Brazilian Legal Amazon Research Articles

Effects of Land Use and Forest Management on the Carbon Cycle in the Brazilian Amazon

SUMMARY.Deforestation in the Brazilian Legal Amazon releases substantial amounts of greenhouse gases. Net committed emissions (the long-term result of emissions and uptakes in a given area that is cleared) totaled 267-278 million t of CO2-equivalent carbon in 1990 (under low and high trace gas scenarios), while the corresponding annual balance of net emissions (the balance in a single year over the entire region, including areas cleared in previous years) in 1990 was 354-358 million t from deforestation plus 62 t from logging. These figures contrast sharply with official pronouncements that claim little or even no net emission from Amazonia. Most emissions are caused by medium and large ranchers (despite recent official statements to the contrary), a fact which means that deforestation could be greatly slowed without preventing subsistence clearing by small farmers. The substantial monetary and non-monetary benefits that avoiding this impact would have provide a rational for making the supply of environmental services a long-term objective in reorienting development in Amazonia.

Atmospheric corrosion tests in Brazilian Legal Amazon - field and laboratory tests

This paper presents the first results concerning tests carried out to evaluate the atmospheric corrosion in Brazilian Legal Amazon, as part of the SIVAM - Amazon Surveillance System. The aim of the present work is to determine and select materials as well as anti-rust paints, which will be employed to protect metallic structures of radar towers, equipment and buildings. Five anti-rust paints on mild and galvanised steels were tested. Field tests are supported by accelerated laboratory results in wet and drying cycles in electrolytes simulating different microclimates. These solutions were prepared in laboratory based on pH, conductivity and chloride content values of locally collected rainwater.

Atmospheric corrosion tests in Brazilian Legal Amazon – field and laboratory tests

Atmospheric corrosion tests in Brazilian Legal Amazon – field and laboratory tests

Mapping the regional extent of tropical forest regeneration stages in the Brazilian Legal Amazon using NOAA AVHRR data

The study aimed to map several stages of tropical forest regeneration across the Brazilian Legal Amazon using 1.1 km NOAA AVHRR data. Regenerating forest extent was defined using an unsupervised classification of AVHRR channels 1, 2 and 3 and the Global Environment Monitoring Index (GEMI). A method for discriminating four forest regeneration stages was then developed, based on relationships between AVHRR channels 1, 2 and 3 and forest age. This method was applied to AVHRR data to map forests associated with Stages I (early colonization phase, open canopy, < 5 years), II (closed, singlelayered canopy, 5-9 years), III (closed canopy with structural development, 9-20 years) and IV (closed multilayered canopy, > 20 years). The maps provided new regional estimates of regenerating forest for the Legal Amazon and indicated that, over the period 1991 to 1994, approximately 35.8% (157 973 km2) of the total deforested area of 440 186 km2 (estimated for 1992) supported regenerating forest, with 48% of these forests aged at less than 5 years. The study concluded that AVHRR data has an important role in mapping and monitoring tropical forest regeneration. The datasets generated provide valuable input to models of regional carbon flux. For example, Grace et al . (1995a, b) reported net annual CO2 absorption 8.5 2.0 moles m 2 for mature forests in south-west Amazonia suggesting

Secondary Forest Age and Tropical Forest Biomass Estimation Using Thematic Mapper Imagery

he Brazilian Legal Amazon encompasses an area of approximately 5,030,000 km 2 , stretching from the states of Maranhao and Tocantins in the east to Amazonas and Acre in the west, and from Roraima and Amapa in the north to Mato Grosso in the south. Approximately 4,090,000 km 2 of this area is forested, 850,000 km 2 is cerrado (wooded grassland), and 90,000 km 2 is water (Skole and Tucker 1993, Fearnside 1996). As of 1988, 230,324 km 2 , or 5.6%, of the approximately 4,090,000 km 2 forested Brazilian Legal Amazon had been deforested (Skole and Tucker 1993, Skole et al. 1994) since theconstruction of the Belem-Brasilia Highway in 1958 (Moran et al. 1994). Each year, approximately 15,000‐20,000 km 2 of additional primary tropical forest in this region are cut and cleared (Skole et al. 1994), although estimates of clearing rates have varied greatly among studies and over the decades (approximately 8000‐10,000 km 2 /yr in the 1970s, Mahar 1988; approximately 35,000 km 2 /yr in the 1980s, Fearnside 1989; approximately 15,200 km 2 /yr from 1978‐1988, Skole and Tucker 1993).

