Root ingrowth in the bog.

Given the difficulty of distinguishing between living and dead roots in the anaerobic bog, root ingrowth cores constructed of rigid polypropylene tubes and filled with commercial peat from a nearby bog are being used to capture newly-grown roots seasonally, across microtopographic positions, and throughout the peat profile.

Upon return to the laboratory, roots are removed from the peat, sorted by species, and separated into absorptive (first three root orders) and transport (4+ orders) fine roots, scanned for morphological characteristics, and analyzed for chemical composition.

We hypothesized that root growth would increase with warming and drying, but that this response would be species-specific. Dr. Avni Malhotra found that warming strongly increased ericaceous shrub root-length production, and larch root biomass production, but that the response was driven by drying of the peat.


Malhotra A, Brice D, Childs J, Graham JD, Hobbie EA, Vander Stel H, Feron SC, Hanson PJ, Iversen CM. 2020. Peatland warming strongly increases fine-root growth. PNAS 117: 17627 – 17634.  See more here.

Related Publications.

Griffiths NA, Hanson PJ, Ricciuto DM, Iversen CM, Jensen AM, Malhotra A, McFarlane KJ, Norby RJ, Sargsyan K, Sebestyen SD, Shi X, Walker AP, Ward EJ, Warren JM, Weston DJ. 2017. Temporal and spatial variation in peatland carbon cycling and implications for interpreting responses of an ecosystem-scale warming experimentSoil Science Society of America Journal 81: 1668-1688.

Hanson PJ, Griffiths NA, Iversen CM, Norby RJ, Sebestyen SD, Phillips JR, Chanton JP, Kolka RK, Malhotra A, Oleheiser KC, Warren JM, Shi X, Yang X, Mao J, Ricciuto DM. 2020. Rapid Net Carbon Loss From a Whole-Ecosystem Warmed PeatlandAGU Advances 1: e2020AV000163.

See associated press here.

Data Sets.

Malhotra, A., D.J. Brice, J. Childs, H.M. Vander Stel, S.E. Bellaire, E. Kraeske, S.M. Letourneau, L. Owens, L.M. Rasnake, C.M. Iversen. 2020. SPRUCE Production and Chemistry of Newly-Grown Fine Roots Assessed Using Root Ingrowth Cores in SPRUCE Experimental Plots beginning in 2014. Oak Ridge National Laboratory, TES SFA, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.

This research is funded by the Office of Biological and Environmental Research in the U.S. Department of Energy’s Office of Science.

Related projects.

Scroll to Top