Location: Hydrology and Remote Sensing LaboratoryTitle: Isoscape analysis for elucidating relationships between soil redistribution and soil carbon dynamics
|LI, X. - US Department Of Agriculture (USDA)
|LEE, S. - University Of Maryland
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 8/30/2019
Publication Date: N/A
Interpretive Summary: Soil redistribution (i.e., erosion and deposition) in agricultural landscapes significantly impacts the global carbon cycle. Movement of soil particles can redistribute soil carbon and change the carbon mineralization rate. This chapter provides a review of isotopic tracer methods useful for assessing linkages between soil movement and carbon dynamics. Topography-based isoscape (isotopic landscape) models can be developed to examine both soil redistribution patterns and carbon dynamics. Such models successfully simulate the spatial patterns of soil carbon distribution over agricultural landscapes and their use can benefit soil carbon dynamic studies in areas with limited on-ground observations. Soil carbon is important for maintenance of soil health for food production as well as reducing levels of carbon dioxide in the atmosphere.
Technical Abstract: Isotopic tracers are useful for assessing linkages between soil movement and soil carbon dynamics in landscapes. Analyses of isotopes and comparison of isoscape (isotopic landscape) with observational data have been employed to investigate spatial distributions of isotopes, to test efficiencies of isotopic models, and to examine soil redistribution patterns and C dynamics. This chapter review the application of natural (7Be, 210Pb) and anthropogenic fallout radionuclides (137Cs, 239,240Pu), and C isotopes (12,13,14C) in understanding mechanisms of soil redistribution and sedimentation. The chapter was organized to cover the formation, sources, and transport of these isotopes; how they are distributed and related to soil redistribution on C dynamics; and importance of their distribution (isoscapes) on investigating soil properties. We also provided a case study to demonstrate the feasibility of applying isotopes and isoscape modelling for understanding soil property variability in response to anthropogenic disturbance in a low-relief cropland field. Results demonstrated advantages of using 137Cs and C isotopic signature (d13C) to trace soil movements and C dynamics. Topography-based 137Cs and C isoscape models were developed using Light Detection and Ranging data (LiDAR) derived topographic metrics. The models successfully simulated the spatial patterns of 137Cs inventory and d13C over an agricultural landscape and can benefit soil sedimentation and C dynamic studies in areas with limited observations.