Impacts of historical ditching on peat volume and carbon in northern Minnesota USA peatlands

Liam Krause; Kevin J McCullough; Evan S Kane; Randall K Kolka; Rodney A Chimner; Erik A Lilleskov

doi:10.1016/j.jenvman.2021.113090

Impacts of historical ditching on peat volume and carbon in northern Minnesota USA peatlands

J Environ Manage. 2021 Oct 15:296:113090. doi: 10.1016/j.jenvman.2021.113090. Epub 2021 Jul 10.

Authors

Liam Krause¹, Kevin J McCullough², Evan S Kane³, Randall K Kolka⁴, Rodney A Chimner⁵, Erik A Lilleskov⁶

Affiliations

¹ Michigan Technological University, 1400 Townsend Drive, Houghton, MI, 49931, USA. Electronic address: lmkrause@mtu.edu.
² USDA Forest Service, Northern Research Station, 1 Gifford Pinchot Dr., Madison, WI, 53726, USA. Electronic address: Kevin.McCullough@usda.gov.
³ Michigan Technological University, 1400 Townsend Drive, Houghton, MI, 49931, USA; USDA Forest Service, Northern Research Station, 410 MacInnes Dr., Houghton, MI, 49931, USA. Electronic address: eskane@mtu.edu.
⁴ USDA Forest Service, Northern Research Station, 1831 Hwy 169 E., Grand Rapids, MN, 55744, USA. Electronic address: Randall.K.Kolka@usda.gov.
⁵ Michigan Technological University, 1400 Townsend Drive, Houghton, MI, 49931, USA.
⁶ USDA Forest Service, Northern Research Station, 410 MacInnes Dr., Houghton, MI, 49931, USA. Electronic address: erik.a.lilleskov@usda.gov.

PMID: 34256296
DOI: 10.1016/j.jenvman.2021.113090

Abstract

Peatlands play a critical role in terrestrial carbon (C) storage, containing an estimated 30% of global soil C, despite occupying only 3% of global land area. Historic management of peatlands has led to widespread degradation and loss of important ecosystem services, including C sequestration. Legacy drainage features in the peatlands of northern Minnesota, USA were studied to assess the volume of peat and the amount of C lost in the ~100 years since drainage. Using high-resolution Light Detection and Ranging (LiDAR) data, we measured elevation changes adjacent to legacy ditches to model pre-ditch surface elevations, which were used to calculate peat volume loss. We established relationships between volume loss and site characteristics from existing geographic information systems datasets and used those relationships to scale volume loss to all mapped peatland ditches in northern Minnesota (USA). We estimated that 0.165 ± 0.009 km³ of peat have been lost along almost 4000 km of peatland ditches. Peat loss upslope of ditches was significantly less than downslope (P < 0.001). Mean width of the entire ditch-effect zone was 333 ± 8.32 m. Using our volume loss estimates, literature estimates of oxidation, and mean bulk density and peat C% values from Minnesota peatlands, we calculate a total historic loss 3.847 ± 0.364 Tg C. Assuming a constant oxidation rate during the 100 years since drainage, euic and dysic peatlands within the ditch effect zone have lost 0.26 ± 0.08 and 0.40 ± 0.13 Mg C ha^-1 yr^-1, respectively, comparable to IPCC estimates. Our spatially-explicit peat loss estimates could be incorporated into decision support tools to inform management decisions regarding peatland C and other ecosystem services.

Keywords: Carbon emissions; Ditching; GIS model; Minnesota peatlands; Peat volume loss; Wetland drainage.

MeSH terms

Carbon* / analysis
Ecosystem
Minnesota
Soil*

Substances

Soil
Carbon