2020/05/06 by Geofe O. Cadiz, Jane G. Cawson, Trent D. Penman +2 · 14 citations
Environmental Science · #Abundance (ecology) #Agronomy #Biology #Canopy #Disturbance (geology) #Dominance (genetics) #Ecology #Ecology and Vegetation Dynamics Studies #Environmental science #Fire effects on ecosystems #Flammability #Flammable liquid #Rangeland and Wildlife Management
paper · pdf · doi:10.1071/bt19112
published in Australian Journal of Botany 68(1), 37-48 (CSIRO Publishing)
openalex publication_date 2020/05/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/27
When flammable plant species become dominant they can influence the flammability of the entire vegetation community. Therefore, it is important to understand the environmental factors affecting the abundance of such species. These factors can include disturbances such as fire, which can promote the dominance of flammable grasses causing a positive feedback of flammability (grass–fire cycle). We examined the potential factors influencing the abundance of a flammable grass found in the understoreys of forests in south-east Australia, the forest wiregrass (Tetrarrhena juncea R.Br.). When wiregrass is abundant, its structural characteristics can increase the risk of wildfire ignition and causes fire to burn more intensely. We measured the cover of wiregrass in 126 sites in mountain ash forests in Victoria, Australia. Generalised additive models were developed to predict cover using climatic and site factors. The best models were selected using an information theoretic approach. The statistically significant factors associated with wiregrass cover were annual precipitation, canopy cover, disturbance type, net solar radiation, precipitation seasonality and time since disturbance. Canopy cover and net solar radiation were the top contributors in explaining wiregrass cover variability. Wiregrass cover was predicted to be high in recently disturbed areas where canopy cover was sparse, light levels high and precipitation low. Our findings suggest that in areas with wiregrass, disturbances such as fire that reduce canopy cover can promote wiregrass dominance, which may, in turn, increase forest flammability.