|
publications > paper > characterization of suspended particles in Everglades wetlands
Characterization of suspended particles in Everglades wetlands
Gregory B. Noe1 and Judson W. Harvey
U.S. Geological Survey, 430 National Center, Reston, Virginia 20192
James E. Saiers
School of Forestry and Environmental Studies, Yale University, 205 Prospect Street, New Haven, Connecticut 06511-2189
1 Corresponding author (gnoe@usgs.gov; tel: 703-648-5826; fax: 703-648-5484).
Abstract
We report the concentration, phosphorus (P) and nitrogen (N) content, and size and chemical fractionation of
fine suspended particles (0.2-100 µm) and colloids (3 kilodalton [kDa]-0.1 µm) in the surface water of Everglades
wetlands along regional and P-enrichment gradients. Total suspended sediment concentrations ranged from 0.7 to
2.7 mg L-1. Total particulate P concentrations increased from 0.05 µmol L-1 to 0.31 µmol L-1 along the P-enrichment
gradient. Particles contained from 20% to 43% of total P but <12% of total N in surface water.
Dissolved (<0.2 µm) organic N contained about 90% of total N, with the 3-100-kDa colloidal size class
containing the most N of any size class. The 0.45-2.7-µm size fraction held the most particulate P at all sites,
whereas particulate N was most abundant in the 2.7-10-µm size class at most sites. Standard chemical
fractionation of particles identified acid-hydrolyzable P as the most abundant species of particulate P, with little
reactive or refractory organic P. Sequential chemical extraction revealed that about 65% of total particulate P was
microbial, while about 25% was associated with humic and fulvic organic matter. The size and chemical
fractionation information suggested that P-rich particles mostly consisted of suspended bacteria. Suspended
particles in Everglades wetlands were small in size and had low concentrations, yet they stored a large proportion
of surface-water P in intermediately reactive forms, but they held little N.
 |
| Figure 1. False-color satellite image of the Everglades and south Florida showing the locations of the sampling sites and individual photos of each sampling site. Generalized flow direction is shown as an arrow on the satellite image. [larger version] |
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
|
