Climatic severity and the response to temperature elevation of Arctic aphids
1 Theory suggests that any given rise in temperature resulting from climate change will have its greatest effect on high Arctic ecosystems where growing seasons are short and temperatures low.2 A small temperature rise, similar to that predicted for the middle of the next century, has profound effects on a population of the high Arctic, Dryas-feeding aphid Acyrthosiphon svalbardicum on Spitsbergen (Strathdee et al. 1993a).3 Here comparative experiments on a closely related Dryas-feeding species, A. brevicorne, at two contrasting sub-Arctic sites are described. Together with the results from Spitsbergen these sites represent two colder sites (high Arctic and upland sub-Arctic) and one warmer site (lowland sub-Arctic).4 Differential responses in aphid population density and overwintering egg production to temperature elevation support the hypothesis that the ecological effects are greatest at sites with the most severe climates; however, there is no similar gradient in advancement of host plant phenology with warming.
Authors: Strathdee, A.T., Bale, J.S., Strathdee, F.C., Block, W.C., Coulson, S.J., Webb, N.R., Hodkinson, I. D.