Additionally, the low temperatures and patchy distribution of cerrado surface fires allow animals ample escape routes and areas of cover. Ecological evidence also shows that moderate intensity fires increase the availability of foods for some taxa, including small vertebrates and arthropods, by stimulating vegetative growth, flowering, and fruiting  — . Ecological studies specifically evaluating the impacts of indigenous burning activities in the cerrado also found no evidence that animal populations, including those of economically important game species, decreased following fires  — .
Contrary to journalistic representations of Xavante hunting with fire as a cause of cerrado degradation and deforestation  ,  or an impediment to vegetation recovery  , ethnographic accounts indicate periodic burning by these indigenous peoples has minimal or desirable effects on cerrado vegetation structure and productivity  , .
Our previous ethnographic research  revealed that the Xavante people, eastern Mato Grosso State, use fire for hunting annually during the dry season primarily July to September and less frequently the moister months of May and June in widely dispersed locations throughout the reserve. Xavante collective hunting with fire often occurs in conjunction with such ceremonial occasions as weddings and adolescent rites of passage . Hunting excursions follow a ritualized format, whereby representatives from opposite exogamous moieties set fire to the vegetation as they run footraces in two wide arcs towards a distant finishing place.
As the fire expands in a shifting mosaic pattern, numerous hunters act individually or in collaboration with other hunters to dispatch fleeing game animals Figure 1. At the conclusion of hunting excursions, the acquired game meat is often pooled and ceremoniously presented to designated recipients, such as in-laws and initiation leaders. From the Xavante perspective, collective hunting with fire is an essential component of the ceremonial activities that distinguish them ethnically and causes no undesirable ecological changes when practiced according to traditional protocols.
To the contrary, Xavante cultural knowledge recognizes that traditional periodic burning accelerates the vegetative growth of some plants, increases the availability of certain animal foods, and reduces the intensity of future fires. Photograph by James R. The legal representative of the depicted individual provided informed written consent for the publication of his image.
Although the Xavante practice agriculture and in the s sold a small portion of rice yields as part of a government development project, today this activity is largely restricted to domestic production in small rotating patches, primarily in narrow gallery forests along river margins . In contrast to agriculture, periodic hunting with fire has a large spatial distribution and therefore greater potential for causing landscape-scale ecological effects within reserve boundaries.
However, Xavante strategies for hunting with fire are highly regulated by specific traditional protocols and knowledge aimed to maximize both short-term hunting productivity and long-term sustainability. Our ethnographic research  shows that when planning fires, Xavante hunters discuss such diverse factors as season, weather, winds, soil and foliage moisture, type of vegetation, and natural barriers in order to control their intensity, spatial distribution, and frequency through time see also  — .
- Betrayed: The Legend of Oak Island (Stories of Canada);
- Maidu Texts.
- Navigation menu?
- Die Förderung von Schülerinnen und Schülern mit Migrationshintergrund in NRW (German Edition);
- Akin To No One;
Among these considerations ample attention is given to the potential negative ecological effects of burning the same patches of vegetation in consecutive years, especially during extended droughts. In this paper, we evaluate conservation narratives regarding the relative long-term ecological impacts of indigenous and agribusiness management of Brazilian neotropical savanna landscapes based on estimates of diachronic environmental changes and indigenous burning patterns in a cerrado landscape in Mato Grosso State.
Specifically, we compared land cover change over four decades inside and within a 20 km buffer area around Pimentel Barbosa Indigenous Reserve Xavante ethnic group in order to ascertain their respective deforestation patterns. Multi-temporal spatial analyses of changes in vegetation cover — were performed utilizing satellite and georeferenced field data, as well as archival research for reconstructing changes in reserve boundaries since Additionally, in order to evaluate the contemporary Xavante burning regime contributing to observed results at the end of this sequence, we analyzed the spatial and temporal distribution of anthropogenic fire within the reserve utilizing a four year sample — This integrated study expands upon our long-term ethnographic and interdisciplinary research carried out in collaboration with the Xavante people since the s  ,  — .
The majority of this territory pertains to the Araguaia River Basin, although a small portion at the western boundary pertains to the Xingu River Basin. The ecological biome is cerrado, with a division occurring between western portions of the reserve, in which cerrado sensu stricto and dry forests predominate, and eastern portions, in which inundated grasslands are more prevalent.
About this book
The boundaries of this reserve underwent a series of alterations during the study period through decrees in , , and , and ratification in The population of Pimentel Barbosa Indigenous Reserve was approximately 1, individuals residing in nine villages . Field data was collected for georeferenced training samples inside and outside the reserve.
