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publications > paper > phosphorus biogeochemistry and the impact of phosphorus enrichment: why is the Everglades so unique?
Phosphorus Biogeochemistry and the Impact of Phosphorus Enrichment: Why Is the Everglades so Unique?
Gregory B. Noe,1 Daniel L. Childers,1,2 and Ronald D. Jones1,2*
1Southeast Environmental Research Center, Florida International University, Miami, Florida 33199, USA; and 2Department of Biological Sciences, Florida International University, Miami, Florida 33199, USA
Received 23 August 2000; Accepted 23 March 2001. *Corresponding author; e-mail: serc@fiu.edu
Abstract
The Florida Everglades is extremely oligotrophic
and sensitive to small increases in phosphorus (P)
concentrations. P enrichment is one of the dominant
anthropogenic impacts on the ecosystem and
is therefore a main focus of restoration efforts. In
this review, we synthesize research on P biogeochemistry
and the impact of P enrichment on ecosystem
structure and function in the Florida Everglades.
There are clear patterns of increased P
concentrations and altered structure and processes
along nutrient-enrichment gradients in the water,
periphyton, soils, macrophytes, and consumers. Periphyton,
an assemblage of algae, bacteria, and associated
microfauna, is abundant and has a large
influence on phosphorus cycling in the Everglades.
The oligotrophic Everglades is P-starved, has lower
P concentrations and higher nitrogen-phosphorus (N:P) ratios, and has oxidized to only slightly reduced
soil profiles compared to other freshwater
wetland ecosystems. Possible general causes and
indications of P limitation in the Everglades and
other wetlands include geology, hydrology, and
dominance of oxidative microbial nutrient cycling.
The Everglades may be unique with respect to P
biogeochemistry because of the multiple causes of P
limitation and the resulting high degree of limitation.
| Table 2. Meta-analysis of Published Data for the Everglades and Other Wetlands |
| Component |
Bedford and Others 1999 |
Everglades |
| Typha |
Typha/Cladium |
Cladium |
Slough/Wet Prairie |
| Water TP |
- |
76.1 ± 38.8 (5)a |
42.3 ± 36.2 (5)a |
10.8 ± 4.8 (5)b |
10.4 ± 2.5 (8)a |
| Water N:P |
- |
94.1 ± 52.6 (4)ab |
228.0 ± 221.1 (4)bc |
542.0 ± 774.8 (3)c |
377.6 ± 164.0 (7)c |
| Periphyton TP |
- |
2885.0 ± 3049.4 (2)a |
898.0 ± 2884.3 (2)b |
242.8 ± 337.1 (3)c |
242.8 ± 120.1 (6)c |
| Periphyton N:P |
- |
- |
86.0 |
165.0 |
151.7 ± 50.2 (4) |
| Soil TP |
900 ± 590 (109) |
1402.9 ± 165.6 (15)a |
947.3 ± 230.5 (10)b |
533.2 ± 94.0 (20)c |
467.1 ± 116.1 (10)c |
| Soil TP load |
- |
0.60 ± 0.31 (4)a |
0.38 ± 0.98 (2)a |
0.09 ± 0.04 (10)b |
- |
| Soil N:P |
47.1 ± 1.3 (109) |
49.0 ± 10.3 (10)a |
77.6 ± 20.5 (6)a |
144.6 ± 30.2 (12)b |
213.0 ± 80.1 (4)c |
| Macrophyte TP |
1400 ± 200 (65) |
1509.3 ± 214.6 (3)a |
515.0 ± 346.7 (4)b |
193.3 ± 32.7 (7)c |
396.5 ± 2268.0 (2)bc |
| Macrophyte N:P |
32.9 ± 3.8 (48) |
16.7 ± 9.0 (3)a |
40.2 ± 21.8 (4)b |
76.7 ± 26.2 (7)c |
62.2 ± 53.3 (3)bc |
Mean ± 95% confidence interval (CI) is presented with the sample size (number of studies) in parentheses for TP concentration (µg L-1 or µg g-1), molar N:P ratio, and annual soil TP load (g m-2 y-1).
Different letters indicate that a significant difference ( 0.05) exists among Everglades habitats, as determined by Tukey's post hoc tests.
Summary statistics are calculated from the analysis by Bedford and others (1999) of nutrient concentrations in temperate North American wetlands. Macrophyte N:P data from Bedford and others (1999) only include values from peat-based wetlands.
The mean is presented when n = 1; - dashes indicate that data was not found in the literature.
Bolded cells indicate that the 95% CI of a parameter in the Everglades and in temperate North American wetlands (Bedford and others 1999) do not overlap. |
Related information:
SOFIA Project: Effect of Water Flow on Transport of Solutes, Suspended Particles, and Particle-Associated Nutrients in the Everglades Ridge and Slough Landscape
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