Fig4 rock rollout 2Biodiversity conservation and protection of infrastructure often require different approaches for managing wildfire risk. Broad-scale prescribed burning is frequently advocated to reduce loss of homes and other buildings from bushfire even though it might be ineffective for biodiversity conservation.

As infrastructure generally has priority over nature, management agencies remain under strong pressure to maintain low fire fuel loads — a pressure that increases with rapid urbanisation.

Rocks are a critical resource for many species providing refuges, basking sites and prey hot-spots. Rock removal can cause declines in biodiversity, particularly when coupled with nutrient enrichment and associated changes in plant community composition. CEED researchers and collaborators set out to discover if we can use rocks in restoration to reduce fire fuel loads, and at the same time overcome conflicts between biodiversity conservation and asset protection.

Optimising habitat restoration for the nationally threatened pink-tailed worm-lizard, Aprasia parapulchella, while reducing fire fuel load in a rapidly developing urban area in Canberra, was the key focus of the research. Rocks are a critical resource for these lizards — they live in burrows under rocks where they feed exclusively on ant eggs and larvae. No rocks, no lizards.

Dense addition of natural rock (30% cover) and native grass revegetation (Themeda triandra and Poa sieberiana) were used to restore critical habitat elements. Combinations of fire and herbicide were used to reduce fuel load and invasive exotic species.
Rock restoration combined with herbicide application met the widest range of restoration goals: it reduced fire fuel load, increased ant occurrence in the short-term and increased the growth and survival of native grasses. Lizards colonised the experimental plots within a year of treatment.

This science-based restoration technique is currently being rolled out by ACT Parks and Conservation in multiple reserves across the territory. It is an innovative way to resolve conflicts between biodiversity conservation and protection of human assets from bushfire in any grassland area where rocks are a critical resource.