Climate change scenarios and models yield conflicting predictions about the future risk of an invasive species in North America

Abstract

1 The pea leafminer Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) is an invasive species in North America and a serious economic pest on a wide variety of crops. We developed a bioclimatic envelope model (BEM) for this species and examined the envelope's potential location in North America under various future climates. 2 We compared the future bioclimatic envelopes for L. huidobrensis using either simple scenarios comprising uniform changes in temperature/precipitation or climate projections from general circulation models (GCMs). Our simple scenarios were: (i) an increase of 0.1 • C per degree in latitude with a 20% increase in summer precipitation and a 20% decrease in winter precipitation and (ii) an overall increase of 3• C everywhere, also with the same changes in precipitation. For GCMmodelled climate change, we used the Canadian Centre for Climate Modelling and Analysis GCM (CGCM2) and the Hadley Centre climate model (HadCM3), each in combination with two scenarios from the Special Report on Emissions Scenarios (A2 and B2). 3 The BEM results using the simple scenarios were more similar to each other than to the results obtained using GCM projections. The results were also qualitatively different (i.e. spatially different and divergent) depending on which GCM-scenario combination was used. 4 This modelling exercise illustrates that: (i) results using first approximation simple climate change scenarios can give predictions very different from those that use GCM-modelled climate projections (comprising a result that has worrying implications for empirical impact research) and that (ii) different GCM-models using the same scenario can give very different results (implying strong model dependency in projected biological impacts).

Climate change and voltinism in Californian insect pest species: sensitivity to location, scenario and climate model choice

“…Mika et al . () found that GCM choice could result in prediction of areas at risk for Contarinia nasturtii that diverged not just in magnitude but also in direction of change; see also Mika & Newman (). Results such as these have worrying implications for impact research and emphasize the need for studies that investigate model dependency of projected biological impacts.…”

Predicted decrease in global climate suitability masks regional complexity of invasive fruit fly species response to climate change

“…Thus, CLIMEX is well suited for investigating the interactions between biological invasions and potential responses to climatic change (e.g. Mika and Newman 2010;Lozier and Mills 2011;Hill et al 2014).…”

Invasions and Insect Conservation

“…Thus, two studies on the Australian Bronze bug ( Thaumastocoris peregrinus , Thaumastocoridae) using different climate modelling schemes (CLIMEX: Saavedra et al 2015 ; WorldClim 1.3: Montemajor et al 2015 ) both forecast considerable future spread of the bug, largely in association with Eucalyptus plantations, but with some differences in detail of likely intensity of invasion across the largely overlapping predicted ranges. Many such models involve predictions of a suitable 'bioclimatic envelope', but many are based on uniform increases of temperature or precipitation levels, which may render them oversimplistic (Mika and Newman 2010 ).…”