Comparison of two rolled sandy heath communities within a single fire patch in Ngarkat Conservation Park, South Australia

Abstract

Cross-ribbed rolling is a technique routinely used to construct firebreaks along the margins and access tracks of Ngarkat Conservation Park, South Australia. These breaks, approximately 20 m wide, contain regenerating heath communities with an overstorey of mallee. The effects of cross-ribbed rolling on community composition and succession were examined in a single fire patch on the western boundary of Ngarkat Conservation Park across 12 sites located in vegetation burnt approximately 35 years ago. Two areas at each site were investigated, one on rolled communities and the other running parallel on the adjacent unrolled vegetation. There was also a difference in the rolled communities sampled; six were on a 3-year-old break, whereas the remainder were on a 5-year-old break. Results indicate no changes to species richness or diversity when comparing rolled and unrolled areas, but there was some alteration to species composition in rolled communities. These results suggest that under current rolling regimes, the main effect is a reduction in biomass and some accompanying alteration to species composition, but not a reduction in overall species diversity or an increase in weeds.