Fogo e emissão de gases de efeito estufa dos ecossistemas florestais da Amazônia brasileira

Fearnside, Philip M.

doi:10.1590/s0103-40142002000100007

Cited by 33 publications

(26 citation statements)

References 22 publications

(10 reference statements)

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“…A conversão de áreas de floresta amazônica em pastagem resulta em mudanças na quantidade e qualidade da biomassa aérea (Fearnside e Barbosa, 1998), nas características físicas e químicas do solo (Pereira et al, 2000;Longo e Espíndola, 2000;Makewitz et al, 2004) e na emissão de gases de efeito estufa durante as operações de queima da floresta e, ou das pastagens (Fearnside, 2002). Com a introdução da pastagem os estoques de C no solo podem decrescer nos primeiros anos da implantação, e aumentar nos anos seguintes, até atingir valores próximos ou superiores aos existentes antes da conversão (Feigl et al, 1995;Melo, 2003;Salimon et al, 2007).…”

Section: Introductionunclassified

Impacto da conversão floresta - pastagem nos estoques e na dinâmica do carbono e substâncias húmicas do solo no bioma Amazônico

Araújo¹,

Ker

Mendonça

et al. 2011

Acta Amaz.

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RESUMOO presente estudo avaliou as consequências do desmatamento e a utilização do solo com Brachiaria brizantha em relação ao estoque e dinâmica de C e frações húmicas em duas floresta-pastagem no Acre. A primeira localizada sequências município de Rio Branco em área de Floresta Aberta com bambu e palmeira e duas pastagens de B. brizantha de 3 e 10 anos com predomínio de Argissolo Vermelho-Amarelo alítico plíntico. O segundo situado no município de Senador Guiomard em área de Floresta Densa e pastagem de B. brizantha de 20 anos em Latossolo Vermelho-Amarelo distrófico. Em cada local foram coletadas, em triplicata, amostras de solos nas profundidades de 0-5, 5-10, 10-20 e 20-40 cm. Nestas amostras foram avaliadas as características físico-químicas, o C das substâncias húmicas e da matéria orgânica leve, e a composição isotópica do solo e das respectivas frações orgânicas até 1 m de profundidade, determinando o percentual de C derivado da pastagem e da floresta. Houve incremento nos estoques de C do solo e nos valores de δ 13 C do solo com o tempo de utilização da pastagem, em ambas as sucessões. A porcentagem de C derivado de pastagem foi expressiva na camada superficial do sistema com 20 anos de uso, com proporções que chegaram a 70% do C total. Os valores de δ 13 C para os ácidos húmicos variaram de -12,19 a -17,57 ‰, indicando maior proporção de C derivado da pastagem. A estabilidade estrutural da MOS, inferida pela relação humina com as frações ácido fúlvico e ácido húmico (HUM/FAF+FAH), tenderam a diminuir nos ecossistemas de pastagem quando comparada com as florestas naturais. PALAVRAS-CHAVE: Amazônia Ocidental, mudanças de uso da terra, Brachiaria brizantha cv Marandu , abundância natural do 13 C. Impact of forest-pasture conversion on stocks and dynamics of soil carbon and humic substances in the Amazon ABSTRACTThis study evaluates the impacts of converting natural Amazonian forests in Brazil to pasture dominated by Brachiaria brizantha concerning to C dynamics and humic fractions in two soil chronosequences in the Acre State, Brazil. The first site, dominated by Plinthic Red Yellow Argissols (Ultisols), is located in the municipality of Rio Branco and comprises an area of bamboo-and palm-dominated open forest with two B. brizantha pastures of 3 and 10 years old. The second site, dominated by a dystrophic Red Yellow Latosol (Oxisol), is located in the municipality of Senador Guiomard and comprises an area of dense forest and a 20-year old B. brizantha pasture. In each site soil samples were collected in triplicate at depths of 0-5, 5-10, 10-20 and 20-40 cm. Samples were evaluated for physical and chemical characteristics, C of humic substances and light organic matter, and the isotopic composition of soil and its organic fractions to 1 m depth, determining the percentage of C derived of both grassland and forest. There were increases in stocks of soil C and δ 13 C soil with the time of grazing in both sites. The percentage of C derived from pasture was much higher in the surface layer of the Senador Guio...

