Recent fire regimes in the Etosha National Park and adjacent areas in northern Namibia

Abstract

• Fires in Etosha are concentrated in the two driest months of the year. • Fire return periods were shorter (6.9 yr) inside the park than outside (31.8 yr) • Fire return periods differed sometimes counter-intuitively between vegetation types. • Exceptionally large fires were infrequent and only occurred in a few years. • Implementing patchy burns to break up fuel loads faces numerous challenges. We assessed the recent fire regimes in the semi-arid savannas of Etosha National Park and adjacent areas in northern Namibia using MODIS satellite imagery from 2001 – 2025 across gradients of vegetation types, mean annual rainfall (200 – 500 mm) and land ownership. Fires were highly seasonal, concentrated in the two driest months of the year (September and October). The average fire return period over 25 years was 6.9 years in Etosha National Park (where fires are often allowed to spread freely and where additional prescribed burns have been implemented), but more than four times greater (31.8 years) on adjacent freehold farms where prescribed fires were not conducted and aggressive fire suppression was practiced. The proportion of the Etosha National Park that burnt annually ranged from zero to 47.6% and the fire regime was characterised by relatively infrequent cases in which an exceptionally large area (44% on average) burnt in a single year. Some findings were counter-intuitive in that certain vegetation types in areas of low mean annual rainfall (< 300 mm) burnt frequently (fire return period 4.3 years) while others in higher rainfall areas (> 400 mm) experienced infrequent fires (fire return periods 34 – 206 years). Fire management has been adapted over time, with the most recent policy seeking to implement patch mosaic burns to break up continuous fuel loads, but implementation is challenging due to a lack of skilled capacity and funding.