Álvaro de Oliveira D'Antona

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazônia Sustentável, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.

Collecting Sketch Maps to Understand Property Land Use and Land Cover in Large Surveys

This article describes a method to collect data on the spatial organization of land use within a rural property as part of a large-scale project examining the linkages between household demographic change and land use and land cover change in the Brazilian Amazon. Previous studies used several different spatial approaches, including maps and satellite images, to improve the information collected in standard survey questionnaires. However, few used sketch maps to obtain information from the point of view of the survey respondent about the spatial organization of land use and infrastructure. We developed a method of creating sketch maps with respondents to describe their properties. These maps then provided a spatially referenced database of the social and land use organization of the properties from the perspective of the respondent. Systematic rules allowed sketches to be used in subsequent spatial analyses in combination with satellite images and Global Positioning System reference points

Estratégia para amostragem da população e da paisagem em pesquisas sobre uso e cobertura da terra

This article describes the strategy used in a study carried out in Santarem, State of Para, Brazil, in 2003, to sample plots represented on maps produced by the Brazilian Government’s Land Reform Department (INCRA). The purpose of this sampling strategy is to describe demographic and environmental changes on the scale of the rural landholdings and on a regional scale. The sample was chosen according to the distribution of plots of land along four different roads that underwent different processes of occupation. Twenty cells of 9km2 each were chosen at random along each road and, in each direction, plots were chosen to be visited. In the field work, persons at all the domestic units existing in each of the plots selected were interviewed. Sampling carried out by successive segmentation of the area of study is described, as well as the way in which the resulting data can be used differently on the scales of domestic units, plots of land, and regions, according to the questions and variables of interest.

Integrando desenhos e imagens de satélite no estudo de mudanças no uso e cobertura da terra

We analyzed the procedure of collecting and processing information in regard to land use and land coverage obtained from sketch maps created together with rural property owners in a settlement area along the Transamazonica, the Transamazon Highway, in Para, Brazil. We assessed the special features of field data and integrated them with data from satellites. We concluded that these sketch maps can be used systematically to improve interdisciplinary approaches in the study of environmental changes.

Contraceptive discontinuation and non-use in Santarém, Brazilian Amazon

In this paper we discuss the causes of non-adherence to reversible contraceptives, especially hormonal methods, among women in rural Santarém in the Brazilian Amazon. The analysis is based on questionnaires with 398 women and visits to health centers. We consider the motives reported by women who: never used contraception; used some method in the past; and who at the time of the survey were using a different method from the ones they used in the past. The results indicate a rejection of hormonal contraception and a preference for female sterilization, an option possibly influenced by the characteristics of health services in the region. The side effects of hormonal contraceptive use reported by part of the interviewees contribute to a generalized fear of the side effects even among women who have never used such methods. To improve womens health services in the Amazon, we recommend further studies of the relationship between reported side effects and available services and prescriptions, as well as an analysis of womens discourse and perceptions.

Estimativa da população em unidades de conservação na Amazônia Legal brasileira: uma aplicação de grades regulares a partir da Contagem 2007

In this paper a method for increasing the resolution of census data is tested and presented, by aggregating the data onto a regular grid. The methodology consists of (1) the aggregation of households, represented by their geographical coordinates obtained by the 2007 Population Count, carried out by the Brazilian Census Office (IBGE) and, (2) the unbundling of the data by census tracts on the basis of proportionality. The grids obtained were used to estimate the resident population of 114 conservation units in Brazilian Legal Amazon, all of them instituted in or before 2006. The intention was to test this methodology on territorial units that follow neither the official political-administrative boundaries of states and cities, nor the boundaries designed by IBGE for collecting data. The methodology also contributes to the study of populations living in protected areas, due to the scarcity of population estimates in the conservation units. The results showed a population of 325,398 inhabitants in the selected units, 297,693 of whom were in units for Sustainable Use and 27,705 in Permanent Protection units. Adjoining areas have an estimated joint population of 1,020,237. Despite the limitations involved in using the 2007 Population Count, the aggregating of data into grids would seem to be a promising methodology in view of the improvements in IBGE’s use of geotechnology. The grid minimizes problems that come up in the use of administrative units or census data and may represent an approach that can be applied usefully in demography and other areas of knowledge.