Data collected included vegetation type, land cover, land use history, regrowth status, notable species, and photographs. Elder members of the indigenous community accompanied all fieldwork activities and assisted with the identification of land use histories at all training sample locations. Each date was created using a mosaic of two and four , , contiguous images. All images were subjected to radiometric and atmospheric calibrations, georeferenced, and image subsets were layer stacked to form multitemporal images. Thematic data extraction for reserve boundaries and a 20 km buffer zone around the reserve was carried out using the tabulate area tool in ArcGIS Classification procedure for the image was based on unsupervised procedures only; for , , and classification was based on a hybrid approach i.
Images were independently classified.
- On His Birthday, Reginald Got?
- Microbial Diversity in Cerrado Biome (Neotropical Savanna) Soils.
- The Cerrados of Brazil | Columbia University Press?
- Welcome to the Neighborhood #1.
- CSIRO PUBLISHING | International Journal of Wildland Fire.
Image classification benefited from field collected georeferenced training samples. Field sites representative of natural vegetation were used as references for all dates, while recently altered sites were used as references for A layer of field sites was created and referenced into the multi-temporal image dataset. Classes were analyzed according to spectral-structural differences relationship between spectral data and indicators of vegetation structure , spatial distribution, and statistical values mean, standard deviation, and covariance for all spectral bands except thermal.
Using supervised procedures, training samples with known vegetation and history of land use were created and used to develop spectral signatures for the classes of interest in each data set for , , and Training samples and unsupervised classes were combined into a single spectral signature file. Analysis of training samples and unsupervised signatures include a combination of Transformed Divergence separability analysis, spectral signature comparison, and correlation analysis of spectral-vegetation data.
Signature sets were submitted to a probability-based Gaussian Maximum-Likelihood classifier. Classification accuracy of the classified image was assessed for aggregated classes i. A set of 30 test fields of known features i. Confusion between classes occurred mainly in areas of transitional vegetation structure with mixed elements of soil, herbaceous, arbustive, and arboreal coverage.
Legal descriptions of historical reserve boundaries dates —, —, —, and present were digitally reconstructed from archival maps and descriptive documents of delimiting landmarks and overlaid on the multi-temporal image dataset in ArcGIS. For the transition matrix analysis grassland and cerrado classes were aggregated. The final thematic layer produced eight classes, including those that remained unaltered across dates i.
The final layer was recoded to show the area deforested for each period. We used cross-tabulation in ArcGIS to allow estimation of deforestation during each period within respective reserve boundaries and outside respective buffer zones the reserve. We used ancillary data to verify the expansion of agriculture and pasture within the reserve during the late s, years not represented in the analysis sequence described above but described by Xavante observers and historical sources as the apex of agribusiness encroachment and deforestation in and around Pimentel Barbosa Indigenous Reserve  , .
These IBGE maps were developed from aerial photographs of the area from and fieldwork from The map was digitized to produce a thematic layer, which was overlaid to a Landsat MSS image for correction. This map discriminates cerrado and areas opened for agriculture and pasture. The resulting thematic layer provides important supporting evidence for the deforestation of cerrado areas within reserve boundaries and the buffer zone towards the end of the s. Images free of clouds were acquired for each month from July-September for each of the four years to capture the primary annual burning season.
As with the land-cover classifications, the imagery used for burned area mapping were coregistered to ensure spatial accuracy. Fifty clusters were initially created using a convergence threshold of 0. Burned areas were isolated from other land covers through spectral signature analysis and visual interpretation. Mixed pixels indicating burning scars were manually digitized if necessary. A final transition matrix image — comprised of 5 classes was created to illustrate land area by number of consecutive years burned i. The evolution of reserve boundaries overlaid on deforestation maps for , , , and show the progression of deforestation and vegetational recovery inside and outside the reserve Figure 2.
Deforestation outside the reserve indicates a pattern of encroachment from the west with its eastern limit shifting through time as reserve boundaries were adjusted. Comparison of intermediate reserve boundaries Figure 2B— and — indicate that most bare soil and agricultural fields or pasture inside the reserve in the years and was in locations previously outside or bordering the reserve limits. Additionally, large deforested patches evident inside the reserve in and , especially near its western and southern boundaries, were greatly reduced in size by Considering the historical reserve boundaries associated with each image year Figure 3 , the deforested area inside the reserve remained stable at 0.
However, intermediate years showed higher proportions 1. The deforested area inside the reserve decreased by The proportion of deforested land in a 20 km buffer area outside historical reserve limits increased continually from 1. Data from Brazilian topographic maps based on aerial photography Figure 4 identify the distribution of commercial livestock pasture and agricultural fields when reserve boundaries were most restricted — These boundaries are also shown without temporally corresponding satellite imagery in Figure 2B.
