Masters Project

Effect of Restoration Design on Spartina alterniflora
Communities in Pierce Marsh
by
Mary Warwick
Masters Project
Submitted to
Environmental Science Program
University of Houston - Clear Lake
Advisor: Dr. Cynthia Howard
August 10, 2015

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ABSTRACT1
The intent of this project was to determine whether salt water marsh restoration designs affect2
Spartina alterniflora communities. Spartina alterniflora is the dominant plant species in3
saltwater marshes of the Gulf Coast. It grows along the marsh edge, the vegetated area within4
5 meters from the non-vegetated bottom, and promotes the growth of the marsh land by5
collecting sediment as well as provides protection for juvenile nekton to grow. Given that6
Spartina alterniflora is the dominant plant species in saltmarshes of the Gulf Coast, the health7
of Spartina alterniflora can be used as a measurement of the overall health of the marsh.8
Saltwater marshes, as well as other wetlands, face destruction and degradation from urban and9
suburban development, subsidence from ground water extraction, surface mining, oil spills, as10
well as oil and natural gas exploration. Two conservation organizations, The Galveston Bay11
Foundation and The Nature Conservancy of Texas, bought land known as Pierce Marsh as a12
study area to compare natural marsh that has been untouched to reconstructed marshes13
differing in design and construction. Subsidence due to ground water extraction and suburban14
sprawl destroyed Piece Marsh and left it as open water. Construction of restoration designs15
began in 1999 and continued until 2009. There are five restored sites and one reference site in16
Pierce Marsh. Three locations, or berms, were randomly selected at each site. At each location17
a 20 m transect was set perpendicular to the marsh edge. Three points were marked along the18
transect, 10 meters apart. These points were called stations. This gave 9 points of data19
collection at each site; 54 points of data collection total. At each point, on each transect, at20
each location, at each site: a ¼ m2
plot made of PVC pipe was laid to the left of the point and all21
plants in the plot were identified and their relative coverage was determined and recorded.22
Spartina alterniflora importance values, species richness, Shannon Diversity Index, Pielou’s23
Index of Evenness, and Jaccard’s Coefficient of Community Similarity were calculated for each24
site. These parameters were then used to compare the restored sites to the reference site, the25
restored sites among themselves and the current data to the data obtained in 2008. Overall,26
the five restored sites fell short of showing significant similarities to the reference site over the27
majority of the compared parameters. In fact, each parameter had only one site that showed28
significant similarities to the reference site. The two oldest sites, grid and sinusoidal, had29
significant differences in their parameters from the reference site in 2013 and showed trends of30
the values dropping and the differences becoming greater between 2008 and 2013. This data31
indicated that these sites were degrading over time. The two zig zag sites showed low Spartina32
alterniflora importance values, but positive trends in mean species richness, Shannon Diversity33
Index and the Pielou’s Index of Evenness values over time, thus closer to replicating the34
reference site than the grid and sinusoidal sites. The beneficial uses site was the only site that35
had a significantly similar Spartina alterniflora importance values, along with significantly36
similar relative coverage and frequency values as well as positive trends in mean species37
richness, Shannon Diversity Index and the Pielou’s Index of Evenness values over time. It most38
closely replicated the reference site. The results of this study can be used by The Galveston Bay39
Foundation, as well as other organizations that restore salt marshes, in determining the40
constructed salt marsh design that most closely emulates natural salt marshes. Having this41
information will save these organizations valuable resources by directing them to the most42
successful design(s) for future salt marsh restorations.43

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INTRODUCTION1
2
Saltmarshes3
Salt, or tidal, marshes are coastal wetlands that experience cycles of flooding and draining4
as tides bring salt and brackish water in and out of the system. Salt marshes exist in protected5
areas where terrestrial, fresh water and marine ecosystems converge (Greenberg et al., 2006).6
Sediments begin to deposit in these areas, which promotes the establishment of plant7
communities. These plant communities help prevent erosion caused by wave action and8
provide a nursery area for many nekton species. In addition, salt marshes provide nesting areas9
for migratory birds, biologically break down pollutants from inflows, serve as a carbon sink, play10
a role in the cycling of nitrogen, and act as a reservoir for flood waters which reduces damage11
to upland habitats (Cullinan et al., 2004, Lester and Gonzales, 2002). Salt marshes have three12
distinct bottom matrices: marsh edge, submerged aquatic vegetation and shallow non-13
vegetated bottom. Juvenile brown shrimp, Farfantepenaeus aztecus, are thought to have14
higher densities in submerged aquatic vegetation where sea grasses are present. However,15
Caldwell et al. (2004) found that the brown shrimp densities in the marsh edge, which is the16
area not more than 5 meters from the Spartina alterniflora growth, are not significantly17
different than the submerged aquatic vegetation. Submerged aquatic vegetation bottom18
configurations account for only 4.5 km2
of the Galveston Bay system, whereas marsh edge19
configurations make up 84.9 km2
. This study demonstrates the importance of marsh edge20
habitats to area nekton.21
22
23

