IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Continental fire density patterns in South America
Autor/es:
DI BELLA, C.M., JOBBAGY, E.G. .; PARUELO, J.M. AND PINNOCK, S.
Revista:
GLOBAL ECOLOGY AND BIOGEOGRAPHY
Referencias:
Año: 2006 p. 192 - 199
ISSN:
0960-7447
Resumen:
ABSTRACT
Aims Quantification of the effects and interactions of natural and anthropogenic
factors, including climate, canopy structure, land use and management conditions,
on vegetation burning. The study of these relationships is fundamental to predict
regional fire patterns and develop sound management and regulation policies for
biomass burning at national and global levels.
Location Southern South America, including Argentina, Brazil, Paraguay, Uru-
guay, Bolivia and Chile.
Methods Based on National Oceanic and Atmosphere AdministrationAdvance
Very High Resolution Radiometer (NOAAAVHRR) satellite images, we identified
fires in southern South America with a daily frequency for two periods (1999/2000
and 2000/01) using a contextual fire detection algorithm and integrating the density
of these fires at a monthly scale into a 0.5 × 0.5.äóêÀgrid. We combined vegetation and
climate global databases and land use information from national census data to
explore the relationship of these factors with fires across the region.
Results The whole study region had a mean fire density of 0.10 and 0.05 fires km -2
year -1
in 1999/2000 and 2000/01, respectively, with extreme values as high as 1.37 in
fires km -2
year -1
in Para State, Brazil. Water deficit estimates, derived from a climatic
water balance, showed the better correlation with fire density (r = 0.28; P < 0.001;
n = 4467), interacting strongly with land use. In areas with low agricultural use fire
density increased with water deficit, whereas in highly agricultural areas this relation-
ship was not observed. Agriculture significantly reduced fire density in prairies and
savannas but increased its frequency in rain forests.
Main conclusions These results suggest that agriculture prevents biomass
burning in semiarid areas but enhances it in humid environments, where biomass
accumulates at faster rates.
Keywords
Agricultural fires, fire occurrence, land cover changes, NOAA/AVHRR, remote
sensing, water deficit.