GPR- Detection of Edaphic Discontinuities with Ground-rating Radar GPR, Stroh, JC - 2001.pdf

Landscape Ecology 16: 377–390, 2001. 377
© 2001 Kluwer Academic Publishers. Printed in herlands.
Research Article
Detection of edaphic discontinuities with ground-rating radar and
ic induction
James C. Stroh1,∗, Steve Archer1, James A. Doolittle2 and Larry Wilding3
1Rangeland Ecology and Management, Texas A&M University, College Station, TX 77843-2126, USA
2US Forest Service, 5 Radnor Corp. Center, Suite 200, 100 Matsonford Rd, Radnor, Pa 19087-4285, USA
3Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
(∗current address: Department of Biology, Morningside College, Sioux City, IA 51106, USA)
Received 7 April 1999; Revised 20 June 2000; Accepted 20 March 2001
Key words: apparent conductivity, argillic horizon, edaphic discontinuity, plant-soil relationships, soil, soil
mapping, soil map unit boundaries, soil survey, spatial variation
Abstract
Quantification of edaphic properties which may regulate the spatial distribution of vegetation is often limited by
the expense and labor associated with collecting and analyzing soil samples. Here we evaluate the utility of two
technologies, ground-rating radar (GPR) and ic induction (EMI), for rapid, extensive and non-
destructive mapping of diagnostic subsurface features and soil series map unit boundaries.
Strong reflectance from fine-textured, near-surface soils obscured radar signal reflectance from deeper horizons
at our field test site in the Rio Grande Plains of southern Texas, USA. As a result, ground-rating radar did not
delineate known edaphic contrasts along catena gradients. In contrast, EMI consistently distinguished boundaries
of soil map units. In several instances, gradients or contrasting inclusions within map units were also identified.
In addition, the location and boundary of calcic or cambic-horizon inclusions embedded within a laterally co-
extensive and well-developed argillic horizon were consistently predicted. Correlations between EMI assessm