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Spartina alterniflora1
Saltwater marshes make up one-tenth-of-one-percent of the Earth’s surface, 45,0002
km2
. However, this small percentage belies the importance of these precious ecosystems. Salt3
water marshes help prevent erosion of upland habitats, provide a nursery area for many nekton4
species, provide nesting areas for migratory birds, biologically break down pollutants from5
inflows, serve as a carbon sink, play a role in the cycling of nitrogen, and act as a reservoir for6
flood waters which reduces damage to upland habitats. Saltwater marshes cover 16,000 km2
of7
the United States, with the majority of this coverage in the South Atlantic and Gulf Coast8
regions (Greenberg et. al, 2006). A smooth cordgrass, Spartina alterniflora, is the dominant9
species in salt marshes of the Gulf Coast. Spartina alterniflora is a monocot from the grass10
family, Poaceae. It can range in height from 0.2 m to 3 m tall (Davis, 1998). The height is11
usually dependent on habitat conditions such as water level, flood frequency, water salinity, as12
well as, soil nitrogen and sulfide concentrations (Mendelssohn et al., 2002). Small plants grow13
in high, dry areas where as taller plants grow at the water’s edge. The Spartina stem grows14
vertically with leaves growing at approximately at 45° angle from the stem (figure 1a). The15
leaves are flat and smooth with parallel venation and salt glands in the epidermal layers. These16
salt glands aid in the removal of excess salts that tend to accumulate inside the plants as the17
roots take in sodium and other salts from the water (figure 1b) (Mendelssohn et al., 2002;18
Davis, 1998).19
20
21
22

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1
Figure 1: (a) Detailed drawing of Spartina alterniflora showing the stem, leave, flower, rhizome,2
and root structures. Photo credit of the USDA Agriculture Yearbook, Fig. 19.3
(b) Close up photograph of Spartina alterniflora showing salt crystal formation on its leaf.4
Photo credit of Joseph DiTomaso.5
6
Spartina grow in clonal colonies attached by an extensive network of rhizomes that run7
horizontally under the soil. The rhizomes anchor the plant in place and allow the plants to8
propagate asexually, store nutrients and survive during difficult conditions when the stems and9
leaves may not be able to survive (Davis, 1998). The Spartina stem grows up from the rhizome10
and the roots grow down. Spartina alterniflora have anchoring roots as well as hair-like11
absorbing roots. The biomass of the roots in healthy Spartina is greater than the biomass of the12

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stem and leaves. Spartina propagate sexually as well, using wind and water dispersion to1
disseminate their seeds.2
Spartina alterniflora live in waterlogged conditions causing the soil to have very low3
oxygen levels. Spartina have adapted to the anoxic conditions by developing an internal tube4
system, called Aerenchyma (figure 2). The internal air spaces of the tubes, called lacunae, carry5
oxygen from the leaves to the roots (Mendelssohn et al., 2002; Davis, 1998).6
7
8
Figure 2: Aerenchyma tissue from Spartina alterniflora showing airspaces, lacunae, which9
transports oxygen from the leaves to the roots. Photo credit: I. Mendelsson10
11
As mentioned previously, salt marshes form as sediments begin to deposit in protected12
areas where terrestrial, fresh water and marine ecosystems converge. The sediments promote13
the development of plant communities. However, Spartina alterniflora also promotes the14
accumulation of sediment and acts as an “environmental engineer” (Mendelssohn et al., 2002).15
As Spartina grows farther away from the dry land of the marsh and into the water, more16

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sediment accumulates which allows for other species to inhabit the new area. As this build-up1
of sediment continues to occur, new land is created. Larger species are then able to inhabit this2
new land and the Spartina continues to grow outward from the land (Mendelssohn et al., 20023
and Davis, 1998).4
5
The Problems Facing Salt Marshes6
Saltwater marshes, as well as other wetlands, face destruction and degradation from urban7
and suburban development, subsidence from ground water extraction, surface mining, oil spills,8
as well as oil and natural gas exploration (Craft et al., 1999 and 2003). According to Costanza9
et. al. (2014) the global area of tidal marshes decreased from 165 million hectares to 12810
million hectares between the years of 1997 and 2011. Many attempts have been made to11
recreate salt marshes that were lost. Most of these marshes are constructed from dredge12
material that is moved from another source. However, some marshes are constructed using13
soil from the existing area and building up terraced areas. In both cases, berms are built up14
from the soil and Spartina alterniflora is planted along the edge of the berms to begin the15
process of sediment accumulation and plant propagation.16
17
Terraced versus Dredge Material Construction18
Terraced marshes are created by excavating sub-tidal, non-vegetated, sediments and19
forming them into ridges at specific heights and slopes as to allow flooding at high tide and the20
planting of marsh vegetation, specifically Spartina alterniflora (figures 3 and 4). The area from21

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which the sediment was taken, the borrow area, will fill with sediment as the hydrology moves1
in and out of the marsh (Gossman, 2000).2
3
4
5
6
7
8
9
Figure 3: Diagram of cross-section of the terrace design used at Pierce Marsh. Measurements10
given are National Geodetic Vertical Datum (NGVD) which uses mean sea level as the baseline.11
Mean low water level, mean high water level, terrace elevation, and terrace slope are given.12
Howard and Dobberstine. 2008.13
14
15
16
17
18
19
20
21
22
23
Figure 4: Digging from the borrow area to create a terraced marsh design. Photo credit: Dan24
Heilman and Jerry Hauske, 2010.25

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The dredge material technique is the older of the two techniques. Dredge material1
marshes are created by taking sediment that has been excavated from another location and2
blowing it into the open water to create a marsh (figure 5). The term “beneficial uses” refers to3
putting excavated sediment from another location to good use by using it to create new marsh4
lands. While terraced designs are formed by using sediment that is already established in the5
marsh, dredge material designs use large amounts of sediment that is brought in from another6
location. Therefore, the parameters important to soil morphology and chemistry are already7
present in the sediment in the terrace. Benthic organisms are also present in this sediment,8
possibly giving it a head-start in providing food chain support. Dredge material is usually9
brought in from a far enough distance that the sediment does not have the same soil10
morphology or chemistry and may take longer to establish.11
12
13
14
15
16
17
18
19
20
21
Figure 5: Blowing dredged material into open water to create a dredge material marsh. Photo22
credit: Dan Heilman and Jerry Hauske, 2010.23

