My research addresses how global change drivers affect ecosystem functioning by integrating biogeochemistry with invertebrate and microbial ecology. Fluxes of organic matter occur among species within ecosystems (e.g. predation) and between the components of landscapes (e.g. terrestrial-aquatic exchanges). These flows and transformations characterise ecosystem processes (e.g. primary production and decomposition) that moderate the provision of important ecosystem services.
My work spans freshwaters, terrestrial environments, and their riparian interface using both observational and experimental approaches at a range of spatial scales. I consider three broad questions that represent a pathway towards my overall aim of informing management and policy:
How do basal resources moderate food-web structure and dynamics?
My fundamental research tests theoretical predictions of how changes in basal resource diversity (e.g. species richness) and nutritional quality (e.g. nitrogen content) mediate the patterns and dynamics of trophic interactions. Most recently, I have been collaborating with Jes Hines and Anne Ebeling to assess how changes in plant diversity affect arthropod functional traits, food-web structure, and network stability (see The Jena Experiment for more).
How will global changes impact ecosystem functioning?
My applied work assesses how global change drivers like land-use and climate change influence ecosystem processes such as whole-ecosystem metabolism. For instance, extreme weather events can redistribute nutrients and biota in river networks and lakes. With Mark Gessner and colleagues from the LakeLab experimental facility (Stechlin, Germany), I demonstrated that wind-induced mixing of a deep lake altered the composition of the phytoplankton community and initiated an algal bloom that conspicuously enhanced whole-lake metabolism.
How can we most effectively manage ecosystems?
There is often limited monitoring of whether management actions are effective at the anticipated spatial extent and within an acceptable timeframe. My honours and doctoral work (with mentors Paul Reich, Ross Thompson and Ralph Mac Nally) focused on how riparian vegetation condition and restoration influenced aquatic invertebrate communities and organic matter dynamics in Australian agricultural streams. An important applied finding was that small stretches of woody replanting can enhance terrestrial inputs to streams and shift primary production and respiration rates towards reference condition within two decades.