Evidence that hyporheic zones increase heterotrophic metabolism and phosphorus uptake in forest streams

• DOI: 10.4319/lo.1997.42.3.0443
• Publication Date: 2010-05-25T23:59:22Z
• Authors: Patrick J. Mulhol...; Erich R. Marzolf; Jackson R. Webster; Deborah R. Hart; Susan P. Hendricks
• Keywords: Hyporheic Zone

We used nondisruptive, whole-stream methods to measure hydraulic characteristics, ecosystem metabolism, and phosphorus cycling in the west fork of Walker Branch (WB), Tennessee Hugh White Creek (HWC), North Carolina. Although similar many their hydrological chemical transient storage zone volume HWC was relatively large (∼1.5 times that flowing water zone), whereas WB small (∼0.1 zone). Both streams were highly heterotrophic (gross primary production: total respiration ratios <0.1), although resppiration rate ∼2.4 greater than WB. Phosphorus uptake ∼2.6 WB, P length 5 longer HWC. Analysis 33P : 3H ratio profiles from 33PO4 3H2O injection experiments indicated within accounted for ∼43% but negligible explaining, part, difference between these streams. The higher surface zone, shorter length, larger uptake: compared with suggest microbial community exerts a demand has affinity streamwater P, presumably as result supply labile organic matter and/or lower nutrient levels