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Rozas and Minello (2001) stated that marshes created with dredge material becomes1
established at a faster rate than terraced marshes and can become a suitable habitat for nekton2
more quickly. However, this technique provides less marsh edge than the terraced design and3
therefore less protection as a nursery area. Streeter (2000) found that three parameters were4
important when using dredge material for marsh construction: site location, protection from5
wave energy, and elevation. Overall, he found there were significant differences between6
natural marshes and dredge material marshes: Spartina alterniflora above and below ground7
biomass, carbon measurements in the sediment, as well as polychaete and crustacean8
densities were all lower in the dredge material marshes. The dredge material marshes also9
attracted different species of birds than did the natural marshes.10
Rozas and Minello (2001) stated that marshes created with dredge material lacked11
sufficient marsh edge habitat, making them inferior to terraced marshes which have12
considerable edge habitat. The marsh edge is considered to be the vegetated area within 513
meters from the non-vegetated bottom (Merino, et al., 2010). It is this critical area of a marsh14
that provides protection from predation for many nekton species that depend on marshes for15
nursery areas. Whaley and Minello (2002) found that the area within he first meter of the16
vegetated area is the most productive for benthic organisms. Furthermore, terraced marshes17
have been shown to reduce wave height, wave fetch (length), decrease turbidity, promote18
deposition and retention of sediments, and decrease erosion in marshes (Rozas and Minello,19
2001 & Gossman, 2000).20
21
22

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Comparing Constructed vs. Natural Marshes1
Craft et. al. (1999) compared two locations that contained marshes created from dredge-2
material and natural salt marshes in coastal North Carolina. Snow’s Cut was created in 19713
and Pine Knoll Shores was created in 1974. In following the progression on these marshes,4
Craft et. al. found that the created marshes and the natural marshes had no significant5
difference in their Spartina alterniflora biomass above ground level within a few years.6
However, root biomass, macro-organic matter, benthic macro-organisms, and soil chemistry7
took longer to mature. At the twenty-five year mark, they found all parameters to be8
statistically similar in the created and natural marshes with the exception of soil nutrients9
which were still lower in the constructed marshes.10
Shafer and Streeter (2000) compared fourteen marshes created from dredge-material, aged11
1 to 23 years, and fourteen natural salt marshes along the Texas Gulf Coast. The parameters of12
comparison were edge area ratios, relative exposure index values, elevation profiles, total soil13
organic carbon, silt-clay content, and underground plant biomass. Relative exposure index14
values refer to the annual wind speed at the location which could affect erosion. They found no15
significant difference in edge area ratios, relative exposure index values as well as total soil16
organic carbon/ silt-clay content. However, there were significant differences in the elevation17
profiles and underground plant biomass. Elevation profiles of the created marsh berms tended18
to be higher than those in natural marshes. Shafer and Streeter (2000) warn that exceptionally19
high berms can lead to premature bird inhabitants, limited nekton activity and interruption of20
normal sediment and nutrient movement. The underground biomass difference showed higher21
underground biomass in the natural marshes, even when comparing the 23 year-old created22

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marsh. The underground biomass is important because Spartina alterniflora depend on the1
underground biomass to survive during unfavorable conditions. Shafer and Streeter (2000)2
stated that their review of literature showed that the underground biomass difference usually3
disappears by age 30 in created salt marshes.4
5
Local Marshes6
The Galveston Bay system has approximately 130,400 acres of marshlands. It has lost7
45,000 acres since 1950 (White, et al., 1993). The Galveston Bay Foundation is a 501(c)(3) non-8
profit organization that was established in 1987 and has been restoring marshes in the9
Galveston Bay area since 1991. They have had much success planting Spartina alterniflora on10
existing marsh edges to aid in the advancement of the marsh and prevent erosion. They have11
also has some successes in creating marshes that have previously been destroyed. Examples of12
these are Burnet Bay, Delhide Cove and Dickinson Bay Island. However, The Galveston Bay13
Foundation wanted to determine the restoration design that provides the closest replication of14
a natural marsh. Pierce Marsh was acquired by The Nature Conservancy of Texas and The15
Galveston Bay Foundation from 1987 to 1998 (Lester and Gonzales, 2002). Subsidence due to16
ground water extraction and suburban sprawl destroyed Piece Marsh and left it as open water17
(Lester and Gonzales, 2002). Construction of restoration designs began in 1999 and continued18
until 2009. At present, there are five restored sites and one reference site in Pierce Marsh.19
Data on sediment composition, bethic macroinvertebrate communities and plant communities20
are collected every five years to follow the development of the designs (Howard and21
Dobberstine, 2008). In 2008, Howard and Dobberstine found that restoration design affected22

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the Spartina alterniflora coverage more than the age of the site. The reference site had the1
40% Spartina alterniflora coverage, the dredge material - beneficial uses site had 50% coverage,2
the zig-zag terraced site had 30% coverage, the sinusoidal terraced site had 15% coverage, and3
the grid terraced site had 10% coverage. The dredge material - beneficial uses site was the4
youngest site yet had the highest Spartina alterniflora coverage of all of the sites. The grid was5
the oldest site and had the lowest coverage.6
7
8
Significance of project / need for project9
Craft, et al. (2003) suggested a need for long-term monitoring of constructed marsh10
projects to determine whether constructed marshes function as natural marshes. This11
suggestion was made due to the significant lag time that occurs before constructed marshes12
begin produce the same benefits as natural marshes. Over 1,000 acres of shoreline and13
tributaries in the Galveston Bay area have had some degree of marsh restoration (Lester and14
Gonzales, 2002). These restoration projects require a large investment of resources.15
Determining which marsh restoration design most closely replicates a natural marsh will assure16
that resources are used wisely in restoring salt water marshes. Pierce Marsh is unique in that 517
constructed marsh designs can be compared within a small area that has the same geomorphic18
position, anthropomorphic stressors, salinity, water quality, water craft traffic, and weather19
conditions. Prior to this study, the sites have not been compared since 2008. Since then, one20
site has been added and Hurricane Ike damaged the surrounding area. It was not known how21