Floods of Fortune

The insertion of emerging business frontiers into the global economy is one of the challenges facing the globalization process. The Brazilian Legal Amazon region is one of these emerging business frontiers. Accounting for 60% of the Brazilian territory, or 4.9 million square kilometers, the Amazon holds the key for the further development and growth of the Brazilian economy. Romantic approaches to the Amazon region, aimed at turning the region into a large botanical garden, do not provide the answer to the Amazon question. However, proposals that take into account both development and conservation measures would certainly provide a more fruitful contribution to the Amazon debate. This paper argues that the Amazon region can and should be explored taking into account the region's specificities, and that appropriate technology should be developed to address the region's multiple vocations. Resumen El surgimiento de nuevas fronteras de negocios en la economía global representa uno de los retos mas importantes en los procesos de globalización. La región amazónica del Brasil es una de estas nuevas fronteras. Los 4.9 millones de kilómeteros cuadrados del amazonas represntan el 60% de todo el territorio brasileño y son la clave del crecimiento y desarrollo económico futuro de este país. Los enfoques romanticistas que implican la transformación de esta región en un enorme jardín botánico no proporcionan la respuesta para el dessarrollo de la misma o de la nación brasileña. Sin embargo, las propuestas que consideran en forma simultánea medidas de conservation ambientales y desarrollo económico, ciertamente producen una contribución mas significativa al debate sobe el Amazonas sin pérdida de la identidad nacional. Este artículo propone que el amazonas puede y debería ser estudiada a través de consideraciones específicas a la region y que la tecnología apropiada debería ser utilizada para promover y apoyar las vocaciones múltiples de la región. Resumo A inserção de fronteiras emergentes de negócios na economia globalizada é um dos desafios ao processo de globalização. A Amazônia Legal brasileira é uma dessas fronteiras emergentes de negócios. Correspondendo a 60% do território brasileiro, ou 4.9 milhões de quilômetros quadrados, a Amazônia Leagal é um componente vital no desenvolvimento e crescimento da economia brasileira. Atitudes “românticas” em relação a questão Amazônica, propõem praticamente, a transformação da região em um grande jardim botânico. Esses enfoques não providenciam soluções pragmáticas para a região. No entanto, projetos que levem em consideração desenvolvimento econômico e medidas que visem a preservação e proteção ambiental, certamente contribuem para uma visão mais realista da Região Amazônica, sem perda da identidade nacional. Este artigo levanta a tese de que a Região Amazônica pode e deve ser explorada economicamente, levando-se também em consideração, o desenvolvimento de tecnologia apropriada as vocações múltiplas da Amazônia.

Carbon uptake by secondary forests in Brazilian Amazonia

Estimating the contribution of deforestation to greenhouse gas emissions requires calculations of the uptake of carbon by the vegetation that replaces the forest, as well as the emissions from burning and decay of forest biomass and from altered emissions and uptakes by the soil. The role of regeneration in offsetting emissions from deforestation in the Brazilian Legal Amazon has sometimes been exaggerated. Unlike many other tropical areas, cattle pasture (rather than shifting cultivation) usually replaces forest in Brazilian Amazonia. Degraded cattle pastures regenerate secondary forests more slowly than do fallows in shifting cultivation systems, leading to lower uptake of carbon. The calculations presented here indicate that in 1990 the 410 x 103 km2 deforested landscape was taking up 29 x 106 t of carbon (C) annually (0.7 t C ha-1 year-1). This does not include the emissions from clearing of secondary forests, which in 1990 released an estimated 27 x 106 t C, almost completely offsetting the uptake from the landscape. Were the present land-use change processes to continue, carbon uptake would rise to 365 x 106 t annually (0.9 t C ha-1 year-1) in 2090 in the 3.9 x 106 km6 area that would have been deforested by that year. The 1990 rate of emissions from deforestation in the region greatly exceeded the uptake from regrowth of replacement vegetation.

