I went to a session on a macroecology yesterday, which featured some wonderful speakers, and came away with an unsure feeling about this field. The Session started off with a fantastic talk by Rob Dunn on how macroecologists differ on what the main mechanisms are for explaining diversity patterns. He argued that perhaps the complexity of natural and human-altered systems make simple generalizations not very fulfilling. Next Lauren Buckley showed how species turnover had complex relationships with broad environmental changes and that species turnover patterns are better correlated with other species turnover then with the environmental variables we think drive the patterns. Next Brian McGill tried to make the case for a truly unified theory. He walked through several general models of random species packing, showing that some models fit observed data very well. I was impressed by the data/model fits but am skeptical of a general theory which lacks biological mechanisms. My view of a scientific theory is that it ought to contain basic mechanisms and that a unified theory should explain patterns and processes at multiple scales. That said, I also think McGill has done more to forward the field than almost any other younger ecologist. In Allen Hurlbert's talk, he nicely showed how independently accounting for energy and area can provide a better basis to constructing and understanding species-area relationships. The basic reason is that area and energy availability differentially affect the number of individuals.
Back to my real life tomorrow!