State Water Resources Research Institute Program
Project ID: 2008AR193B
Title: Biogeochemical controls and interactions of carbon and nutrient cycling in karst hydrologic systems.
Project Type: Research
Start Date: 3/01/2008
End Date: 2/29/2009
Congressional District: 3
Focus Categories: Hydrogeochemistry, Nitrate Contamination, Water Quality
Keywords: soil karst, water quality, hydrology, biochemistry
Principal Investigators: Pollock, Erik; Brahana, John Van (University of Arkansas); Hays, Phil D
Federal Funds: $ 20,814
Non-Federal Matching Funds: $ 41,628
Abstract: The karst hydrology pervasive in northern Arkansas, coupled with increasingly intensive agricultural and urban land-use patterns, has led to widespread water-quality degradation in this region of the southern Ozarks. An understanding of the interplay of hydrology and biogeochemical processes that control transport and processing of nutrients in karst watersheds is critical to the design of effective animal-manure and sustainable-agriculture practices, effective septic systems, and waste-treatment outfalls. Our understanding of the processes operating in karst systems, however, lags considerably behind that of other aquatic ecosystems (such as marine, riverine, wetlands, and granular aquifers). The availability of dissolved organic matter, a strong control in biogeochemical cycling of nutrients within the karst soil system, is easily altered by agricultural and other activities in the karst watersheds. Whereas karst ground water movement has recently received focused study, controls on the carbon availability and movement, particularly the DIC-DOC-CO2 (g) dynamics have received little attention. Carbon is the basic substrate which must be available for processing nutrients--and specifically in the case of this proposal, nitrate. Basic geochemical monitoring to be conducted in the proposed study includes continuous pCO2 measurement and isotopic characterization of DIC and DOC through the karst-soil system. These data will facilitate source identification and delineation of the complex interaction between water quality and nutrient cycling. This project will establish controls on the effect of carbon cycling and local hydrology on the effective processing of nutrients in mantled-karst watersheds of the Ozarks.
Progress/Completion Report, PDF