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Smith CC, Espírito-Santo FDB, Healey JR, Young PJ, Lennox GD, Ferreira J, Barlow J. Secondary forests offset less than 10% of deforestation-mediated carbon emissions in the Brazilian Amazon. Glob Chang Biol 2020; 26:7006-7020. [PMID: 32969561 DOI: 10.1111/gcb.15352] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Secondary forests are increasing in the Brazilian Amazon and have been cited as an important mechanism for reducing net carbon emissions. However, our understanding of the contribution of secondary forests to the Amazonian carbon balance is incomplete, and it is unclear to what extent emissions from old-growth deforestation have been offset by secondary forest growth. Using MapBiomas 3.1 and recently refined IPCC carbon sequestration estimates, we mapped the age and extent of secondary forests in the Brazilian Amazon and estimated their role in offsetting old-growth deforestation emissions since 1985. We also assessed whether secondary forests in the Brazilian Amazon are growing in conditions favourable for carbon accumulation in relation to a suite of climatic, landscape and local factors. In 2017, the 129,361 km2 of secondary forest in the Brazilian Amazon stored 0.33 ± 0.05 billion Mg of above-ground carbon but had offset just 9.37% of old-growth emissions since 1985. However, we find that the majority of Brazilian secondary forests are situated in contexts that are less favourable for carbon accumulation than the biome average. Our results demonstrate that old-growth forest loss remains the most important factor determining the carbon balance in the Brazilian Amazon. Understanding the implications of these findings will be essential for improving estimates of secondary forest carbon sequestration potential. More accurate quantification of secondary forest carbon stocks will support the production of appropriate management proposals that can efficiently harness the potential of secondary forests as a low-cost, nature-based tool for mitigating climate change.
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Affiliation(s)
| | - Fernando D B Espírito-Santo
- Leicester Institute of Space and Earth Observation, Centre for Landscape and Climate Research, School of Geography, Geology and Environment, University of Leicester, Leicester, UK
| | - John R Healey
- School of Natural Sciences, College of Environmental Sciences and Engineering, Bangor University, Bangor, UK
| | - Paul J Young
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
- Centre of Excellence for Environmental Data Science, Lancaster University, Lancaster, UK
| | - Gareth D Lennox
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | | | - Jos Barlow
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
- Federal University of Lavras, Minas Gerais, Brazil
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Withey K, Berenguer E, Palmeira AF, Espírito-Santo FDB, Lennox GD, Silva CVJ, Aragão LEOC, Ferreira J, França F, Malhi Y, Rossi LC, Barlow J. Quantifying immediate carbon emissions from El Niño-mediated wildfires in humid tropical forests. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2017.0312. [PMID: 30297469 DOI: 10.1098/rstb.2017.0312] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2018] [Indexed: 11/12/2022] Open
Abstract
Wildfires produce substantial CO2 emissions in the humid tropics during El Niño-mediated extreme droughts, and these emissions are expected to increase in coming decades. Immediate carbon emissions from uncontrolled wildfires in human-modified tropical forests can be considerable owing to high necromass fuel loads. Yet, data on necromass combustion during wildfires are severely lacking. Here, we evaluated necromass carbon stocks before and after the 2015-2016 El Niño in Amazonian forests distributed along a gradient of prior human disturbance. We then used Landsat-derived burn scars to extrapolate regional immediate wildfire CO2 emissions during the 2015-2016 El Niño. Before the El Niño, necromass stocks varied significantly with respect to prior disturbance and were largest in undisturbed primary forests (30.2 ± 2.1 Mg ha-1, mean ± s.e.) and smallest in secondary forests (15.6 ± 3.0 Mg ha-1). However, neither prior disturbance nor our proxy of fire intensity (median char height) explained necromass losses due to wildfires. In our 6.5 million hectare (6.5 Mha) study region, almost 1 Mha of primary (disturbed and undisturbed) and 20 000 ha of secondary forest burned during the 2015-2016 El Niño. Covering less than 0.2% of Brazilian Amazonia, these wildfires resulted in expected immediate CO2 emissions of approximately 30 Tg, three to four times greater than comparable estimates from global fire emissions databases. Uncontrolled understorey wildfires in humid tropical forests during extreme droughts are a large and poorly quantified source of CO2 emissions.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.
