Skip to Main Content
Seasonal changes in the chemical quality and biodegradability of dissolved organic matter exported from soils to streams in coastal temperate rainforest watershedsAuthor(s): Jason B. Fellman; Eran Hood; David V. D'Amore; Richard T. Edwards; Dan White
Source: Biogeochemistry. 95: 277-293
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
Download Publication (3.08 MB)
DescriptionThe composition and biodegradability of streamwater dissolved organic matter (DOM) varies with source material and degree of transformation. We combined PARAFAC modeling of fluorescence excitation-emission spectroscopy and biodegradable dissolved organic carbon (BDOC) incubations to investigate seasonal changes in the lability of DOM along a soil-stream continuum in three soil types: bog, forested wetland and upland forest. The percentage of BDOC ranged from 7 to 38 across all sites, and was significantly greater in soil compared to streamwater in the bog and forested wetland, but not in the upland forest. The BDOC also varied significantly over the entire sampling period in soil and streamwater for the bog and forested wetland, as BDOC peaked during the spring runoff and was lowest during the summer months. Moreover, the chemical quality of DOM in wetland soil and streamwater was similar during the spring runoff and fall wet season, as demonstrated by the similar contribution of protein-like fluorescence (sum of tyrosine and tryptophan fluorescence) in soil water and in streams. These findings suggest that the tight coupling between terrestrial and aquatic ecosystems is responsible for the delivery of labile DOM from wetland soils to streams. The contribution of protein-like fluorescence was significantly correlated with BDOC (p < 0.001) over the entire sampling period indicating DOM is an important source of carbon (C) and nitrogen (N) for heterotrophic microbes. Taken together, our findings suggest that the production of protein-rich, labile DOM and subsequent loss in stream runoff might be an important loss of labile C and N from coastal temperate watersheds.
- Visit PNW's Publication Request Page to request a hard copy of this publication.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationFellman, J.B.; Hood, E.; D'Amore, D.V.; Edwards, R.T.; White, D. 2009. Seasonal changes in the chemical quality and biodegradability of dissolved organic matter exported from soils to streams in coastal temperate rainforest watersheds. Biogeochemistry. 95: 277-293.
Keywordsbiodegradable dissolved organic carbon, dissolved organic matter, dissolved organic nitrogen, fluorescence, PARAFAC, peatland, biogeochemistry
- Changes in the concentration, biodegradability, and fluorescent properties of dissolved organic matter during stormflows in coastal temperate watersheds
- Fluorescence characteristics and biodegradability of dissolved organic matter in forest and wetland soils from coastal temperate watersheds in southeast Alaska
- Salmon influences on dissolved organic matter in a coastal temperate brown-water stream: an application of fluorescence spectroscopy.
XML: View XML