Transcript A Biogeochemical Survey of Wetlands in Southwestern Indiana David A. Stuckey University of Florida Wetland Functions and Benefits  Water Resources  Flood Control: Water storage  Reduce flow velocity.

A Biogeochemical Survey of
Wetlands in Southwestern Indiana
David A. Stuckey
University of Florida
2005
Wetland Functions and Benefits

Water Resources

Flood Control:
Water storage
 Reduce flow velocity and dampen peaks or runoff


Water Quality:
Absorb excess organic and inorganic nutrients from
fertilizer and septic system runoff
 Filter sediments and trap pollutants such as pesticides and
metals, for storage or recycling within the wetland system

Wetland Functions and Benefits

Biological/Ecological

Erosion Control


Roots bind soil, vegetation absorbs wave energy
Fisheries
Habitat and food sources
 Spawning and nursery grounds


Wildlife

~900 vertebrate species require wetlands during some
period in their life cycles
Wetland Functions and Benefits

Biological/Ecological

Wildlife
Principal habitat for waterfowl and other birds, mammals,
reptiles and amphibians
 Excellent habitat for non-wetland-dependent species
 ~35% of all rare and endangered species wetlanddependent


Recreation
75,000 user days/year in Indiana by duck and goose
hunters
 >1,000,000 user days/year of non-consumptive recreation

Wetlands Lost
Major Causes of Wetland Loss and
Degradation

Human Actions
- Drainage
- Dredging/Stream Channelization
- Deposition of fill material
- Diking and damming
- Tiling for crop production
- Levees
- Logging
- Mining
- Construction
- Runoff
- Air and water pollutants
- Changing nutrient levels
- Releasing toxic chemicals
- Introducing nonnative species
- Grazing by domestic animals

Natural Disturbance
- Erosion
- Subsidence
- Sea level rise
- Droughts
- Hurricanes and other storms
Patoka River National Wildlife Refuge protects
one of the most significant bottomland hardwood
forests remaining in the Midwest.
The Landscape:
Row Crops, Pasture, Livestock
Forestry
Coal Mining
Background



Nutrient concentration levels play a critical role in the
integrity and functionality of wetlands.
To fully assess the status and condition of wetland
ecosystems, knowledge of nutrient flow and cycling is
required.
Although water quality nutrient data is readily available
for many water bodies, there is limited information
regarding nutrient concentrations in wetlands especially
within the soil and vegetation at wetland sites.
Background

1972 Clean Water Act required states to establish
designated uses for water bodies, and to
establish protective criteria for those uses.

1998 Clean Water Action Plan required states to
establish numeric nutrient criteria instead of
narrative criteria.
Background


EPA would like to recommend numeric criteria
be set at the ecoregion level, however some
ecoregions cover broad latitude and longitudinal
areas.
In addition, wetland strata most representative
of nutrient condition across these broad
regional scales is unknown.
U.S. EPA Ecoregions
Ecoregions IX, XII and XIV
N
Southern Temperate Forests
WPlains and
E Hills (IX)
Southern Coastal Plain (XII)
S
Eastern Coastal Plain (XIV)
Rationale

To address this need for consistency and
comparability in the reporting data, as well as
establishment of numeric criteria, an EPAfunded project, Southeastern Wetlands
Biogeochemical Survey, was conducted.

A biogeochemical survey of wetlands of
Southwestern Indiana was conducted as a
geographical subset.
Objectives




Survey dominant wetland types in Southwestern
Indiana
Evaluate appropriate aggregation of wetland
communities
Determine which sampling strata (water, litter, soil,
vegetation) is most responsive to nutrient enrichment.
Contrast Indiana reference wetlands to Southeastern
US wetlands in Ecoregion IX to determine validity of a
single numeric criteria.
Sample Site Selection



Southwestern Indiana Wetland Biogeochemical Survey
Southeastern U.S. Wetlands Biogeochemical Survey
Hydrologic Connectivity



