Volume 16, Number 34: 21 August 2013
Writing in Ecology and Evolution, Oney et al. (2013) note that species distribution modeling (SDM) is "an important tool to assess the impact of global environmental change." However, they say that many species exhibit ecologically relevant intraspecific variation, but that "few studies have analyzed its relevance for species distribution modeling." And, therefore, in an attempt to add to those few studies and enlarge upon their significance, the four researchers compared the results of three SDM techniques as applied to the highly variable lodgepole pine tree (Pinus contorta).
First, they employed a conventional approach called MaxEnt to model the tree as a single species, based on presence-absence observations. Second, they used MaxEnt to model each of the three most prevalent subspecies independently, after which they combined their projected distributions. And third, they used a universal growth transfer function (UTF) to incorporate intraspecific variation utilizing provenance trial tree growth data.
The end result of these various operations was that under future anticipated climatic conditions, the different projections of lodgepole pine habitat suitability significantly diverged. In particular, as they put it, "when the species' intraspecific variability was acknowledged, the species was projected to better tolerate climatic change as related to suitable habitat without migration."
In light of this finding, Oney et al. concluded that "models derived from within-species data produce different and better projections, and coincide with ecological theory," leading them to also conclude that "intraspecific variation may buffer against adverse effects of climate change," which ultimately implies that many climate-alarmist horror stories of various species extinctions occurring in response to projected global warming are likely enormously overstated, as in totally false.
Sherwood, Keith and Craig Idso
Reference
Oney, B., Reineking, B., O'Neill, G. and Kreyling, J. 2013. Intraspecific variation buffers projected climate change impacts on Pinus contorta. Ecology and Evolution 3: 437-449.