Management to enhance farm dam condition improves outcomes for amphibians

Abstract

The conversion of natural habitats to agricultural land has contributed considerably to global amphibian declines. Despite this, some amphibian species can utilise habitats within agricultural landscapes, such as farm dams. However, the suitability of farm dams for amphibians and how management interventions can enhance habitat values remain poorly understood. We aimed to quantify the impacts of management interventions on amphibian biodiversity in farm dams. Our study focused on the intensively farmed and cleared South West Slopes bioregion of south-eastern Australia, where 96 % of the area is freehold land, and over 80 % of the woody vegetation cover has been cleared. We conducted detailed surveys of adult frogs across 85 farm dams. These dams were either enhanced dams, having undergone management including fencing to exclude livestock and facilitate revegetation, or control dams, with no interventions, and management practices consistent with the paddocks in which they were embedded. We found enhanced dams had significantly greater total frog and Crinia parinsignifera abundance than control dams. Total abundance was also negatively associated with higher total dissolved solids concentration. Additionally, species abundance was greater at dams with higher topographic wetness and increased rainfall in the 30 days preceding surveys. Key variables positively associated with species richness were enhanced dams, littoral leaf litter and survey year, but only littoral ground vegetation was significant. The key variables for species-level analysis showed significant inter-specific variation. Our results indicate that that enhancing dams through excluding livestock and establishing vegetation can improve habitat for amphibians. Show more