Research

swirlOur group's research within the field of ecosystem ecology and plant physiological ecology focuses on forest carbon cycling. 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 slowing climate change. Rates of forest carbon uptake (i.e., photosynthesis) and release (i.e., respiration) are affected by multiple variables, including land-use history, ecosystem structure, 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 our research.

Ongoing research includes:

1) Forest canopy structure-carbon cycling interactions (NSF EAGER-NEON supported). Canopy structure, an ecosystem feature that can be broadly characterized using remote sensing technologies, is a well-established determinant of forest carbon storage, with the quantity of canopy leaves a universal predictor of carbon storage that is incorporated into models used to forecast how the forested landscape affects climate. Recent work from a limited number of sites shows that the arrangement of leaves within a volume of canopy may be as influential to forest carbon storage as leaf quantity. Results from these studies suggest that leaf quantity and arrangement provide unique, complementary information about the underlying biological controls on forest carbon storage. Thus, coordinated measurements of both leaf quantity and arrangement within the canopies of a diverse array of forests may lead to substantially improved modeled estimates of carbon storage by the Nation’s forests. In support of this goal, work here uses sites from the National Ecological Observatory Network (NEON) to evaluate whether canopy structural complexity, or the spatial variability in leaf arrangement within a canopy, is a global predictor of forest carbon storage within and across sites varying in physical structure, species composition and diversity, and climate.

2) Carbon fluxes this image floats to the leftand storage in forests (DOE Core Site, NSF LTREB, and VCU supported). This component of my research explores how and why forest carbon cycling changes in response to climate, disturbance, and ecological succession. We use multiple techniques to quantify forest carbon fluxes and storage, measuring processes such as photosynthesis and respiration at the leaf level, and also the growth and carbon uptake 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. This work presently focuses on forest ecosystems in the upper Midwest and the mid-Atlantic, and includes upland and wetland forests.

3) Mechanisms sustaining high rates of forest productivity in old forests (DOE Core Site and NSF LTREB supported).
Growing evidence indicates that many old forests, contrary to early ecological theory, store carbon for centuries; however, the mechanisms responsible for sustained high rates of forest productivity are largely unknown. At the University of Michigan Biological Station, we are examining how forest structural changes that occur over time intervals relevant to ecological succession (i.e., decades) are linked to sustained high rates of carbon storage. Recent work at our site has demonstrated that increases in forest canopy structural and biological diversitthis image floats to the lefty play integral roles in maintaining productivity as forests age. This work has important implications for how old forests, once thought to sequester carbon at nominal rates, are managed for carbon storage.

4) Controls on carbon storage in urban ecosystems.
The goal of this research program is to identify the physical and human constraints on carbon cycling in urban ecosystems. Rates of terrestrial carbon storage are sensitive to human disturbance, and consequently vary as the footprint and intensity of human dominance shifts. Several studies have quantified spatial variation in urban carbon storage. However, few have directly examined the importance of human intervention in shaping trajectories of carbon storage across complex, heterogeneous landscapes that comprise urban areas. Recent work conducted locally in Richmond and now published (see "Publications") with undergraduate collaborators at VCU indicates that soil carbon storage in urban ecosystems is strongly correlated with human demography (e.g., neighborhood affluence). We also found that partially restored ecosystems in urban areas exhibit rapid functional resilience following human abandonment, with rates of carbon storage potentially increasing following vacancy.

Chris Gough 2016, Updated June 1, 2016| cmgough@vcu.edu