Mario Hiraoka

The economic value of managing the açaí palm (Euterpe oleracea Mart.) in the floodplains of the Amazon estuary, Pará, Brazil

Abstract Extraction of non-timber forest products (NTFPs) can provide important income for the inhabitants of tropical developing countries. The present research focuses on NTFP extraction in the Amazon estuary by evaluating the economics of managing acai ( Euterpe oleracea ), a predominant palm species of the Amazon floodplains. The productivity, revenues and costs associated with traditional household management of acai were examined in secondary forests and in homegardens. The present value of the net revenue (NPV) of lands managed for fruit and palm-heart was calculated at different distances from the central market of Belem, Para, Brazil. Intensity of acai management was dependent on distance from the market and household resources, ranging from simple collection in natural forest to intense cultivation. All calculations of revenues accounted for variation in prices due to seasonality of production. Acai ws found to be a highly valuable production system even at high rates of interest. At a 15% interest rate, the net present values were US

Land use changes in the Amazon estuary

1337–2693 ha −1 in managed secondary forests and US

Humus composition of Amazonian Dark Earths in the Middle Amazon, Brazil

4266–6930 ha −1 in homegardens.

The Development of Amazonia

The estuarine floodplain inhabitants of Amazon near Belem, Brazil, are making the transition from swidden farming to permanent farming based on palm agro-forests. The region is characterized by rapidly increasing population, proximity to major urban centres, and inhabitants who are fully participating in the market economy. These factors, however, have not led to an intensified use of labour and land. Instead, the pattern has been toward less intense use with higher returns than the previous one. A combination of factors, including social, economic, and political changes within the past two decades, the cultural patterns of the region, and the distinctive environment are responsible for the new pattern. This case study suggests that there are no universal paradigms to explain labour and land use changes.

Forest biomass and wood consumption in the lower course of the Amazon: a case study of the Urubueua Island

Abstract The process of humus accumulation has been one of the most important aspects in the pedogenesis of Amazonian Dark Earths (ADE) and Terra Mulata (TM). ADE has been characterized by higher contents of P, Ca and humus than adjacent Yellow Latosol (YL) under anthropogenic effects, and TM has been characterized by slightly less dark topsoil than ADE. The objective of this study was to analyze the composition of humus in ADE using the Kumadas method. A total of 20 soil samples of the A horizons and the transitional AB and BA horizons from three soil profiles of ADE (12 samples), adjacent two YL (4 samples) and a TM (4 samples) were subjected to a humus composition analysis, in which successive extraction with NaOH and Na4P2O7 was conducted. The amounts of the humic acid fractions in NaOH and Na4P2O7 extracts from ADE were distinctly higher than those from the adjacent YL. The RF values, the absorbance at 600 nm per unit concentration of humic acids in 0.1 mol L−1 NaOH of ADE, were not necessarily the highest in the surface horizons, but the darkest humic acids often existed in the transitional AB or BA horizons. The humic acids extracted with NaOH from seven of 16 samples of ADE and TM were classified into Type A, the most humified group, while the humic acids extracted with Na4P2O7 were Type A in 11 samples. Moreover, the amounts of humic acid fractions and RF values of humic acids were positively correlated with the Al + Fe contents in humic acid fractions, especially those extracted with Na4P2O7. Thus, it is possible that humic substances in ADE are stabilized by forming complexes with Al and Fe.

The Economic Use of Palms in- Amazonia: Raphia taedigera in the estuary.

Probably no region of Latin America received as much attention as Amazonia did during the past decade. Central governments viewed this enormous, yet sparsely inhabited area as a place where development could solve multiple problems. However, the ill-conceived plans and techniques employed in the development of the region have become the focus of concern and debates. Current discussions mainly question the strategies for development, their effects on native inhabitants and on the environment, and the prospects for the region. Among the conferences held on the area and its problems, one of the most notable was the Conference on the Development of Amazonia in Seven Countries, held at the University of Cambridge in September, 1979.1 The conference was characterized by interdisciplinary examination of multiple issues of development; the meeting served to identify important problems, trends, and possible solutions. The topics covered at the conference can be categorized in four themes: ecological issues, characteristics of development, problems of colonization, and effects on Amerindians. Concerted efforts to open the tropical lowlands began in the 1950s. Extension of roads, planned small-scale colonization projects, and oil-drilling activities in the 1960s and 1970s were the mechanisms for rapid occupation of the upper Amazon. In the Brazilian Amazonia, major inroads by subsistence farmers and cattle ranchers occurred after 1960 with the construction of the Belem-Brasilia and Cuiaba-Porto Velho highways. Two programs accelerated the development process after 1971: the ambitious, but short-lived National Integration Plan that led to the construction of the Transamazon and CuiabaSantar6m highways as well as the establishment of planned colonies along them; and the Polamazonia program devised to promote regional growth by attracting large agricultural, mining, and lumbering concerns through tax exemptions, financial incentives, and credit availability.

