HR: 11:45h
AN: NB52D-05 [Abstracts]
TI: Spatial Variability of Denitrification and Associated Soil Properties on a Restored and a Natural Floodplain
AU: * Rogers, K
EM: kristyrogers@wisc.edu
AF: Center for Limnology, University of Wisconsin, Madison, 680 N. Park St., Madison, WI 53706 United States
AU: Predick, K
EM: kipredick@wisc.edu
AF: Center for Limnology, University of Wisconsin, Madison, 680 N. Park St., Madison, WI 53706 United States
AU: Orr, C
EM: csorr@wisc.edu
AF: Center for Limnology, University of Wisconsin, Madison, 680 N. Park St., Madison, WI 53706 United States
AU: Stanley, E
EM: ehstanley@wisc.edu
AF: Center for Limnology, University of Wisconsin, Madison, 680 N. Park St., Madison, WI 53706 United States
AB:
Floodplains often exhibit high levels of variability in biotic parameters at relatively small spatial scales. Even so, we
have limited insight about the structure of this variability. In this study we measured the spatial variation of
denitrification rates and determined the scale of spatial autocorrelation and how it differs between a restored and a natural floodplain. Denitrification enzyme activity (DEA, μgN2O-N/ kg soil/hr), nitrate, carbon, total nitrogen, and moisture
were measured on 116 soil samples collected using a cyclic sampling design to increase sampling efficiency and spatial
information. Mean DEA rate was lower on the natural than on the restored floodplain (0.70 vs. 1.85) despite similar ranges
(0-5.3 and 0-5.5 respectively), probably due to the increased prevalence of inactive samples (17.2% vs. 2.5%).
Furthermore, the CV for DEA was higher in the natural floodplain (137%) than the restored floodplain (60%). The restored
floodplain also had a greater range of spatial autocorrelation, suggesting that there was greater spatial structure in
denitrification on the restored floodplain. These results contradict conventional wisdom about the homogeneity of restored
sites relative to less impacted ones.
DE: 1806 Chemistry of fresh water
DE: 1890 Wetlands
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly