Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Environ Manage ; 354: 120354, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38394876

RESUMO

In recent years, the loss of forest in the Brazilian Amazon has taken on alarming proportions, with 2021 recording the largest increase in 13 years, particularly in the Abunã-Madeira Sustainable Development Reserve (SDR). This has significant environmental, social, and economic repercussions globally and for the local communities reliant on the forest. Analyzing deforestation patterns and trends aids in comprehending the dynamics of occupation and deforestation within a critical Amazon region, enabling the inference of potential occupation pathways. This understanding is crucial for identifying deforestation expansion zones and shaping public policies to curb deforestation. Decisions by the Brazilian government regarding landscape management will have profound environmental implications. We conducted an analysis of deforestation patterns and trends up to 2021 in the municipality (county) of Lábrea, located in the southern portion of Amazonas state. Deforestation processes in this area are likely to spread to the adjacent "Trans-Purus" region in western Amazonas, where Amazonia's largest block of remaining rainforest is at risk from planned highways. Annual deforestation polygons from 2008 to 2021 were categorized based on occupation typologies linked to various actors and processes defined for the region (e.g., diffuse, linear, fishbone, geometric, multidirectional, and consolidated). These patterns were represented through 10 × 10 km grid cells. The findings revealed that Lábrea's territory is predominantly characterized by the diffuse pattern (initial occupation stage), mainly concentrated in protected areas. Advanced occupation patterns (multidirectional and consolidated) were the primary contributors to deforestation during this period. Observed change trajectories included consolidation (30.8%) and expansion (19.6%) in the southern portion of the municipality, particularly along the Boi and Jequitibá secondary roads, providing access to large illegal landholdings. Additionally, non-change trajectories (67%) featured initial occupation patterns near rivers and in protected areas, likely linked to riverine and extractive communities. Tailoring measures to control deforestation based on actor types and considering stages of occupation is crucial. The techniques developed in this study provide a comprehensive approach for Amazonia and other tropical regions.


Assuntos
Conservação dos Recursos Naturais , Florestas , Brasil , Floresta Úmida , Desenvolvimento Sustentável
2.
J Environ Manage ; 288: 112310, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33761331

RESUMO

Forest fires and deforestation are the main threats to the Amazon forest. Extreme drought events exacerbate the impact of forest fire in the Amazon, and these drought events are predicted to become more frequent due to climate change. Fire escapes into the forest from agriculture and pasture areas. We assessed the potential drivers of deforestation and forest fires in the central Brazilian Amazon and show that over a period of 31 years (1985-2015) forest fires occurred only in years of extreme drought induced by El Niño (1997, 2009 and 2015). The association of forest fires with strong El Niños shows the vulnerability of forest to climate change. The areas deforested were closely associated with navigable rivers: 62% of the total deforestation from 2000 to 2018 was located within the 2 km of rivers. There was a notable increase in deforestation and forest fire during the 2015 El Niño in comparison to previous years. Only a small part of the forest that burned was deforested in the years following the wildfires: 7% (1997), 3% (2009) and 1.5% (2015). Forest close to roads, rivers and established deforestation is susceptible to deforestation and fire since these areas are attractive for agriculture and pasture. Indigenous land was shown to be important in protecting the forest, while rural settlement projects attracted both forest fire and deforestation. Of the total area in settlement projects, 40% was affected by forest fires and 17% was deforested. Rivers are particularly important for deforestation in this part of Amazonia, and efforts to protect forest along the rivers are therefore necessary. The ability to predict where deforestation and fires are most likely to occur is important for designing policies for preventative actions.


Assuntos
Incêndios Florestais , Brasil , Conservação dos Recursos Naturais , Florestas , Árvores
3.
J Environ Manage ; 268: 110555, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32383662

RESUMO

Brazil's Amazon deforestation is a major global and national environmental concern, and the ability to model and project both its course and the effect of different policy options depends on understanding how this process occurs at present and how it might change in the future. The present paper addresses one key factor in Amazon deforestation: land-tenure concentration in settlements. Brazil's policies for establishing and regulating settlement projects represent critical government decisions shaping the landscape in the 5 × 106 km2 Legal Amazonia region. We used remote-sensing data and information provided by the National Institute for Colonization and Agrarian Reform (INCRA) to evaluate the effect of land-tenure concentration in a settlement project (Projeto de Assentamento) located in a frontier area where cattle-ranching is expanding. We identified the actors and their deforestation patterns in the Matupi settlement in the southern part of Brazil's state of Amazonas. We spatially identified actors who concentrated "lots" (the parcels of land distributed to individual settlers) in 2011 and assessed whether the concentration was done by individual landholders or by "families" (where members merged their lots and the clearing was done together). Deforestation rates (1995-2011) were estimated for each type of actor and the trajectory of deforestation in the settlement (cumulative deforestation to 1994 and annual deforestation 1995-2016) was also analyzed. Concentrators occupied 28% (9653 ha) of the settlement and 29% of the lots (152 lots) analyzed; the numbers of lots concentrated ranged from two to ten. Concentrators of two lots and non-concentrators were the predominant actor types in the settlement. The mean annual clearing per landholding for concentrators of two lots (families: 4.1 ± 2.8 ha (mean ± SD); individuals: 5.1 ± 4.6 ha) was greater than for non-concentrators (1.7 ± 1.2 ha), despite their having similar patterns of small clearings. Concentrators of three or more lots had mean annual clearing per landholding between 6.2 ± 12.2 ha and 23.9 ± 38.7 ha and, the pattern of patches cleared per year >34 ha in area was predominant. The deforestation rate per lot was higher among concentrators as compared to non-concentrators, showing that lot concentration speeds deforestation. Analysis of deforestation patterns helps to better understand the process of lot concentration by spatially identifying the predominant patterns of each type of actor. The approach used in our study could assist authorities in identifying and monitoring land-tenure concentration in settlements. Agrarian-reform policymakers need to monitor this process, since it speeds deforestation in Amazonian settlement projects, as well as undermining the social objectives of the agrarian-reform program.


Assuntos
Conservação dos Recursos Naturais , Florestas , Animais , Brasil , Bovinos , Fatores Socioeconômicos
4.
Biota Neotrop. (Online, Ed. ingl.) ; 20(supl.1): e20190905, 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1131963

RESUMO

Abstract: Infrastructure projects and agriculture expansion are increasingly threatening forest conservation in Pará state (Brazil). It becomes necessary to address the implications of these activities on the Amazon complex socio-ecological system, considering both material and non-material aspects of Nature´s Contributions to People (NCP). Multiple studies developed future scenarios for the Amazon, but only a few have focused on discussing positive futures derived from policies and interventions based on conservation and human well-being. Here, we aim at understanding the drivers of forest cover change to produce positive scenarios for the future of the Amazon forest in Pará state. By using the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) conceptual framework, we identified as direct drivers of forest cover change: (i) roads construction; (ii) forest degradation; (iii) hydropower projects; (iv) urban expansion; (v) agriculture and pasture expansion; (vi) rural land occupation; (vii) mining; (viii) climate change. As indirect drivers we identified: (i) energy demand; (ii) population growth; (iii) land prices; (iv) commodity demand; (v) consumption behavior. The development of conservation strategies in the borders of deforested areas is needed given the high demand for Nature´s Contributions to People supply. We also propose policies to address the main drivers of forest cover change, influencing land management and consumption behavior in the state. At last, we envision future positive scenarios that would emerge from policy applications and sustainable actions. Based on our study, we discuss the importance of social learning for developing pathways leading to positive futures that consider the integrity and development of both ecological and social systems.


Resumo: Projetos de infraestrutura e expansão agrícola estão cada vez mais ameaçando a conservação florestal no estado do Pará (Brasil). Assim, torna-se necessário abordar as implicações dessas atividades no complexo sistema sócio ecológico da Amazônia, considerando aspectos materiais e não materiais das Contribuições da Natureza para as Pessoas (NCP).Vários estudos desenvolveram cenários para o futuro da floresta Amazônica, porém poucos foram aqueles focados em discutir futuros positivos, derivados da aplicação de políticas e de intervenções baseadas em estratégias de conservação e de sustentabilidade. Neste trabalho buscamos entender os principais fatores determinantes da mudança na cobertura florestal no estado do Pará, de forma a produzir cenários positivos para o futuro da floresta amazônica nesse estado. A partir da estrutura conceitual proposta pela Plataforma Intergovernamental sobre Biodiversidade e Serviços Ecossistêmicos (IPBES) identificamos as principais pressões diretas e indiretas que influenciam na perda de floresta no estado, e os articulamos em um modelo conceitual. As pressões diretas identificadas foram: (i) construção de estradas; (ii) degradação florestal; (iii) projetos para construção de hidrelétricas; (iv) expansão urbana; (v) expansão da agricultura e da pecuária; (vi) ocupação de terras rurais; (vii) mineração; (viii) mudanças climáticas. As pressões indiretas identificadas foram: (i) demanda por energia; (ii) crescimento populacional; (iii) preços da terra; (iv) demanda por commodities; (v) hábitos de consumo. Assim, evidenciamos a importância do desenvolvimento de estratégias de conservação nas áreas de fronteiras de desmatamento devido à alta demanda e oferta por Contribuições da Natureza para as Pessoas (NCPs). Foram propostas políticas para influenciar mudança no gerenciamento da terra e nos hábitos de consumo de forma a abordar os principais fatores de mudança da cobertura florestal no estado. Por fim, nós construímos cenários futuros positivos que emergiriam da aplicação de políticas e ações voltadas para sustentabilidade da natureza e dos serviços ecossistêmicos. Com base em nossa avaliação, enfatizamos a importância do aprendizado social para que possam ser discutidos os caminhos que levam a futuros positivos, que consideram a integridade e o desenvolvimento tanto dos sistemas sociais quanto dos sistemas ecológicos..

