Variation in thermal performance curves for oxygen consumption and loss of critical behaviors in co-occurring species indicate the potential for ecosystem stability under ocean warming

Abstract

Species-level differences in responses to environmental factors may increase a community's ability to retain key functions under environmental change. We compared the oxygen consumption rates and maintenance of critical behaviors for three co-occurring intertidal gastropod species over a temperature range of 30 °C. Each species exhibited a distinct thermal performance curve (TPC) for oxygen consumption. The TPC of Lunella granulata was horizontally shifted to be significantly warmer than that of Chlorostoma argyrostoma. Monodonta labio's TPC was vertically shifted compared to the other two species, reflecting greater oxygen consumption overall. L. granulata and M. labio maintained critical behaviors at temperatures 3-5 °C warmer than C. argyrostoma. These differences in the thermal tolerances of similar, co-occurring species provide space for the insurance effect of biodiversity to occur. Understanding the degree to which co-occurring species respond differently to increased temperature may help us predict community resistance in the face of climate change.

Keywords: Climate change; Functional redundancy; Insurance hypothesis; Intertidal; Tropics.