Using a bioinspired model to determine the extinction risk of Calotriton asper populations as a result of an increase in extreme rainfall in a scenario of climatic change

Abstract

Climate-induced changes in hydrology are potentially one of the greatest threats to most aquatic-breeding amphibians. Collectively, studies indicate that the frequency of heavy precipitation events (or the proportion of severe rainfall from heavy falls) is expected to increase in most areas during the 21st century. Given these projections, it is pertinent to establish whether Calotriton asper populations have the capacity to withstand an increase in the frequency of extreme rainfall. Building a reliable model is a key step towards understanding the future dynamics of newt populations in a potential scenario of climatic change.We propose a population dynamics P-system model (PDP) for the Pyrenean newt (C. asper) population that takes into account the basic processes of reproduction, mortality, movement via streams and flood risk. With this model, we aim to determine the response of C. asper populations to various hypothetical scenarios of increases in extreme rainfall frequency. Our results show that the proposed PDP model is useful to predict annual fluctuations of C. asper population size and the future evolution of the species.C. asper extinction was predicted in only one scenario in the Pi Valley population. However, a reduction in population levels is observed under all scenarios of increased frequency of extreme rainfall. Consequently, the risk of extinction rises as indicated by an increase in the coefficient of variation. Larval mortality by catastrophic drift is considerable, leading to a lack of recruitment in the third year, the time at which small newts reach sexual maturity and return to the water.