Substrate Characterization of an Experimental Marsh and Three Natural Marshes1
- C. W. Lindau and
- L. R. Hossner2
Dredge material from the Gulf Intracoastal Waterway near Galveston, Tex., was used as a substrate material in the construction of an experimental intertidal salt marsh. Chemical and physical properties of dredge substrate samples at 270 sites were monitored over a 16-month period. Cation exchange capacity (CEC), extractable phosphorus (P), total Kjeldahl nitrogen (TKN), NH4-N, and organic matter increased from 3.0 to 7.4 meq/100 g, 24 to 96 µg P/g, 85 to 296 µg N/g, 3.0 to 9.9 µg N/g, and 0.2 to 0.5%, respectively. No significant increases in N and P were observed in the substrate due to fertilization.
A separate study comparing substrate properties of the experimental marsh to three natural marshes demonstrated that organic matter, TKN, and NH4-N concentrations in the experimental marsh were lower. Organic matter, TKN, and NH4-N in the experimental marsh substrate averaged 0.6%, 260 µg N/g, and 5.4 µg N/g compared to 2.3%, 650 µg N/g, and 12.1 µg N/g, respectively, for the three natural marshes. Within each of the four marsh sites extreme spatial heterogeneity of chemical and physical properties was apparent.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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