Proposed projects:

Testing the progressive nitrogen limitation hypothesis with stable nitrogen isotopes in tree rings

Quantification of soil CO₂ priming under elevated CO₂

Ongoing projects:

Rhizosphere priming effects on soil N availability: the role of root exudates in coupling ecosystem C and N cycles under elevated CO₂

Effects of nitrogen deposition on fine-root lifespan

Molecular-level changes in soil organic matter structure with global warming

Investigation of intraday variations of aerosol chemical composition in support of the biogenic emissions project.

Inverse ¹⁴C labeling to understand the mechanisms of carbon input and retention in soils under elevated CO₂.

Long-term analyses of carbon sequestration in a loblolly pine –hardwood forest growing under elevated CO₂

Reducing Uncertainty In Current And Projected Carbon Sequestration In Southeastern US

Soil carbon sequestration, turnover, and chemistry after twelve years of CO₂ fumigation at the Duke Forest FACE experiment

Reduced Atmospheric Methane Consumption by Temperate Forest Soils Under Elevated Atmospheric CO₂: Causative Factors

Completed projects:

Controls on the isotopic composition of fixed CO₂ and ecosystem respired CO₂ in southeastern pine forests

Detection and quantification of photosynthetic signal in soil respiration of contrasting biomes

Continuous Measurements and Modeling of Subsurface CO₂ Production Rates.

Quantification of the effects of elevated atmospheric CO₂ and nutrient amendments on forest floor CO₂ efflux.

The Role of Nitrogen, Phosphorus and New Carbon Availability in the Turnover and Storage of Soil Organic Carbon: Investigating Unexplored Mechanisms Underlying Impacts of Global Environmental Change

LIFT remote measurements of photosynthetic competence in terrestrial ecosystems

Measurements and Modeling of Net Carbon Exchange over Southeastern Loblolly Pine Plantation at the Duke Forest AmeriFlux Site

The role of canopy structure in variability of water and heat fluxes from forested watersheds

Changes in nitrogen cycling as a result of forest growth at high CO₂

Changes in Soil Carbon Storage with Forest Growth under Free-Air CO₂ Enrichment

Relative Transipration Rates between FACE High CO₂ and Control Plot Plants Using d¹⁸O and dD Measurements

Carbon and nutrient flow through multiple trophic levels in CO₂-enriched plant communities

Carbon storage in CO₂-enriched plant systems: belowground processes

Greenhouse Gas (N₂O, CH₄) Exchange and N Cycling Dynamics in a CO₂-Fertilized (FACE) Temperate Forest

Analysis of the C budget of the FACE site using isotopic techniques

Changes in Soil Respiration, Soil pCO₂, and Rock Weathering accompanying forest growth at high CO₂, using Free-Air CO₂ Enrichment

FACE Site Radon Gas Exchange

Control of Net Ecosystem exchange at an old field, a Pine plantation, and a Hardwood forest under identical climatic and edaphic conditions

The role of root exudates in ameliorating nutrient limitation and understanding carbon sequestration

Effects of elevated CO₂ on the components of ecosystem respiration using stable isotopes

The effects of global climate change on carbon transport to groundwater under forest vegetation in the Free - Air CO₂ Enrichment (FACE) experiment at the Duke Forest

Effects of elevated CO₂ on soil weathering and chemistry of soil waters

Changes in belowground carbon and nitrogen pools and fluxes

Effects of elevated CO₂ on forest N cycling: Assessment with large-scale ¹⁵N tracers and modeling

A preliminary test of CO₂ effects on ¹⁸O fractionation

Soil carbon budget in Northern forests

The effects of CO₂-enrichment on the organic composition of plant tissues: Implications for carbon preservation and food web utilization

Direct measurements of the O₂/CO₂ stoichiometry in terrestrial ecosystems

Isotopic partitioning of soil effluxes in a pine plantation under various CO₂ concentrations

Analysis of oxygen and carbon isotopes in cellulose extracted from trees grown under enriched CO₂

Measurement of soil gas diffusivity at the FACE site

Direct assessment of organic nitrogen use by fungi under ambient and elevated CO₂

Elevated CO₂ and N-fertilization effects on foliar metal concentration and nitrate assimilation in loblolly pine and sweetgum