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Geographic distribution of isolated indigenous societies in Amazonia and the efficacy of indigenous territories.

Kesler DC, Walker RS - PLoS ONE (2015)

Bottom Line: Isolated villages were identified at mid elevations, within 20 km of the tops of watersheds and at greater distances from existing roads and trails.We further used model results, combined with boundaries of the existing indigenous territory system that is designed to protect indigenous lands, to assess the efficacy of the existing protected area network for isolated peoples.Our results are intended to help inform policies that can mitigate against future external threats to isolated peoples.

View Article: PubMed Central - PubMed

Affiliation: Fisheries and Wildlife Sciences Department, University of Missouri, Columbia, Missouri 65211, United States of America.

ABSTRACT
The headwaters of the Amazon Basin harbor most of the world's last indigenous peoples who have limited contact with encroaching colonists. Knowledge of the geographic distribution of these isolated groups is essential to assist with the development of immediate protections for vulnerable indigenous settlements. We used remote sensing to document the locations of 28 isolated villages within the four Brazilian states of Acre, Amazonas, Roraima, and Rondônia. The sites were confirmed during previous over-flights and by image evidence of thatched-roof houses; they are estimated to host over 1,700 individuals. Locational data were used to train maximum entropy models that identified landscape and anthropogenic features associated with the occurrence of isolated indigenous villages, including elevation, proximity to streams of five different orders, proximity to roads and settlements, proximity to recent deforestation, and vegetation cover type. Isolated villages were identified at mid elevations, within 20 km of the tops of watersheds and at greater distances from existing roads and trails. We further used model results, combined with boundaries of the existing indigenous territory system that is designed to protect indigenous lands, to assess the efficacy of the existing protected area network for isolated peoples. Results indicate that existing indigenous territories encompass all of the villages we identified, and 50% of the areas with high predicted probabilities of isolated village occurrence. Our results are intended to help inform policies that can mitigate against future external threats to isolated peoples.

No MeSH data available.


Related in: MedlinePlus

Maps of Amazon Basin study area in Brazil.Study area includes states and locations of isolated villages (triangles, panel A), and locations of isolated villages and existing indigenous reserves (crosshatch, panel B). Panel C illustrates MaxEnt model results, with red areas indicating higher probabilities of occurrence for isolated tribes. Panel D includes both MaxEnt model results and overlays of existing indigenous reserves. Panel E illustrates areas with MaxEnt occurrence probabilities that are higher than areas in which isolated tribes have actually been observed (minimum training presence), and panel F includes the overlay of existing indigenous reserves.
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pone.0125113.g002: Maps of Amazon Basin study area in Brazil.Study area includes states and locations of isolated villages (triangles, panel A), and locations of isolated villages and existing indigenous reserves (crosshatch, panel B). Panel C illustrates MaxEnt model results, with red areas indicating higher probabilities of occurrence for isolated tribes. Panel D includes both MaxEnt model results and overlays of existing indigenous reserves. Panel E illustrates areas with MaxEnt occurrence probabilities that are higher than areas in which isolated tribes have actually been observed (minimum training presence), and panel F includes the overlay of existing indigenous reserves.

Mentions: We used the full village distribution model to assess whether existing indigenous territories encompassed areas with high predicted occurrence values for isolated villages. We identified areas with predicted occurrence values equal to, or higher than, model values where we observed settlements of isolated tribes, or minimum training presence (MTP) areas [32,47]. All cells with a model predicted probability of occurrence greater than the MTP value from the full village distribution model were amalgamated into polygons. For each state, we report the proportion of MTP polygons within the currently existing indigenous reserves [53], and the proportion outside existing reserve boundaries. Further, we identified the locations of MTP areas that are not encompassed by existing indigenous reserve boundaries (Fig 2). We excluded deforested areas, urban areas, rivers, and streams, and then summed values for cells inside and outside the boundaries of indigenous territories within each of the four states.


