Document


Title

The role of watershed characteristics, permafrost thaw, and wildfire on dissolved organic carbon biodegradability and water chemistry in Arctic headwater streams
Document Type: Journal Article
Author(s): J. R. Larouche ; Benjamin W. Abbott ; William B. Bowden ; Jeremy B. Jones Jr.
Publication Year: 2015

Cataloging Information

Keyword(s):
  • carbon
  • climate change
  • disturbance
  • fire frequency
  • fire management
  • soil temperature
  • streams
  • tundra
  • water
  • watershed management
  • watersheds
  • wildfires
Region(s):
Record Maintained By:
Record Last Modified: November 6, 2018
FRAMES Record Number: 54233
Tall Timbers Record Number: 31897
TTRS Location Status: Not in file
TTRS Call Number: Available
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

In the Alaskan Arctic, rapid climate change is increasing the frequency of disturbance including wildfire and permafrost collapse. These pulse disturbances may influence the delivery of dissolved organic carbon (DOC) to aquatic ecosystems, however the magnitude of these effects compared to the natural background variability of DOC at the watershed scale is not well known. We measured DOC quantity, composition, and biodegradability from 14 river and stream reaches (watershed sizes ranging from 1.5-167 km2) some of which were impacted by permafrost collapse (thermokarst) and fire. We found that region had a significant impact on quantity and biodegradability of DOC, likely driven by landscape and watershed characteristics such as lithology, soil and vegetation type, elevation, and glacial age. However, contrary to our hypothesis, we found that streams disturbed by thermokarst and fire did not contain significantly altered labile DOC fractions compared to adjacent reference waters, potentially due to rapid ecosystem recovery after fire and thermokarst as well as the limited spatial extent of thermokarst. Overall, biodegradable DOC ranged from 4 to 46% and contrary to patterns of DOC biodegradability in large Arctic rivers, seasonal variation in DOC biodegradability showed no clear pattern between sites, potentially related to stream geomorphology and position along the river network. While thermokarst and fire can alter DOC quantity and biodegradability at the scale of the feature, we conclude that tundra ecosystems are resilient to these types of disturbance. © Authors 2015. Open access. CC Attribution 3.0 License. Published by Copernicus Publications on behalf of the European geosciences Union.

Online Link(s):
Citation:
Larouche, J. R., B. W. Abbott, W. B. Bowden, and J. B. Jones. 2015. The role of watershed characteristics, permafrost thaw, and wildfire on dissolved organic carbon biodegradability and water chemistry in Arctic headwater streams. Biogeosciences, v. 12, no. 14, p. 4221-4233. 10.2194/bg-12-4221-2015. http://www.biogeosciences.net/12/4221/2015/bg-12-4221-2015.pdf.