Research
We work on a variety of projects studying human influences on ecosystem structure and function in terrestrial ecosystems.
Small Forests
The majority of temperate deciduous forests are small forests embedded across developed landscapes and surrounded by high population density. In the U.S., temperate deciduous forests are located in the most densely populated region (i.e., east coast) with various land-use legacies and current anthropogenic pressures. The inherent heterogeneity among these small forests necessitates a large-scale collaborative approach to understanding ecosystem structure and function across regions. Thus, we work within the long-term urban forest ecology network, the FRAME, established in 2008 by researchers at the University of Delaware and the USDA Forest Service. We study the effects of urbanization and non-native plant invasion on plants and soils.
Plant Physiology and Biochemistry
Research on red maple tree physiology, biochemistry, and morphology is led by PhD candidate, Covel McDermot. We are investigating how trees respond to urbanization intensity by comparing red maple trees growing in forests embedded within a small (Newark, DE) versus large (Philadelphia, PA) city. Red maple saplings were utilized as biomonitors to isolate the potential effects of aboveground (e.g., ozone) versus belowground (e.g., heavy metals, drought) stressors on tree physiology and biochemistry.
Tree-soil Interactions
Research on how tree canopy structure influences soil carbon and nitrogen is led by Post-Doc, Carl Rosier. We are assessing whether two tree species with differing canopy structures alter soil carbon (C) and nitrogen (N) stocks within both surface (< 20 cm) and subsurface (> 20 cm) soils across an urbanization gradient. Additionally, we are studying soil microbial community composition and diversity across urban, suburban, and rural forests. Differences in soil moisture and temperature across the urbanization gradient are expected to drive observed shifts in bacterial community dynamics.
Non-Native Plant Invasion
In the FRAME network, we are studying how non-native plant invasion alters herbaceous species composition and forest regeneration, work led by PhD student, Eric Moore. To elucidate controls on species dynamics, we are experimentally testing easy-to-implement, cost-effective non-native plant management techniques that reduce secondary invasion and enhance soil nutrient sinks post-removal.
Sea Level Rise
Small forests across the mid-Atlantic region are subject to the effects of sea level rise over the next century. Along with plant invasion and urbanization, forests adjacent to developed landscapes and projected to experience salt water intrusion experience multiple environmental pressures. We are working with colleagues at UM-College Park and UM-Eastern Shore to map the extent of forests squeezed by urbanization and sea level rise projections in the Delmarva region, and to assess the extent of non-native plant invasion in these forests threatened by development and climate alterations.
Residential Lawns
Lawns have a substantial influence on biogeochemical cycling in urban environments due to large inputs of water and nutrients to establish and maintain this greenspace. Turfgrass is now the largest irrigated crop in the United States representing an important component of local and regional elemental cycles. Research in our lab focuses on understanding the controls on carbon and nitrogen cycling in residential lawns in cities across the US. We are collaborating with many PIs across the US to understand how management practices influence ecosystem structure (i.e., plant, insect, and bird community composition) and function (e.g., soil C and N cycling) as part of the NSF-funded macrossytems project titled “Alternative futures for the American Residential Macrosystem” lead by Peter Groffman at CUNY Advanced Science Research Center.
