Effects of increased temperatures simulating climate change on terrestrial invertebrates on Ross Island, Antarctica

Passive cloches were deployed for 27 months (three austral summers) at Cape Bird, Ross Island, Antarctica (77degrees13'S, 166degrees26'E) to investigate the response of soil invertebrates to increased temperatures. Soil surface temperatures in cloches were significantly higher than in lidless control plots or unmanipulated sites. Soil surfaces in cloche plots exceeded 0 C and 8 C (the approximate threshold for growth and development in several invertebrate species) for longer than in control plots. No consistent changes in populations of Gomphiocephalus hodgsoni (Collembola), Stereotydeus mollis (Acari) Nanorchestes antarcticus (Acari) or observed in the cloche plots after 3 growing seasons at higher temperatures. Abundance of S. mollis was strongly related to algal biomass, but abundances of other species were not clearly related to the environmental characteristics of manipulation plots. Although low temperatures may have a role as a limiting factor on a geographical scale, local populations of invertebrates are probably influenced more by the availability of liquid water; and invertebrate responses could be very slow owing to short growing seasons and long life cycles in continental Antarctica.