Vegetative Classification



Riparian
Non-Riparian
Swamp
Marsh
Nutrient Condition


Impacted
Least-Impacted
Hydrologic Connectivity


Wetlands were distinguished by hydrologic
connectivity, as riparian or non-riparian.
If the wetland perimeter was located within 40
meters of an adjacent stream or river, it was
classified as riparian.
Vegetative Classification



Based on the dominant vegetative community,
sites were divided into swamps or marshes.
Swamps were characterized by woody vegetation
at least six meters in height.
Marshes were typically emergent wetlands with
erect, rooted, herbaceous hydrophytes present
Vegetative Classification
Riparian Swamp
Non-Riparian Swamp
Non-Riparian Marsh
Vegetative Classification
Riparian Swamp
Non-Riparian Swamp
Non-Riparian Marsh
Sampling Site Selection

Wetland sampling sites were identified by:
Topographical and Aerial Maps
 USFWS National Wetlands Inventory Database
 Indiana Geological Survey’s GIS Atlas.


In consultation with:
Natural resource professionals from the USFWS
 Indiana DNR
 Indiana Chapter of the Nature Conservancy

Wetland Community Types Surveyed
in Southwest Indiana
Impacted
Riparian
Swamp
3
Least
Impacted
2
Riparian
Marsh
0
0
Non riparian
Swamp
1
6
Non riparian
Marsh
1
3
Sampling Sites in Southwestern Indiana
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Wetland Community Types Surveyed in the
Southeastern United States (Greco 2004.)
(Paris 2005).
Ecoregion IX
Riparian Swamp
40
Riparian Marsh
4
14
Non riparian
Swamp
Non riparian
Marsh
3
Southeastern Wetland Biogeochemical Survey
Impacted sites = 94
Least impacted = 115
Eastern Coastal Plain (XIV)
Southern Costal Plain (XII)
Southeastern Forested Plain (IX)
Distribution of Sampling Sites in Both Surveys
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Site Sampling



Sites were surveyed for
twenty biogeochemical
indicators including plant,
litter, soil and water column
nutrient parameters.
An adjacent land use
assessment was conducted
prior to sampling.
Based on characterization of
adjacent land use, the
wetlands were classified as
impacted or least-impacted.
“Reference” Wetlands


Recognizing that all wetlands are impacted by
anthropogenic activities to some degree, it was
presumed that the least-impacted sites would
represent a reference condition that was not
significantly disturbed such that the ecological
integrity of the site is unimpaired.
These reference, or least impacted wetlands can
be used to define EPA’s numeric nutrient
criteria.
Sampling Scheme

Three Transects




Composite Sampling


Transect A (inner
wetland)
Transect B (outer wetland
Upland
Three samples into one
sample/transect
Vegetation Sampling

Throughout wetland
Sampling Scheme
B) Small non-riparian
A) Riparian
(a)
B1
A1
A
B1
Upland
A1
Center
B2
B3 A3
A2
Edge
A2
B2
B3
A3
Ecotone
Upland
(not sampled)
Edge Center River
Upland
A1
B1
A2
B2
Center
A3
B3
Edge
C) Large non-riverine
Sampled Strata

