Stephen G. Perz

An Exploratory Framework for the Empirical Measurement of Resilience

Deliberate progress towards the goal of long-term sustainability depends on understanding the dynamics of linked social and ecological systems. The concept of social-ecological resilience holds promise for interdisciplinary syntheses. Resilience is a multifaceted concept that as yet has not been directly operationalized, particularly in systems for which our ignorance is such that detailed, parameter-rich simulation models are difficult to develop. We present an exploratory framework as a step towards the operationalization of resilience for empirical studies. We equate resilience with the ability of a system to maintain its identity, where system identity is defined as a property of key components and relationships (networks) and their continuity through space and time. Innovation and memory are also fundamental to understanding identity and resilience. By parsing our systems into the elements that we subjectively consider essential to identity, we obtain a small set of specific focal variables that reflect changes in identity. By assessing the potential for changes in identity under specified drivers and perturbations, in combination with a scenario-based approach to considering alternative futures, we obtain a surrogate measure of the current resilience of our study system as the likelihood of a change in system identity under clearly specified conditions, assumptions, drivers and perturbations. Although the details of individual case studies differ, the concept of identity provides a level of generality that can be used to compare measure of resilience across cases. Our approach will also yield insights into the mechanisms of change and the potential consequences of different policy and management decisions, providing a level of decision support for each case study area.

Land Use and Land Cover Change in Forest Frontiers: The Role of Household Life Cycles

Tropical deforestation remains a critical issue given its present rate and a widespread consensus regarding its implications for the global carbon cycle and biodiversity. Nowhere is the problem more pronounced than in the Amazon basin, home to the world’s largest intact, tropical forest. This article addresses land cover change processes at household level in the Amazon basin, and to this end adapts a concept of domestic life cycle to the current institutional environment of tropical frontiers. In particular, it poses a risk minimization model that integrates demography with market-based factors such as transportation costs and accessibility. In essence, the article merges the theory of Chayanov with the household economy framework, in which markets exist for inputs (including labor), outputs, and capital. The risk model is specified and estimated, using survey data for 261 small producers along the Transamazon Highway in the eastern sector of the Brazilian Amazon.

Grand Theory and Context-Specificity in the Study of Forest Dynamics: Forest Transition Theory and Other Directions

Abstract This article critically reviews forest transition theory, which posits a decline in forest cover followed by expansion during the course of development. Whereas case studies in advanced industrial nations provided an empirical foundation, more recent cross-national modeling efforts and studies in developing regions have raised doubts. Forest transition theory has limitations in its concept of forests, its treatment of forest dynamics, its explanation for forest transitions, and its generalizability. This critique provides the basis for research needs to link studies of forest dynamics on various timescales to other land use/land cover research, as via historical-comparative methods and interdisciplinary theoretical frameworks.

Secondary Forest Expansion in the Brazilian Amazon and the Refinement of Forest Transition Theory

This article examines forest change in the Brazilian Amazon in light of forest transition theory. We draw on satellite-based land cover data matched in a geographic information system (GIS) to census-based social and agricultural data for Brazilian municipalities at multiple time points. Subregions with distinct settlement histories serve as proxies for different stages along the forest transition, theorized to exhibit depletion of forest cover, eventually followed by a recovery. Satellite images allow for distinctions between primary (old-growth) and secondary (successional) forests, but the data indicate more successional forests than expected. We argue that biophysical impediments (e.g., poor soils) and social obstacles (e.g., capital scarcity) led to limited land settlement, low incomes, urbanization, and a shift from crops to pasture, resulting in the rapid expansion of secondary forests without primary forest depletion. These findings call for refinements in forest transition theory that can better ...

Household Life Cycles and Secondary Forest Cover Among Small Farm Colonists in the Amazon

Abstract This paper provides a household-level framework to understand the occurrence of secondary forests. We focus on the role of household life cycles as determinants of secondary vegetation on small farms in tropical Latin America. Following a review of socioeconomic research on secondary growth and a theoretical discussion of life cycle dynamics and land use, we pursue an empirical analysis of the determinants of fallows and abandoned plots among farm lots in Uruara, a colony in the Brazilian Amazon. The findings indicate strong effects of life cycle factors, and bear implications for policies aiming to foster agricultural production alongside forest conservation.

Household demographic factors as life cycle determinants of land use in the Amazon.

This paper seeks to broaden the application of demographyto environmental studies by complementing existing macro-level approaches, which feature aggregate populations, with a micro-level approach that highlights household life cycles. I take up the case of small farm households in the Brazilian Amazon to present a theoretical framework that identifies demographic characteristics which dispose families to engage in different forms of land use as household age structures change. Empirical models show that net of theeffects of farmer background, neighborhood context, institutional context, and off-farm incomes, demographic variables indicative of the household life cycle exert significant effects on the prominence of land uses with distinct environmental ramifications. The findings not only reveal micro-level demographic factors which affect Amazon land cover, they yield implications forfuture changes in rainforest landscapes in northern Brazil, and suggest household life cycle models as an avenue for further demographic research on environmental change in Latin America and other contexts.

