Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University Agrarian models, frontier models, markets, “Spatial Agent-based Models of Human- environment Interactions” Feb 18, 2009

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University Plan for today MR POTATOHEAD Land-use change in frontier regions MP/OWL illustration

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University “Frontier” “ We define “frontier” as an area of changing resource use, such as might occur with changing technology, transportation, or economic relations” May or may not involve immigration (but usually does), location on the periphery “A frontier is a place of land-use change and part of a continuing advance of that change across space “

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University Goal of effort Theoretical meta-model of LUCC in frontier regions Understand what is important to model and whether or not we are modeling it Understand what might happen in other cases in future Draw extrapolations beyond case studies

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University What is the land-use change process? New population with new tools, resources, tastes, cultures Perceived greater opportunities/relative resource abundance Populations often maintain links to home Transition through time from subsistence to market-oriented prodcution -> increasing integration

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University More process Various and changing risks (subsistence vs.market) Household is often unit of analysis and demographics are important Land holding consolidation triggered by outmigraion, economic integration, speculative land uses, shifts in ag strategies Fragmentation can occur through inheritance Outmigration also important

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University ｷ In-migration of a distinctly new set of agent types, possessing different technology, cultural preferences, and connections to external regions; ｷ A gradual process of market integration, potentially driven by increases in accessibility through improvements in transportation infrastructure, through the connection of the new agent populations with external regions, or both; ｷ A variety of land fragmentation vs. land consolidation outcomes in terms of both land ownership/management and land cover, potentially driven by relative changes in mortality and fertility, in-migrants’ rates of success and failure and resulting out-migration rates, the degree of land vs. labor scarcity resulting from these processes, the levels of and variability in biophysical suitability of the area, and the particular land tenure and land transfer institutions present in each location; ｷ A variety of land tenure and land transfer institutions, whose development may be influenced by the degrees of land scarcity and market integration present in each location; ｷ Outcomes that may depend on individual heterogeneity (such as risk management strategies, risk preferences, knowledge, and resources); ｷ Outcomes that depend on biophysical heterogeneity (soil quality, topography, and climate). Summary of key complex processes/drivers

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University Key questions: What processes should be included, and why are they important? What conclusions follow from models that have these processes? Can we draw any generalizations?

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University Comparison points from MP model: 1.Spatial data structure. (I.1) How do the agent-parcel relationships and the decision making units in the model allow representation of processes of changes in household density, land consolidation, and diversification in response to risk? What are the outcomes of these processes? 2.Non-spatial social networks. (I.3) What social networks are important in each study site, and how might inclusion of these networks in models change outcomes? How do social networks influence information flow, mutual aid, land transfers (inheritance through kinship networks as well as markets), migration into and out of the area, and flows of remittances? 3.Land suitability and resulting potential land uses. (I.6) How have biophysical conditions in each site influenced evolution of land use in the region, including the potential success of subsistence crops, opportunities for resource extraction, and development of ties with external markets?

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University More comparison points: 1.The varied land-use knowledge, cultural preferences, and capital of indigenous vs. in-migrant land users. (III.1) How do variations in land-use knowledge, cultural preferences, and capital affect land productivity (I.7)? What new land uses have in-migrant populations brought, and how have these affected the differential success of each population in local and market contexts? 2.Land exchange. (V) How have the institutions shaping land exchange/use influenced patterns of resource use, distributions of land holdings, and the relationship between household size and land holding size? How have these patterns evolved as land exchange institutions have changed? 3.Internal and external economic and institutional drivers. (I4 & I5) How do internal markets exacerbate or mitigate relative resource scarcity? How have external drivers influenced rates of market integration, differential success rates between agent types, and ultimately, land-use and land-cover consolidation?

Spatial ABM H-E Interactions, Lecture 4 Dawn Parker, George Mason University General conclusions and future directions: Need to better model land consolidation and land fragmentation (Land markets?) Non-spatial social networks important, need to improve multiple social relations, position in networks, Land suitability/transitions well modeled Need better modeling of interactions between in- migrants and indigenous pops Need to model local markets with endogenous prices, including land markets