Abiotic factors affect the performance of the terrestrial isopod Porcellionides pruinosus

Abstract

Abiotic factors constitute one of the most important drivers shaping soil ecosystems. Although being a strongly buffered environment, soil heterogeneous nature combined with the limited mobility of its organisms can make them highly sensitive to unfavourable conditions. A thorough knowledge of these relationships is thus a critical starting point to understand the challenges posed to edaphic organisms in a context of global environmental changes and the implications arising therefrom. In this study we evaluated the influence of temperature, soil moisture and UV radiation on the performance of the terrestrial isopod Porcellionides pruinosus using several endpoints: survival, locomotor activity, feeding parameters and avoidance behaviour. At the range assessed, temperature did not affect isopods’ survival but showed marked effects on sublethal endpoints. Both feeding parameters and locomotor activity showed a right-shifted response with gradual temperature-induced optimisation in isopods’ performance until reaching an optimum temperature and abruptly declining thereafter. On the contrary, soil moisture was found to significantly affect isopods’ survival but the effects on the feeding parameters were not clear. Although exhibiting a clear preference for intermediate soil moistures, isopods were particularly sensitive to drier environments since higher percentages of avoidance were found. UV radiation affected survival, body weight and locomotor performance. Abiotic factors affect soil organisms at relevant conditions and must therefore be considered while developing tools for edaphic ecosystems’ protection such as ecotoxicological testing and further environmental risk assessment.