Large tree mortality and the decline of forest biomass following Amazonian wildfires

Abstract

Surface fires in Amazonian forests could contribute as much as 5% of annual carbon emissions from all anthropogenic sources during severe El Niño years. However, these estimates are based on short-term figures of post-burn tree mortality, when large thicker barked trees (representing a disproportionate amount of the forest biomass) appear to resist the fires. On the basis of a longer term study, we report that the mortality of large trees increased markedly between 1 and 3 years, more than doubling current estimates of biomass loss and committed carbon emissions from low-intensity fires in tropical forests

Tree Diversity Changes over a Decade (2003-2013) in Four Inland Tropical Dry Evergreen Forest Sites on the Coromandel Coast of India

“…In many instances, the carbon stocks in forests may change without a change in forest area. Examples include losses of biomass associated with selective wood harvest, forest fragmentation, ground fires, shifting cultivation, browsing, and grazing (e.g., Lauranceet al 1998;Nepstad et al 1999;Laurance et al 2000;Barlow et al 2003 andHoughton 2005), and accumulation of biomass in growing and recovering (or secondary) forests. Over a decade, biomass of trees increased in higher girth class (151-180 and ≥210 cm) in all the study sites, but decreased in lower girth class (10-30 cm) except in SP.…”

The mammalian communities in coffee plantations around a protected area in the Western Ghats, India

“…For example, in the Amazon, a region that has not experienced frequent burning over evolutionary time, forests are extremely vulnerable to damage from fire. In such forests, even very low-intensity ground fires can cause mortality of thin-barked adult trees (Cochrane and Schultz 1998;Barlow et al 2003). There is some observational evidence from Indian forests to suggest that the higher relative abundance of certain thick-barked species, or species that are able to resprout vegetatively (e.g., Boswellia serrata, Dalbergia paniculata, and Sterculia sp.…”

Rapid land-use change and its impacts on tropical biodiversity

“…Canopy openness was four times greater than in unburned forest (ranging from 12-32%) and light levels had risen dramatically in the forest understory [Barlow et al, 2003b;Peres et al, 2003]. As a result, a dense flush of vegetation, dominated by disturbance-loving pioneer trees, bamboo, sedges, and coarse herbs, had proliferated in the understory.…”

“…The initial fire in rainforests typically kills 10-40% of all trees and most vines [Barbosa and Fearnside, 1999;Barlow et al, 2003b]. As a result, the forest canopy becomes fragmented and the quantity of dead fuels rises as dead leaves and trees begin to fall.…”

“…The second fire is usually much hotter and more destructive than the initial burn, killing 40-50% of remaining trees and overwhelming even large, thickbarked trees [Peres, 1999;Barlow et al, 2003b]. Moreover, whereas the initial surface fire might require an extensive drought, subsequent fires can occur after just a few weeks without rain.…”