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each site is progressing at this point in time or if the restoration design was still continuing to1
affect the Spartina alterniflora coverage more than the age of the site.2
Given that Spartina alterniflora is the dominant plant species in saltmarshes of the Gulf3
Coast and all of the above mentioned parameters of salt marsh health are interconnected, the4
health of Spartina alterniflora can be used as a measurement of the overall health of the marsh.5
The results of this study can be used by The Galveston Bay Foundation, as well as other6
organizations that restore salt marshes, in determining the constructed salt marsh design that7
most closely emulates natural salt marshes. Having this information will save these8
organizations valuable resources by directing them to the most successful design(s) for future9
salt marsh restorations.10
11
12
Specific Objectives13
1. Use Spartina alterniflora importance values to compare the restored sites to the14
reference site, the restored sites among themselves and the current data to the data15
obtained in 2008.16
2. Use species richness, Shannon Diversity Index, Pielou’s Index of Evenness, and Jaccard’s17
Coefficient of Community Similarity to compare the restored sites to the reference site,18
the restored sites among themselves and the current data to the data obtained in 2008.19
20
21

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MATERIALS AND METHODS1
2
Site Description – Galveston Bay3
The Galveston Bay system (figure 6a) is located along the upper Texas coast. Its 2,020 km2
4
area makes it the 7th
largest estuary in the United States. The system includes Upper Galveston5
Bay, East Bay, West Bay, Trinity Bay, and Christmas Bay and is fed by the 62,159.70 km2
6
Galveston Bay watershed. Each one of the bays in the system offers differing vegetation as a7
result of their different bottom matrix, including oyster reef, mangroves, tidal mudflats, sub-8
tidal bay bottoms, intertidal marshes, and submerged aquatic vegetation (Caldwell et. al, 2004).9
10
Site Description - Pierce Marsh11
Pierce Marsh (figure 6b) is located north of West Bay, between the communities of12
Hitchcock and Bayou Vista, Texas. It is flanked on the north and east by Texas Highway 6 and13
Interstate 45, respectively. It is approximately 7.5 km from the Texas City, Texas petrochemical14
industrial complex. Pierce March, which encompasses 2,346 acres, is an intertidal salt marsh15
that serves as a nursery for many of the nekton and shellfish species that live in the Galveston16
Bay system (Merino, et al., 2010; Galveston Bay Foundation). As with other marshes of the Gulf17
Coast, Spartina alterniflora is the dominant plant species. Fresh water inflows from Highland18
Bayou and an adjacent smaller bayou come from the north while tidal flows come from the Gulf19
of Mexico via San Luis Pass and Galveston’s West Bay to the south (Lester and Gonzales, 2002).20
21
22

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1
Figure 6: a) Map of the Galveston Bay System showing Galveston Bay, Trinity Bay, East Bay,2
West Bay and Christmas Bay. The yellow star marks the location of Pierce Marsh. Photo credit:3
Texas A&M Galveston Bay Information Center, 2014. b) Map showing the location of the Pierce4
Marsh, north of West Bay, 29°19’ N, 94°57W, 2014.5
6
7
Pierce Marsh has one reference site, which is an area of the marsh that did not subside8
and has continued to develop undamaged, and five restored sites. PRC 1 is the reference site9
(figure 7 (1); figure 8) and is in the northeast corner of the marsh, closest to Highway 6. PRC 210
was constructed in 2004 and is a restored site made from terraced berms built in a zig-zag11
pattern (figure 7 (2); figure 8). PRC 3 was constructed in 1999 and is a restored site made from12
terraced berms built in a grid pattern (figure 7 (3); figure 8). PRC 4 was constructed in 2001 and13
is a restored site made from terraced berms built in a sinusoidal pattern (figure 7 (4);14
15

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1
Figure 7: Map of Pierce Marsh showing the Reference Site (1), Zigzag berms, 2004 (2), Grid2
berms, 1999 (3), Sinusoidal berms, 2001 (4), Beneficial uses berms, 2005 (5), and Zigzag berms,3
2009 (6). 2014.4
5
figure 8). PRC 5 was constructed in 2005 and is a restored site made from dredge material built6
in a large area surrounded by temporary berms for protection against wave action (figure 7 (5);7
figure 8). PRC 6 was constructed in 2009 and is a restored site made from terraced berms built8
in a zig zag pattern (figure 7 (5); figure 8).9
10
11

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1
Figure 8: Photos of the reference site and 5 reconstructed sites at Pierce Marsh. Site names,2
numbers and dates of installation included with each picture. Photo credit: Mary Warwick,3
2013.4
5
6

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Other Plant Species in Pierce Marsh1
While Spartina alterniflora was the dominant plant species in salt marshes, many other2
plants inhabited Pierce Marsh. Salicornia virginica, creeping glasswort; Salicornia bigelorii,3
annual glasswort; Batis maritina, saltwort; Distichlis spiccta, coastal salt grass; Borrichia4
frutescens, sea-oxeye-daisy; Sesuvim maritum, sea purslane; and Solidago sempervirens,5
seaside goldenrod were all represented in plots throughout the marsh (figure 9). Spartina6
alterniflora inhabited the mid and lower elevations of the marsh, which were prone to regular7
flooding. The other plants species of the marsh tended to inhabit the dryer, higher elevations.8
Like Spartina alterniflora, each plant species in the marsh had its own set of adaptions for9
surviving in the salt marsh envrionment.10
11
12
13
14
15
16
17
18
19
20
21
22