A Conservation Gap Analysis of Brazil's Amazonian Vegetation.

Vegetation types lacking protection in the existing conservation units of the nine states in the Brazilian Legal Amazon were identified, and locations were noted where these vegetation types could be protected. Maps of vegetation, protected areas, and semi-protected areas, such as Amerindian and forestry reserves, were digitized and overlaid using a geographic information system. There are 28 natural vegetation types in the Brazilian Legal Amazon. Locations of new areas for protection were selected using a minimum criterion of protecting at least one example of each vegetation type in each state (here called "vegetation zones"). There are 111 vegetation zones in the Legal Amazon, of which only 37 (33%) have some portion of their area protected. There are few protected areas in the most heavily deforested states along the southeastern fringe of the forest. In Maranhão, where 60% of the original forest had been lost by 1990, only one of 10 vegetation types is protected. Negotiating agreements with indigenous tribes, and to a lesser extent with extractivists who harvest nontimber products from the forest, represents a major opportunity to increase significantly the area and representativeness of the conservation units. Additional conservation units need to be established quickly before rapidly increasing deforestation and land prices preclude this opportunity; otherwise, some vegetation types may virtually disappear. Un análisis de conservación de la vegetación Amazónica del Brasil.

Assessment of AVHRR data for deforestation estimation in Mato Grosso (Amazon Basin)

Abstract A large area (∼ 900,000 km2) corresponding to Mato Grosso, a southern most State of the Brazilian Legal Amazon region, was selected for this study. All five channels of selected dates of 1988, 1989, and 1990, full resolution NOAA AVHRR data were investigated to map “forest” and “non‐forest” (“cerrado”) using on the screen visual interpretation. Maximum likelihood classifier (MLC) was used to classify deforestation for the 1988 AVHRR images. The vegetation map obtained by interpretation of AVHRR data agreed well with the available vegetation map used as reference. Results based on cells of 1° by 1.5° showed r2 = 0.94 (significant at α = 0.01) between the AVHRR map of forest and the available vegetation map. Comparisons for 1988 between AVHRR deforestation estimates and two independent estimates using TM data, i.e. Landsat TM band 5 habitat fragmentation and Landsat TM bands 3, 4, and 5 color composite deforestation estimates were within 3% of each other for the entire State (range from 71,128 km2 ...

Layer enhancements of tropospheric ozone in regions of biomass burning

Several field expeditions were organized in recent years to study modifications introduced into the lower atmosphere of the Amazon region, as a result of anthropogenic influence. In a simplified way, the legal Brazilian Amazon is formed by the rainforest ecosystem in the North and west, and the savanna ( cerrado) in the central region. The frontier region between these two quite different types of vegetation is where most burning occurs, and due to the large areas and amounts of phytomass involved these burnings may represent sources of Global importance. This report describes enhancements of atmospheric ozone concentrations in the remote cerrado troposphere which are believed to result from biomass burning activity. The measurements were obtained in two field expeditions to the Brazilian cerrado region of central Brazil, an area subject to cyclic burning, during the local dry season. Ozone concentrations are known to increase in the burning season. However, this process is normally a gradual increase over the season and proportional at all heights. Occasionally, large layer enhancements are seen. Three such cases are discussed, showing concentrations of ozone between 80 and 120 ppbv (parts per billion by volume), when normal averages are about 60 ppbv. To our knowledge this is the first time that such large concentrations were observed in areas of biomass burning. In one event the ozone mixing ratio was increased in a layer near 800 mbar (2.0 km above ground) to a maximum of 112 ppbv, when the known maximum observed near this height was 80 ppbv. Other events show a layer near 250 mbar (10.9 km above ground) reaching 120 and 122 ppbv at the peak. It is believed that these are special events which could be produced by a coincidence of chemical production and dynamical layering effects.