Chorover et al., 2011

Talk/Poster

Carbon, water and weathering limitations in the semi-arid critical zone.

J. Chorover, P.A. Troch, J.D. Pelletier, C. Rasmussen, P.D. Brooks, J.C. McIntosh, D.D. Breshears, T.E. Huxman, S.A. Papuga, K.A. Lohse, T. Meixner, M.G. Schaap, M.E. Litvak, A.A. Harpold, J.N. Perdrial, M. Durcik (2011)
AGU Fall Meeting Presentations Abstract B41H-05.  

Abstract

We postulate that carbon and water fluxes drive CZ evolution, and that quantifying system inputs leads to predictions of non-linear and threshold effects in CZ structure formation. We are testing this hypothesis in the semi-arid, Jemez - Santa Catalina CZO through conjunctive measurements of CZ fluid fluxes, regolith composition and landscape form. In mixed conifer forest sites, eddy flux measurements of ecosystem photosynthesis, respiration and evapotranspiration reveal a strong seasonal CZ “metabolism” driven by surficial vegetation during snowmelt that fuels subsurface biogeochemical reactions. This is reflected in depth-dependent concentrations and molecular forms of dissolved and solid phase organic matter, and its complexes with soluble and precipitated lithogenic weathering products that are heterogeneously distributed in the landscape. Spatial variation in soluble weathering products across instrumented catchments is convoluted by flow path convergence, giving rise to discharge-dynamic chemistry and stoichiometry of catchment surface waters. Conjunctive collection and evaluation of time-series and spatial CZO data sets suggest that coupling of biotic, geochemical and hydrologic processes during event-based pulses of carbon and water has long-term consequences for the rate and stoichiometry of landscape chemical denudation, pedogenesis and flow path formation, and ultimately affects the balance between regolith production and erosion.

Citation

J. Chorover, P.A. Troch, J.D. Pelletier, C. Rasmussen, P.D. Brooks, J.C. McIntosh, D.D. Breshears, T.E. Huxman, S.A. Papuga, K.A. Lohse, T. Meixner, M.G. Schaap, M.E. Litvak, A.A. Harpold, J.N. Perdrial, M. Durcik (2011): Carbon, water and weathering limitations in the semi-arid critical zone. AGU Fall Meeting Presentations Abstract B41H-05..