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 (1.3 MB bytes)

Title: Constraining climatic controls on hillslope dynamics using a coupled model for the transport of soil and tracers: Application to loess-mantled hillslopes, Charwell River, South Island, New Zealand

Author: Roering, J.J.; Almond, P.; Tonkin, P.; McKean, J.;

Date: 2004

Source: Journal of Geophysical Research-Earth Surface, v. 109, F01010, doi:10.1029/2003JF000034.

Publication Series: Miscellaneous Publication

Description: Landscapes reflect a legacy of tectonic and climatic forcing as modulated by surface processes. Because the morphologic characteristics of landscapes often do not allow us to uniquely define the relative roles of tectonic deformation and climate, additional constraints are required to interpret and predict landscape dynamics. Here we describe a coupled model for the transport of soil and tracer particles at the hillslope scale. To illustrate the utility of this methodology, we modeled the evolution of two synthetic hillslopes with identical initial and boundary conditions but different histories of climateinduced changes in the efficiency of soil transport. While one hillslope experienced an initial phase of rapid transport followed by a period of retarded transport, the other hillslope experienced the opposite sequence. Both model hillslopes contain a subsurface layer of tracer particles that becomes exhumed and incorporated into the soil due to transport and mixing processes. Whereas the morphology of the two model hillslopes cannot be easily distinguished at the simulation conclusion, the spatial distribution of tracer particles along the slope is distinctive for the two cases. We applied the coupled model to our study site along the Charwell River, South Island, New Zealand, where tephra deposits within loess-dominated soils have been exhumed and incorporated into an upper layer of bioturbated and mobile soil. We reconstructed the late Pleistocene hillslope geometry using soil stratigraphic data gathered along the study transect. Because bioturbation appears to be the predominant transport mechanism, the efficiency of soil transport likely varies with time, reflecting the influence of climate-related changes in the dominant floral or faunal community. The modeled evolution of hillslope form and tephra concentration along the study transect is consistent with observations obtained from topographic surveys and laboratory analysis of tephra concentrations in continuous-core soil samples. Low transport rates are apparently associated with grass/shrub-dominated slopes during the late Pleistocene, whereas forest colonization during the Holocene increased flux rates, transforming flat, locally incised slopes into broadly convex ones. Our results attest to the utility of coupled models for tasks such as deciphering landscape history and predicting the downslope flux of soil organic carbon.

Keywords: landscape evolution, soil transport, tracers, hillslope erosion, bioturbation, numerical model

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.
  • You may send email to rmrspubrequest@fs.fed.us to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)

XML: View XML

Citation:


Roering, J.J.; Almond, P.; Tonkin, P.; McKean, J. 2004. Constraining climatic controls on hillslope dynamics using a coupled model for the transport of soil and tracers: Application to loess-mantled hillslopes, Charwell River, South Island, New Zealand. Journal of Geophysical Research-Earth Surface, v. 109, F01010, doi:10.1029/2003JF000034.

 


 [ 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.