ires in Amazonian Blackwater Floodplain Forests: Causes, Human Dimension, and Implications for Conservatio

Autor(es)

Carvalho, Tayane Costa ^[1] ; Wittmann, Florian ^[2] ; Piedade, Maria Teresa Fernandez ^[1] ; de Resende, Angelica Faria ^{[1, 3]} ; Silva, Thiago Sanna Freire ^{[4, 5]} ; Schongart, Jochen ^[1]

Afiliação do(s) autor(es)

^[1] Natl Inst Amazon Res INPA, Ecol Monitoring & Sustainable Use Wetlands MAUA, Coordinat Environm Dynam, Manaus, Amazonas - Brazil

^[2] Karlsruhe Inst Technol KIT, Inst Geog & Geoecol, Wetland Ecol, Rastatt - Germany

^[3] Univ Sao Paulo, Lab Trop Forestry LASTROP, Dept Forest Sci, Luiz de Queiroz Coll Agr ESALQ, Piracicaba - Brazil

^[4] Univ Estadual Paulista Unesp, Inst Geociencias & Ciencias Exatas, Rio Claro - Brazil

^[5] Univ Stirling, Fac Nat Sci, Biol & Environm Sci, Stirling - Scotland

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN FORESTS AND GLOBAL CHANGE; v. 4, DEC 14 2021.
• Citações Web of Science: 0

Resumo

The Amazon basin is being increasingly affected by anthropogenic fires, however, most studies focus on the impact of fires on terrestrial upland forests and do not consider the vast, annually inundated floodplains along the large rivers. Among these, the nutrient-poor, blackwater floodplain forests (igapos) have been shown to be particularly susceptible to fires. In this study we analyzed a 35-year time series (1982/1983-2016/2017) of Landsat Thematic Mapper from the Jau National Park (Central Amazonia) and its surroundings. Our overall objective was to identify and delineate fire scars in the igapo floodplains and relate the resulting time series of annual burned area to the presence of human populations and interannual variability of regional hydroclimatic factors. We estimated hydroclimatic parameters for the study region using ground-based instrumental data (maximum monthly temperature-T-max, precipitation-P, maximum cumulative water deficit-MCWD, baseflow index-BFI, minimum water level-WLmin90 of the major rivers) and large-scale climate anomalies (Oceanic Nino Index-ONI), considering the potential dry season of the non-flooded period of the igapo floodplains from September to February. Using a wetland mask, we identified 518,135 ha of igapo floodplains in the study region, out of which 17,524 ha (3.4%) burned within the study period, distributed across 254 fire scars. About 79% of the fires occurred close to human settlements (<10 km distance), suggesting that human activities are the main source of ignition. Over 92.4% of the burned area is associated with El Nino events. Non-linear regression models indicate highly significant relationships (p < 0.001) with hydroclimatic parameters, positive with T-max (R(2)adj. = 0.83) and the ONI (R(2)adj. = 0.74) and negative with P (R(2)adj. = 0.88), MCWD (R(2)adj. = 0.90), WLmin90 (R(2)adj. = 0.61) and BFI (R(2)adj. = 0.80). Hydroclimatic conditions were of outstanding magnitude in particular during the El Nino event in 2015/2016, which was responsible for 42.8% of the total burned floodplain area. We discuss these results under a historical background of El Nino occurrences and a political, demographic, and socioeconomic panorama of the study region considering the past 400 years, suggesting that disturbance of igapos by fires is not a recent phenomenon. Concluding remarks focus on current demands to increase the conservation to prevent and mitigate the impacts of fire in this vulnerable ecosystem. (AU)

• Processo FAPESP: 19/24049-5 - Monitoramento das florestas em restauração do Estado do São Paulo: aplicação de novas ferramentas de sensoriamento remoto e subsídios para políticas públicas
• Beneficiário: Angelica Faria de Resende
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado