Abstract: Enhanced Vegetation Index images are made by means of bands in the electromagnetic spec... more Abstract: Enhanced Vegetation Index images are made by means of bands in the electromagnetic spectrum in the range of blue, red and near infrared. This index minimizes the response effects of soil and atmosphere, besides having high response to ...
This study is an ecological analysis of the use of resources by two potentially competitive group... more This study is an ecological analysis of the use of resources by two potentially competitive groups, the commercial and recreational fishermen of Rio Grande, located on the border of the States of SÃo Paulo and Minas Gerais. Tourism at Rio Grande was intensified after the construction of the hydroeletric plant of Marimbondo in 1974, and local fishermen have complained about its interference. Values of niche dimensions, such as fishing periods, grounds, and prey caught were obtained through data gathered at landing points. Local and recreational fishermen usually fish in different parts of the river and catch different fish, because they use different gear. However, in transition months between the wet and dry seasons, when fish are less abundant, there is conflict or competition related to fishing grounds, reinforced by the territorial fishing rights of local longline fishermen in this period. We show how ecological concepts, such as niche and competition, may help to understand strategies of exploitation by human groups, fundamental information for the management of tropical areas.
On the Grande River (Rio Grande, Brazil), fishermen from two communities use different fishing ge... more On the Grande River (Rio Grande, Brazil), fishermen from two communities use different fishing gear (cast nets, longlines, gillnets or fishing rods) in different seasons, marked by the river water level. This study is an ecological analysis of fishing strategies at Grande River, downstream of a hydroelectric plant. Procedures included interviews and systematic observations of fishing trips. Corimba (Prochilodus lineatus) is caught especially in the wet season (November–March), barbado (Pinirampus pirinampu) is caught in the transitional months between seasons (April and October) and a relatively high diversity of fish is caught in the dry season (May–September). Cast nets are used especially in the wet season, longlines in the transition period, and gillnets and fishing rods in the dry season. In the wet season, P. lineatus is abundant and fishermen concentrate on fishing, whereas in the dry season some fishermen look for other jobs in construction, agriculture and local distilleries, and fishing is almost for subsistence. In the transition period, only fishermen who have rights on fishing grounds, used for longlines to catch P. pirinampu, continue to fish commercially. Predictability of fish migrations, fish abundance and market value of fish species are factors determining gears used, territorial rights and shift of economic activities at Grande River.
The region around Altamira, Brazil, located in the Eastern Amazon, has experienced rapid landcove... more The region around Altamira, Brazil, located in the Eastern Amazon, has experienced rapid landcover change since the initiation of government sponsored colonization projects associated with the construction of the Trans-Amazon Highway. The 30 years since colonization (1971) have been marked by a net loss of forest cover and an increase in the amount of cultivated/productive land, particularly for pasture and annual/perennial crop production. This research presents a parcel-level model of landcover change for smallholders in the Altamira study area. The utility of specific land-use activities is calculated to identify those land-uses that are most optimal at each time point, and labor is allocated to these activities based on the availability of household and wage labor. The model reports the proportion of the parcel in the following landcover classes at each time point using a 1-year interval: mature forest, secondary successional forest, perennial crops, annual crops and pasture. A graphical user interface is used for scenario testing, such as the impact of high/low (population) fertility, the increase of out-migration to urban areas, or changes in cattle and crop prices. The model shows a rapid reduction in the amount of mature forest in the 30 years following initial settlement, after which the parcel is composed of a mosaic of secondary succession, pasture and crops. The nature and rapidity of this landcover change is the function of a variety of household and external variables incorporated in the model. In particular, the model produces different landcover compositions as a function of demographic rates (fertility, mortality) and agricultural prices.
Traditionally, the ribeirinhoeconomy has been based on strategies of multiple resource use includ... more Traditionally, the ribeirinhoeconomy has been based on strategies of multiple resource use including agriculture, fishing, and small-scale stock raising. In the last two decades though, ribeirinhostrategies of resource management have undergone major changes due to the decline of jute production (the principal cash crop), and the intensification of the commercial fisheries. As a result of these trends, there has been a shift of ribeirinholabor from agriculture to commercial fishing. Today, the diversity which once characterized ribeirinhosubsistence strategies is disappearing, and fishing has become the primary economic activity for the great majority of varzeafamilies. As pressure on varzeafisheries has increased, ribeirinhocommunities have attempted to assert control over local varzealakes and exclude fishermen from outside the community. In a number of cases, ribeirinhocommunities have closed lakes to outsiders and established informal lake reserves under local community management. These lake reserves are a promising strategy for managing lake fisheries on a sustainable basis.
The relationship between resource management, local populations, and property regimes has long pu... more The relationship between resource management, local populations, and property regimes has long puzzled researchers and policy-makers. The constant failure of conservation policy reliant upon privatization and statization, has led both policy makers and researchers to recognize the importance of customary practices to achieve conservation. Yet, the overemphasis on "traditional populations" and "collective property regimes" as the way to promote conservation can be misleading. In this paper, we discuss the debate on local populations and resource conservation in the Southeastern Atlantic Forest, Brazil. The analysis focuses on 1) the concept of traditional populations; 2) the complexity of overlapping property regimes; 3) the potential for a loose relationship between "traditional populations" and "collective property regimes," and; 4) the implications of this approach for "non-traditional populations." We conclude that the bias toward "tradition" and "collective property regimes" threatens the entire range of local communities along what might be called a traditional-non-traditional populations gradient.
