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Marie-Anne de Graaff

Assistant Professor, Department of Biological Sciences
Year arrived at BSU:   2010

Mailing Address:MA profile pic
Department of Biology
Boise State University
Boise, ID 83725-1515

Office Location:   Science Building, Room 115
Office Number:   208-426-1256
Fax Number: 208-426-1040

E-Mail Address:

Academic Degrees

  • Postdoctoral Research Associate – Biosciences Division, Molecular Microbial Ecology Group, Oak Ridge National Laboratory (2008-2010)
  • Ph.D. – Environmental Science, Wageningen University, the Netherlands (2007)
  • M.Sc. – Nature conservation and development, Wageningen University, the Netherlands (2003)
  • B.Sc. – Forestry and Nature Management, Wageningen University, the Netherlands (2001)

Research Interests

Broadly our lab studies how changes in climate and land-use affect ecosystem processes that drive the global carbon cycle. We are especially interested in the question of how plant roots and soil microorganisms interact to affect soil carbon and nutrient dynamics.


Research projects


At the root of sustainable bioenergy: using genetic variation in root traits to maximize soil carbon sequestration and biomass yields

Collaborators: Julie Jastrow (ANL), Johan Six (UC-Davis), Geoff Morris (University of South Carolina) Funded by USDA-NIFA.

Land use change for bioenergy production can create substantial green house gas emissions through removal of standing vegetation and disturbance of soil carbon pools. With this project we assess: (1) whether shifting C3-dominated nonnative perennial grasslands to C4-dominated native perennial grasslands repay the carbon debt of land-use change by increasing soil carbon sequestration within the early years of establishment; (2) whether increased variation in root traits in species and cultivar mixes of native perennial grasses will enhance biomass production, soil carbon storage and the efficiency of nitrogen (N) cycling (i.e., decrease N losses); and (3) whether energy gain resulting from an increase in soil carbon storage and yield, along with a decrease in nutrient inputs and losses in low-input diverse mixtures of perennial grasses, is sufficient to offset energy gain from relatively greater biomass production in high input monocultures of perennial grasses.


Litter quality controls on the temperature sensitivity of litter and soil organic carbon decomposition

Collaborators: Julie Jastrow (ANL), Stan Wullschleger (ORNL), Melanie Mayes  (ORNL) Funded by DOE

It is uncertain which factors control the temperature sensitivity of litter decomposition. This study aims to examine how decomposition-induced changes in the quantity and quality of litter through time affect the temperature kinetics of decomposition processes. 

Root and soil depth controls on microbial utilization of labile soil carbon inputs

Collaborators: Julie Jastrow (ANL), Chris Schadt (ORNL), Stan Wullschleger (ORNL) Funded by DOE

Root derived labile carbon inputs can mediate decomposition of soil organic carbon via priming of microbial activity. A priming effect can be large or small, and positive or negative, but the mechanisms by which root-carbon controls the magnitude and direction of soil organic carbon priming is poorly understood. With this study we evaluated how subtle versus large differences in labile soil carbon availability affect microbial processing of simulated root exudate inputs and decomposition of soil organic carbon.

Precipitation impacts on soil carbon dynamics in semi-arid grasslands

Collaborators: Kevin Feris (BSU), Matt Germino (USGS), Keith Reinhardt (ISU), Kitty Lohse (ISU) Funded by NSF-EPSCoR

Precipitation shifts are expected to have a large impact on the soil carbon sink in semi arid grasslands of the Intermountain West. With this study we aim to assess how precipitation affects the quantity and quality of both above-and belowground soil carbon inputs and how these changes feed back to alter microbial decomposition processes. The experiments take place at an ecohydrological research site, located in the cold desert at the Idaho National Laboratory, which has been exposed to three precipitation treatments since 1993.


