• >> Home
• > Research
• > Publications
• > Teaching
• > Curriculum Vitae
• > In the News
• > For Students
• > Contact

Research

My research within the field of ecosystem ecology and plant physiological ecology focuses on understanding the relationship between forest carbon cycling and global change. Forests are an important component of the global carbon cycle, storing carbon in biomass, detritus, and soils. Plants remove carbon dioxide from the atmosphere, thereby absorbing anthropogenic greenhouse gas emissions and potentially slowing climate change. The rate of forest carbon uptake (i.e., photosynthesis) and release (i.e., respiration) is affected by multiple variables, including land-use history, disturbance, succession, climate, soil fertility, and management. Exploration of these controls on carbon cycling processes at the leaf, whole-plant, and ecosystem scales is the focus of my research.

I am currently co-principal investigator of a project entitled “Disturbance, Succession, and Forest Carbon Dynamics: a Large-Scale Manipulation at the University of Michigan Biological Station”, which is supported by the Department of Energy's National Institute for Climate Change through 2011 and operates within the Ameriflux Network of long-term carbon cycle research. Our ecosystem-scale experiment, which was initiated in Spring 2008, will speed the successional transition from an even-aged aspen-dominated forest to an uneven-aged mixed deciduous-conifer forest, and will result in major changes in plant species composition, forest age distribution, canopy structure, detritus production, and other variables that will affect a broad array of ecological processes at all trophic levels, including the carbon cycle.

Ongoing research includes:

1) Quantifying and predicting forest carbon fluxes and storage. This component of my research explores carbon cycling in forests over time and in response to a climate, disturbance, and succession. We use multiple techniques to quantify forest carbon fluxes and storage, monitoring processes such as photosynthesis and respiration at the leaf level, and also the growth and production of forests at the ecosystem scale. Forest carbon flux and storage estimates derived from physiological and ecological data are validated against independently calculated estimates, including those derived from meteorological and modeling methods.

2) Understanding how legacies of disturbance and management affect carbon cycling. Disturbance and management may have profound effects on the long-term trajectory of forest carbon cycling. Collaborators and I recently determined that fire disturbance reduced rates of carbon storage and wood production for several decades following forest regrowth. Also, we showed that disturbance to soils in managed forests affected rates of soil carbon cycling and storage. Similar approaches could be applied to investigating the role that disturbance and management play in modifying carbon cycling processes in other ecosystems, including urban and agricultural.

3) Evaluating the coupling of the nitrogen and carbon cycles. Nitrogen originating from fertilizer applications and atmospheric deposition affects rates of photosynthesis and respiration, and processes affecting carbon allocation. This component of my research seeks to better understand the relationship between these elements, with an emphasis on elucidating changes in carbon cycling processes that occur at the leaf and whole-plant level, and are manifested at the ecosystem level in response to altered nutrition.