5.
Environ Manage ; 60(3): 367-382, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28510059

RESUMO

In 2012 Brazil's National Congress altered the country's Forest Code, decreasing various environmental protections in the set of regulations governing forests. This suggests consequences in increased deforestation and emissions of greenhouse gases and in decreased protection of fragile ecosystems. To ascertain the effects, a simulation was run to the year 2025 for the municipality (county) of Boca do Acre, Amazonas state, Brazil. A baseline scenario considered historical behavior (which did not respect the Forest Code), while two scenarios considered full compliance with the old Forest Code (Law 4771/1965) and the current Code (Law 12,651/2012) regarding the protection of "areas of permanent preservation" (APPs) along the edges of watercourses. The models were parameterized from satellite imagery and simulated using Dinamica-EGO software. Deforestation actors and processes in the municipality were observed in loco in 2012. Carbon emissions and loss of forest by 2025 were computed in the three simulation scenarios. There was a 10% difference in the loss of carbon stock and of forest between the scenarios with the two versions of the Forest Code. The baseline scenario showed the highest loss of carbon stocks and the highest increase in annual emissions. The greatest damage was caused by not protecting wetlands and riparian zones.


Assuntos
Sequestro de Carbono , Carbono/análise , Conservação dos Recursos Naturais/tendências , Florestas , Modelos Teóricos , Brasil , Mudança Climática , Conservação dos Recursos Naturais/legislação & jurisprudência , Ecossistema , Regulamentação Governamental , Imagens de Satélites , Áreas Alagadas
6.
Environ Manage ; 59(3): 393-409, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27778066

RESUMO

We estimate deforestation and the carbon stock in 2740 (82 %) of the 3325 settlements in Brazil's Legal Amazonia region. Estimates are made both using available satellite data and a carbon map for the "pre-modern" period (prior to 1970). We used data from Brazil's Project for Monitoring Deforestation in Amazonia updated through 2013 and from the Brazilian Biomes Deforestation Monitoring Project (PMDBBS) updated through 2010. To obtain the pre-modern and recent carbon stocks we performed an intersection between a carbon map and a map derived from settlement boundaries and deforestation data. Although the settlements analyzed occupied only 8 % of Legal Amazonia, our results indicate that these settlements contributed 17 % (160,410 km2) of total clearing (forest + non-forest) in Legal Amazonia (967,003 km2). This represents a clear-cutting of 41 % of the original vegetation in the settlements. Out of this total, 72 % (115,634 km2) was in the "Federal Settlement Project" (PA) category. Deforestation in settlements represents 20 % (2.6 Pg C) of the total carbon loss in Legal Amazonia (13.1 Pg C). The carbon stock in remaining vegetation represents 3.8 Pg C, or 6 % of the total remaining carbon stock in Legal Amazonia (58.6 Pg C) in the periods analyzed. The carbon reductions in settlements are caused both by the settlers and by external actors. Our findings suggest that agrarian reform policies contributed directly to carbon loss. Thus, the implementation of new settlements should consider potential carbon stock losses, especially if settlements are created in areas with high carbon stocks.


Assuntos
Sequestro de Carbono , Carbono/análise , Conservação dos Recursos Naturais/tendências , Ecossistema , Florestas , População Rural/tendências , Biomassa , Brasil , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...