Water


Soil


Top 10 cm of Soil
Litter


Grab sample (if present)
Grab sample
Vegetation

Sampled by species presence
Laboratory Analysis


All samples shipped to Wetland Biogeochemical
Laboratory for analysis
Soil


Litter


TP, TN, TC
Vegetation


Total Phosphorus (TP), Total Nitrogen (TN), Total Carbon (TC)
TP, TN, TC
Water

TP, TN
Objective 1
(Results)
Evaluate appropriate aggregation of wetland
communities:
Water Column
No significant differences in water column TN or TP among the aggregation
Wetlands
Classification
All Wetlands
Total Phosphorus
Total Nitrogen
Mean + 1SD
----- mg/l-----
Mean + 1SD
------ mg/l----
0.295 + 0.169
2.69 + 1.52
Hydrologic
Riparian
0.284 + 0.191
a
2.56 + 1.40
a
Non-Riparian
0.298 + 0.168
a
2.72 + 1.59
a
Swamp
0.327 + 0.180
a
2.77 + 1.68
a
Marsh
0.186 + 0.039
a
2.39 + 0.84
a
Riparian Swamp
0.284 + 0.191
a
2.56 + 1.40
a
Non-Riparian Swamp
0.345 + 0.180
a
2.86 + 1.83
a
Non-Riparian Marsh
0.186 + 0.390
a
2.39 + 0.85
a
Vegetative
Community Type
Significant differences determined by Tukey’s HSD at a = 0.05
Litter
Significant differences were found between riparian and non-riparian TP
Wetlands
Classification
All Wetlands
Total Phosphorus
Total Nitrogen
Mean + 1SD
----- %-----
Mean + 1SD
------ % ----
2.66 + 7.64
1.44 + 0.525
Hydrologic
Riparian
2.88 + 8.32
a
1.28 + 0.44
a
Non-Riparian
2.47 + 6.89
a
1.51 + 0.55
a
Swamp
2.87 + 6.60
a
1.31 + 0.34
a
Marsh
1.69 + 3.18
a
1.85 + 0.78
a
Riparian Swamp
2.88 + 8.32
a
1.28 + 0.44
a
Non-Riparian Swamp
2.86 + 4.05
a
1.33 + 0.28
a
Non-Riparian Marsh
1.69 + 3.18
b
1.85 + 0.78
a
Vegetative
Community Type
Significant differences determined by Tukey’s HSD at a = 0.05
Soil
Significant differences were found between riparian and non-riparian TN
Wetlands
Classification
All Wetlands
Total Phosphorus
Total Nitrogen
Mean + 1SD
----- %-----
Mean + 1SD
------%----
7.78 + 2.19
0.38 + 0.16
Hydrologic
Riparian
7.00 + 1.60
a
0.24 + 0.086
a
Non-Riparian
8.15 + 2.37
a
0.45 + 0.144
b
Swamp
8.00 + 2.46
a
0.36 + 0.16
a
Marsh
7.16 + 1.01
a
0.47 + 0.14
a
Riparian Swamp
7.00 + 1.60
a
0.24 + 0.086
a
Non-Riparian Swamp
8.76 + 2.77
a
0.44 + 0.155
b
Non-Riparian Marsh
7.16 + 1.01
a
0.47 + 0.136
b
Vegetative
Community Type
Significant differences determined by Tukey’s HSD at a = 0.05
Vegetation
No significant differences were found in TN and TP
Wetlands
Classification
Total Phosphorus
Total Nitrogen
Mean + 1SD
----- %-----
Mean + 1SD
------ %----
0.22 + 0.14
a
2.56 + 0.98
Riparian
0.17 + 0.08
a
2.12 + 0.46
a
Non-Riparian
0.23 + 0.15
a
2.66 + 1.05
a
Swamp
0.18 + 0.11
a
2.11 + 0.69
a
Marsh
0.28 + 0.18
a
3.05 + 1.05
a
Riparian Swamp
0.17 + 0.08
a
2.12 + 0.46
a
Non-Riparian Swamp
0.18 + 0.12
a
2.11 + 0.83
a
Non-Riparian Marsh
0.28 + 0.18
a
3.05 + 1.05
a
All Wetlands
a
Hydrologic
Vegetative
Community Type
Significant differences determined by Tukey’s HSD at a = 0.05
Objective 1
(Conclusions)