Cartographic data were digitized with permission from IBGE topographic maps . Vegetation burning matrix analyses show the distribution of lands inside the reserve by number of consecutive years burned from to Figure 5. The majority of the reserve burned at least once during the four-year period The largest areas were burned one Only 0. Additionally, The proportion of deforested land inside reserve boundaries increased in — and —, but decreased in — Considering the entire period —, the proportion of deforestation remained constant at an extremely low level 0.
Most deforestation inside the reserve occurred along the western and southern boundaries, which suffered the greatest impacts of regional eastward economic expansion since the mids Figure 6. A notable factor in this progression is the evolution of reserve boundaries through time. In particular, Xavante political action  resulted in substantial increases in the reserve size By returning these areas to indigenous management, previously deforested lands subsequently underwent vegetational recovery, thereby restoring the proportion of deforested land inside the reserve to the value observed four decades earlier 0.
This interpretation is corroborated by evidence from topographic maps generated in , when the reserve was reduced to its smallest size, showing extensive agribusiness deforestation in areas which were subsequently incorporated or reincorporated into the reserve. The comparatively smaller increase observed in — contrasts with a regional pattern of rapid agribusiness expansion in the same period . This difference may be attributable to decreased economic advantage of agricultural expansion along the western boundary of Pimentel Barbosa Indigenous Reserve given the extensive availability of lands nearby that were less intensively deforested before Comparison of Figures 2D and 5 reveals that vegetation cover was maintained or recovered even in areas of high fire periodicity within the reserve.
Thus, the observed Xavante burning pattern involved predominantly low fire periodicity and did not cause deforestation even where fires occurred in multiple consecutive years. Although these data do not allow us to draw direct comparisons with non-anthropogenic cerrado fire regimes, differences are likely to occur in terms of seasonality and frequency. In particular, whereas we observed the Xavante hunt with fire most often during the dry season, most cerrado fires not ignited through human agency are caused by lightning during rainy or transitional seasons  ,  , .
However, in general terms, both scenarios involve highly varied surface fire periodicity and patchy distributions. Ecological studies demonstrate that periodic cerrado fires can have positive effects on species diversity, as well as other environmental measures, and ought to be considered a strategic technique for environmental management in this biome  ,  ,  ,  ,  , .
This practice has yet to be incorporated in environmental management policies by the Brazilian government as it is in some other parts of the world with fire-adapted landscapes  — .
Cerrado - Wikipedia
This oversight may result from a tendency for the Brazilian rainforests, which are not fire adapted, to receive more attention from conservationists and environmental policies than the cerrado biome and to frame narratives of conservation and climate change mitigation in Brazil. However, the cerrado landscape and the indigenous reserves in Central Brazil face different threats than the Brazilian rainforests due to their distinct economic potentials for commercial agricultural development and ecological responses to anthropogenic fire  ,  ,  , .
For the past 50 years, the cerrado has been massively exploited through large scale clearing techniques largely absent in the Brazilian rainforests, involving mechanized tree-chaining that uproots trees in such a manner that regrowth is completely averted Figure 7. Conversely, commercial exploitation of Amazonian rainforests in some cases involving indigenous peoples involves some deforestation activities that are less frequent in the cerrado of Central Brazil, including illegal timber logging, large-scale industrial burning, and gold mining.
As the Brazilian government and the agribusiness sector respond to international pressures to curb carbon emission from deforestation in the Amazonian rainforests, economic pressure on the cerrado and associated forest clearing activities tend to increase. Photograph by Carlos E. Coimbra Jr. Much of policy and public discourse on tropical conservation presumes the positive value of non-alteration of tropical landscapes. Similarly, scientific conservation discourse in Brazil often assumes that anthropogenic burning in the cerrado, whether practiced by indigenous peoples or others, is uniformly destructive, contributes to global warming, and threatens the value of indigenous reserves and other conservation areas  — .
However, as demonstrated by the results of the present study, indigenous Xavante landscape management practices over four decades, including periodic collective hunting with fire and political advocacy for federal recognition of traditional lands, maintained the integrity of the cerrado landscape and sustained vegetational recovery as compared to adjacent lands under non-indigenous management. This point is especially pertinent because rapid plant regrowth in the cerrado quickly re-assimilates carbon emissions from appropriate fire regimes  , . Furthermore, our results suggest a need to reassess the implications of overreaching conservation and reduction in carbon emission narratives, increasingly shared by contrasting interest groups in Brazil and elsewhere, about the purportedly destructive nature of indigenous land use, particularly landscape management with fire  , .
Browse Subject Areas? Click through the PLOS taxonomy to find articles in your field. Abstract International efforts to address climate change by reducing tropical deforestation increasingly rely on indigenous reserves as conservation units and indigenous peoples as strategic partners. Introduction Efforts to reduce the negative environmental and biodiversity impacts of commercial agriculture and pasture activities are increasingly recognized to benefit from locally based knowledge and practices . Download: PPT. Figure 1.
