Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (2.0 MB bytes)

Title: Tracing the source of soil organic matter eroded from temperate forest catchments using carbon and nitrogen isotopes

Author: McCorkle, Emma P.; Berhe, Asmeret Asefaw; Hunsaker, Carolyn T.; Johnson, Dale W.; McFarlane, Karis J.; Fogel, Marilyn L.; Hart, Stephen C.;

Date: 2016

Source: Chemical Geology

Publication Series: Scientific Journal (JRNL)

Description: Soil erosion continuously redistributes soil and associated soil organic matter (SOM) on the Earth's surface, with important implications for biogeochemical cycling of essential elements and terrestrial carbon sequestration. Despite the importance of soil erosion, surprisingly few studies have evaluated the sources of eroded carbon (C). We used natural abundance levels of the stable and radioactive isotopes of C (13C and 14C) and stable isotope of nitrogen (15N) to elucidate the origins of SOMeroded fromlow-order catchments along the western slopes of the Sierra Nevada of California, USA. Our work was conducted in two relatively undisturbed catchments (low elevation = 1800 m, and high elevation = 2300 m) of the Kings River Experimental Watersheds (KREW) in the Sierra National Forest. Sediment captured in basins at the outlet of each gauged watershed were compared to possible source materials, which included: upland surficial organic horizons (i.e., forest floor) and mineral soils (0–0.6 m) from three landform positions (i.e., crest, backslope, and toeslope), stream bank soils (0–0.6m), and stream-bedmaterials (0–0.05 m).We found that most of the organic matter (OM) in the captured sediments was composed of O-horizon material that had high C concentrations. Radiocarbon analyses also showed that the captured OM is composed of modern (post-1950) C, with fraction modern values at or above 1.0. Our results suggest that surface (sheet) erosion, as opposed to channeling through established streams and episodic mass wasting events, is likely the largest source of sediment exported out of these minimally disturbed, headwater catchments. The erosional export of sediment with a high concentration of C, especially in the form of relatively undecomposed litter from the O horizon, suggests that a large fraction of the exported C is likely to be decomposed during or after erosion; hence, it is unlikely that soil erosion acts as a significant net sink for atmospheric CO2 in these low-order, temperate forest catchments.

Keywords: erosion, radiocarbon, sediment sources, Sierra Nevada, soil organic matter, stable isotopes

Publication Notes:

  • 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.

XML: View XML

Citation:


McCorkle, Emma P.; Berhe, Asmeret Asefaw; Hunsaker, Carolyn T.; Johnson, Dale W.; McFarlane, Karis J.; Fogel, Marilyn L.; Hart, Stephen C. [In Press]. Tracing the source of soil organic matter eroded from temperate forest catchments using carbon and nitrogen isotopes. Chemical Geology.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.