Research

Ecological communities perform and depend on fluxes and transformations of matter and energy. These ubiquitous flows characterise ecosystem processes such as decomposition, and may occur between interacting species (e.g. predation) and across ecosystem boundaries (e.g. terrestrial-aquatic exchanges). My research focuses on how global changes affect these dynamics by integrating biogeochemistry with invertebrate and microbial ecology.  My work spans freshwaters, terrestrial environments, and the interface between them using experimental and observational approaches at a range of temporal and spatial scales.

My research addresses three core questions that represent a pathway towards my overall aim of improving ecological health:

How does resource quality and diversity affect food-web structure and function?
My fundamental research tests theoretical predictions of how changes in basal resource diversity (e.g. species richness) or nutritional quality (e.g. nitrogen content) mediate patterns of trophic interactions and processes such as consumer growth rates. Most recently, I have been collaborating with Jes Hines and Anne Ebeling to assess how changes in plant diversity affect consumer trait distributions, the associated food-web structures and network stability (see The Jena Experiment for more).

How do global changes impact resource availability and ecosystem functioning?
The provision of ecosystem services is being threatened by global change drivers such as land-use and climate change. My research assesses how perturbations impacts ecosystem functions such as metabolic rates and decomposition. For instance, extreme weather events such as storms 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 phytoplankton functional composition and initiated an algal bloom that conspicuously enhanced whole-lake metabolism.

How can we effectively manage and restore ecosystems?
Despite high investment, there is often limited monitoring of whether management actions are effective at the anticipated spatial extent and 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, omnivore diets 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.

 

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