Earth Sciences Division (ESD) Department of Energy (DOE) Lawrence Berkeley National Laboratory (LBNL)

Earth Sciences Division Staff: Caitlin E. Hicks Pries

Caitlin Pries

Caitlin E. Hicks Pries

Postdoctoral Research Associate

Climate Sciences Department



Phone: 413-530-8481

Fax: 510-486-5686


Biographical Summary

I am broadly interested in the carbon cycle and how the carbon balance of ecosystems is determined by the interplay of soil and plant processes with climate. At LBL, I will be focusing on deep soil organic carbon and what processes determine its stability and how those stabilization processes are affected by climate change.

I received both a masters degree in Soil and Water Science and a doctorate degree in Biology from the University of Florida in Gainesville, FL. For my masters, I studied whether the sediments of restored seagrass and mangrove ecosystems were actively accumulating carbon and which plant sources were contributing to their soil carbon.  For my PhD, my main project was partitioning ecosystem respiration of tundra undergoing permafrost thaw into plant and soil sources. Warming in the subarctic is causing permafrost to thaw, which causes increased ecosystem respiration rates, meaning more CO2 is respired to the atmosphere where it can cause further warming. The source of that ecosystem respiration increase partly determines what the implications are for our climate. I found that both plant and respiration of old, deep soil carbon were increased with both natural permafrost thaw and experimentally-induced warming. My PhD also included measuring soil carbon accumulation rates in soils undergoing permafrost thaw and a decomposition study. The decomposition study used a common substrate to measure changes in the decomposition environment that occur with natural thaw and experimental warming and a common garden study to understand how changes in plant community composition that occur with thaw may affect the quality and quantity of carbon inputs to the soil.

In my research, I use carbon isotopes as tools. At LBL, I will be using plant litter enriched in 13C and 15N to trace the fate of organic matter in deep soils. For my masters, I used the δ13C of various plants (mangroves, seagrasses, phytoplankton, Spartina) to trace which of these plants were contributing to sediment organic carbon. For my PhD, I used the δ13C and ∆14C (radiocarbon) of respired CO2 to calculate the contributions of plant and soil respiration to total ecosystem respiration. I also used the radiocarbon values of soil organic carbon to model carbon accumulation rates.

Research Focus

How the carbon cycle of terrestrial soils responds to climate change.


  • Ph.D. (2012) Biology, University of Florida
    Dissertation: Carbon cycle changes in a changing climate: Effects of permafrost thaw on ecosystem respiration, soil C accumulation, and decomposition.
    Advisor: Edward A. G. Schuur
  • M.S. (2007) Soil and Water Science, University of Florida
    Thesis:  Sediment organic carbon pools and sources in a recently constructed mangrove and seagrass ecosystem.
    Advisor: K. Ramesh Reddy
  • B.A. (2004) Biology and Environmental Studies (summa cum laude), Middlebury College
    Independent Project: Stochastic modeling of Caretta caretta populations in the Southeastern United States.
  • Field/Lab Courses: Radiocarbon in Ecology and Earth System Science, UC Irvine, 2009
    Semester in Environmental Science, Woods Hole Marine Biological Lab, 2003

Professional Experience

  • 2007-2012 Doctoral Student, Effects of permafrost thaw and warming on carbon cycling in Alaskan tundra, Dr. Ted Schuur, University of Florida
  • 2005-2007 Masters Student, Carbon pools and sources in a constructed mangrove and seagrass habitat, Dr. K. Ramesh Reddy, University of Florida
  • 2004-2005 Research Assistant, Landscape ecology of urban ecosystems and river/savanna boundaries, Drs. Steward Pickett and Mary Cadenasso, Cary Institute of Ecosystem Studies
  • 2004 Undergraduate Research Project, Stochastic modeling of Caretta caretta populations in the Southeastern United States, Dr. Stephen Trombulak, Middlebury College
  • 2003 Undergraduate Research Project, Nutrient limitations on peat decomposition and nutrient loading in Atlantic White Cedar Swamps, Semester in Environmental Science, Woods Hole Marine Biological Laboratory
  • 2003 Sea Turtle Intern, Monitoring sea turtle nesting and hatching, Bald Head Island Conservancy, Bald Head Island, NC
  • 2002 REU Intern, Marine Benthic Ecology, Dr. Les Watling, Darling Marine Center, University of Maine
  • 2001  Research Assistant, Pollination ecology, Dr. Helen Young, Middlebury College

