Research Foci

Our overarching goal is to:

  • Integrate feedbacks between the three major processes governing the critical zone -- the water cycle, the mineral cycle, and the carbon cycle ...
  • within contrasting land uses...
  • as materials are transported and transformed across geophysical boundaries that traditionally separate scientific disciplines  (i.e. sapprolite → topsoils → aquifers → riparian floodplains → wetlands → river networks → salt marshes → estuaries → sea). 

Our overall hypotheses are that:

  • Hydrological, chemical, & biological processes that produce and mix mineral surfaces and organic carbon are rate limiting to watershed-scale chemical weathering, soil production & carbon sequestration.
  • Humans accelerate rates of carbon-mineral mixing, resulting in anthropogenic carbon sequestration significant to local, regional & global budgets

Our multi-disciplinary objectives

are described below.

Conceptual model illustrating our hypothesis that processes that mix minerals and carbon are rate limiting to watershed-scale chemical weathering, soil production & carbon sequestration.  Credit: Aufdenkampe & Yoo.

Move laterally: Calhoun | Catalina-Jemez | Christina | Eel | IML | Luquillo | Reynolds | Sierra

1. Carbon-mineral-microbe-water interactions and feedbacks to reaction rates

Contact: Anthony Aufdenkampe

Q1.1. What determines OC complexation potential?

Q1.2. What is the role of microorganisms in the formation, aging, and maintenance of Fe oxide-OC complexes?

2. Co-evolution of Critical Zone Structure, Hydro-Bio-Geo-Chemical Function and Carbon Complexation

Contact: Kyungsoo Yoo, Paul Imhoff

Q2.1: How do physical and hydro-chemical weathering produce mineral SA and pore structure within the critical zone and how are these processes altered by biological C cycling and landscape redistribution of water and solutes?

Q2.2: How do increases in mineral SA and pore space from mineral weathering alter water retention, water and gas transport, and carbon-mineral interactions? Do these changes provide a positive feedback that increases rates of mineral weathering?

Q2.3: How do agricultural practices that physically disturb colluvial soil alter the C-cycle, moisture retention, and mineral weathering?

3. Mobilization, Transport, and Depositional Controls on Carbon-Mineral Supply, Mixing, and Burial.

Contact: Jim Pizzuto, Rolf Aalto

Q3.1: What are the dominant water and DOC source areas, flowpaths, and residence times (transit times) across CZO watersheds and stream networks?

Q3.2. How does surface/subsurface water exchange influence the movement of DOC at different scales and in different environments?

Q3.3. What are the transport pathways and residence times of mineral-carbon complexes as they move through the Piedmont uplands, the tidally influenced Coastal Plain, and the estuary?

4. Saprolite to Sea Integration of Erosion-Driven Caron Sequestration

Contact: Anthony Aufdenkampe, J. Denis Newbold

Q4.1 How are erosion-deposition processes linked to alteration of net CO2 fluxes between land and atmosphere?