Ecosystem function is driven by intersections between abiotic environments and biota inhabiting those environments. The biota is shaped by and also shapes these environments. Our ability to understand impacts of these linkages on ecosystem function has matured as we learn more about functional ecology (traits) of organisms. This trait-based approach provides us tools to examine consequences of where species sit in functional trait space on their interactions with one another in particular locations globally. Plants and fungi are distantly related, largely sessile clades with numerous associations (e.g., fungi act as plant pathogens, inhabit plant tissues as free-living symbionts, facilitate nutrient and water uptake by plant roots, and decay plants after they senesce). Much of our understanding of functional ecology of plants and fungi has come through local studies. Through a series of projects, we have compiled global databases of plant and fungal functional traits to examine ecology and evolution of these taxa, as well as their impact on ecosystem function (e.g., carbon turnover during decay). Here we synthesize our work to examine what we have learned to date, as well as promises and challenges of using such databases going forward to predict ecosystem function in a changing world.
In our syntheses, we have found that the types of traits that are measured differ between fungi and plants, due in part to the differences in how we are able to sample those taxa (e.g., many fungi are not observable to the naked eye). Additionally, those traits that are critical for organisms to make a living may differ to those that shape how they influence ecosystem function (e.g., traits that mediate the form and rate that carbon is released from deadwood). Many of the most critical and harder to sample traits relate to the functional genetic architecture, enzyme profile, and chemistry of both clades. As it becomes increasingly cheaper to sequence species and environmental samples, we expect more information on these critical traits. Finally, despite the rapid growth in public databases describing the functional ecology of different species, large gaps remain limiting the spatial and taxonomic inferences we can draw in our studies. Such limitations may impact our ability to predict how trait ecology will affect ecosystem function into the future.