Theorizing Land Cover and Land Use Change: The Peasant Economy of Amazonian Deforestation

Abstract This article addresses deforestation processes in the Amazon basin, using regression analysis to assess the impact of household structure and economic circumstances on land use decisions made by colonist farmers in the forest frontiers of Brazil. Unlike many previous regression-based studies, the methodology implemented analyzes behavior at the level of the individual property, using both survey data and information derived from the classification of remotely sensed imagery. The regressions correct for endogenous relationships between key variables and spatial autocorrelation, as necessary. Variables used in the analysis are specified, in part, by a theoretical development integrating the Chayanovian concept of the peasant household with spatial considerations stemming from von Thünen. Results from the empirical model indicate that demographic characteristics of households, as well as market factors, affect deforestation in the Amazon basin associated with colonists. Therefore, statistical results from studies that do not include household-scale information may be subject to error. From a policy perspective, the results suggest that environmental policies in the Amazon based on market incentives to small farmers may not be as effective as hoped, given the importance of household factors in catalyzing the demand for land. The article concludes by noting that household decisions regarding land use and deforestation are not independent of broader social circumstances, and that a full understanding of Amazonian deforestation will require insight into why poor families find it necessary to settle the frontier in the first place.

Road building, land use and climate change: prospects for environmental governance in the Amazon

Some coupled land–climate models predict a dieback of Amazon forest during the twenty-first century due to climate change, but human land use in the region has already reduced the forest cover. The causation behind land use is complex, and includes economic, institutional, political and demographic factors. Pre-eminent among these factors is road building, which facilitates human access to natural resources that beget forest fragmentation. While official government road projects have received considerable attention, unofficial road building by interest groups is expanding more rapidly, especially where official roads are being paved, yielding highly fragmented forest mosaics. Effective governance of natural resources in the Amazon requires a combination of state oversight and community participation in a ‘hybrid’ model of governance. The MAP Initiative in the southwestern Amazon provides an example of an innovative hybrid approach to environmental governance. It embodies a polycentric structure that includes government agencies, NGOs, universities and communities in a planning process that links scientific data to public deliberations in order to mitigate the effects of new infrastructure and climate change.

Land-Cover and Land-Use Change in the Brazilian Amazon: Smallholders, Ranchers, and Frontier Stratification

Abstract Tropical deforestation is a significant driver of global environmental change, given its impacts on the carbon cycle and biodiversity. Loss of the Amazon forest, the focus of this article, is of particular concern because of the size and the rapid rate at which the forest is being converted to agricultural use. In this article, we identify what has been the most important driver of deforestation in a specific colonization frontier in the Brazilian Amazon. To this end, we consider (1) the land-use dynamics of smallholder households, (2) the formation of pasture by large-scale ranchers, and (3) structural processes of land aggregation by ranchers. Much has been written about relations between smallholders and ranchers in the Brazilian Amazon, particularly those involving conflict over land, and this article explicates the implications of such social processes for land cover. Toward this end, we draw on panel data (1996–2002) and satellite imagery (1986–1999) to show the deforestation that is attributable to small- and largeholders, and the deforestation that is attributable to aggregations of property arising from a process that we refer to as frontier stratification. Evidently, most of the recent deforestation in the study area has resulted from the household processes of smallholders, not from conversions to pasture pursuant to the appropriations of smallholders’ property by well-capitalized ranchers or speculators.

Roads as drivers of change: Trajectories across the Tri-National Frontier in MAP, the Southwestern Amazon

Regional studies of land cover change are often limited by available data and in terms of comparability across regions, by the transferability of methods. This research addresses the role of roads and infrastructure improvements across a tri-national frontier region with similar climatic and biophysical conditions but very different trajectories of forest clearing. The standardization of methodologies and the extensive spatial and temporal framework of the analysis are exciting as they allow us to monitor a dynamic region with global significance as it enters an era of increased road connectivity and massive potential forest loss. Our study region is the “MAP” frontier, which covers Madre de Dios in Peru, Acre in Brazil, and Pando in Bolivia. This tri-national frontier is being integrated into the global economy via the paving of the Inter-Oceanic Highway which links the region to ports in the Atlantic and Pacific, constituting a major infrastructure change within just the last decade. Notably, there are differences in the extent of road paving among the three sides of the tri-national frontier, with paving complete in Acre, underway in Madre de Dios, and incipient in Pando. Through a multi-temporal analysis of land cover in the MAP region from 1986 to 2005, we found that rates of deforestation differ across the MAP frontier, with higher rates in Acre, followed by Madre de Dios and the lowest rates in Pando, although the dominant land cover across the region is still stable forest cover (89% overall). For all dates in the study period, deforestation rates drop with distance from major roads although the distance before this drop off appears to relate to development, with Acre influencing forests up to around 45 km out, Madre de Dios to about 18 km out and less of a discernable effect or distance value in Pando. As development occurs, the converted forest areas saturate close to roads, resulting in increasing rates of deforestation at further distances and patch consolidation of clearings over time. We can use this trend as a basis for future change predictions, with Acre providing a guide to likely future development for Madre de Dios, and in time potentially for Pando. Given the correspondence of road paving to deforestation, our findings imply that as road paving increases connectivity, flows of people and goods will accelerate across this landscape, increasing the likelihood of dramatic future changes on all sides of the tri‑national frontier.