Determining the Effects of Warming in Size-Structured Ecosystems
Brose, U., Dunne, J.A., Montoya, J.M., Petchey, O.L., Schneider, F.D. and Jacob, U. 2012. Climate change in size-structured ecosystems. Philosophical Transactions of the Royal Society B 367: 2903-2912.
So when all was said and done - in the body of the six scientists' article and the separate reports of the other researchers contributing to the theme issue - Brose et al. report that "warming directly accelerates individual metabolic rates (Peters, 1983; Gillooly et al., 2001; Brown et al., 2004; Ehnes et al., 2011), which causes increased feeding rates (Rall et al., 2012; Twomey et al., 2012)," which "can lead to increased top-down control and trophic cascades." However, they also note that since "increases in feeding rates with warming are generally weaker than those of metabolism (Rall et al., 2010; Vucic-Pestic et al., 2011; Twomey et al., 2012)," this consequence "should lead to reduced consumer densities and long-term reductions in top-down control and trophic cascades [italics added]."
In the concluding paragraph of their introductory article, where they sum up the gist of what their scouring of the pertinent scientific literature revealed, the team of researchers from Germany, Spain, Switzerland and the United States write that "warming modifies the size structure of communities with effects on top-down and bottom-up control that exceed the direct temperature effects [italics added]." And they say that "these indirect warming effects can lead to severely changed community compositions (Frelich et al., 2012; Lurgi et al., 2012a; Perdomo et al., 2012), food-web topologies (Lurgi et al., 2012b; Woodward et al., 2012), predator-prey size relations (Lurgi et al., 2012b), network dynamics (Binzer et al., 2012) and drastically altered ecosystem functioning (Blanchard et al., 2012; Yvon-Durocher and Allen, 2012) [italics added]."
So what does it all mean? From the complexities noted above, it means that we still have a lot to learn about global warming effects on ecosystems. But one thing stands out rather clear. With respect to the climate-alarmists' "thermal envelope" approach to the issue of potential global warming effects on species ranges, that concept doesn't even begin to properly address the issue.
Binzer, A.A., Guill, C., Brose, U. and Rall, B.C. 2012. The dynamics of food chains under climate change and nutrient enrichment. Philosophical Transactions of the Royal Society B 367: 2935-2944.
Blanchard, J.L., Jennings, S., Holmes, R., Harle, J., Merino, G., Allen, J.I., Holt, J., Dulvy, N.K. and Barange, M. 2012. Potential consequences of climate change for primary production and fish production in large marine ecosystems. Philosophical Transactions of the Royal Society B 367: 2979-2989.
Brown, J.H., Gillooly, J.F., Allen, A.P., Savage, V.M. and West, G.B. 2004. Toward a metabolic theory of ecology. Ecology 85: 1771-1789.
Ehnes, R.B., Rall, B.C. and Brose, U. 2011. Phylogenetic grouping, curvature and metabolic scaling in terrestrial invertebrates. Ecology Letters 14: 993-1000.
Frelich, L.E., Peterson, R.O., Dovciak, M., Reich, P.B., Vucetich, J.A. and Eisenhauer, N. 2012. Trophic cascades, invasive species and body-size hierarchies interactively modulate climate change responses of ecotonal temperate-boreal forest. Philosophical Transactions of the Royal Society B 367: 2955-2961.
Gillooly, J.F., Brown, J.H., West, G.B., Savage, V.M. and Charnov, E.L. 2001. Effects of size and temperature on metabolic rate. Science 293: 2248-2251.
Kolokotrones, T., Savage, V., Deeds, E.J. and Fontana, W. 2010. Curvature in metabolic scaling. Nature 464: 753-756.
Lurgi, M., Lopez, B.C. and Montoya, J.M. 2012a. Novel communities from climate change. Philosophical Transactions of the Royal Society B 367: 2913-2922.
Lurgi, M., Lopez, B.C. and Montoya, J.M. 2012b. Climate change impacts on body size and food web structure on mountain ecosystems. Philosophical Transactions of the Royal Society B 367: 3050-3057.
Perdomo, G., Sunnucks, P. and Thompson, R.M. 2012. The role of temperature and dispersal in moss-microarthropod community assembly after a catastrophic event. Philosophical Transactions of the Royal Society B 367: 3042-3049.
Peters, R.H. 1983. The Ecological Implications of Body Size. Cambridge University Press, New York, New York, USA.
Rall, B.C., Brose, U., Hartvig, M., Kalinkat, G., Schwarzmuller, F., Vucic-Pestic, O. and Petchey, O.L. 2012. Universal temperature and body-mass scaling of feeding rates. Philosophical Transactions of the Royal Society B 367: 2998-3007.
Rall, B., Vucic-Pestic, O., Ehnes, R., Emmerson, M. and Brose, U. 2010. Temperature, predator-prey interaction strength and population stability. Global Change Biology 16: 2145-2157.
Twomey, M., Brodte, E., Jacob, U., Brose, U., Crowe, T.P. and Emmerson, M.C. 2012. Idiosyncratic species effects confound size-based predictions of responses to climate change. Philosophical Transactions of the Royal Society B 367: 2971-2978.
Vucic-Pestic, O., Ehnes, R.B., Rall, B.C. and Brose, U. 2011. Warming up the system: higher predator feeding rates but lower energetic efficiencies. Global Change Biology 17: 1301-1310.
Woodward, G., Brown, L.E., Edwards, F.K., Hudson, L.N., Milner, A.M., Reuman, D.C. and Ledger, M.E. 2012. Climate change impacts in multispecies systems: drought alters food web size structure in a field experiment. Philosophical Transactions of the Royal Society B 367: 2990-2997.
Yvon-Durocher, G. and Allen, A.P. 2012. Linking community size structure and ecosystem functioning using metabolic theory. Philosophical Transactions of the Royal Society B 367: 2998-3007.