Mycorrhizal fungi in sage-steppe ecosystems

Collaborators: Marcelo Serpe (BSU); Kevin Feris (BSU) Funded by the ID National Guard

Sagebrush is an obligate mycorrhizal species. Cheatgrass invasion may reduce mycorrhizal abundance and change their communities, thereby complicating sagebrush restoration success. With this study we aim to investigate how arbuscular mycorrhizal fungi (AMF) communities and abundance differ between sagebrush and cheatgrass dominated ecosystems, and how invasion by cheatgrass affects plant performance and carbon allocation to AMF in sagebrush seedlings.

Impacts of fuel reduction treatments on plant-soil feedbacks in cheatgrass dominated ecosystems of the Intermountain West 

Collaborators: David Pilliod (USGS), Mike Schinneman (USGS), Anne Halford (BLM). Funded by USGS and BLM

Invasion of Sagesteppe ecosystems by cheatgrass is a large problem in the Intermountain West. With a manipulative field experiment (PI’s Pilliod and Schinneman) we set out to assess how grazing, fuel reduction treatments (i.e. mowing, herbicide application, and a combination of both) and follow-up seedings affect the invasibility of ecosystems by cheatgrass.

SpeakerImpacts of noise pollution on trophic casacades in sage-steppe ecosystems

Collaborators: Keith Reinhardt (ISU), Jesse Barber (BSU)

Birds and bats are important “top-down” predators that provide helpful ecosystem-services such as pollination and predation on herbivorous-insects. Increasing human activities such as noise-pollution associated with energy development are altering bird and bat presence, which could impact ecosystem services, with effects evident across many trophic levels (predators-insects-plants-soil). Since 2014 we quantify the cascading effects of noise-pollution using an experimental approach wherein we broadcast recorded natural-gas-compressor-station noise in sagebrush steppe sites. We study how experimental-noise affects bird and bat abundance and behavior, and how experimentally-induced reduction in predation impacts herbivorous-insect presence and damage, plant physiology, and leaf litter chemistry and decomposition.


Funded by NSF

Reynolds Creek Critical Zone Observatory (RC CZO) is focused on the quantification of soil carbon and the critical zone processes governing it. Most of the world’s terrestrial carbon is found in the critical zone, where it is predominantly stored as soil carbon and sensitive to climate change and land management. Despite its importance, soil carbon remains a large source of uncertainty in both carbon cycling and global climate models. The RC CZO will address the grand challenges of improving prediction of soil carbon storage and flux from the pedon to landscape scale.


 lab group 2015

Marie-Anne de Graaff  PPicture11-300x226I of the lab



Shay Gillette Laboratory coordinator – started 2010

MS. Ecology from Appalachian State University



Xochi CamCYMERA_20150213_114012pos MS-student – started in 2012

Xochi studies how changes in precipitation affect plant-microbe interactions.


HassiHasini_Delvinne_200_200_80auto_s_c1ni Delvinne MS student – Started in 2014

Hassini studies soil carbon stabilization and destabilization processes in the Reynold’s Creek CZO.


Peggy MPeggy Martinez Fall14artinez MS student – Started in 2014

Peggy studies how noise pollution in sage steppe ecosystems impacts litter chemistry and decomposition.

Aislinn JohnsAislinn Johns – started in 2014

Aislinn studies how intra specific variation in switchgrass cultivars impacts soil C and N cycling.


Leslie Nichols – started in 2012: Leslie received a research grant through the IDoTeach program at Boise State University to study how different types of land management affect the success of sagebrush ecosystem restoration projects.

Billy Bringman – started in 2013: Billy received a research grant through the IDoTeach program at Boise State University to study how imazapic applications in sage steppe ecosystems affect native forb performance.

Michael Brucker – started in 2013: Michael studies soil carbon stabilization and destabilization processes in the Reynold’s Creek CZO.

Micki Keiser – started in 2014: Micki studies how noise pollution impacts trophic cascades in sage steppe ecosystems.

Ashlee Webb – started in 2014: Ashlee studies soil carbon stabilization and destabilization processes in the Reynold’s Creek CZO.