アマゾン河流域におけるヤシの経済的利用-河口部におけるRaphia taedigera種の事例-(英文)

Florestas de varzea e de terra-firme na foz do Amazonas foram comparadas, com relacao a sua estrutura, incrementos de volume madeireiro e biomassa florestal. O volume madeireiro de floresta de varzea e menor que o de florestas de terra-firme, especialmente quando se considera a intervencao humana (o cultivo da palmeira acai) na referida analise. Esta diferenca e ampliada na comparacao de peso florestal, pelo fato das arvores de varzea apresentarem uma baixa densidade madeireira. As arvores de florestas de varzea nao sao diretamente influenciadas pela escassez caracteristica do periodo prolongado de seca, devido a madeira de alta densidade ser formada em arvores de terra-firme. Na ilha em estudo, cuja area e de 36.200 ha, o desaparecimento anual da area florestal devido as queimadas provocadas pelas olarias, e cerca de 276 ha. Assumindo-se que as florestas tem um periodo de rotacao de 25 a 30 anos, a area total deflorestada esta entre 6.87-69480 ha/25 anos a 8.244-8.337 ha/30 anos. Este resultado demonstra que o balanco entre a biomassa e sua utilizacao nao esta em crise; entretanto este balanco pode sofrer alteracoes, caso nao sejam substituidos os meios de producao de energia na regiao.

The Economic Use of Palms in Amazonia

This paper presents a biogeographical and socio-economic study of the significance of jupati (Raphia taedigera) for peasant livelihood strategies in the Amazon esutuary. It engages current research interest in indigenous agroforestry systems as an alternative to deforestation in Amazonia and especially, the role of palms for providing marketable products and sustainable land use systems. While several studies illuminate the economic importance of marketing acai (Euterpe oleracea) fruits, there is very little attention to other wetland palms, like Raphia, which provide valuable products to rural people but are less visible in the cash economy. Such is the case with Raphia taedigera, which attains its broadest areal extension in the Amazon estuary and whose petioles are used to fashion shrimp traps. Shrimp sales constitute an important income source for ribeirinho (ribereno) families in the estuary. This study presents an overview of the biogeographical range of Raphia taedigera in the lower Amazon, the hydrological conditions that favor its establishment, and the depth of indigenous knowledge of its use within ribeirinho livelihood systems.

Agricultural development in the upper Amazon of Ecuador.

This paper presents a biogeographical and socio-economic study of the significance of jupati (Raphia taedigera) for peasant livelihood strategies in the Amazon esutuary. It engages current research interest in indigenous agroforestry systems as an alternative to deforestation in Amazonia and especially, the role of palms for providing marketable products and sustainable land use systems. While several studies illuminate the economic importance of marketing acai (Euterpe oleracea) fruits, there is very little attention to other wetland palms, like Raphia, which provide valuable products to rural people but are less visible in the cash economy. Such is the case with Raphia taedigera, which attains its broadest areal extension in the Amazon estuary and whose petioles are used to fashion shrimp traps. Shrimp sales constitute an important income source for ribeirinho (ribereno) families in the estuary. This study presents an overview of the biogeographical range of Raphia taedigera in the lower Amazon, the hydrological conditions that favor its establishment, and the depth of indigenous knowledge of its use within ribeirinho livelihood systems.

Contemporary Use and Management of Amazonian Dark Earths

This paper presents a biogeographical and socio-economic study of the significance of jupati (Raphia taedigera) for peasant livelihood strategies in the Amazon esutuary. It engages current research interest in indigenous agroforestry systems as an alternative to deforestation in Amazonia and especially, the role of palms for providing marketable products and sustainable land use systems. While several studies illuminate the economic importance of marketing acai (Euterpe oleracea) fruits, there is very little attention to other wetland palms, like Raphia, which provide valuable products to rural people but are less visible in the cash economy. Such is the case with Raphia taedigera, which attains its broadest areal extension in the Amazon estuary and whose petioles are used to fashion shrimp traps. Shrimp sales constitute an important income source for ribeirinho (ribereno) families in the estuary. This study presents an overview of the biogeographical range of Raphia taedigera in the lower Amazon, the hydrological conditions that favor its establishment, and the depth of indigenous knowledge of its use within ribeirinho livelihood systems.