『Abstract
Nutrient loading from the Everglades Agricultural Area and nearby
urban communities plus water flow rate and canal size have significantly
influenced the amount of sediment and phosphorus (P) pools stored
in the Water Conservation Area (WCA) canals in the Everglades.
A study was conducted to characterize the potential impact that
sediments might have on the overlying water column by conducting
an inventory of total P (TP) and major P forms in sediments of
all major canals in the WCAs. Sediment samples and sediment depth
measurements were taken at transects every 1.6-km along all canals
reaches. A total sediment volume of about 6.8 million m3,
with a P mass of approximately 1808 Mg was estimated to be stored
within all WCA canals, with the eastern canal accounting for 71％
of the total sediment volume and about half of TP mass. Phosphorus
fractions associated with Ca- and Mg-compounds and residual organic
P (Po) were the dominant forms stored in these canals, with the
greatest P mass observed in the western side of the WCAs. These
results indicates that ＞80％ of the TP mass stored in surface sediments
in the WCAs is fairly stable, and represent an important long-term
sink for P. Canal sediments from the eastern side of the WCAs
were low in bulk density, highly organic and more susceptible
to resuspension and transport during strong drainage events. These
sediments showed higher Fe- and Al-bound P and organic-bound P
fractions, making them more susceptible to changes in the redox
potential of the sediments that could result in the long-term
release of Fe-bound P to the overlying water column.』
(Introduction)
Materials and methods
Sediment inventory
Site description and sampling techniques
Sediment analytical methods
Sediment phosphorus forms
Sampling and analysis
Phosphorus fractionation
Data analysis
Results and discussion
Sediment physicochemical properties
Sediment depths and volume in main canals
Phosphorus storage in canal sediments
Inorganic phosphorus fractions
Organic phosphorus fractions
Conclusions
Acknowledgments
References
※P分別法はHieltjes and Lijklema（1980）を修正したもの。