Two plenary talks were particularly memorable for me. First, Sandra Diaz gave a really elegant talk that spanned from patterns of functional diversity to the philosophy of ecology. A woven carpet provided the central analogy. A carpet includes the warp – the underlying structure of the carpet – and the weft – the supplementary threads that produce the designs. Much like species, a great diversity of colors and patterns arise from the weft, but the warp provides the underlying structure. The search for a small number of general functional relationships one way ecologists can look for the structural fabric of life. Much like Phil Grimes, an earlier speaker, Diaz has attempted to identify generalities in ecology. It’s worth reading the paper she discussed for much of her talk, which attempts to describe a global spectrum of plant function (Diaz et al. 2016). Diaz noted, however, that your focus should be determined by your questions. And you need both details and generalities if you want to provide predictions at a global scale but with a local resolution.
The other plenary of note was from Stephen Hubbell (it actually preceded Diaz’s talk), and it provided a contrasting approach. Hubbell discussed a number of detailed analyses to derive a general conclusion about processes maintaining tropical tree diversity. Data from the Barro Colorado island provides information about changes in growth rate, abundances, presence/absence, distances between species. It shows seemingly large shifts in abundance and composition through time. And Hubbell (in a fairly provocative mood) suggests that it shows that ‘community ecology is a failure’. I would argue against that statement, and what Hubbell really seemed to be saying is that expectations of equilibrium and equilibrium models (L-V, etc) are not useful. Instead, factors such as weak stabilizing mechanisms and demographic stochasticity may be enough to understand high diversity regions.