The impact of fire on riparian vegetation in Australia's tropical savanna

© 2015 by The Society for Freshwater Science. Intermittent streams drain much of the world's tropical savannas, yet these vitally important stream ecosystems are among the most poorly understood components of tropical savannas. Fire is a widely used management tool in tropical savannas, but the effects of prescribed burning on savanna streams or riparian zones have not been investigated experimentally. This study was undertaken within a catchment-scale, replicated experiment to determine the effect of prescribed burning on savanna riparian zones in northern Australia. Regardless of position along the stream, burning had dramatic effects on the composition and structure of the riparian vegetation. Woody species richness and total abundance, the abundance of small- and medium-sized trees, total basal area, canopy cover, and the richness and cover of vines were reduced by burning, whereas grass cover was much higher in burned areas. Fire also reduced seed production of the dominant riparian eucalypt. This study adds greatly to our understanding of the effects of fire management on savanna riparian zones and demonstrates that they are far more fire sensitive than the surrounding savanna.