Resilience to climate change: complex relationships among wetland hydroperiod, larval amphibians and aquatic predators in temporary wetlands

Abstract

Amphibians that utilise temporary wetlands with unpredictable hydrology are living on the edge, maintaining viable populations under variable climatic conditions. Information on their breeding ecology will provide insight into their adaptive capacity and resilience to climate change. The environmental factors influencing breeding of a temporary wetland breeding frog (Litoria olongburensis) from eastern Australia were examined over two breeding seasons from August 2009 to March 2011. The influence of biotic and abiotic wetland characteristics on the abundance and seasonality of L. olongburensis aquatic larvae was quantified throughout the latitudinal range of the species. Substantial variation in yearly precipitation resulted in changes to the timing of breeding, and patterns of tadpole and predator abundance, which also varied along a hydroperiod gradient. Litoria olongburensis displayed adaptive strategies, including breeding when hydrological conditions were likely to last longest, and short time to hatching and metamorphosis. Concentrating breeding efforts early during wetland filling coincided with low predator densities. These pre-adaptations may reflect an adaptive capacity to predicted changes in frequency and reliability of precipitation as a result of climate change, and may apply to other temporary wetland species. Their conservation depends on preserving wetlands with a variety of hydroperiods within a landscape matrix.