Work

The impacts of recent drought on fire, forest loss, and regional smoke emissions in lowland Bolivia

Year: 2018

Type: article

Abstract: . In the southern Amazon relationships have been established among drought, human activities that cause forest loss, fire, and smoke emissions. We explore the effects of recent drought on fire, forest loss, and atmospheric visibility in lowland Bolivia. To assess human influence on fire, we consider climate, fire and vegetation dynamics in an area largely excluded from human activities since 1979, Noel Kempff Mercado National Park (NK) in northeastern Bolivia. We use data from five sources: the Moderate Resolution Imaging Spectroradiometer Collection 6 active fire product (2001–2015) (MODIS C6), Global Fire Weather Database data (1982–2015) (GFWED), MODIS land-cover data (2001–2010), MODIS forest loss data (2000–2012), and extinction coefficient derived from horizontal visibility data from the World Meteorological Organization (WMO)-level surface stations (1973–2015), which is affected by smoke and acts as a proxy for regional fire activity. In lowland Bolivia from 2001–2015, interannual Drought Code (DC) variability was linked to fire activity, while from 1982–2015, interannual DC variability was linked to Bext visibility data. From 2001–2015, the regional extinction coefficient for the southwestern Amazon Bext and MODIS C6 active fire data for lowland Bolivia captured fire seasonality, and covaried between low and high fire years. Consistent with previous studies, our results suggest the extinction coefficient Bext can be used as a longer-term proxy of regional fire activity in southwestern Amazonia. Overall, our study found drought conditions were the dominant control on interannual fire variability in lowland Bolivia, and fires within NK were limited to the cerrado and seasonally-inundated wetland biomes. Our results suggest lowland Bolivia tropical forests were susceptible to human activities that may have amplified fire during times of drought. Human activities and drought need to be considered in future projections of southern Amazonia fire, in regard to carbon emissions and global climate.

Source: Biogeosciences

DOI: 10.5194/bg-15-4317-2018

Authors: Joshua P. Heyer, Mitchell J. Power, Robert D. Field, Margreet J. E. van Marle