Biomass and Nutrient Dynamics Associated with Slash Fires in Neotropical Dry Forests

• DOI: 10.2307/1939509
• Publication Date: 2006-05-09T15:10:41Z
• Authors: J. Boone Kauffman; Robert L. Sanford; Dian L. Cummings; I. H. Salcedo; E. V. S. B. Sampaio
• Keywords: Biogeochemical Cycle; Plant litter; Dry season; Slash (logging); Slash-and-burn

Unprecedenteded rates of deforestation and biomass burning in tropical dry forests are dramatically influencing biogeochemical cycles, resulting resource depletion, declines biodiversity, atmospheric pollution. We quantified the effects varying levels slash—fire severity on nutrient losses redistribution a second—growth forest ("Caatinga") near Serra Talhada, Pernambuco, Brazil. Total aboveground prior to was °74 Mg/ha. Nitrogen phosphorous concentrations were highest litter, leaves attached slash, fine wood debris (<0.64 cm diameter). While these components comprised only 30% prefire biomass, they accounted for °60% pools N P. Three experimental fires conducted during 1989 season. In treatments consumption 78, 88, 95% total biomass. As much as 96% C 56% P pool lost combustion processes. exceeded 500 kg/ha 20 greatest severity. With increasing fire severity, ash decreased while concentration Ca increased. This indicates greater amounts nutrients volatilized (i.e., ecosystem occurred) with Following fire, up 47% residual 84% form ash, which quickly from site via wind erosion. Fires appeared have minor immediate effect N, C, or soils. However, soils no history cultivation had significantly higher than forests. Based upon measured single slash—burning events, it would likely require century more fallow reaccumulation occur. current periods this region 15 yr less.