Controls and Sources of Dissolved Organic Carbon in Intermittent Headwater Streams

Tej Pandey, Kathleen Lohse, and Dr. Kathleen Lohse, Department of Biological Sciences, Idaho State University,921 S 8th avenue, Pocatello Idaho 83209

Water extractable organic carbon (WEOC) accounts for the availability of dissolved organic carbon (DOC) and soil organic matter (SOM) in the stream headwater ecosystems. The availability and controls on water extract organic carbon and its links to streams are poorly characterized in intermittent streams. In this study, we dug soil pits to 1 m or refusal from 4 different habitats within Gibson Jack watershed in southeastern Idaho and sampled soils to analyze the availability of DOC and related this to pH and SOM. We hypothesized that the riparian habitat would have more WEOC than the other three habitats owing to higher SOM. We also hypothesized that higher pH would account for less dissolved carbon and SOM and WEOC would be positively correlated. To test these hypothesized mechanisms, we extracted soil for water extractable organic carbon by shaking the samples overnight, then filtered the samples using 0.45 µm AQUA Whatman filter[KAL1] [Clu2] , and analyzed the samples on a Shimadzu TOC/TN analyzer. We found that the sagebrush habitat had higher pH values and lower SOM with depth compared to other habitats. WEOC decreases with depth in the sagebrush habitat. In contrast, WEOC values were higher in the riparian zone with depth. WEOC: SOM varies along the depth on all habitats, which partially supported our hypothesizes. Results suggested DOC availability depends on the soil characteristics especially SOM contents. Results supported that riparian accounts for more organic carbon pools which were more available than other habitats. Understanding DOC predicts the Carbon balance in these habitats.


Additional Abstract Information

Presenter: TEJ PANDEY

Institution: Idaho State University

Type: Oral

Subject: Biology

Status: Approved

Time and Location

Session: Oral 6
Date/Time: Tue 2:00pm-3:00pm
Session Number: 605
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