Based on the results for water column or
vegetation nutrient indicators, separation by
wetland community type does not appear to be
required for assessment.
For litter TP, a distinction should be considered
between riparian and non-riparian wetlands.
For soil TN, a distinction should be considered
between riparian and non-riparian wetlands.
Objective 2
(Results)
Determine which sampling strata (water, litter, soil
or vegetation) is most responsive to nutrient
enrichment :
Nutrient Indicator Strata
Wetland Nutrient Condition
Least Impacted
Impacted
Strata
Nutrient
Water
P%
0.32 + 0.17
0.22 + 0.17
N%
2.89 + 1.63
2.11 + 1.24
P%
2.46 + 0.71
2.88 + 0.81
N%
1.56 + 0.555
1.16 + 0.33
P%
0.60 + 0.12
N%
0.42 + 0.16
P%
0.23 + 0.16
0.19 + 0.09
N%
2.70 + 1.11
2.20 + 0.43
Litter
Soil
Vegetation
*
*
0.86 + 0.21
0.27 + 0.07
There
There
There
There
were
were
were
were
nonosignificant
no
significant
significant
significant
differences
differences
differences
differences
ininwater
in
vegetation
soil
litter
column
TPTP
or TN.
TP
orTP
TN
ororTN
TN.
Objective 2
(Conclusions)


Based on the results, water column, litter and
vegetation samples analyzed for TP and TN do
not indicate nutrient enrichment in wetlands.
Only soils were able to distinguish between
impacted and least-impacted wetlands.
Objective 3
(Results)
Contrast SW Indiana reference wetlands to
Southeastern US wetlands in Ecoregion IX to
determine validity of a single numeric criteria:
Water Column Total Phosphorus
Water column TP was significantly different
0.8
0.7
Total Phosphorus, mg/l
0.6
0.5
b
0.4
0.3
0.2
a
a
0.1
a
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
Water Column Total Nitrogen
Water column TN was not significantly different
14
13
12
11
Total Nitrogen, mg/l
10
9
8
7
6
5
4
a
a
3
a
a
2
1
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
Litter Phosphorus
Litter TP was significantly different among some areas of ecoregion IX
6
Total Phosphorus %
5
4
c
3
bc
c
ab
2
a
1
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
South Carolina
South
Carolina
Litter Nitrogen
Litter TN was significantly different with sites in the state of Florida
3
2.5
Nitrogen, %
2
b
b
b
1.5
ab
a
1
0.5
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
South Carolina
South
Carolina
Vegetative Tissue Phosphorus
Vegetation TP was significantly different from sites in Florida
0.5
Phosphorus, %
0.4
0.3
ab
b
b
0.2
ab
a
0.1
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
South Carolina
South Carolina
Vegetation Tissue Nitrogen
Vegetation TN was significantly different from sites in Florida
4.5
4
Nitrogen, %
3.5
3
b
2.5
ab
b
ab
2
a
1.5
1
0.5
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
South Carolina
South
Carolina
Soils Phosphorus
Soil phosphorus was significantly different among all areas of ecoregion IX
c
Soil TP %
0.1
b
b
a
a
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
South Carolina
South Carolina
Soils Nitrogen
Soil TN was not significantly different
2.5
2
Soil TN
1.5
1
ab
0.5
ab
ab
b
a
0
Indiana
Indiana
Alabama
Alabama
Florida
Florida
State
Georgia
Georgia
South Carolina
South
Carolina
Objective 3
(conclusions)


Significant differences in total phosphorus
concentrations in the water column, litter, and
soil were noted between Least Impacted SW
Indiana wetlands and Least Impacted SE U.S.
wetlands within Ecoregion IX.
The results imply that a single numeric criteria
established for all wetlands within Ecoregion IX
would likely be overly protective of SW Indiana
wetlands.
Implications for EPA in Establishment
of Numeric Nutrient Criteria



In Southwestern Indiana there does not appear to be a
need to sub classify wetlands by hydrologic or
vegetative community type to properly assess nutrient
conditions.
Soils appear to provide the most sensitive indicator of
nutrient impacts to wetlands as compared to water,
vegetation or litter.
A single numeric criteria for ecoregion IX would either
be overly protective or under protective of ecological
integrity based on reference nutrient condition.
Acknowledgements
Committee:
 Mark W. Clark, PhD, Chair
 Ramesh Reddy, PhD
 Matt Cohen, PhD
Colleagues:
 Jeremy Paris
 Stacie Greco
 UF Wetland Biogeochemical
Laboratory
My Wife and Sons:
 Sandra, Sam and Dean