Current and future patterns of fire-induced forest degradation in Amazonia
Amazon droughts directly increase forest flammability by reducing forest understory air and fuel moisture. Droughts also increase forest flammability indirectly by decreasing soil moisture, triggering leaf shedding, branch loss, and tree mortality—all of which contribute to increased fuel loads. The...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/aa69ce |
| _version_ | 1797748315298725888 |
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| author | Bruno L De Faria Paulo M Brando Marcia N Macedo Prajjwal K Panday Britaldo S Soares-Filho Michael T Coe |
| author_facet | Bruno L De Faria Paulo M Brando Marcia N Macedo Prajjwal K Panday Britaldo S Soares-Filho Michael T Coe |
| author_sort | Bruno L De Faria |
| collection | DOAJ |
| description | Amazon droughts directly increase forest flammability by reducing forest understory air and fuel moisture. Droughts also increase forest flammability indirectly by decreasing soil moisture, triggering leaf shedding, branch loss, and tree mortality—all of which contribute to increased fuel loads. These direct and indirect effects can cause widespread forest fires that reduce forest carbon stocks in the Amazon, with potentially important consequences for the global carbon cycle. These processes are expected to become more widespread, common, and intense as global climate changes, yet the mechanisms linking droughts, wildfires, and associated changes in carbon stocks remain poorly understood. Here, we expanded the capabilities of a dynamic forest carbon model to better represent (1) drought effects on carbon and fuel dynamics and (2) understory fire behavior and severity. We used the refined model to quantify changes in Pan-Amazon live carbon stocks as a function of the maximum climatological water deficit (MCWD) and fire intensity, under both historical and future climate conditions. We found that the 2005 and 2010 droughts increased potential fire intensity by 226 kW m ^−1 and 494 kW m ^−1 , respectively. These increases were due primarily to increased understory dryness (109 kW m ^−1 in 2005; 124 kW m ^−1 in 2010) and altered forest structure (117 kW m ^−1 in 2005; 370 kW m ^−1 in 2010) effects. Combined, these historic droughts drove total simulated reductions in live carbon stocks of 0.016 (2005) and 0.027 (2010) PgC across the Amazon Basin. Projected increases in future fire intensity increased simulated carbon losses by up to 90% per unit area burned, compared with modern climate. Increased air temperature was the primary driver of changes in simulated future fire intensity, while reduced precipitation was secondary, particularly in the eastern portion of the Basin. Our results show that fire-drought interactions strongly affect live carbon stocks and that future climate change, combined with the synergistic effects of drought on forest flammability, may strongly influence the stability of tropical forests in the future. |
| first_indexed | 2024-03-12T16:03:09Z |
| format | Article |
| id | doaj.art-f6a67c7b7db34149a735c0d428a3b01c |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T16:03:09Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-f6a67c7b7db34149a735c0d428a3b01c2023-08-09T14:33:23ZengIOP PublishingEnvironmental Research Letters1748-93262017-01-0112909500510.1088/1748-9326/aa69ceCurrent and future patterns of fire-induced forest degradation in AmazoniaBruno L De Faria0https://orcid.org/0000-0002-8560-0034Paulo M Brando1Marcia N Macedo2Prajjwal K Panday3Britaldo S Soares-Filho4Michael T Coe5Federal University of Viçosa , Avenue P H Rolfs s/n, Viçosa, MG, 36570-000, Brazil; Federal Institute of Technology North of Minas Gerais (IFNMG) , Avenida Humberto Mallard, 1355, Pirapora, MG, 39270-000, Brazil; Author to whom any correspondence should be addressed.The Woods Hole Research Center , 149 Woods Hole Road, Falmouth, MA 02540-1644, United States of America; Instituto de Pesquisa Ambiental da Amazônia (IPAM) , Brasilia, DF, BrazilThe Woods Hole Research Center , 149 Woods Hole Road, Falmouth, MA 02540-1644, United States of America; Instituto de Pesquisa Ambiental da Amazônia (IPAM) , Brasilia, DF, BrazilNichols College, Environmental Science , Dudley, MA 01571, United States of AmericaFederal University of Minas Gerais , Avenida Antônio Carlos 6627, Belo Horizonte, MG, 31270-901, BrazilThe Woods Hole Research Center , 149 Woods Hole Road, Falmouth, MA 02540-1644, United States of AmericaAmazon droughts directly increase forest flammability by reducing forest understory air and fuel moisture. Droughts also increase forest flammability indirectly by decreasing soil moisture, triggering leaf shedding, branch loss, and tree mortality—all of which contribute to increased fuel loads. These direct and indirect effects can cause widespread forest fires that reduce forest carbon stocks in the Amazon, with potentially important consequences for the global carbon cycle. These processes are expected to become more widespread, common, and intense as global climate changes, yet the mechanisms linking droughts, wildfires, and associated changes in carbon stocks remain poorly understood. Here, we expanded the capabilities of a dynamic forest carbon model to better represent (1) drought effects on carbon and fuel dynamics and (2) understory fire behavior and severity. We used the refined model to quantify changes in Pan-Amazon live carbon stocks as a function of the maximum climatological water deficit (MCWD) and fire intensity, under both historical and future climate conditions. We found that the 2005 and 2010 droughts increased potential fire intensity by 226 kW m ^−1 and 494 kW m ^−1 , respectively. These increases were due primarily to increased understory dryness (109 kW m ^−1 in 2005; 124 kW m ^−1 in 2010) and altered forest structure (117 kW m ^−1 in 2005; 370 kW m ^−1 in 2010) effects. Combined, these historic droughts drove total simulated reductions in live carbon stocks of 0.016 (2005) and 0.027 (2010) PgC across the Amazon Basin. Projected increases in future fire intensity increased simulated carbon losses by up to 90% per unit area burned, compared with modern climate. Increased air temperature was the primary driver of changes in simulated future fire intensity, while reduced precipitation was secondary, particularly in the eastern portion of the Basin. Our results show that fire-drought interactions strongly affect live carbon stocks and that future climate change, combined with the synergistic effects of drought on forest flammability, may strongly influence the stability of tropical forests in the future.https://doi.org/10.1088/1748-9326/aa69ceAmazonclimate changedroughtfire intensityfire severityCMIP5 |
| spellingShingle | Bruno L De Faria Paulo M Brando Marcia N Macedo Prajjwal K Panday Britaldo S Soares-Filho Michael T Coe Current and future patterns of fire-induced forest degradation in Amazonia Environmental Research Letters Amazon climate change drought fire intensity fire severity CMIP5 |
| title | Current and future patterns of fire-induced forest degradation in Amazonia |
| title_full | Current and future patterns of fire-induced forest degradation in Amazonia |
| title_fullStr | Current and future patterns of fire-induced forest degradation in Amazonia |
| title_full_unstemmed | Current and future patterns of fire-induced forest degradation in Amazonia |
| title_short | Current and future patterns of fire-induced forest degradation in Amazonia |
| title_sort | current and future patterns of fire induced forest degradation in amazonia |
| topic | Amazon climate change drought fire intensity fire severity CMIP5 |
| url | https://doi.org/10.1088/1748-9326/aa69ce |
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