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Fine- vs. Coarse-Scale (Envelope) Models of Climate-Induced Vegetation Change
Reference
Feurdean, A., Tamas, T., Tantau, I. and Farcas, S. 2012. Elevational variation in regional vegetation responses to late-glacial climate changes in the Carpathians. Journal of Biogeography 39: 258-271.

Background
The authors state that species distribution models run at either finer scales (Trivedi et al., 2008; Randin et al., 2009) or including representations of plant demography (Hickler et al., 2009) and more accurate dispersal capability (Engler and Guisan, 2009) appear to predict a much smaller habitat and species loss in response to climate model predictions than do more coarse-scale models (Thomas et al., 2004; Thuiller et al., 2005; Araujo et al., 2008)," and these observations prompted the German and Romanian researchers to conduct their own real-world empirical study of the subject.

What was done
In the words of Feurdean et al., "seven fossil pollen sequences from Romania situated at different elevations were analyzed to examine the effects of climate change on community composition and biodiversity between 15,000 and 10,500 cal. yr BP in this biogeographically sensitive region of Europe," because this period, as they describe it, "was characterized by large-amplitude global climate fluctuations occurring on decadal to millennial time scales (Johnsen et al., 1992; Jouzel et al., 2007)," which enabled them to explore "how repeated temperature changes have affected patterns of community composition and diversity" and to analyze "recovery processes following major disruptions of community structure."

What was learned
The four scientists report discovering that (1) "community composition at a given time was not only the product of existing environmental conditions, but also the consequence of previous cumulative episodes of extirpation and recolonization," that (2) "many circumpolar woody plants were able to survive when environmental conditions became unfavorable," and that (3) "these populations acted as sources when the climate became more favorable again," which behavior, in their words, "is in agreement with modeling results at the local scale, predicting the persistence of suitable habitats and species survival within large-grid cells in which they were predicted to disappear by coarse-scale models."

What it means
The findings of Feurdean et al. add to those of the growing number of studies that demonstrate the shortcomings of climate-alarmist-approved "climate envelope" models of both vegetation and animal responses to rising temperatures, which models are used by climate alarmists to predict massive species extinctions as a result of the "unprecedented" CO2-induced global warming predicted by equally deficient climate models. Clearly, these two "wrongs" do not make a "right."

References
Araujo, M.B., Nogues-Bravo, D., Reginster, I., Rounsevell, M. and Whittaker, R.J. 2008. Exposure of European biodiversity to changes in human-induced pressures. Environmental Science and Policy 11: 38-45.

Engler, R. and Guisan, A. 2009. MIGCLIM: predicting plant distribution and dispersal in a changing climate. Diversity and Distributions 15: 590-601.

Hickler, T., Fronzek, S., Araujo, M.B., Schweiger, O., Thuiller, W. and Sykes, M.T. 2009. An ecosystem-model-based estimate of changes in water availability differs from water proxies that are commonly used in species distribution models. Global Ecology and Biogeography 18: 304-313.

Johnsen, S.J., Clausen, H.B., Dansgaard, W., Fuhrer, K., Gundestrup, N., Hammer, C.U., Iversen, P., Jouzel, J., Stauffer, B. and Steffensen, J.P. 1992. Irregular glacial interstadials recorded in a new Greenland ice core. Nature 359: 311-313.

Jouzel, J., Stievenard, M., Johnsen, S.J., Landais, A., Masson-Delmotte, V., Sveinbjornsdottir, A., Vimeux, F., von Grafenstein, U. and White, J.W.C. 2007. The GRIP deuterium-excess record. Quaternary Science Reviews 26: 1-17.

Randin, C., Engler, R., Normans, S., Zappa, M., Zimmermann, N.E., Perman, P.B., Vittoz, P., Thuiller, W. and Guisan, A. 2009. Climate change and plant distribution: local models predict high-elevation persistence. Global Change Biology 15: 1557-1569.

Thomas, C.D., Cameron, A., Green, R.E., Bakkenes, M., Beaumont, L.J., Collingham, Y.C., Erasmus, B.F.N., Siqueira, M.F.D., Grainger, A. and Hannah, L. 2004. Extinction risk from climate change. Nature 427: 145-148.

Thuiller, W., Lavorel, S., Araujo, M.B., Sykes, M.T. and Prentice, I.C. 2005. Climate change threats to plant diversity in Europe. Proceedings of the National Academy of Sciences USA 102: 8245-8250.

Trivedi, M.R., Berry, P.M., Morecroft, M.D. and Dawson, T.P. 2008. Spatial scale affects bioclimate model projections of climate change impacts on mountain plants. Global Change Biology 14: 1089-1103.

Reviewed 27 June 2012