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1
Figure 9: Plant species observed at Pierce Marsh in addition to Spartina alterniflora.2
Photo credit: Mary Warwick, 2013 unless otherwise indicated.3
4
5

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Methodology1
Plot-transect sampling was used to collect data. Three locations, or berms, were2
randomly selected at each site. At each location a 20 m transect was set perpendicular to the3
marsh edge (figure 10).4
5
Figure 10: Setting the 20 meter transect on the first berm of the grid site. Photo Credit: Mary6
Warwick7
8
9
Three points were marked with orange flags along the transect, 10 meters apart (figure 11).10
These points were called stations. This gave 9 points of data collection at each site; 54 points of11
data collection total.12
13

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1
Figure 11: Second berm of beneficial uses site showing the three stations marked with orange2
flags. Photo Credit: Mary Warwick3
4
5
At each point, on each transect, at each location, at each site: a ¼ m2
plot made of PVC6
pipe (figure 12) was laid to the left of the point and all plants in the plot were identified and7
their relative coverage was determined and recorded. The percentage of bare ground and8
detritus were also recorded. The comparison year, 2008, had 18 points of data collection at9
sites 1 through 4 and 12 points of data collection at site 5.10
11

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1
2
3
4
5
6
7
8
9
10
Figure 12: A ¼ m2 plot made of PVC pipe similar to the one used in this study. Photo Credit:11
Mary Warwick12
13
14
Data Analysis15
Measures of importance were calculated using Microsoft Excel 2010 and analyzed first.16
The Spartina alterniflora relative frequency and relative coverage were calculated for each site17
(table 1, appendix II). Relative frequency refers to the frequency of a given species as a18
proportion of the sum of the frequencies of all species. It was calculated by determining the19
frequency of the species being studied using the formula fi=ji/k, where ji is the number of plots20
in which species i occurs and k is the total number of plots sampled. The frequency is then21
divided by the sum of all of the frequencies observed in the study area to obtain the relative22
frequency. Relative coverage refers to the coverage of a given species expressed as a23

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proportion of the total coverage for all species. It was determined in the field by taking the1
percent coverage. The importance value is a measure of a species dominance in the2
community and was calculated using the formula IVi= Rfi+RCi (Brower et. al., 1998, appendix II).3
Measures of diversity were calculated and analyzed next (table 1). The species richness4
at each plot, number of species present, was determined and recorded in the field. The mean5
species richness was calculated for each site using the data from the various plots (appendix6
IV). The Shannon-Weiner Diversity Index is a measurement of species diversity using species7
richness and relative abundance, where pi is the relative abundance. It was calculated using the8
formula H’=-∑(pi)[(ln(pi)] (appendix VI). Since numbers of individuals were not counted at the9
sites, pi was calculated by using the percent coverage data obtained in the field. (Brower et. al.,10
1998). Pielou’s Index of Evenness measurement was calculated using the formula E=H’/Hmax11
(appendix VI). Evenness is a measurement of equitability among species in the community12
using the Shannon-Weiner Function, where Hmax is the species diversity under maximum13
equitable conditions and is calculated by taking the natural log of the number of species in the14
community (Brower et al., 1998). The Jaccard’s Coefficient of Community Similarity is a15
measurement of how similar communities are based on the number of species common to all16
communities (appendix VIII). It was calculated using the formula CCj=c/S, where c is the17
number of species common to all communities and S is the total number of species found in all18
communities (Brower et. al., 1998).19
Histograms for each parameter were produced in Microsoft Excel 2010 as well.20
Descriptive statistics were run on the results of each parameter to obtain the standard error21

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Measure
Frequency (fi) fi=ji/k ji=number of samples in which species i occurs, k=total number
Relative Frequency (Rfi) Rfi=fi/∑f
Coverage (Ci) Ci=ai/A
Relative Coverage (RCi) RCi=Ci/TC=Ci/∑C
Importance Value (IVi) IVi=Rfi+RCi
Species Richness (s)
Shannon Diversity Index (H') H'=-∑pi ln pi
pi =ni /N
Pielou’s Index of Evenness E=H’/Hmax
Jaccard’s Coefficient of Community Similarity CCj=c/S
of species common to all communities
c = the number of species common to all communities
S = the total number of species found in all communities
(Brower et al, 1998)
N= total number of individuals
Hmax is the species diversity under maximum equitable conditions
and is calculated by taking the natural log of the number of species
in the community
measurement of how similar communities are based on the number
Percent coverage calculated in the field used
for relative coverage
number of species present
pi = proportion of the total number of individuals occuring in species i
ni =number of individuals representing species i
Percent coverage calculated in the field
used for pi
Differences from Brower Used in StudyBrower Equations and Description
Measures of Importance
Measures of Diversity
of samples (plots)
ai=total area covered by species i, A=total habitat sampled
TC=∑C=total coverage for all species
measurement. Error bars were added to the histograms, using the standard error1
measurements, to compare the significant similarities and differences in the data obtained.2
3
Table 1: Formulas for relative frequency, relative coverage, importance values, species richness,4
Shannon Diversity Index, Pielou’s Index of Evenness, and Jaccard’s Coefficient of Community5
Similarity. Brower et. al., 1998.6
7
8
RESULTS9
10
Objective 1: Use Spartina alterniflora importance values to compare the restored sites to the11
reference site, the restored sites among themselves and the current data to the data obtained12
in 2008.13
14
Importance Values in 2013:15