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“…Carbon emission from itinerant farming can reach 1.1 Pg per year, which means that is responsible for 25 % of the world's total CO 2 emission (Fearnside, 2000). In Brazil, one of the seven largest emitting countries (Walser, 2008), 70 % of the total CO 2 emission comes from uncontrolled fires, which release approximately 69 t ha -1 of CO 2 of burned forest (Fearnside, 2002). Therefore, finding an alternative for slash-and-burn agriculture is justified firstly by the pressing need to increase agricultural productivity, and secondly by the urgency to reduce the environmental impact of burning.…”

Section: Introductionmentioning

confidence: 99%

Environmental and agricultural benefits of a management system designed for sandy loam soils of the humid tropics

Aguiar

Amorim²,

Coelho³

et al. 2009

Rev. Bras. Ciênc. Solo

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SUMMARYA sustainable management of soils with low natural fertility on family farms in the humid tropics is a great challenge and overcoming it would be an enormous benefit for the environment and the farmers. The objective of this study was to assess the environmental and agronomic benefits of alley cropping, based on the evaluation of C sequestration, soil quality indicators, and corn yields. Combinations of four legumes were used in alley cropping systems in the following treatments: Clitoria fairchildiana + Cajanus cajan; Acacia mangium + Cajanus cajan; Leucaena leucocephala + Cajanus cajan; Clitoria fairchildiana + Leucaena leucocephala; Leucaena leucocephala + Acacia mangium and a control. Corn was used as a cash crop. The C content was determined in the different compartments of soil organic matter, CEC, available P, base saturation, percentage of water saturation, the period of the root hospitality factor below the critical level and corn yield. It was concluded that alley cropping could substitute the slash and burn system in the humid tropics. The main environmental benefit of alley cropping is the maintenance of a dynamic equilibrium between C input and output that could sustain up to 10 Mg ha -1 of C in the litter layer, decreasing atmospheric CO 2 levels. Alley cropping is also beneficial from the agricultural point of view, because it increases base saturation and decreases physical resistance to root penetration in the soil layer 0 -10 cm, which ensures the increase and sustainability of corn yield.Index terms: corn, alley cropping, litterfall, rootability.(

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“…The focus of other studies has been on changes caused by land use conversion on chemical properties (Mcgrath et al, 2001;Braz et al, 2013), soil C stocks and dynamics Araújo et al, 2011;van Straaten et al, 2015), changes in the quantity and quality of shoot biomass (Fearnside and Barbosa, 1998;Lohbeck et al, 2015), emission of greenhouse gases through burning of forests and/or pastures (Fearnside, 2002;Fujisaki et al, 2015), soil biological activity (Silva et al, 2012;Rodrigues et al, 2013;Cram et al, 2015), reduction in ecosystem services , and negative impacts on the invertebrate communities .…”

Section: Introductionmentioning

confidence: 99%

Characterization and Classification of Soils under Forest and Pasture in an Agroextractivist Project in Eastern Amazonia

Zenero

Silva

Castilho³

et al. 2016

Rev. Bras. Ciênc. Solo

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Knowledge of soils in the Amazon rainforest is becoming increasingly essential due to dynamics adopted by farmers that substitute forest for pastures, together with growing pressure from diverse segments of society towards adoption of sustainable production systems. The objective of this study was to characterize the soils along two toposequences, one under forest (F) and the other under pasture (P), and to verify how the change in land use influences soil attributes, evaluating their inclusion in the Brazilian Soil Classification System (SiBCS). The soils were sampled in pits located at the summit, backslope and footslope positions for morphological, chemical, physical, and clay mineralogy analysis. The results show that the soils are chemically poor and predominately kaolinitic. Sandy and loamy sand soils are in the surface horizons, with an increase in clay content with depth. The highest values of bulk density and lowest values of macroporosity were observed in the Bt horizons due to the change from a granular structure in the surface to an angular and subangular blocky structure in these horizons. The morphological properties observed in the field are strongly influenced by the annual soil water dynamics, the parent material, and the landscape, representing diagnostic characteristics that influenced classification of the soils, such as aquic with episaturation (epirredóxico), saprolitic, and gravelly. These diagnostic characteristics in the Argissolo Amarelo (Hapludults) are important morphological properties that have not been highlighted by the current edition of the SiBCS.

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“…For this reason, the prevailing form of agricultural management in these regions, including many parts of Brazil, is low-yield shifting cultivation, where vegetation is slashed and burned to make way for crops. This land use results in a short-lived production because of the rapid depletion of soil nutrients, and also negatively affects biodiversity and contributes to global warming (Fearnside 2002). Finding an alternative for slash and burn cultivation is necessary for two reasons, (1) the pressing need to increase agricultural productivity, and (2) the urgent need to reduce the environmental impacts of burning.…”

Section: Introductionmentioning

confidence: 99%

Nutrient recycling and physical indicators of an alley cropping system in a sandy loam soil in the pre-Amazon region of Brazil

