John O. Browder

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.

Patterns of Development on the Metropolitan Fringe: Urban Fringe Expansion in Bangkok, Jakarta, and Santiago

Abstract This paper revisits the question of how best to characterize settlements on the metropolitan fringe of developing countries. We examine the socioeconomic composition and structure of such urban fringe settlements, using three sets of household surveys undertaken in Bangkok (Thailand), Jakarta (Indonesia), and Santiago (Chile) during June-August 1990. The findings reveal the metropolitan fringe areas to be populated mainly by middle- and lower-middle-income households formally employed in service occupations. Informal economic activity exists, but is not significant. Micro-enterprises are the exception. Most fringe residents had moved from other neighborhoods within the capital city rather than from rural settlements. Linkages to rural areas and to agriculture are largely absent; the fringe is spatially and functionally well-integrated into the metropolitan economy. The paper recommends that foreign-assistance program officers and local planners resist global “common themes” or approaches to devel...

The urban-rural interface: Urbanization and tropical forest cover change

A considerable body of empirical and theoretical literature on the causes of tropical deforestation has emerged over the last twenty years. Recognizing that small-farmers in the Amazon Basin are a key agent in the process of primary forest conversion, a growing genre of studies at the household level have attempted to quantify the influence of various factors on small-farmer land-use decisions. Many of these studies have acknowledged the seeming importance of urban centers as hubs of propulsive activity and information, yet none have comprehensively captured the “urbanization factor” in rural land use decisions. I argue that this methodological shortcoming in empirical work to-date reflects an inadequate conceptualization of the range of urban-based networks and their inter-relationships. In an effort to overcome this roadblock to further empirical discovery, I review several leading schools of thought that might be pressed into service in developing a framework for interpreting the urban influences on rural landscapes. I call this construct the “Urban-Rural Interface.” This is not a complete theoretical model or a unique methodology, but rather an initial effort to develop a general framework from which more sophisticated formulations might proceed.

Agroforestry performance on small farms in Amazonia: Findings from the Rondonia Agroforestry Pilot Project

Experiences from not only ‘success stories’ but also ‘failed’ agroforestry projects provide potentially useful lessons for future agroforestry-project designers. Experimental one-hectare agroforestry plots were established on 50 small-scale farms in the western Brazilian Amazon State of Rondonia from 1993 to 1995. Drawing from a menu of 25 different species (10 tropical hardwoods and softwoods and 15 fruits and palms), this species trial shows encouraging survival and growth performance for most species under wide ranging plot management regimes. Tropical hardwood survival rates (after 18 months) ranged from 65% for Cerejeira (Torresea acreana) to 88% for mahogany (Swietenia macrophylla). Survival rates for commercial fruit and palm species were even higher. A comparison of attributes of two sub-groups (successful and unsuccessful planters) suggests that previous experience with perennial monocultural cropping, greater social participation, land use history, and soil chemistry are positively associated with successful agroforestry species performance, while no significant differences exist between successful and unsuccessful planters in household size, area deforested, area in pasture, and land tenure security. A closer analysis of ‘failed’ agroforestry plots indicates the primary importance of social factors originating at the household-level (e.g. inadequate plot maintenance, improper planting techniques, illness, etc.). Twelve different causes of plot failure were cited, falling into three classes. Of the total number of reasons given for plot failure, household level factors represented 54% of all causes cited. Project design and implementation factors (inappropriate plot design, defective planting material, etc.) were cited 25% of the times and environmental factors (soil fertility constraints and pasture grass invasion) were cited 21% of the times.

Is sustainable tropical timber production financially viable? A comparative analysis of mahogany silviculture among small farmers in the Brazilian Amazon

Abstract Conservationist arguments for international trade restrictions on tropical hardwoods, along with counter-arguments by the wood industry, are both based on the claim that key hardwoods, like mahogany, can be either sustainably managed in their natural forest habitat or sustainably produced in silvicultural settings. This paper examines the financial feasibility of three mahogany planting regimes found among small-scale family farmers in the Brazilian Amazon State of Rondonia: degraded fallow enrichment, agroforest consorciation (e.g., mahogany and coffee), and pure-stand plantation. The sensitivity of net future and present values from each of the three systems to changes in real interest rate of capital, opportunity cost of labor, production time, seedling survival rate, and producer roundwood price was tested under 10 scenarios. Overall, mahogany production was found to be financially viable in 21 of the 30 alternative scenarios considered, with pure-stand plantations offering the most profitable alternative. Based on financial criteria alone the most promising approach to blending tropical timber trade with natural forest conservation would be through mahogany plantations, especially if they are located outside the tropical forest zone of the Amazon region.

Comparison of segment and pixel-based non-parametric land cover classification in the brazilian amazon using multitemporal landsat TM/ETM+ imagery

This study evaluated segment-based classification paired with non-parametric methods (CART ® and kNN) and inter- annual, multi-temporal data in the classification of an 11-year chronosequence of Landsat TM/ETMimagery in the Brazilian Amazon. The kNN and CART ® classification meth- ods, with the integration of multi-temporal data, performed equally well in the separation of cleared, re-vegetated, and primary forest classes with overall accuracies ranging from 77 percent to 91 percent, with pixel-based CART ® classifica- tions resulting in significantly lower variance than all other methods (3.2 percent versus an average of 13.2 percent). Segmentation did not improve classification success over pixel-based methods with the used datasets. Through appropriate band selection methods, multi-temporal bands were chosen in 38 of 44 total classifications, strongly suggesting the utility of inter-annual, multi-temporal data for the given classes and region. The land-cover maps from this study allow for an accurate annualized analysis of land- cover and landscape change in the region.

Comparing farmer-based and satellite-derived deforestation estimates in the Amazon basin using a hybrid classifier

The Amazon basin remains a major hotspot of tropical deforestation, presenting a clear need for timely, accurate and consistent data on forest cover change. We assessed the utility of a hybrid classification technique, iterative guided spectral class rejection (IGSCR), for accurately mapping Amazonian deforestation using annual imagery from the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) from 1992 to 2002. The mean overall accuracy of the 11 annual classifications was 95% with a standard deviation of 1.4%, and z‐score analysis revealed that all classifications were significant at the 0.05 level. The IGSCR thus seems inherently suitable for monitoring forest cover in the Amazon. The resulting classifications were sufficiently accurate to assess preliminarily the magnitude and causes of discrepancies between farmer‐reported and satellite‐based estimates of deforestation at the household level using a sample of 220 farms in Rôndonia mapped in the field in 1992 and 2002. The field‐ and satellite‐derived estimates were significantly different only at the 0.10 level for the 220 farms studied, with the satellite‐derived deforestation estimates 8.9% higher than estimates derived from in situ survey methods. Some of this difference was due to a tendency of farmers to overestimate the amount of forest within their property in our survey. Given the objectivity and reduced expense of satellite‐based deforestation monitoring, we recommend that it be an integral part of household‐level analysis of the causes, patterns and processes of deforestation.