Thanks for visiting! Here, you will find information about our research in plant physiological and ecosystem ecology. Our emphasis is on understanding how climate, disturbance, succession, and ecosystem structure affect leaf to ecosystem-scale function, with a focus on forest and wetland carbon cycling. Currently, we seek undergraduate student collaborators to conduct Department of Energy (DOE), National Science Foundation (NSF), and NASA supported research at VCU's Rice Rivers Center, and the University of Michigan Biological Station. Please contact Chris.
Our research focuses on how disturbance, succession, and climate shape ecosystem structure and function, particularly production and the carbon cycle. Our primary study system is forests and, more recently, wetlands.
Disturbance, succession, and forest carbon cycling.
Forests store immense amounts of carbon in biomass and soils, and mitigate climate change by absorbing atmospheric carbon dioxide. We use large-scale experiments, computer models, and remote sensing to evaluate how and why disturbance and succession (i.e., forest age) affect the carbon cycle. We are particularly interested in what ecological characteristics lead to greater and more stable carbon sequestration in the face of accelerating disturbance occurrence from insect pests, fungal pathogens, extreme weather, and fire. Ongoing work focuses on understanding how different disturbance types and varying disturbance severities — causing low to high tree mortality — alter the carbon cycle. We’re also interested in understanding why many old forests, counter to theoretical expectations, sustain high rates of carbon sequestration. This work is supported by two National Science Foundation awards (1655095, 1856319) conducted at the University Michigan Biological Station, and engages undergraduate and graduate student and postdoc collaborators.
Next generation remote sensing of forest structure-function interactions.
Leaf and stem arrangements and densities within forest canopies provide information about ecosystemfunctioning. Long-used measures of leaf area, for example, broadly predict forest growth and animal habitat suitability. Newer, ground-, air-, and space-borne 3-dimensional measurements of forest structure may be even more potent indicators of ecosystem functioning. This research thrust aims to use ecological theory and knowledge, the latest remote sensing tools, and computer models to develop, interpret, and apply a next generation of ecologically relevant forest structural metrics. Such metrics could prove useful to forest adaptive management in response to disturbance and climate change, the prediction of forest growth and yield, and habitat characterization. Our initial work was supported by the National Science Foundation, Emerging Frontiers (1550657), and continues with a recent award from NASA’s Decadal Survey through partnerships with the National Ecological Observatory Network’s (NEON) Keith Krause and Rochester Institute of Technology’s Jan Van Aardt. Image credit: Daulton White, lab resident artist biologist.
Ameriflux Core Site: University of Michigan Biological Station.
For over 20 years, the University of Michigan Biological Station Ameriflux site has supplied carbon cycling and climate data to researchers worldwide. These data are used by modelers, remote sensing scientists, observationalists, and other investigators from across the globe to evaluate large spatial scale carbon cycling patterns, parameterize and evaluate simulation (including climate) models, and gauge the capacity of northern temperate forests to sequester carbon. As an Ameriflux Core Site supported by the Department of Energy, we help collect, deliver, and synthesize data for two co-located research forests: US-UMB and US-UMd. Established in 1998, US-UMB supplies carbon cycling data for a 100-yr-old secondary forest and US-UMd, launched in 2007, measures carbon fluxes originating from an experimental forest in which a third of all trees were killed to simulate a moderate severity disturbance, similar to that which occurs from insects. Our team collects complementary on-the-ground carbon cycling data, which is openly available via Ameriflux. Data from our site have contributed to hundreds of research papers.
Carbon dioxide and methane exchange in a tidal freshwater marsh.
Wetlands take up carbon dioxide and store large amounts of carbon, while releasing methane, a potent greenhouse gas. The environmental and biological controls over the exchange of greenhouse gases between wetlands and the atmosphere, however, are numerous, complex, and do not necessarily parallel those of upland terrestrial ecosystems, which are more thoroughly studied. This research, supported by the Department of Energy, engages a continent-wide network of meteorological “flux” towers on the east and west coasts of North America to elucidate what controls greenhouse gas emissions and uptake in tidal wetlands. We partner with numerous sites, institutions, and researchers on both coasts, while maintaining our data collection from within a restored, early successional marsh at the Rice Rivers Center, adjoining the James River.