Grants and Fellowships

  • 2011 University of Florida Graduate Student Research Abroad Program, The effect of permafrost warming on arctic carbon balance, $9,995
  • 2010 National Science Foundation Doctoral Dissertation Improvement Grant, Carbon cycle changes in a changing climate: Using 13C and 14C to partition ecosystem respiration in tundra undergoing permafrost thaw, $14,941
  • 2010 Denali National Park Murie Science and Learning Center Research Fellowship, Carbon cycle changes in warming Alaska: Do plants or soil microbes drive changes in ecosystem respiration?, $4,580
  • 2009 Science Partners in Inquiry-based Collaborative Education (SPICE) Fellowship, National Science Foundation GK-12 Program, $33,000 stipend and tuition
  • 2007 Alumni Graduate Fellowship, University of Florida, 2 years of $18,000 stipend and tuition


  • 2012 Graduate Student Mentoring Award, University of Florida, $500
  • 2012 Terrestrial Ecosystem Science Meeting Student Travel Grant, U.S. Department of Energy, $1,000
  • 2012 Departmental Service Award, University of Florida, Biology Department, $150
  • 2011  Abisko Scientific Research Station Scholarship, $1,300
  • 2008 Best Masters Thesis, University of Florida, College of Agriculture and Life Sciences, $600
  • 2007    Best Masters Thesis, University of Florida, Soil and Water Science Department, $150
  • 2007    Grinter Fellowship, University of Florida, $6,000
  • 2006    William K. Robertson Fellowship, University of Florida, Soil and Water Science Department, $1,000
  • 2006 Honorable Mention, Student Poster Contest at the 3rd National Conference on Coastal and Estuarine Habitat Restoration
  • 2006 Best Student Poster at the 7th Annual Soil and Water Science Department Research Forum, $500
  • 2004 Phi Beta Kappa, Beta Chapter of Vermont
  • 2004 Elbert C. Cole ‘15 Memorial Fund Prize for Outstanding Biology Student, Middlebury College, $2,000
  • 2000 Henry David Thoreau Scholarship for Environmental Studies, $30,000
  • 2000  Big Y Scholarship, $2,000

Teaching Experience

  • 2012, 2008 Teaching Assistant, Ecology, University of Florida
  • 2011, 2008 Teaching Assistant, Biological Sciences II, University of Florida
  • 2009-2011 SPICE Fellow, Developed lessons and taught eighth grade Physical Science, University of Florida and Westwood Middle School
  • 2006  Teaching Assistant, Wetland Biogeochemistry, University of Florida
  • 2004  Teaching Assistant, Ecology, Middlebury College
  • 2003 Sea Turtle Intern, Taught children and general public about sea turtle biology and coastal ecology, Bald Head Island Conservancy, Bald Head Island, NC

Guest Lectures

  • 2012 Ecology, Energy flow through ecosystems, University of Florida
  • 2010 Ecosystem Ecology, Soil organic carbon, University of Florida
  • 2008 Ecology, Physiological ecology, University of Florida


  • 2010-2012 Senior Thesis and Independent Project Advisor to Elaine Pegoraro, University of Florida
  • 2008-2011 Supervisor to Undergraduate Volunteers, University of Florida
  • 2008-2009 Senior Thesis Advisor to Chase Mason, University of Florida


  • Professional
    • 2011-present  Reviewer, JGR-Biogeosciences
  • Departmental
    • 2011-2012 Oversaw undergraduate research assistantship program and organized undergraduate research symposium, Department of Biology, University of Florida
    • 2011-2012 Graduate committee representative, Department of Biology, University of Florida
    • 2010-2011 Seminar committee representative, Department of Biology, University of Florida
    • 2009-2010 Secretary, Biology Graduate Student Association, University of Florida
    • 2008-2009 Student/Faculty Liaison, Botany Graduate Student Association, University of Florida
  • Community
    • 2006-present Alumni Interviewer, Middlebury College Admissions
    • 2009-2012 Science Fair Judge, Alachua County School District, Florida

Professional Society Memberships

  • 2009-Present American Geophysical Union
  • 2007-Present Ecological Society of America