Paper No. JAWRA-10-0187-P of the Journal of the American Water Resources Association (JAWRA). Discussions are open until six months from print publication.
Periphyton Nutrient Limitation and Maximum Potential Productivity in the Beaver Lake Basin, United States1
Article first published online: 23 MAY 2012
© 2012 American Water Resources Association
JAWRA Journal of the American Water Resources Association
Volume 48, Issue 5, pages 896–908, October 2012
How to Cite
Ludwig, A., Matlock, M., Haggard, B. and Chaubey, I. (2012), Periphyton Nutrient Limitation and Maximum Potential Productivity in the Beaver Lake Basin, United States. JAWRA Journal of the American Water Resources Association, 48: 896–908. doi: 10.1111/j.1752-1688.2012.00657.x
- Issue published online: 1 OCT 2012
- Article first published online: 23 MAY 2012
- Received October 21, 2010; accepted February 23, 2012.
- water quality;
- nutrient-diffusing substrata;
- watershed management;
Ludwig, Andrea, Marty Matlock, Brian Haggard, and Indrajeet Chaubey, 2012. Periphyton Nutrient Limitation and Maximum Potential Productivity in the Beaver Lake Basin, United States. Journal of the American Water Resources Association (JAWRA) 48(5): 896-908. DOI: 10.1111/j.1752-1688.2012.00657.x
Abstract: The objectives of this study were to measure periphytic growth responses to enrichment with nitrogen (N), phosphorus (P), and simultaneous N and P using in situ bioassays in streams draining Beaver Reservoir Basin, Northwest Arkansas; compare periphytic growth responses measured with in situ bioassays with a range of land use and point sources; and test the lotic ecosystem trophic status index (LETSI) as a simplifying metric to compare effects of nonpoint-source pollutant-limiting variables of N, P, and sediment across the basin. P limitation was observed at sites across a transect of stream orders throughout the basin; however, at the two sites with highest ambient nitrogen concentrations, limitation was often coupled with nitrogen limitation. Nutrients were at nonlimiting levels at both of two sites below wastewater treatment plants in all seasonal deployments. A Michaelis-Menten growth equation described LETSI as a function of ambient PO4-P concentrations (p < 0.05); the midpoint (LETSI of 0.50) corresponded with a PO4-P concentration of approximately 3 μg/l. Change-point analysis indicated a threshold point at LETSI of 0.80 and 15 μg/l PO4-P. These low values show that the periphytic community has a high affinity for available P, and that the watershed as a whole is sensitive to available nutrient inputs.