Rapid Analysis of Moisture, Carbon and Nitrogen in Peat Cores from Northern Manitoba by Near-infrared Spectroscopy.

Peatlands store 25% of global terrestrial carbon. Peatlands cover 12.3% of Canada’s land area, contain >150 Giga tonnes of carbon, an estimated 60% of Canada’s carbon stock, and mainly occur in Manitoba, Alberta, Saskatchewan and Ontario. Peatlands are threatened by climate change through melting of permafrost, drying, and increase in fire risk. Nonetheless, monitoring of peatlands in Canada is sparse.  Near-infrared spectroscopy (NIRS) can be a tool to facilitate inventorying of carbon and monitoring changes in moisture.  It allows large numbers of samples to be analyzed rapidly and cost-effectively with little sample presentation and with simple-to-use instrumentation.  It may also facilitate decentralized monitoring by remote communities.

Near-infrared spectroscopy was employed for the analysis of moisture, carbon, and nitrogen in 18 cores, up to 2.5 m long, from five peatland sampling sites in the Traditional Territory of the Poplar River First Nation on the east side of Lake Winnipeg, Manitoba.  This study demonstrated that NIRS is effective in determining moisture, carbon, and nitrogen in field-moist, “as is” samples from peatlands using the field-portable Zeiss Corona visible/near-infrared spectrometer. The calibration models between moisture content of samples obtained by oven drying and the spectral data explained 92 to 98% of the variance in moisture content.  The models explained 87% and 77%, respectively, of the variance in carbon and nitrogen on a wet weight basis.  The technology is suggested as a tool for the comprehensive monitoring of peatlands in Canada for response to climate change as well as to increase knowledge of carbon inventories and quality. Using field-portable instruments, peat analysis can be conducted in remote areas, reducing some costs of sample handling and storage.