Wetlands on Clay Settling Areas

1
Wetlands on Clay Settling Areas
What we do and dont know...
2
Main phosphate formation the bone valley
3
Wetlands on Clay Settling Areas...
Phosphate Strip Mining...
4
(No Transcript)
5
Wetlands on Clay Settling Areas...
Phosphate matrix is slurred and pumped to the
beneficiation plant
6
Wetlands on Clay Settling Areas...
Clays are pumped to Settling Areas
7
Wetlands on Clay Settling Areas...
Stages in CSA ecosystem development...
8
Wetlands on Clay Settling Areas...
A CSA after about 5 - 6 yearsdominated by
carolina willow in wet areas...
9
Wetlands on Clay Settling Areas...
CSA in north Florida planted in wetland trees
about 5 years old.
10
Wetlands on Clay Settling Areas...
2 year old site dominated by marsh vegetation
Open water
Marsh
11
12 year old site Dominated by willow/
cattail/primrose willow
Carolina willow
Cattail / primrose willow
12
30 year old site dominated by mixed hardwoods
and willow
Mixed hardwood / willow
Hardwood forest
13
40 year old site dominated by mix of hardwoods /
willows / and marsh vegetation
Upland forest
Willows
Marsh vegetation
14
Wetlands on Clay Settling Areas...
30 year old siteshowing consolidated clays and
hardwood swamp close to seed source.
15
Wetlands on Clay Settling Areas...
Detail of a section of the 30 year old
siteshowing the relationship between hydrology
and vegetation colinization
16
Wetlands on Clay Settling Areas...
60 year old dredge pit back-filled with sand and
clay...
17
Wetlands on Clay Settling Areas...
60 year old dredge pit back-filled with sand and
clay (south transect)
18
Wetlands on Clay Settling Areas...
40 year old control site...Wetland at lake
Panasoffkee exhibiting classical succession.
19
Wetlands on Clay Settling Areas...
Seed rain is significantly affected by distance
20
Soils.

• Soils develop with age but depend on
• vegetative cover
• hydrologic regime

21
Role of early successional nuisance species...

• Build OM 5x faster
• Increase N cycling
• Provide structure

22
Wetlands on Clay Settling Areas...

• What we knowHydrologically speaking
• Clays will consolidate differentially resulting
  in a heterogeneous hydrologic function
• Surface runoff from CSAs may be difficult to
  predict
• Hydrology may be dominated by ET
• Interior dikes may provide wicks for dewatering

23
Wetlands on Clay Settling Areas...

• What we knowEcologically speaking
• Vegetation exhibits arrested succession if
  there is no seed source
• Vegetation on CSAs exhibits classical
  succession if there is available seed source
• Communities are new types of elevated wetland
  ecosystems... high nutrient perched wetlands

24
Wetlands on Clay Settling Areas...

• What we knowTechnologically speaking
• Particles in slurry drop out differentially and
  CSAs are sloped from inlet to outlet
• After some consolidation, dikes can be pushed
  onto clays
• Sandy upland areas can be created that provide
  water storage and seepage
• Dikes can be created to seep and therefore
  CSAs can act as headwaters in regional drainage
  network

25
Wetlands on Clay Settling Areas...

• What we dont know
• Long term hydrology
• How to account for long term consolidation
• Vegetative species mix for soils and hydrology
  characteristic of CSAs
• Ecological benefits/costs of herbiciding
  vegetation and replanting desirable species