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Affiliation(s)
- Kieran Withey
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Erika Berenguer
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.,Environmental Change Institute, University of Oxford, Oxford OX1 3QY, UK
| | - Alessandro Ferraz Palmeira
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa, 01, Campus Guamá, Belém, PA CEP: 66075-110, Brazil
| | - Fernando D B Espírito-Santo
- Centre for Landscape and Climate Research (CLCR) and Leicester Institute of Space and Earth Observation (LISEO), School of Geography, Geology and Environment, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Gareth D Lennox
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Camila V J Silva
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Luiz E O C Aragão
- Remote Sensing Division, National Institute for Space Research, Avenida dos Astronautas, 1.758, 12227-010 São José dos Campos, São Paulo, Brazil.,College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK
| | - Joice Ferreira
- Embrapa Amazônia Oriental, Travessa Dr Enéas Pinheiro, s/n, CP 48, 66095-100 Belém, Pará, Brazil
| | - Filipe França
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.,Embrapa Amazônia Oriental, Travessa Dr Enéas Pinheiro, s/n, CP 48, 66095-100 Belém, Pará, Brazil.,Instituto Federal de Minas Gerais, Rodovia Bambuí/Medeiros, Km-05, 38900-000 Bambuí, Minas Gerais, Brazil
| | - Yadvinder Malhi
- Environmental Change Institute, University of Oxford, Oxford OX1 3QY, UK
| | - Liana Chesini Rossi
- Departamento de Ecologia, Universidade Estadual Paulista, 13506-900 Rio Claro, São Paulo, Brazil
| | - Jos Barlow
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
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Espírito-Santo FDB, Gloor M, Keller M, Malhi Y, Saatchi S, Nelson B, Oliveira Junior RC, Pereira C, Lloyd J, Frolking S, Palace M, Shimabukuro YE, Duarte V, Mendoza AM, López-González G, Baker TR, Feldpausch TR, Brienen RJW, Asner GP, Boyd DS, Phillips OL. Corrigendum: Size and frequency of natural forest disturbances and the Amazon forest carbon balance. Nat Commun 2015; 6:6638. [PMID: 25833221 PMCID: PMC4396392 DOI: 10.1038/ncomms7638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Chambers JQ, Asner GP, Morton DC, Anderson LO, Saatchi SS, Espírito-Santo FDB, Palace M, Souza C. Regional ecosystem structure and function: ecological insights from remote sensing of tropical forests. Trends Ecol Evol 2007; 22:414-23. [PMID: 17493704 DOI: 10.1016/j.tree.2007.05.001] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 03/30/2007] [Accepted: 05/01/2007] [Indexed: 10/23/2022]
Abstract
Ecological studies in tropical forests have long been plagued by difficulties associated with sampling the crowns of large canopy trees and large inaccessible regions, such as the Amazon basin. Recent advances in remote sensing have overcome some of these obstacles, enabling progress towards tackling difficult ecological problems. Breakthroughs have helped transform the dialog between ecology and remote sensing, generating new regional perspectives on key environmental gradients and species assemblages with ecologically relevant measures such as canopy nutrient and moisture content, crown area, leaf-level drought responses, woody tissue and surface litter abundance, phenological patterns, and land-cover transitions. Issues that we address here include forest response to altered precipitation regimes, regional disturbance and land-use patterns, invasive species and landscape carbon balance.
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Affiliation(s)
- Jeffrey Q Chambers
- Tulane University, Ecology and Evolutionary Biology, 310 Dinwiddie Hall, New Orleans, LA 70118, USA.
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