A hierarchical Bayesian model of wildfire in a Mediterranean biodiversity hotspot : implications of weather variability and global circulation
Date
2010
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
In this study we combined an extensive database of observed wildfires with high-resolution
meteorological data to build a novel spatially and temporally varying survival model to analyze
fire regimes in the Mediterranean ecosystem in the Cape Floristic Region of South Africa (CFR)
during the period 1980-2000. The model revealed an important influence of seasonally
anomalous weather on fire probability, with increased probability of fire in seasons that are
warmer and drier than average. In addition to these local-scale influences, the Antarctic Ocean
Oscillation (AAO) was identified as an important large scale influence or teleconnection to
global circulation patterns. Fire probability increased in seasons during positive AAO phases,
when the subtropical jet moves northward and low level moisture transport decreases. These
results confirm that fire occurrence in the CFR is strongly affected by climatic variability at both
local and global scales, and thus likely to respond sensitively to future climate change.
Comparison of the modeled fire probability between two periods (1951-1975 and 1976-2000)
revealed a four year decrease in an average fire return time. If, as currently forecasted, climate
change in the region continues to produce higher temperatures, more frequent heat waves, and/or
lower rainfall, our model thus indicates that fire frequency is likely to increase substantially. The
regional implications of shorter fire return times include shifting community structure and
composition, favoring species that tolerate more frequent fires.
Description
The original publication is available at www.elsevier.com.
Keywords
Fire regime -- South Africa -- Cape Floristic Region, Fynbos -- South Africa -- Cape Floristic Region, Climate change -- South Africa -- Cape Floristic Region, Hierarchical Bayesian model
Citation
Wilsona, A.M., Latimerb, A.M., Silander, J.A., Gelfandc, A.E. & De Klerk, H. 2010. A Hierarchical Bayesian model of wildfire in a Mediterranean biodiversity hotspot: implications of weather variability and global circulation. Ecological Modelling 221 (2010), 106–112, doi: 10.1016/j.ecolmodel.2009.09.016