Emilio F. Moran

The causes of land-use and land-cover change: moving beyond the myths

Common understanding of the causes of land-use and land-cover change is dominated by simplifications which, in turn, underlie many environment-development policies. This article tracks some of the major myths on driving forces of land-cover change and proposes alternative pathways of change that are better supported by case study evidence. Cases reviewed support the conclusion that neither population nor poverty alone constitute the sole and major underlying causes of land-cover change worldwide. Rather, peoples’ responses to economic opportunities, as mediated by institutional factors, drive land-cover changes. Opportunities and

Complexity of Coupled Human and Natural Systems

Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.

Framing Sustainability in a Telecoupled World

Interactions between distant places are increasingly widespread and influential, often leading to unexpected outcomes with profound implications for sustainability. Numerous sustainability studies have been conducted within a particular place with little attention to the impacts of distant interactions on sustainability in multiple places. Although distant forces have been studied, they are usually treated as exogenous variables and feedbacks have rarely been considered. To understand and integrate various distant interactions better, we propose an integrated framework based on telecoupling, an umbrella concept that refers to socioeconomic and environmental interactions over distances. The concept of telecoupling is a logical extension of research on coupled human and natural systems, in which interactions occur within particular geographic locations. The telecoupling framework contains five major interrelated components, i.e., coupled human and natural systems, flows, agents, causes, and effects. We illustrate the framework using two examples of distant interactions associated with trade of agricultural commodities and invasive species, highlight the implications of the framework, and discuss research needs and approaches to move research on telecouplings forward. The framework can help to analyze system components and their interrelationships, identify research gaps, detect hidden costs and untapped benefits, provide a useful means to incorporate feedbacks as well as trade-offs and synergies across multiple systems (sending, receiving, and spillover systems), and improve the understanding of distant interactions and the effectiveness of policies for socioeconomic and environmental sustainability from local to global levels.

INTEGRATING AMAZONIAN VEGETATION, LAND-USE, AND SATELLITE DATA

Attention to differential patterns and rates of secondary succession on deforested land in the Amazon Basin can help formulate future policies. Amazon deforestation is driven by policies that favor cattle over people as occupants of the frontier, not primarily population growth as in Asia. Deforestation has transformed Brazil into the worlds fourth major contributor of carbon to the atmosphere. This article discusses the following topics: How and why deforestation occured; use of Landsat satellite data to study deforestation and vegetation patterns; analytical procedures for satellite data analysis; Transamazon highway vegetational change. 62 refs., 5 figs., 3 tabs.

Deforestation and Cattle Ranching in the Brazilian Amazon: External Capital and Household Processes

This paper decomposes recent deforestation in four study areas in the Brazilian Amazon into components associated with large ranches and small producers. It then assesses in an inferential framework small producer deforestation with respect to the proximate causes of their farming systems, and the household drivers of their farming system choices. It is shown that, for areas with substantial in-migration of small producers, forest clearance at the household level is mainly attributable to the availability of hired labor, and not to household labor force or the physical capital at their disposal. The paper conducts the inferential analysis of small producer deforestation using measures of forest clearance taken from satellite image classification and directly from field surveys. A substantial discrepancy in the measures is identified, which has implications for household level research on land cover change.

Deforestation and Land Use in the Brazilian Amazon

Deforestation in the Brazilian Amazon was less than 1% before 1975. Between 1975 and 1987 the rate increased exponentially. By 1985, world opinion and attention to the destruction of the richest biome on earth led to elimination of some of the major incentives that had fueled deforestation. Favorable credit policies for cattle ranchers, rather than population growth, explains the process of deforestation in the Brazilian Amazon. The paper suggests other actions that may be taken to reduce deforestation, and examines the rapid growth rates of secondary successional species in a colonization area.

