Application of remote sensing to understanding fire regimes and biomass burning emissions of the tropical Andes

Abstract

In the tropical Andes, there have been very few systematic studies aimed at understanding the biomass burning dynamics in the area. This paper seeks to advance on our understanding of burning regimes in this region, with the first detailed and comprehensive assessment of fire occurrence and the derived gross biomass burning emissions of an area of the Peruvian tropical Andes. We selected an area of 2.8 million hectares at altitudes over 2000 m. We analyzed fire occurrence over a 12 year period with three types of satellite data. Fire dynamics showed a large intra-annual and interannual variability, with most fires occurring May-October (the period coinciding with the dry season). Total area burned decreased with increasing rainfall until a given rainfall threshold beyond which no relationship was found. The estimated fire return interval (FRI) for the area is 37 years for grasslands, which is within the range reported for grasslands, and 65 years for forests, which is remarkably shorter than other reported FRI in tropical moist forests. The greatest contribution (60-70%, depending on the data source) to biomass burning emissions came from burned montane cloud forests (4.5 million Mg CO 2 over the study period), despite accounting for only 7.4-10% of the total burned area. Gross aboveground biomass emissions (7.55 ± 2.14 Tg CO 2 ; 0.43 ± 0.04 Tg CO; 24,012 ± 2685 Mg CH 4 for the study area) were larger than previously reported for the tropical Andes.

Can We Go Beyond Burned Area in the Assessment of Global Remote Sensing Products with Fire Patch Metrics?

“…For South American savannas, we then confirm the same missing small fires as other ecosystems, as already suggested in local studies in the region [40,[45][46][47] and in other tropical savannas [48]. We then warn here of both the omission of small fire patches below 450 ha in global BA products (OE varies between 0.7 and 0.95), and, when detected, a high risk of commission (CE varies between 0.68 and 0.97).…”

The global tropospheric ammonia distribution as seen in the 13-year AIRS measurement record

“…The greatest emissions from BB in the NH appear in the summer months over Siberia and eastern Russia as well as over Alaska, US. The highest concentrations due to BB in the SH appear over South America in September to November (spring for the SH) when precipitation is minimal and burning extensive (Oliveras et al, 2014). Over SE Asia where the dry season and most BB occur in March to May, we find another local maximum (Lin et al, 2013).…”

Global change effects on humid tropical forests: Evidence for biogeochemical and biodiversity shifts at an ecosystem scale

“…In particular, deforestation in humid tropical forests promotes wildfire associated clearing, which can be particularly severe during times of drought. In Peru, the fire return interval (i.e., the average period between fires) between 2000 and 2011 in humid montane forests was shorter than that of more fire‐prone lowland Amazonian forest, most likely related to forest clearing and burning practices in the high‐altitude region [ Oliveras et al ., ]. In the Brazilian Amazon, fires intended to burn felled trees in preparation for crops or pasture, or to improve pasture forage, often spread as wildfire into undisturbed forests [ Nepstad et al ., ].…”