Stream dissolved organic matter bioavailability and composition in watersheds underlain with discontinuous permafrost

Kelly L. Balcarczyk; Jeremy B. Jones; Rudolf Jaffe; Nagamitsu Maie

doi:10.1007/s10533-009-9324-x

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Stream dissolved organic matter bioavailability and composition in watersheds underlain with discontinuous permafrost

Formally Refereed

Authors:

Kelly L. Balcarczyk, Jeremy B. Jones, Rudolf Jaffe, Nagamitsu Maie

Year:

2009

Type:

Scientific Journal

Station:

Pacific Northwest Research Station

DOI:

https://doi.org/10.1007/s10533-009-9324-x

Source:

Biogeochemistry. 94: 255-270

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Abstract

We examined the impact of permafrost on dissolved organic matter (DOM) composition in Caribou-Poker Creeks Research Watershed (CPCRW), a watershed underlain with discontinuous permafrost, in interior Alaska. The stream draining the high permafrost watershed had higher DOC and dissolved organic nitrogen (DON) concentrations, higher DOCDON and greater specific ultraviolet absorbance (SUVA) than the streams draining the low and medium permafrost watersheds. All sites had a high proportion of humic components, a low proportion of protein components, and a low fluorescence index value (1.3 - 1.4), generally consistent with terrestrially derived DOM. Principal component analysis revealed distinct groups in our fluorescence data determined by diagenetic processing and DOM source. Our results indicate that the degradation of permafrost in CPCRW will result in a decrease in DOC and DON concentrations, a decline in DOC DON, and a reduction in SUVA, possibly accompanied by a change in the proportion of bioavailable DOC.

Keywords

Bioavailability, boreal forest, discontinuous permafrost, dissolved organic matter, fluorescence, thermokarst

Citation

Balcarczyk, K.L.; Jones, J.B., Jr.; Jaffe, R.; Maie, N. 2009. Stream dissolved organic matter bioavailability and composition in watersheds underlain with discontinuous permafrost. Biogeochemistry. 94: 255-270.