Marcellus Caldas

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.

Road Investments, Spatial Spillovers, And Deforestation In The Brazilian Amazon

Understanding the impact of road investments on deforestation is part of a complete evaluation of the expansion of infrastructure for development. We find evidence of spatial spillovers from roads in the Brazilian Amazon: deforestation rises in the census tracts that lack roads but are in the same county as and within 100 km of a tract with a new paved or unpaved road. At greater distances from the new roads the evidence is mixed, including negative coefficients of inconsistent significance between 100 and 300 km, and if anything, higher neighbor deforestation at distances over 300 km.

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.

Loggers and Forest Fragmentation: Behavioral Models of Road Building in the Amazon Basin

Abstract Although a large literature now exists on the drivers of tropical deforestation, less is known about its spatial manifestation. This is a critical shortcoming in our knowledge base since the spatial pattern of land-cover change and forest fragmentation, in particular, strongly affect biodiversity. The purpose of this article is to consider emergent patterns of road networks, the initial proximate cause of fragmentation in tropical forest frontiers. Specifically, we address the road-building processes of loggers who are very active in the Amazon landscape. To this end, we develop an explanation of road expansions, using a positive approach combining a theoretical model of economic behavior with geographic information systems (GIS) software in order to mimic the spatial decisions of road builders. We simulate two types of road extensions commonly found in the Amazon basin in a region showing the fishbone pattern of fragmentation. Although our simulation results are only partially successful, they call attention to the role of multiple agents in the landscape, the importance of legal and institutional constraints on economic behavior, and the power of GIS as a research tool.

Spatial Processes in Scalar Context: Development and Security in the Brazilian Amazon

This paper discusses the evolution of the development and security discourse since the waning of the cold war period, and examines how such notions influenced policies pursued by the Brazilian government regarding Amazonian development and national security during the same time period. The theoretical framework presented examines the socio-political construction of security across a nested hierarchy of spatial scales. In general, the paper contends that the development and security agenda served to undermine the security of Amazonias poor, rural population, which is defined here as the right of individuals to access land necessary for subsistence and improvement of social welfare. In turn, threats to security at this level may directly affect national security if land competition intensifies social tension and mobilization, impacting political stability, and possibly leading to civil unrest. Furthermore, the spatial articulation of land conflict in the Amazon may exacerbate deforestation, thus threatening the environmental security of nation-states as defined by the global community. The paper outlines a conceptual framework illustrating the interaction of local and regional human security with global environmental security concerns, and presents preliminary findings from 292 household surveys and key informant interviews conducted in 12 settlement sites in the south of Pará in the summer of 2006 that support the models assertions.
 Este artigo discute a evolução do discurso sobre desenvolvimento e segurança desde o fim da Guerra Fria, e examina como tais noções influenciaram as políticas públicas adotadas pelo governo brasileiro com relação ao desenvolvimento da Amazônia e a segurança nacional durante este mesmo período de tempo. O arcabouço teoríco utilizado examina a construção socio-política da segurança, utilizando para isto, uma hierarquia espacial de escalas. Em geral, este artigo afirma que a agenda de desenvolvimento e segurança serviram para debilitar a segurança da pobre população rural da Amazônia, o qual é definida aqui como, o direito dos indivíduos de ter acesso a terra necessária para a sobrevivência e melhoria do bem-estar social. Por sua vez, ameaças a segurança a este nível pode diretamente afetar a segurança nacional, se a competição por terra intensificar a tensão social e a mobilização, impactando a estabilidade política, e possivelmente levando a uma intranquilidade da sociedade civil. Além disso, a articulação espacial do conflito de terra na Amazônia pode aumentar o desmatamento, e consequentemente, ameaçar a segurança das nações-estados, como definido pela comunidade internacional. Finalmente, o artigo esboça um arcabouço conceitual ilustrando a interação entre a segurança humana local e regional, com as preocupações com a seguranca ambiental global, e apresenta resultados preliminaries de 292 questionários, e entrevistas com informante chaves, conduzidos em 12 assentamentos localizados no Sul do Pará, no verão de 2006, dando suporte ao modelo e as afirmações feitas.

Spatial Patterns of Frontier Settlement: Balancing Conservation and Development

Amazonian deforestation has declined recently, but Brazil’s infrastructure plans continue to target the region. In the interest of sustainable development, this article engages the spatial discourses in conservation planning and landscape ecology. It does so by addressing fishbone fragmentation, commonly observed in development frontiers in Brazil. The article demonstrates the importance of road-building by private citizens as key to explaining this particular development geometry. It also suggests that fishbone fragmentation may promote human welfare, and at the same time provide a porous disturbance “filter” with vegetative corridors linking areas of low disturbance across areas of human occupation, thereby enhancing connectivity to support biodiversity conservation.