26 | P a g e
When comparing the Spartina alterniflora importance values for 2013, the reference1
site had the highest Spartina alterniflora importance value at 71.2% (table 2). Its high relative2
coverage, 46.9%, was responsible for its high importance value (figure 14) and was the highest3
of all of the sites. Its relative frequency, 24.3%, was the third highest and was identical to the4
2004 zig zag site.5
The beneficial uses site had the second highest Spartina alterniflora importance value at6
60.9% (table 2). This was not significantly different from the reference site (figure 13). Its high7
relative coverage, 33.7%, was the second highest of the sites and not significantly different than8
the reference site (figure 16). Its relative frequency, 27.3%, was the highest of all of the sites9
(table 2) but was significantly similar to the reference site and the two zig zag sites (figure 15).10
Coverage and frequency played an equal role in contributing to the importance value at this site11
(figure 14).12
The 2004 zig zag site had the third highest Spartina alterniflora importance value at13
34.9% (table 2). This was most similar to the 2009 zig zag site; however, it was not significantly14
different than the sinusoidal site (figure 13). Its relative frequency, 24.3%, was responsible for15
its importance value (figure 14). As stated earlier, it was the third highest of the sites and16
identical to the reference site. Its relative frequency was also significantly similar to the17
beneficial uses site and the 2009 zig zag site (figure 15). Its relative coverage, 10.6%, was the18
third highest of the sites but significantly lower than that of the reference and beneficial uses19
sites. Its relative coverage was most similar to the zig zag site of 2009; however, was not20
significantly different than the grid or the sinusoidal sites (figure 16).21

27 | P a g e
The 2009 zig zag site had the fourth highest Spartina alterniflora importance value at1
32.9% (table 2). This was most similar to the 2004 zig zag site; however, it was not significantly2
different than the sinusoidal site (figure 13). Its relative frequency, 25.8%, was the second3
highest of the sites and was responsible for its importance value (figure 14). Its relative4
frequency was significantly similar to that of the reference site, the beneficial uses site and the5
2009 zig zag site (figure 15). Its relative coverage, 7.1%, was the fourth highest of the sites and6
was most similar to the zig zag site of 2004. However, its relative coverage was not significantly7
different than the grid or the sinusoidal sites (figure 16).8
The sinusoidal site had the fifth highest Spartina alterniflora importance value at 19.1%9
(table 2). This was most similar to the grid site: however, it was not significantly different than10
the two zig zag sites (figure 13). Its relative frequency, 16.7%, was the fifth highest of the sites11
and was responsible for its importance value (figure 14). Its relative frequency was also12
significantly similar to the grid site (figure 15). Its relative coverage, 2.4%, was also the fifth13
highest but did not contribute significantly to its importance value (figure 14). Its relative14
coverage was most similar to the grid site; however, it was not significantly different from the15
zig zag sites (table 16).16
The grid site had the lowest Spartina alterniflora importance value at 14.0% (table 2).17
This was significantly similar to the sinusoidal site (figure 13). Its relative frequency, 12.2%, was18
also the lowest of the sites but responsible for its importance value (figure 14). This was also19
significantly similar to the sinusoidal site (figure 15). Its relative coverage, 1.8%, was again the20
lowest of the sites and did not contribute much to its importance value (figure 14). Its relative21

28 | P a g e
Relative
frequency
Relative
Coverage
Importance
Values
PRC 1 Reference 0.243 0.469 0.712
PRC 2 Zig Zag 2004 0.243 0.106 0.349
PRC 3 Grid 0.122 0.018 0.140
PRC 4 Sinusoidal 0.167 0.024 0.191
PRC 5 Beneficial Uses 0.273 0.337 0.609
PRC 6 Zig Zag 2009 0.258 0.071 0.329
2013 Spartina alterniflora Measures of Importance
Site
coverage was most similar to the sinusoidal site; however, it was not significantly different from1
the zig zag sites (table 16).2
When comparing the age of the restored sites to the Spartina alterniflora relative3
coverage values, the grid site, the oldest site, had the lowest relative coverage value, 1.78%.4
The sinusoidal site, the second oldest site, had the second lowest Spartina alterniflora relative5
coverage value, 2.44%. The 2009 zig zag site, had the third lowest Spartina alterniflora relative6
coverage value, 7.11%. The 2004 zig zag site, had the fourth lowest Spartina alterniflora7
relative coverage value, 10.56%. The beneficial uses site, the second to the newest site, had8
the highest Spartina alterniflora relative coverage value, 33.67 % (figure 17).9
10
11
Table 2: Comparing relative frequency, relative coverage, and importance values for Spartina12
alterniflora between the reference site and the restored sites. 2013. Pierce Marsh.13
14
15
16
17
18
19
20
21
22
23
24

29 | P a g e
Figure 13: Comparing importance values of Spartina alterniflora among the six sites at Pierce1
Marsh showing the standard error bars for significance comparison. 2013.2
3
4
5
6
7
8
9
10
11
12
13
14
Marsh using relative coverage and relative frequency. 2013.16
17

30 | P a g e
1
2
3
4
5
6
7
8
9
Figure 15: Comparing relative frequency values of Spartina alterniflora among the six sites at10
Pierce Marsh. 2013.11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Figure 16: Comparing relative coverage values of Spartina alterniflora among the six sites at31

31 | P a g e
1
2
3
4
5
6
7
8
Figure 17: Comparing relative coverage values of Spartina alterniflora among the five9
constructed sites by year built at Pierce Marsh. 2013.10
11
12
Importance Values 2008 to 2013:13
When the Spartina alterniflora importance values for 2008 and 2013 are compared, the14
reference site had a Spartina alterniflora importance value of 72.1% in 2008 and 71.2% in 201315
(table 3). This was a decrease of 0.9%; the lowest of all of the sites. The Spartina alterniflora16
relative frequency dropped by 6.7% while the relative coverage increased by 5.8% (table 3 and17
figure 18).18
The 2004 zig zag site had a Spartina alterniflora importance value of 68.1% in 2008 and19
34.9% in 2013 (table 3). This was a decrease of 33.2%. This was the second highest decrease of20
the sites. The Spartina alterniflora relative frequency dropped by 13.2% while the relative21
coverage decreased by 20.0% (table 3 and figure 18). The 2004 zig zag site was the most similar22
site to the reference site in 2008; however, this was no longer the case in 2013 (figure 18). The23