Abstract: Enhanced Vegetation Index images are made by means of bands in the electromagnetic spec... more Abstract: Enhanced Vegetation Index images are made by means of bands in the electromagnetic spectrum in the range of blue, red and near infrared. This index minimizes the response effects of soil and atmosphere, besides having high response to ...
This study is an ecological analysis of the use of resources by two potentially competitive group... more This study is an ecological analysis of the use of resources by two potentially competitive groups, the commercial and recreational fishermen of Rio Grande, located on the border of the States of SÃo Paulo and Minas Gerais. Tourism at Rio Grande was intensified after the construction of the hydroeletric plant of Marimbondo in 1974, and local fishermen have complained about its interference. Values of niche dimensions, such as fishing periods, grounds, and prey caught were obtained through data gathered at landing points. Local and recreational fishermen usually fish in different parts of the river and catch different fish, because they use different gear. However, in transition months between the wet and dry seasons, when fish are less abundant, there is conflict or competition related to fishing grounds, reinforced by the territorial fishing rights of local longline fishermen in this period. We show how ecological concepts, such as niche and competition, may help to understand strategies of exploitation by human groups, fundamental information for the management of tropical areas.
On the Grande River (Rio Grande, Brazil), fishermen from two communities use different fishing ge... more On the Grande River (Rio Grande, Brazil), fishermen from two communities use different fishing gear (cast nets, longlines, gillnets or fishing rods) in different seasons, marked by the river water level. This study is an ecological analysis of fishing strategies at Grande River, downstream of a hydroelectric plant. Procedures included interviews and systematic observations of fishing trips. Corimba (Prochilodus lineatus) is caught especially in the wet season (November–March), barbado (Pinirampus pirinampu) is caught in the transitional months between seasons (April and October) and a relatively high diversity of fish is caught in the dry season (May–September). Cast nets are used especially in the wet season, longlines in the transition period, and gillnets and fishing rods in the dry season. In the wet season, P. lineatus is abundant and fishermen concentrate on fishing, whereas in the dry season some fishermen look for other jobs in construction, agriculture and local distilleries, and fishing is almost for subsistence. In the transition period, only fishermen who have rights on fishing grounds, used for longlines to catch P. pirinampu, continue to fish commercially. Predictability of fish migrations, fish abundance and market value of fish species are factors determining gears used, territorial rights and shift of economic activities at Grande River.
The region around Altamira, Brazil, located in the Eastern Amazon, has experienced rapid landcove... more The region around Altamira, Brazil, located in the Eastern Amazon, has experienced rapid landcover change since the initiation of government sponsored colonization projects associated with the construction of the Trans-Amazon Highway. The 30 years since colonization (1971) have been marked by a net loss of forest cover and an increase in the amount of cultivated/productive land, particularly for pasture and annual/perennial crop production. This research presents a parcel-level model of landcover change for smallholders in the Altamira study area. The utility of specific land-use activities is calculated to identify those land-uses that are most optimal at each time point, and labor is allocated to these activities based on the availability of household and wage labor. The model reports the proportion of the parcel in the following landcover classes at each time point using a 1-year interval: mature forest, secondary successional forest, perennial crops, annual crops and pasture. A graphical user interface is used for scenario testing, such as the impact of high/low (population) fertility, the increase of out-migration to urban areas, or changes in cattle and crop prices. The model shows a rapid reduction in the amount of mature forest in the 30 years following initial settlement, after which the parcel is composed of a mosaic of secondary succession, pasture and crops. The nature and rapidity of this landcover change is the function of a variety of household and external variables incorporated in the model. In particular, the model produces different landcover compositions as a function of demographic rates (fertility, mortality) and agricultural prices.
Traditionally, the ribeirinhoeconomy has been based on strategies of multiple resource use includ... more Traditionally, the ribeirinhoeconomy has been based on strategies of multiple resource use including agriculture, fishing, and small-scale stock raising. In the last two decades though, ribeirinhostrategies of resource management have undergone major changes due to the decline of jute production (the principal cash crop), and the intensification of the commercial fisheries. As a result of these trends, there has been a shift of ribeirinholabor from agriculture to commercial fishing. Today, the diversity which once characterized ribeirinhosubsistence strategies is disappearing, and fishing has become the primary economic activity for the great majority of varzeafamilies. As pressure on varzeafisheries has increased, ribeirinhocommunities have attempted to assert control over local varzealakes and exclude fishermen from outside the community. In a number of cases, ribeirinhocommunities have closed lakes to outsiders and established informal lake reserves under local community management. These lake reserves are a promising strategy for managing lake fisheries on a sustainable basis.
The relationship between resource management, local populations, and property regimes has long pu... more The relationship between resource management, local populations, and property regimes has long puzzled researchers and policy-makers. The constant failure of conservation policy reliant upon privatization and statization, has led both policy makers and researchers to recognize the importance of customary practices to achieve conservation. Yet, the overemphasis on "traditional populations" and "collective property regimes" as the way to promote conservation can be misleading. In this paper, we discuss the debate on local populations and resource conservation in the Southeastern Atlantic Forest, Brazil. The analysis focuses on 1) the concept of traditional populations; 2) the complexity of overlapping property regimes; 3) the potential for a loose relationship between "traditional populations" and "collective property regimes," and; 4) the implications of this approach for "non-traditional populations." We conclude that the bias toward "tradition" and "collective property regimes" threatens the entire range of local communities along what might be called a traditional-non-traditional populations gradient.
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