones RT, Dearing JA (2002) The impact of clearance and irrigation on the environment in the Lake Erhai catchment from the ninth to the nineteenth century. East Asian Hist 23:1–60 Foster DR (2002) Insights from historical geography to ecology and conservation: lessons from the new England landscape. J Biogeogr 29:1269–1275 Foster DR, Aber JD (2004) Forests in time: the environmental consequences of 1000 years of change in new England. Yale University Press, New Haven, p 477 Foster DR, Clayden S, Orwig DA, Hall B, Barry S (2002b) Oak chestnut and fire: climatic and cultural controls of long term forest dynamics in new England USA. J Biogeogr 29:1359–1379 Foster DR, Motzkin G, Bernardos D, Cardoza J (2002a) Wildlife dynamics in the changing new England landscape. J Biogeogr 29:1337–1358 Foster DR, Motzkin G, Slater B (1998) Land-use history as longterm broad-scale disturbance: regional forest dynamics in central new England. Ecosystems 1:96–119 Foster DR, Swanson F, Aber J, Burke I, Brokaw N, Tilman D, Knapp A (2003a) The importance of land-use legacies to ecology and conservation. Bioscience 53:77–88 Foster GC, Dearing JA, Jones RT, Crook DS, Siddle DJ, Harvey AM, James PA, Appleby PG, Thompson R, Nicholson J, Loizeau J-L (2003b) Meteorological and land use controls on past and present hydro-geomorphic processes in the pre-alpine environment: an integrated lake-catchment study at the Petit Lac d’Annecy France. Hydrol Process 17:3287–3305 Gaillard M-J, Birks HJB, Ihse M, Runborg S (1998) Pollen/landscape calibration based on modern pollen assemblages from surface-sediment samples and landscape mapping—a pilot study in south Sweden. In: Gaillard M-J, Berglund B, Frenzel B, Huckriede U (eds) Quantification of land surface cleared of forest during the Holocene. Palaeoklimaforschung/Palaeoclimatic Res 27:31–55; Fischer Verlag, Stuttgart Gustav Geist HJ, Lambin EF (2002) Proximate causes and underlying driving forces of tropical deforestation. Bioscience 52:143–150 Gimblett HR (2002) Integrating geographic information systems and agent-based modeling techniques for simulating social and ecological processes. Oxford University Press, Oxford, p 342 Guiot J, Pons A, de Beaulieu J-L, Reille M (1989) A 140,000 year climatic reconstruction from two European pollen records. Nature 338:309–313 Hooker TD, Compton JE (2003) Forest ecosystem carbon and nitrogen accumulation during the first century after agricultural abandonment. Ecol Appl 13:299–313 Hornborg A, Butzer KW, Crumley CA (eds) (in press) World system history and global environmental change. Left Coast Books, Santa Barbara Hulme M, Jenkins GJ, Lu X, Turnpenny JR, Mitchell TD, Jones RG, Lowe J, Murphy JM, Hassell D, Boorman P, McDonald R, Hill S (2002) Climate change scenarios for the United Kingdom: the UKCIP02 scientific report. Tyndall centre for climate change research. School of Environmental Sciences, University of East Anglia, Norwich, UK, p 120

Jeppesen E, Leavitt PR, De Meester L, Jensen JP (2001) Functional ecology and palaeolimnology: using cladoceran remains to reconstruct anthropogenic impact. Trends Ecol Evol 16:191–198 Kaplan JO, Bigelow NH, Prentice IC, Harrison SP, Bartlein PJ, Christensen TR, Cramer W, Matveyeva NV, McGuire AD, Murray DF, Razzhivin VY, Smith B, Walker DA, Anderson PM, Andreev AA, Brubaker LB, Edwards ME, Lozhkin AV (2003) Climate change and Arctic ecosystems II: modeling paleodata-model comparisons and future projections. J Geophys Res 108(D19):8171 Lambin EF, Geist HJ, Lepers E (2003) Dynamics of land-use and land-cover change in tropical regions. Ann Rev Environ Resour 28:1–14 Lambin EF, Turner BL, Geist HJ (2001) The causes of land-use and land-cover change: moving beyond the myths. Glob Environ Change 11:261–269 Langenfields RL, Francey RJ, Pak BC et al. (2002) Interannual growth rate variations in atmospheric CO2 and its d13C, H2, CH4 and CO between 1992 and 1999 linked to biomass burning. Glob Biogeochem Cycles 16:21-1–21-7 Oldfield F (1970) The ecological history of Blelham Bog, National Nature Reserve. In: Walker D, West RG (eds) Studies of the vegetational history of the British Isles. Cambridge University Press, Cambridge, pp 141–157 Oldfield F (2005) Environmental change: key issues and alternative approaches. Cambridge University Press, Cambridge p 363 Ostrom E (1990) Governing the commons. The evolution of institutions for collective action. Cambridge University Press, Cambridge Parker DC, Berger T, Manson SM (eds) (2001) Agent-based models of land use and land cover change. LUCC Report Series no 6 LUCC Focus 1 Office, Indiana University, p 124 Prentice IC, Guiot J, Huntley B, Jolly D, Cheddadi R (1996) Reconstructing biomes from palaeoecological data: a general method and its application to European pollen data at 0 and 6 ka. Climate Dyn 12:185–194 Prentice IC, Jolly D, BIOME 6,000 members (2000) Mid-Holocene and glacial maximum vegetation geography of the northern continents and Africa. J Biogeogr 27:507–519 Ruddiman WF (2003) The anthropogenic era began thousands of years ago. Climatic Change 61:261–293 Smol JP (2002) Pollution of lakes and rivers: a paleoenvironmental perspective. Arnold Publishers, London, p 280 Stainforth DA, Aina T, Christensen C, Collins M, Faull N, Frame DJ, Kettleborough JA, Knight S, Murphy JM, Piani C, Sexton D, Smith LA, Spicer RA, Thorpe AJ, Allen MR (2005) Uncertainty in predictions of the climate response to rising levels of greenhouse gases. Nature 433:403–406 Sugita S, Gaillard M-J, Brostro¨m A (1999) Landscape openness and pollen records: a simulation approach. Holocene 9:409–421 Swetnam TW, Allen CD, Betancourt JL (1999) Applied historical ecology: using the past to manage for the future. Ecol Appl 9:1189–1206 International Climate Change Taskforce (2005) Meeting the climate challenge. Recommendations of the International Climate Change Taskforce. The Institute for Public Policy Research, London, p 40 Torrens PM, O’ Sullivan D (2001) Cellular automata and urban simulation: where do we go from here? Environ Planning B 28:163–168 Tucker GE, Slingerland R (1997) Drainage basin responses to climate change. Water Resour Res 33:2031–2047