Rock supplementation as an ecological restoration strategy for temperate grassland reptiles

Abstract

AbstractTemperate grassland ecosystems support highly diverse assemblages of plants and animals but have been predominantly cleared for urban infrastructure and modified for agriculture. Temperate grasslands that remain in south‐eastern Australia are often degraded. For example, surface rocks have been extensively removed, potentially affecting long‐term persistence of grassland reptiles that depend on this resource. Rock habitat restoration is a strategy that can promote the survival of grassland reptiles and restore degraded temperate grasslands. In this study, we examined the benefit of supplementing locally sourced rock to improve reptile outcomes in degraded grassland reserves in the ACT. We established a BACI design across five ACT grassland reserves with 10 plots where rocks were added and 10 equivalent control plots to assess (i) the effect of rock supplementation on reptile relative abundance and composition, and (ii) the characteristics of the sites and rocks that reptiles used. Surveys were conducted over the spring and summer period each year over 3 years (2015–2017). Early results (one‐year post‐study) indicate that reptiles used supplemented rock and that reptiles show a preference for large (7600–29 000 cm3), flat rocks. Reptiles also show a preference for sites with higher grass cover and native vegetation composition, highlighting the need to manage site‐scale conditions to maximize the success of rock supplementation. Our study concludes rock restoration will support the persistence of grassland reptile populations, particularly if coupled with site‐scale grassland management, and will likely be an important strategy to use under changing climate regimes.