32 | P a g e
drop in relative coverage had the most significant impact in this difference (table 3 and figure1
19).2
The grid site had a Spartina alterniflora importance value of 31.5% in 2008 and 14.0% in3
2013 (table 3). This was a decrease of 17.6%. This was the fourth highest decrease of the sites.4
The Spartina alterniflora relative frequency dropped by 11.2% while the relative coverage5
decreased by 6.4%. The drop in relative coverage had the most significant impact on Spartina6
alterniflora importance values at this site (table 3 and figure 19). The grid site was similar to7
the sinusoidal site in 2008 and 2013 (figure 18).8
The sinusoidal site had a Spartina alterniflora importance value of 41.4% in 2008 and9
19.1% in 2013 (table 3). This was a decrease of 0.25. This was the third highest decrease of the10
sites. The Spartina alterniflora relative frequency dropped by 10.6% while the relative coverage11
decreased by 11.7%. The two parameters had an equal role on the impact on Spartina12
alterniflora importance values at this site (table 3 and figure 19). The sinusoidal site was similar13
to the grid site in 2008 and 2013 (figure 18).14
The beneficial uses site had a Spartina alterniflora importance value of 100% in 200815
and 60.9% in 2013 (table 3). This was a decrease of 39.1%. This was the highest decrease of16
the sites. The Spartina alterniflora relative frequency dropped by 22.7% while the relative17
coverage decreased by 16.3%. Again, the two parameters had an equal role on the impact on18
Spartina alterniflora importance values at this site (table 3 and figure 19).The beneficial uses19
site was not significantly similar to the reference site in 2008; however, it was in 2013 (figure20
18). The reference site had a 36.3% larger relative coverage in 2013; however, their relative21
frequencies were identical (table 3).22

33 | P a g e
2008 2013 % Change 2008 2013 % Change 2008 2013 % Change
PRC 1 0.310 0.243 -0.067 0.411 0.469 0.058 0.721 0.712 -0.009
PRC 2 0.375 0.243 -0.132 0.306 0.106 -0.200 0.681 0.349 -0.332
PRC 3 0.234 0.122 -0.112 0.082 0.018 -0.064 0.315 0.140 -0.176
PRC 4 0.273 0.167 -0.106 0.141 0.024 -0.117 0.414 0.191 -0.223
PRC 5 0.500 0.273 -0.227 0.500 0.337 -0.163 1.000 0.609 -0.391
PRC 6 n/a 0.258 n/a n/a 0.071 n/a n/a 0.329 n/a
Relative frequency Relative Coverage Importance Values
Spartina alterniflora Measures of Importance
When comparing the age of a restored sites to the change in Spartina alterniflora1
importance values between 2008 and 2013, the oldest site, the grid site, had the smallest2
decease in importance value, 17.6%. The sinusoidal site, the second oldest site, had the second3
smallest difference, 22.3%. The 2004 zig zag site, the third oldest site, had the third smallest4
difference, 33.2%. The beneficial uses, the newest comparable site, had the largest difference,5
39.1% (figure 20).6
The Spartina alterniflora importance values could not be compared for the 2009 zig zag7
site as it was built after the 2008 data was obtained.8
9
10
11
12
Table 3: Comparing relative frequency, relative coverage, and importance values for Spartina13
alterniflora in years 2008 and 2013. Pierce Marsh.14
15
16
17
18
19
20
21

34 | P a g e
1
2
3
4
5
6
7
8
Marsh for the years 2008 and 2013.10
11
12
13
14
Marsh, using relative coverage and relative frequency for the years 2008 and 2013.16

35 | P a g e
1
2
3
4
5
6
7
8
Figure 20: Comparing the age of the restored sites to the percent decrease in Spartina9
alterniflora importance values between the years 2008 and 2013. Pierce Marsh.10
11
12
Objective 2: Use species richness, Shannon Diversity Index, Pielou’s Index of Evenness, and13
Jaccard’s Coefficient of Community Similarity to compare the restored sites to the reference14
site, the restored sites among themselves and the current data to the data obtained in 2008.15
16
Species Richness 2013:17
When comparing the species richness values for 2013, the sinusoidal site had the18
highest mean species richness value at 2.89. The grid site had the second highest mean species19
richness value at 2.67. The sinusoidal and grid sites had significantly similar species richness20
values. The reference site had the third highest mean species richness value at 2.22. The 200421
zig zag site had the fourth highest mean species richness value at 2.11. The reference and 200422
zig zag site had significantly similar species richness values. The beneficial uses site had the fifth23

36 | P a g e
Richness
PRC 1 Reference 2.22
PRC 2 Zig Zag 2004 2.11
PRC 3 Grid 2.67
PRC 4 Sinusoidal 2.89
PRC 5 Beneficial Uses 1.67
PRC 6 Zig Zag 2009 1.44
Mean Species Richness 2013
Site
highest mean species richness value at 1.67. The 2009 zig zag site had the lowest mean species1
richness value at 1.44. The beneficial uses and 2009 zig zag site had significantly similar species2
richness values (table 5 and figure 21).3
When comparing the age of the restored sites to the species richness values, the grid4
site, the oldest site, had the second highest mean species richness value, 2.67. The sinusoidal5
site, the second oldest site, had the highest mean species richness value, 2.89. The 2004 zig zag6
site, had the third highest mean species richness value, 2.11. The beneficial uses site, built in7
2005, had the fourth highest mean species richness value, 1.67. The 2009 zig zag site, the8
newest site, had the lowest mean species richness value, 1.44 (figure 22).9
10
11
Table 5: Comparing species richness between the reference site and the restored sites. 2013.12
Pierce Marsh.13
14
15
16
17
18
19

