We explore why and how community composition changes across
ecological settings and what the ecosystem-level consequences are of
these changes. Our focus is typically not at the species but at the
trait composition level, as selection will be acting within and among
species via their expressed functional traits. We ask whether
particular traits or suites of traits lead to differences in
distribution and performance to understand the linkage between
structure and function. Additionally, we examine these linkages within
an evolutionary framework, investigating where in phylogenies the
greatest divergences in trait values occur, as well as whether traits
change in a coordinated fashion across phylogenies.
NSW: With support from the University of Western Sydney and an ARC Discovery Grant, we have a rot plot at the Hawkesbury Campus in Richmond, NSW with Jeff Powell, Brendan Choat, Peter Reich, and Will Cornwell. This project looks at variation in wood decay across different species and stem sizes. It also compares the succession of microbial communities across the decay trajectory.
QLD: We have decay experiments running in rainforest and savanna to examine the relative roles of termites and saprotrophic microbes across a rainfall gradient and through time. We have also measured the diversity of termites and amount of living and deadwood across this gradient.
The assembly and turnover of microbial communities in plant tissues is poorly understood. We are investigating differences in microbial community composition and structure across years and between tissues for oaks in the Pyrenees and different tree species near Bordeaux. Additionally, leaf and stem hydraulic function is usually examined separately. We are beginning to explore the interactive effects of this joint hydraulic system in conifers and angiosperms.
MD: At the Smithsonian Environmental Research Center, we are monitoring the phenology of fungal fruiting as well as wood decay activity, measured through wood respiration and enzyme activity levels, to determine whether fungal wood decay activity responds to the same environmental drivers as fungal fruiting. This research will help put shifts in fungal fruiting phenology observed in Michigan and northern Europe into the context of ecosystem function in temperate forests.
MO: Woody plant stems hold much of the carbon in the terrestrial biosphere. The release of carbon from this pool and consequent changes in the climate system, depends on tree mortality and decay. While the general relationship between microclimate and decay is well known, we have a much weaker understanding of how plant construction contributes to variation in mortality and decomposition rates among species. We are examining these topics at Washington University's Tyson Research Center.
Across the globe, we are determining the relative role of saprotrophic microbes and insects in breaking down wood. This project partners with a large series of collaborators interested in examining these differences in natural and human-modified systems along different environmental gradients.
Functional trait databases
As trait databases grow in size, we can begin to ask ecological and evolutionary questions across the history of large clades, such as plants and fungi. We have been building global functional trait databases for both of these clades. With collaborators, we are running a series of projects including: 1. Ecology and evolution of plant traits along environmental gradients, 2. Evolution of conduit anatomy with growth form, 3. Overlap among large databases, 4. Evolution of plant dependencies, 5. Evolution of plant decomposability, 6. Synthesis of what we know about fungal functional ecology.