Polarização da estrutura fundiária e mudanças no uso e na cobertura da terra na Amazônia

The objective of this article is to present Polarization of Agrarian Structure as a single, more complete representation than models emphasizing rural exodus and consolidation of land into large agropastoral enterprises of the dynamics of changing land distribution, land use / cover, and thus the rural milieu of Amazonia. Data were collected in 2003 using social surveys on a sample of 587 lots randomly selected from among 5,086 lots on a cadastral map produced in the 1970s. Georeferencing of current property boundaries in the location of these previously demarcated lots allows us to relate sociodemographic and biophysical variables of the surveyed properties to the changes in boundaries that have occurred since the 1970s. As have other authors in other Amazonian regions, we found concentration of land ownership into larger properties. The approach we took, however, showed that changes in the distribution of land ownership is not limited to the appearance of larger properties, those with 200 ha or more; there also exists substantial division of earlier lots into properties with fewer than five hectares, many without any agropastoral use. These two trends are juxtaposed against the decline in establishments with between five and 200 ha. The variation across groups in land use / land cover and population distribution shows the necessity of developing conceptual models, whether from socioeconomic, demographic or environmental perspectives, look beyond a single group of people or properties.

Strategy for a sampling of the population and the land structure in studies on the use, covering and domestic units of the land

This article describes the strategy used in a study carried out in Santarem, State of Para, Brazil, in 2003, to sample plots represented on maps produced by the Brazilian Government’s Land Reform Department (INCRA). The purpose of this sampling strategy is to describe demographic and environmental changes on the scale of the rural landholdings and on a regional scale. The sample was chosen according to the distribution of plots of land along four different roads that underwent different processes of occupation. Twenty cells of 9km2 each were chosen at random along each road and, in each direction, plots were chosen to be visited. In the field work, persons at all the domestic units existing in each of the plots selected were interviewed. Sampling carried out by successive segmentation of the area of study is described, as well as the way in which the resulting data can be used differently on the scales of domestic units, plots of land, and regions, according to the questions and variables of interest.

Land use and land cover dynamics: prospects and challenges for demography

This paper is about studies on the relationships between environment and population from an integrated perspective, and changes in the use of the land cover, focusing on the contributions and challenges for demography. Demography approached this issue in the mid-1990s and its main contribution was to highlight the importance of population components in the models, which, until then, had been presented mainly from a simple perspective and as secondary components. Although Brazilian demographers dedicated to environmental issues were studying primarily urban themes, they collaborated indirectly to the field by proposing new ways of thinking about relations between population and environment. This paper is based on the Brazilian Amazon Region and shows how the population has been considered in theories about changes in the uses and cover of the land. Growth related to the expansion of the agricultural frontiers has also been treated, as well as the model of the household life cycle (fertility and household composition) in the 1990s and, more recently, a focus on the migration component. For demography, the article argues how essential it is to broaden studies on demographic elements, rather than their volume and space, and its effects. For the construction of Land Change Science, the author insists on the importance of urban dynamics in research, the adoption of a methodology and the exercise of dialogue among the various fields of study, incorporating the contribution of demography more systematically.

Dinámicas en el uso y cobertura de la tierra: perspectivas y desafíos de la Demografía

This paper is about studies on the relationships between environment and population from an integrated perspective, and changes in the use of the land cover, focusing on the contributions and challenges for demography. Demography approached this issue in the mid-1990s and its main contribution was to highlight the importance of population components in the models, which, until then, had been presented mainly from a simple perspective and as secondary components. Although Brazilian demographers dedicated to environmental issues were studying primarily urban themes, they collaborated indirectly to the field by proposing new ways of thinking about relations between population and environment. This paper is based on the Brazilian Amazon Region and shows how the population has been considered in theories about changes in the uses and cover of the land. Growth related to the expansion of the agricultural frontiers has also been treated, as well as the model of the household life cycle (fertility and household composition) in the 1990s and, more recently, a focus on the migration component. For demography, the article argues how essential it is to broaden studies on demographic elements, rather than their volume and space, and its effects. For the construction of Land Change Science, the author insists on the importance of urban dynamics in research, the adoption of a methodology and the exercise of dialogue among the various fields of study, incorporating the contribution of demography more systematically.