TY  - JOUR
AU  - Archibald, S.
AU  - Roy, David P.
AU  - van Wilgen, B.W.
AU  - Scholes, R.J.
PY  - 2009//
TI  - What limits fire? An examination of drivers of burnt area in southern Africa
JO  - Global Change Biology
SP  - 613
EP  - 630
VL  - 15
IS  - 3
KW  - Africa
KW  - area
KW  - burned area
KW  - burnt area
KW  - climatic control
KW  - cultivation
KW  - data
KW  - dry season
KW  - environmental factor
KW  - fire
KW  - fire regime
KW  - forest
KW  - fuel
KW  - grazing
KW  - human
KW  - human activity
KW  - human control
KW  - ignition
KW  - journal articles
KW  - map
KW  - model
KW  - moisture
KW  - population density
KW  - predictive model
KW  - rainfall
KW  - regression
KW  - regression tree
KW  - resolution
KW  - road
KW  - satellite data
KW  - seasonality
KW  - southern Africa
KW  - spatial
KW  - spatial data
KW  - spatial variation
KW  - sub-Saharan Africa
KW  - tree
KW  - variance
KW  - variation
KW  - weather
KW  - wildfire
N2  - The factors controlling the extent of fire in Africa south of the equator were investigated using moderate resolution (500m) satellite-derived burned area maps and spatial data on the environmental factors thought to affect burnt area. A random forest regression tree procedure was used to determine the relative importance of each factor in explaining the burned area fraction and to address hypotheses concerned with human and climatic influences on the drivers of burnt area. The model explained 68% of the variance in burnt area. Tree cover, rainfall in the previous 2 years, and rainfall seasonality were the most important predictors. Human activities – represented by grazing, roads per unit area, population density, and cultivation fraction – were also shown to affect burnt area, but only in parts of the continent with specific climatic conditions, and often in ways counter to the prevailing wisdom that more human activity leads to more fire. The analysis found no indication that ignitions were limiting total burnt area on the continent, and most of the spatial variation was due to variation in fuel load and moisture. Split conditions from the regression tree identified (i) low rainfall regions, where fire is rare; (ii) regions where fire is under human control; and (iii) higher rainfall regions where burnt area is determined by rainfall seasonality. This study provides insights into the physical, climatic, and human drivers of fire and their relative importance across southern Africa, and represents the beginnings of a predictive framework for burnt area.
SN  - http://dx.doi.org/10.1111/j.1365-2486.2008.01754.x
UR  - http://dx.doi.org/10.1111/j.1365-2486.2008.01754.x
N1  - exported from refbase (http://eros.usgs.gov/refbase/show.php?record=24074), last updated on Fri, 21 Sep 2012 12:00:47 -0500
ID  - Archibald_etal2009
ER  -