Aguiar

Bicudo

Sobrinho

et al. 2009

Nutr Cycl Agroecosyst

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The sustainable management of soils has proved a key challenge for the smallholder agriculture in southeastern Amazonia, Brazil. We assessed the capacity of an alley cropping system to sustain corn productivity. The experiment included six treatments: Clitoria ? Pigeon Pea; Leucaena ? Pigeon Pea; Acacia ? Pigeon Pea; Clitoria ? Leucaena; Leucaena ? Acacia and Control treatment (no legumes). We determined chemical and physical indicators of soil quality. Leucaena had the highest macronutrient concentrations (40.17 g N kg -1 ), except for P. All legumes had high Ca (13.82-17.84 g kg -1 ) and very low P (0.51-2.83 g kg -1 ) and Mg (1.73-2.92 g kg -1 ) concentrations. Acacia had the lowest N, P, K and Mg concentrations. Pre-planting soil analysis indicated that soil quality indicators were below the critical levels needed for a productive agricultural system, especially for phosphorus, sum of bases and base saturation. Physical indicators of quality, such as bulk density (1.40-1.30 Mg m -3 ), total porosity (0.46-0.50 m m -3 ) and soil aeration capacity (0.10-0.17 m m -3 ), were substantially improved as a result of the surface application of residues. There was a cumulative effect of residue application on corn crop productivity. Because of its capacity to recycle nutrients and improve soil quality over the period of 3 years, alley cropping in association with no-tillage, can be an efficient strategy for maintaining productivity in the low-fertility soils of the humid tropics.

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“…Given such an environment, it is key to study the impact that Manaus has on atmospheric conditions. Studies have shown that the Amazon rainforest is sensitive to the variability and changes in the climate system due to both natural variations and anthropogenic 95 actions, such as the increase in the concentration of GHG and aerosols in the atmosphere and changes in land use and land cover (LULC) (Fearnside et al, 2002;Artaxo et al, 2006;Betts et al, 2008;de Souza e Alvalá, 2014;Marengo e Espinoza, 2015).…”

mentioning

confidence: 99%

MOVEIM v1.0: Development of a bottom-up motor vehicular emission inventories for the urban area of Manaus in central Amazon rainforest

Teixeira

Freitas

Correia³

2018

Preprint

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Abstract.Emissions of gases and particulates in urban areas are associated with a mixture of various sources, both natural and anthropogenic. Understanding and quantifying these emissions is necessary in studies of climate change, local air pollution issues and weather modification. Studies have highlighted that the transport sector is key to closing the world's emissions gap. 15Vehicles contribute substantially with the emission of carbon dioxide (CO 2 ), carbon monoxide (CO), nitrogen oxides (NO x ), nonmethane hydrocarbon (NMHC), particulate matter (PM), methane (CH 4 ), hydrofluorocarbon (HFC) and nitrous oxide (N 2 O).Several studies show that vehicle emission inventories are an important approach to providing a baseline estimate of on-road emissions in several scales, mainly in urban areas. This approach is essential to areas with incomplete or non-existent monitoring networks as well as for air quality models. Conversely, the direct downscale of global emission inventories in chemical transport 20and air quality models may not be able to reproduce the observed evolution of atmospheric pollution processes at finer spatial scales. To address this caveat, we developed a bottom-up vehicular emission inventory along the 258 main traffic routes from Manaus, based on local vehicle fleet data and emission factors (EFs). The results show that the light vehicles are responsible for the largest fraction of the pollutants, contributing 2.6, 0.87, 0.32, 0.03, 456 and 0.8 ton/h of CO, NO x , CH 4 , PM, CO 2 and NMHC, respectively. Including the emissions of motorcycles, buses and trucks, our total estimation of the emissions is 4.1, 1.0 , 25 0.37, 0.07, 63.5 and 2.56 ton/h, respectively. We also noted that light vehicles accounted for about 62.8%, 84.7%, 87.9%, 45.1%, 71.8%, and 33.9% and motorcycles in the order of 32.3 %, 6.5 %, 12.1 %, 6.2 %, 14.8 %, 8.7 %, respectively. Nevertheless, we can highlight the bus emissions which are around 35.7% and 45.3 % for NMHC and PM. Our results indicate a better distribution over the domain reflecting the influences of standard behavior of traffic distribution per vehicle category. Finally, this inventory provides more detailed information to improving the current understanding of how vehicle emissions contribute to the ambient 30 pollutant concentrations in Manaus and their impacts on regional climate changes. This work will also contribute to improved air quality numerical simulations, provide more accurate scenarios for policymakers and regulatory agencies to develop strategies for controlling the vehicular emissions, and, consequently, mitigate associated impacts on local and regional scales of the Amazon ecosystems. 35Key words: Vehicle emission inventories, bottom-up approach, urban air pollution, Amazon forest Geosci. Model Dev. Discuss., https://doi

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Fogo e emissão de gases de efeito estufa dos ecossistemas florestais da Amazônia brasileira

Cited by 33 publications

References 22 publications

Impacto da conversão floresta - pastagem nos estoques e na dinâmica do carbono e substâncias húmicas do solo no bioma Amazônico

Environmental and agricultural benefits of a management system designed for sandy loam soils of the humid tropics

Characterization and Classification of Soils under Forest and Pasture in an Agroextractivist Project in Eastern Amazonia

Nutrient recycling and physical indicators of an alley cropping system in a sandy loam soil in the pre-Amazon region of Brazil

MOVEIM v1.0: Development of a bottom-up motor vehicular emission inventories for the urban area of Manaus in central Amazon rainforest

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