Geographic distribution of isolated indigenous societies in Amazonia and the efficacy of indigenous territories.

Kesler DC, Walker RS - PLoS ONE (2015)

Maps of Amazon Basin study area in Brazil.Study area includes states and locations of isolated villages (triangles, panel A), and locations of isolated villages and existing indigenous reserves (crosshatch, panel B). Panel C illustrates MaxEnt model results, with red areas indicating higher probabilities of occurrence for isolated tribes. Panel D includes both MaxEnt model results and overlays of existing indigenous reserves. Panel E illustrates areas with MaxEnt occurrence probabilities that are higher than areas in which isolated tribes have actually been observed (minimum training presence), and panel F includes the overlay of existing indigenous reserves.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430527&req=5

pone.0125113.g002: Maps of Amazon Basin study area in Brazil.Study area includes states and locations of isolated villages (triangles, panel A), and locations of isolated villages and existing indigenous reserves (crosshatch, panel B). Panel C illustrates MaxEnt model results, with red areas indicating higher probabilities of occurrence for isolated tribes. Panel D includes both MaxEnt model results and overlays of existing indigenous reserves. Panel E illustrates areas with MaxEnt occurrence probabilities that are higher than areas in which isolated tribes have actually been observed (minimum training presence), and panel F includes the overlay of existing indigenous reserves.
Mentions: We used the full village distribution model to assess whether existing indigenous territories encompassed areas with high predicted occurrence values for isolated villages. We identified areas with predicted occurrence values equal to, or higher than, model values where we observed settlements of isolated tribes, or minimum training presence (MTP) areas [32,47]. All cells with a model predicted probability of occurrence greater than the MTP value from the full village distribution model were amalgamated into polygons. For each state, we report the proportion of MTP polygons within the currently existing indigenous reserves [53], and the proportion outside existing reserve boundaries. Further, we identified the locations of MTP areas that are not encompassed by existing indigenous reserve boundaries (Fig 2). We excluded deforested areas, urban areas, rivers, and streams, and then summed values for cells inside and outside the boundaries of indigenous territories within each of the four states.

Bottom Line: Isolated villages were identified at mid elevations, within 20 km of the tops of watersheds and at greater distances from existing roads and trails.We further used model results, combined with boundaries of the existing indigenous territory system that is designed to protect indigenous lands, to assess the efficacy of the existing protected area network for isolated peoples.Our results are intended to help inform policies that can mitigate against future external threats to isolated peoples.

View Article: PubMed Central - PubMed

Affiliation: Fisheries and Wildlife Sciences Department, University of Missouri, Columbia, Missouri 65211, United States of America.

ABSTRACT
The headwaters of the Amazon Basin harbor most of the world's last indigenous peoples who have limited contact with encroaching colonists. Knowledge of the geographic distribution of these isolated groups is essential to assist with the development of immediate protections for vulnerable indigenous settlements. We used remote sensing to document the locations of 28 isolated villages within the four Brazilian states of Acre, Amazonas, Roraima, and Rondônia. The sites were confirmed during previous over-flights and by image evidence of thatched-roof houses; they are estimated to host over 1,700 individuals. Locational data were used to train maximum entropy models that identified landscape and anthropogenic features associated with the occurrence of isolated indigenous villages, including elevation, proximity to streams of five different orders, proximity to roads and settlements, proximity to recent deforestation, and vegetation cover type. Isolated villages were identified at mid elevations, within 20 km of the tops of watersheds and at greater distances from existing roads and trails. We further used model results, combined with boundaries of the existing indigenous territory system that is designed to protect indigenous lands, to assess the efficacy of the existing protected area network for isolated peoples. Results indicate that existing indigenous territories encompass all of the villages we identified, and 50% of the areas with high predicted probabilities of isolated village occurrence. Our results are intended to help inform policies that can mitigate against future external threats to isolated peoples.

No MeSH data available.


Related in: MedlinePlus