Aims of this study In this paper, we evaluate conservation narratives regarding the relative long-term ecological impacts of indigenous and agribusiness management of Brazilian neotropical savanna landscapes based on estimates of diachronic environmental changes and indigenous burning patterns in a cerrado landscape in Mato Grosso State. Georeferenced field data Field data was collected for georeferenced training samples inside and outside the reserve. Results The evolution of reserve boundaries overlaid on deforestation maps for , , , and show the progression of deforestation and vegetational recovery inside and outside the reserve Figure 2.
Figure 2. Mosaic of calibrated satellite imagery overlaid with reserve boundaries and deforestation mapped from to , Pimentel Barbosa Indigenous Reserve, Brazil, — After this period, however, the urban and industrial development of the Southeast Region has forced agriculture to the Central-West Region. From until the beginning of the s, many governmental programs have been launched with the intent of stimulating the development of the Cerrado region, through subsidies for agriculture. On the other hand, the urban pressure and the rapid establishment of agricultural activities in the region have been rapidly reducing the biodiversity of the ecosystems, and the population in the Cerrado region more than doubled from to , going from The Cerrado was thought challenging for agriculture until researchers at Brazil's agricultural and livestock research agency, Embrapa , discovered that it could be made fit for industrial crops by appropriate additions of phosphorus and lime.
The Cerrados of Brazil
In the late s, between 14 million and 16 million tons of lime were being poured on Brazilian fields each year. The quantity rose to 25 million tons in and , equalling around five tons of lime per hectare. This manipulation of the soil allowed for industrial agriculture to grow exponentially in the area. Researchers also developed tropical varieties of soybeans , until then a temperate crop, and currently, Brazil is the world's main soyabeans exporter due to the boom in animal feed production caused by the global rise in meat demand.
Coffee produced in the Cerrado is now a major export. Charcoal production for Brazil's steel industry comes in second to agriculture in the Cerrado. When land is being cleared to make more land for agriculture, the tree's trunks and roots are often used in the production of charcoal, helping to make money for the clearing. The Brazilian steel industry has traditionally always used the trunks and roots from the Cerrado for charcoal but now that the steel mills in the state of Minas Gerais are the world's largest, it has taken a much higher toll on the Cerrado.
The Cerrado is the second largest biome in South America and the most biodiverse savanna in the world. However, it is not currently recognized by the Brazilian Constitution as a National Heritage. Brazilian agriculturalists and ministers regard it as it has no conservation value, and the government has protected merely 1.
The gallery forests in the region have been among the most heavily affected.
It is estimated that only about , km2, or During the last 25 years this biome has been increasingly threatened by industrial single-crop monoculture farming, particularly soybeans, the unregulated expansion of industrial agriculture, the burning of vegetation for charcoal and the development of dams to provide irrigation are drawing criticisms and have been identified as potential threats to several Brazilian rivers. This industrial farming of the Cerrado, with the clearing of land for Eucalyptus and Soya plantation, has grown so much because of various forms of subsidy, including very generous tax incentives and low interest loans, this has caused an enormous establishment of highly mechanized, capital intensive system of agriculture.
One issue with expanding this reserve is that research needs to be done to choose the location of these reserves because the Cerrado biome is floristically very heterogeneous and constitutes a biological mosaic. From Wikipedia, the free encyclopedia. Cerrado Vegetation in northwest Minas Gerais , Brazil.
See also: Category:Flora of the Cerrado. See also: Category:Fauna of the Cerrado. Archived from the original on Retrieved CS1 maint: Archived copy as title link. Columbia University Press, Annals of Botany, pp. Biotropica, pp. A physiognomic analysis of the 'cerrado' vegetation of central Brazil. A Flora do Cerrado. IV SimpoUsio sobre o cerrado. Soil resources and plant communities of the Central Brazilian cerrado and their development.
Biodiversity of the flora of the cerrado. Symposium on Tropical Savannas. Planaltina, DF, Brazil. Seasonal pattern of insect abundance in the Brazilian cerrado. Foraging ecology of attine ants in a Neotropical savanna: seasonal use of fungal substrate in the cerrado vegetation of Brazil. Ant-plant-herbivore interactions in the neotropical cerrado savanna. Biodiversity hotspots for conservation priorities. An Introduction to the Ecology of Cerrado Lizards. Local richness and distribution of the lizard fauna in natural habitat mosaics of the Brazilian Cerrado. Phylogeny and ecology determine morphological structure in a snake assemblage in the central Brazilian Cerrado.