Deeper snow increases the net soil organic carbon accrual rate in moist acidic tussock tundra: 210 Pb evidence from Arctic Alaska

• Main Authors: DeFranco, Karyn C., Ricketts, Michael P., Blanc-Betes, Elena, Welker, Jeffrey M., Gonzalez-Meler, Miquel A., Sturchio, Neil C.
• Format: Dataset
• Language: unknown
• Published: Taylor & Francis 2020
• Subjects: 59999 Environmental Sciences not elsewhere classified; FOS Earth and related environmental sciences; 39999 Chemical Sciences not elsewhere classified; FOS Chemical sciences; Ecology; FOS Biological sciences; 69999 Biological Sciences not elsewhere classified; Marine Biology; Science Policy; Arctic; Global warming; permafrost; Tundra; Alaska
• Online Access: https://dx.doi.org/10.6084/m9.figshare.12988267; https://tandf.figshare.com/articles/dataset/Deeper_snow_increases_the_net_soil_organic_carbon_accrual_rate_in_moist_acidic_tussock_tundra_sup_210_sup_Pb_evidence_from_Arctic_Alaska/12988267

The net change in the carbon inventory of arctic tundra remains uncertain as global warming leads to shifts in arctic water and carbon cycles. To better understand the response of arctic tundra carbon to changes in winter precipitation amount, we investigated soil depth profiles of carbon concentration and radionuclide activities ( 7 Be, 137 Cs, 210 Pb, and 241 Am) in the active layer of a twenty-two-year winter snow depth manipulation experiment in moist acidic tussock tundra at Toolik Lake, Alaska. Depth correlations of cumulative carbon dry mass (g cm −2 ) vs. unsupported 210 Pb activity (mBq g −1 ) were examined using a modified constant rate of supply (CRS) model. Results were best fit by two-slope CRS models indicating an apparent step temporal increase in the accumulation rate of soil organic carbon. Most of the best-fit model chronologies indicated that the increase in carbon accumulation rate apparently began and persisted after snow fence construction in 1994. The inhomogeneous nature of permafrost soils and their relatively low net carbon accumulation rates make it challenging to establish robust chronologic records. Nonetheless, the data obtained in this study support a decadal-scale increase in net soil organic carbon accumulation rate in the active layer of arctic moist acidic tussock tundra under conditions of increased winter precipitation.