Shifting fire regimes from late to early dry-season fires to abate greenhouse emissions does not completely equate with terrestrial vertebrate biodiversity co-benefits on Cape York Peninsula, Australia

Abstract

Carbon farming initiatives have rapidly developed in recent years, influencing broad scale changes to land management regimes. In the open carbon market a premium can be secured if additional benefits, such as biodiversity conservation or social advancement, can be quantified. In Australia, there is an accepted method for carbon abatement that requires shifting fire frequency from predominantly late, defined as fires occurring after August 1, to early dry-season fires or by reducing overall fire frequency. There is an assumption and some evidence that this might accrue co-benefits for biodiversity. We tested this assumption by comparing terrestrial vertebrate biodiversity patterns (richness and abundance of reptiles, birds and mammals) against increasing fire frequency in the early and late dry-season at the same spatial resolution as the fire management for emission abatement method. We systematically sampled 202 sites on Cape York Peninsula, and examined the relationship between vertebrate fauna, fire and environmental metrics. We found that within the approved vegetation type, open woodlands in tropical savanna woodland, early and late dry-season fire frequency had the same weak linear relationship with only some elements of the observed fauna. Additionally, the response of each taxa to fire frequency were different across broad vegetation structural categories, suggesting that a more nuanced species-specific monitoring approach is required to expose links between savanna burning for carbon abatement and burning for biodiversity benefit.