Using Vegetative Nutrient Stocks to Compare Restored and Reference Wetlands in the Upper Klamath Basin, Oregon
Vegetative diversity metrics are often used to characterize wetland restoration success. Here we examine whether other important vegetative traits (nutrient standing stocks and tissue nutrient concentrations) can improve our understanding of the structure of restored and reference wetlands and aid in the assessment of functional equivalency. We focus on wetlands of the Upper Klamath Basin (UKB), Oregon because this basin supports a mosaic of remnant, restored, and degraded wetlands dominated by a limited number of common emergent plant species. We summarize nutrient standing stocks using 11 growth limiting micro- and macronutrients present in aboveground tissues of three emergent plant species. We show that interspecific variation in nutrient standing stocks and tissue nutrient concentrations was high and greater than inter-site differences. Interspecific variation for nitrogen standing stocks was 3X larger than inter-site variation. Although less common, inter-site differences in nutrient standing stocks and tissue nutrient concentrations were detected and tissue phosphorus concentrations in a recently restored wetland were nearly twice those of a reference wetland; corresponding levels of aboveground biomass in this wetland were not detected. Our detection of elevated phosphorus in the vegetation of a recently restored wetland is consistent with predictions from both experimental and observational work in UKB and demonstrates that nutrient standing stocks provide important clues about the fate and retention of nutrients in restoration wetlands. Importantly, we show that these vegetative attributes also provide a measure of functional equivalency that is rarely used in the assessment of restoration success.
KeywordsNutrient stocks, Tissue nutrients Aboveground biomass Nutrient ratios Upper Klamath Lake
The U.S. Bureau of Reclamation (R10AP20603 and 08FG200155 to AMR) and U.S. Bureau of Land Management providing funding for this work. The U.S. Fish and Wildlife Service and The Nature Conservancy of Oregon provided access to field sites and logistical support. We would especially like to thank C. Doehring, C. Fujishin, H. Hendrixson, C. Erdman, and S. Wong for help in the field. We thank R. Inouye, S. Wong, H. Ray, and H. Hendrixson for their thoughtful reviews of earlier versions of this manuscript. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
- Aerts R, Chapin FS (2000) The mineral nutrition of wild plants revisited: a re-evaluation of processes and patterns. Advances in Ecological Research 30:2–67Google Scholar
- Akins GJ (1970) The effects of land use and land management on the wetlands of the Upper Klamath Basin. MSc Thesis. Western Washington State CollegeGoogle Scholar
- Boyd CE (1970) Chemical analyses of some vascular aquatic plants. Archiv Fur Hydrobiologie 67:78–85Google Scholar
- Elseroad A, Rudd N, Hendrixson H (2011) Williamson River Delta Preserve vegetation monitoring: Tulana third-year post-breaching results. The Nature Conservancy, PortlandGoogle Scholar
- Geiger NS (2001) Reassociating wetlands with Upper Klamath Lake to improve water quality. Klamath Fish and Water Management Symposium, Arcata, CAGoogle Scholar
- Gotelli NJ, Ellison AM (2004) A primer in ecological statistics. Sinauer Associates, Inc. Publishers, SunderlandGoogle Scholar
- Lindenberg MK, Wood TM (2009) Water quality of a drained wetland, Caledonia Marsh on Upper Klamath Lake, Oregon, after flooding in 2006: U.S. Geological Survey Scientific Investigations Report 2009–5025Google Scholar
- Snyder DT, Morace JL (1997) Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon. U.S. Geological Survey, Water-Resources Investigations Report 97–4059Google Scholar
- Walker WW (2001) Development of a phosphorus TMDL for Upper Klamath Lake, Oregon. Oregon Department of Environmental Quality, PortlandGoogle Scholar