Colonist household decisionmaking and land-use change in the Amazon Rainforest: an agent-based simulation

An agent-based model was developed as a tool designed to explore our understanding of spatial, social, and environmental issues related to land-use/cover change. The model focuses on a study site in a region of the Amazon frontier, characterized by the development of family farms on 100-ha lots arranged along the Transamazon highway and a series of side roads, west of Altamira, Brazil. The model simulates the land-use behaviour of farming households on the basis of a heuristic decisionmaking strategy that utilizes burn quality, subsistence requirements, household characteristics, and soil quality as key factors in the decisionmaking process. Farming households interact through a local labour pool. The effects of the land-use decisions made by households affect the land cover of their plots and ultimately that of the region. This paper describes this model, referred to as LUCITA, and presents preliminary results showing land-cover changes that compare well with observed land-use and land-cover changes in the region.

COMPARISON OF LAND-COVER CLASSIFICATION METHODS IN THE BRAZILIAN AMAZON BASIN

Four distinctly different classifiers were used to analyze multispectral data. Which of these classifiers is most suitable for a specific study area is not always clear. This paper provides a comparison of minimum-distance classifier (MDC), maximumlikelihood classifier (MLC), extraction and classification of homogeneous objects (ECHO), and decision-tree classifier based on linear spectral mixture analysis (DTC-LSMA). Each of the classifiers used both Landsat Thematic Mapper data and identical field-based training sample datasets in a western Brazilian Amazon study area. Seven land-cover classes— mature forest, advanced secondary succession, initial secondary succession, pasture lands, agricultural lands, bare lands, and water—were classified. Classification results indicate that the DTC-LSMA and ECHO classifiers were more accurate than were the MDC and MLC. The overall accuracy of the DTCLSMA approach was 86 percent with a 0.82 kappa coefficient and ECHO had an accuracy of 83 percent with a 0.79 kappa coefficient. The accuracy of the other classifiers ranged from 77 to 80 percent with kappa coefficients from 0.72 to 0.75.

Legacy of fire slows carbon accumulation in Amazonian forest regrowth

Amazonian farmers and ranchers use fire to clear land for agriculture and pasture as part of extensive land-use strategies that have deforested 500 000 km2 over the past 25 years. Ash from burning biomass fertilizes crops and pastures, but declining productivity often occurs after a few years, generally leading to land abandonment and further clearing. Subsequent forest regrowth partially offsets carbon emissions from deforestation, but is often repeatedly cleared and burned. In the first quantitative, basin-wide assessment of the effect of repeated clearing and burning on forest regrowth, our analysis of data from 93 stands at nine locations across the region indicates that stands with a history of five or more fires suffer on average a greater than 50% reduction in carbon accumulation. In the absence of management interventions, Amazonian landscapes dominated by this pronounced legacy of fire are apt to accumulate very little carbon and will remain highly susceptible to recurrent burning.

Land use change in the Amazon estuary: Patterns of caboclo settlement and landscape management

Landsat TM scenes for 1985 and 1991 are used to produce a georeferenced map of land cover and land use for an area of the Amazon estuary inhabited by three populations of caboclos with distinct patterns of land use. This information is combined in a geographic information system with ethnographic and survey research carried out over the past 5 years to develop representative spectral “signatures” which permit measurement and differentiation of land uses and the detection of change even between small areas of managed floodplain forest and unmanaged forest, and between three distinct age/growth classes of secondary succession following deforestation. Implementation of these procedures permit the scaling up or down of research at different resolutions. Three distinct patterns of land use are examined with differential impact on the environment. Mechanized agriculture at one site has eliminated virtually all the mature upland forest and is now dominated by secondary successional vegetation. The more traditional system of diversified land use at the next site shows a subtle cycling of flooded forest to managed palm forest through time in response to the price of palm fruit and cycling in the use of fallow land. A third site, based on palm fruit extractivism, shows minimal changes in land cover due to persistent specialization on management of flooded forest extraction. There is little evidence that the community with the greatest impact on forest cover is any better off economically than the two communities which have minimal impact on the landscape. This study suggests how a balance between use and conservation in Amazonia may be achieved in floodplain and estuarine areas, and the effectiveness of monitoring these types of land cover from satellite platforms.