The Fire and Fodder Reversal Phenomenon: Vertebrate Herbivore Activity in Burned and Unburned Tasmanian Ecosystems

Abstract

Very few multi-species or ecosystem comparisons of post-fire vertebrate herbivore activity and food preference exist to inform fire management and conservation strategies. We inferred post-fire (1–3 years) native and introduced vertebrate herbivore activity and attraction to six diverse temperate vegetation communities (grassland to rainforest) from scat counts. We hypothesised that where fire reduced herbaceous and grassy vegetation (‘fodder’), vertebrate herbivores would decline, and that post-fire preferences of native versus exotic herbivores would differ significantly. Instead, we found evidence for a ‘fire and fodder reversal phenomenon’ whereby native macropod and exotic deer scats were more abundant after fire in consistently ‘fodder-poor’ vegetation types (e.g., heath) but less abundant after fire in previously fodder-rich vegetation communities (e.g., grassland). Fodder cover predicted native macropod, wombat, and introduced deer activity and bare ground cover was strongly associated with introduced herbivore activity only, with the latter indicating post-fire competition for food sources due to their abundance in high-altitude open ecosystems. We, therefore, found environmental and vegetation predictors for each individual species/group and suggest broadscale multi-environment, multispecies observations to be informative for conservation management in potentially overlapping post-fire niches.

Keywords

• Tasmania
• Australia
• herbivory
• macropods
• soil moisture
• grazing