Elise Thiel – started in 2014: Elise studies soil carbon stabilization and destabilization processes in the Reynold’s Creek CZO.

Madison Ellis – started in 2014: Madison studies how noise pollution impacts trophic cascades in sage steppe ecosystems.

Riley Johnson – started in 2014: Riley received a research grant through the IDoTeach program at Boise State University to study how noise pollution impacts trophic cascades in sage steppe ecosystems.


Janina Dierks MS student 2012-2014: Janina studied feedbacks between mycorrhizal fungi and sagebrush plants. Now a PhD student at ETH-Zurich.

Jessica van der Veen Undergraduate student   2011: Jessica received an REU-grant to study how altered precipitation regimes in desert ecosystems affect soil carbon storage. Now a researcher at the USGS.

Jamie Hicks Undergraduate student –  2010-2013: Jamie received an REU-grant to study how altered precipitation regimes in desert ecosystems affect soil carbon dynamics. Now a researcher at Simplot.

Ian Duvall Undergraduate student – 2011-2013: Ian studied feedbacks between mycorrhizal fungi and sagebrush plants. Finishing up a degree in secondary education.

Mac Jones Undergraduate student  2012-2014: Mac received a grant through the honors college to study how cattle grazing in ecosystems of the Inter-Mountain West affect soil microbial communities. Now in medical school

Ariane Shannon Undergraduate student  2013-2014: Arianne studied feedbacks between mycorrhizal fungi and sagebrush plants. Now an intern at the Mote Marine Laboratory.

Mary Finnell Undergraduate student2013-2014: Mary studied how intra specific diversity in switchgrass cultivars impacts soil C storage.

Kimberly Tate Undergraduate student  2014: Kimberly studied how intra specific diversity in switchgrass cultivars impacts soil C storage. Now a graduate student at the University of ID.

Trevor Thornton Undergraduate student  2014-2015: Trevor studied soil carbon stabilization and destabilization processes in the Reynold’s Creek CZO.

Jaron Adkins Undergraduate student –  2011-2015: Jaron received a fellowship from the Boise State Student Research Program and studied how land conversion for cellulosic biofuel production affects soil carbon stabilization, how soil biodiversity impacts the carbon cycle, and how changes in soil temperature impacts soil C cycling. Now a PhD student at Michigan State University.

Recent Publications

  • Adkins J., Jastrow J.D., Morris G., Six J., de Graaff M-A. (in revision) Effects of switchgrass cultivars and intraspecific differences in root morphology on soil carbon stabilization.
  • Austreng A., de Graaff M-A., Pellant M., Pierce J., Benner S. (in revision) Large Soil Carbon Losses Follow Cheatgrass Invasion of Sagebrush.
  • de Graaff M-A., Adkins J., Kardol P., Throop H.L. (2015) A meta-analysis of soil biodiversity impacts on the carbon cycle. Soil 1, 257-271.
  • de Graaff M-A., Throop H.L., Verburg P.S.J., Arnone J.A., Campos X. (2014) A synthesis of climate change and vegetation cover effects on biogeochemical cycling in shrub dominated drylands. Ecosystems 5, 931-945.
  • Smith A.P, Marin-Spiotta E., de Graaff M-A., Balser T.C. (2014) Microbial community structure varies across soil organic matter aggregate pools during tropical land cover change. Soil Biology & Biochemistry 77, 292-303.
  • De Graaff M-A., Jastrow J.D., Gillette S., Johns A., Wullschleger S.D.  (2014) Differential priming of soil carbon driven by soil depth and root impacts on carbon availability. Soil Biology & Biochemistry 69, 147-156.
  • De Graaff M-A., Six J., Jastrow J.D., Schadt C.W., Wullschleger S.D.  (2013) Variation in root architecture among switchgrass cultivars impacts root decomposition rates. Soil Biology & Biochemistry 58, 198-206.
  • De Graaff M-A., Schadt C.W., Six J., Schweitzer J.S., Rula K., Classen A.T. (2011) Elevated CO2 and plant species diversity interact to slow root decomposition. Soil Biology & Biochemistry, 43, 2347-2354.
  • De Graaff M-A., Castro H., Classen A.T., Garten C.T. Schadt C.W. (2010) Root exudates mediate plant residue decomposition rates by regulating the microbial community structure. New Phytologist, 188, 1055-1064.
  • De Graaff M-A., Six J., van Kessel C. (2009) Rhizodeposition-induced decomposition increases N availability to wild and cultivated wheat genotypes. Soil Biology & Biochemistry, 41, 1094-1103.
  • Hungate B.A., van Groenigen K.J., Six J., Jastrow J.D., Luo Y., de Graaff M-A., van Kessel C., Osenberg C.W. (2009) Assessing the effect of elevated CO2 on soil carbon: a comparison of four meta-analyses. Global Change Biology, 15, 2020-2034.
  • De Graaff M-A., Six J., van Kessel C. (2008) The impact of long-term elevated CO2 on C and N retention in stable SOM pools. Plant and Soil, 303, 311-321.
  • De Graaff M-A., Six J., van Kessel C. (2007) Elevated CO2 increases rhizodeposition and microbial immobilization of root-derived nitrogen. New Phytologist, 173, 778–786.
  • De Graaff M-A., van Groenigen K.J., Six J., Hungate B., van Kessel C. (2006) Interactions between plant growth and soil nutrient cycling under elevated CO2: a Meta-Analysis. Global Change Biology, 12, 1-15.
  • Van Kessel C., Boots B., de Graaff M-A., Six J. (2006) Soil C and N sequestration in a grassland following 10 years of Free Air CO2 Enrichment. Global Change Biology, 12, 1-13.
  • Van Groenigen K.J., Six J., Hungate B., de Graaff M-A., van Breemen N., van Kessel C. (2006) Element interactions limit soil carbon storage. Proceedings of the National Academy of Sciences, 103, 6571-6574.
  • De Graaff M-A., Six J., van Kessel C. (2006) Prolonged elevated atmospheric CO2 does not affect decomposition of plant material. Soil Biology & Biochemistry, 38, 187-190.
  • Van Groenigen, K.J., de Graaff M-A., Six J., Harris D., Kuikman P., van Kessel C. (2005) The impact of elevated [CO2] on soil C and N dynamics: a meta-analysis. In: Nösberger J, Long SP, Norby RJ, Stitt M, Hendrey GR, Blum H, eds. Managed Ecosystems and CO2 Case Studies, Processes and Perspectives. Berlin Heidelberg, Germany: Springer-Verlag, 373-388.
  • De Graaff M-A., Six J., Harris D., van Kessel C. (2004) Decomposition of soil and plant carbon from pasture systems after 9 years of exposure to elevated CO2: impact on C cycling and modeling. Global Change Biology, 10, 1922-1935.


  • General Biology II (BIOL 192)
  • Ecosystem Ecology (BIOL 497/ 597)
  • Conservation Biology (BIOL 422/ 522)
  • Global Change Biology (BIOL 197)
  • General Ecology (Biol 323)
  • Graduate seminar: “Plant-Soil Relations and Ecosystem Processes under Climate Change” (Biol 597)
  • Graduate seminar: “Global Climate Change and Solutions: ecological, social and economic perspectives” (Biol 597)
  • Graduate seminar: “Agricultural Challenges in the 21st Century: How to Feed 9 Billion People Without Destroying the Earth?” (Biol 597)

Prospective graduate students

I’m happy to receive applications for graduate school. If you like to apply, please write me a short letter outlining why you are interested to work in my lab, how your interests would contribute to the research (see descriptions above) in the ecosystem ecology lab and why you want to go to graduate school. Thanks for your interest!