37 | P a g e
Figure 21: Comparing the mean species richness among the six sites at Pierce Marsh. 2013.1
2
3
4
5
6
7
8
9
10
11
Figure 22: Comparing species richness values among the five constructed sites by year built at12
14

38 | P a g e
Species Richness 2008 to 2013:1
When the species richness values for 2008 and 2013 are compared, the reference site’s2
mean species richness value remained constant from 2008 to 2013. It was 2.22 in both years3
(table 6). The reference site was similar to the sinusoidal and the 2004 zig zag site in 2008.4
However, in 2013 it was similar only to the 2004 zig zag site (figure 23).5
The mean species richness values decreased at only one site from 2008 to 2013. The6
grid site had a mean species richness value of 3.33 in 2008 and 2.67 in 2013 (table 6). This was7
a decrease of 0.67. The grid site was similar only to the sinusoidal site in 2008. However, in8
2013 it was similar to the reference site as well as the sinusoidal site (figure 23).9
The mean species richness values increased at three sites from 2008 to 2013. The10
beneficial uses site had a mean species richness value of 1.00 in 2008 and 1.67 in 2013 (table 6).11
This was an increase of 0.67. This was the highest increase of the sites. In 2008, the beneficial12
uses site was significantly similar to the 2004 zig zag site. However, in 2013 it was similar to the13
2009 zig zag site (figure 23). The 2004 zig zag site had a mean species richness value of 1.67 in14
2008 and 2.11 in 2013 (table 6). This was an increase of 0.44. This was the second highest15
increase of the sites. The 2004 zig zag site was significantly similar to the reference site and the16
beneficial uses site in 2008. However, in 2013 it was significantly similar to only the reference17
site (figure 23). The sinusoidal site had a mean species richness value of 2.78 in 2008 and 2.8918
in 2013 (table 6). This was an increase of 0.11. This was the third highest increase of the sites.19
The sinusoidal site was significantly similar to the reference and grid sites in 2008. However, in20
2013 it was significantly similar to only the grid site (figure 23).21

39 | P a g e
2008 2013 Difference
PRC 1 Reference 2.22 2.22 0.00
PRC 2 Zig Zag 2004 1.67 2.11 0.44
PRC 3 Grid 3.33 2.67 -0.67
PRC 4 Sinusoidal 2.78 2.89 0.11
PRC 6 Zig Zag 2009 n/a 1.44 n/a
Mean Species Richness
Site
The mean species richness values could not be compared for the 2009 zig zag site as it1
was built after the 2008 data was obtained.2
3
Table 6: Comparing species richness in years 2008 and 2013. Pierce Marsh.4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Figure 23: Comparing mean species richness among the six sites at Pierce Marsh for the years20
2008 and 2013.21
22

40 | P a g e
Scientific name Common Name 2008 2013 2008 2013 2008 2013 2008 2013 2008 2013 n/a 2013
Spartina alterniflora Saltwater cord grass X X X X X X X X X X X
Salicornia virginica Creeping glasswort X X X X X X X X X X
Salicornia bigelovii Annual glasswort X X X
Batis maritima Saltwort X X X X X X X X X
Aster tenuifolius Salt marsh aster X X X X
Borrichia frutescens Bushy seaside-tansy X X X X
Distichlis spicata Coastal salt grass X X X X
Cuscuta salina Salt marsh dodder X
Iva frutescens Jesuit’s-bark X
Lycium carolinianum Carolina desert thorn X
Sesuvium portulacastrum Sea purslane X X
Solidago sempervirens Seaside goldenrod X
Suaeda linearis Annual seepweed X X
Site/YearSpecies
Plant Species Present at Pierce Marsh 2008 and 2013
PRC 1 PRC 2 PRC 3 PRC 4 PRC 5 PRC 6
When comparing the species present at each site in 2008 and 2013, Spartina alterniflora1
was the only species present at each site on both years. Salicornia virginica, creeping2
glasswort, was present at all sites on both years with the exception of one site in 2008. Batis3
maritima, saltwort, was present at all sites on both years with the exception of one site in 20084
and one site in 2013. Three species were present at only four sites. Aster tenuifolius, salt5
marsh aster, was present at four sites in 2008 only. Borrichia frutescens, bushy seaside-tansy,6
was present at two sites in 2008 and 2013. Distichlis spicata, coastal salt grass, was present at7
two sites in 2008 and was also present at one site in 2008 and 2013. Salicornia bigelovii, annual8
glasswort, was present at one site in 2008 and two sites in 2013. Sesuvium portulacastrum, sea9
purslane, was present at one site in 2008 and 2013. Suaeda linearis, annual seepweed, was10
present at two sites in 2008. Four species were present at only one site. Cuscuta salina, salt11
marsh dodder; Iva frutescens, Jesuit’s-bark; and Lycium carolinianum, Carolina desert thorn12
were each present at one site in 2008 only. Solidago sempervirens, seaside goldenrod was13
present at one site only in 2013 (table 7).14
Table 7: Comparing plant species present at Pierce Marsh in 2008 and 2013. Pierce Marsh.15
16
17
18

41 | P a g e
Shannon Diversity Index 2013:1
When comparing the Shannon Diversity Index values for 2013, the reference site had2
the highest Shannon Diversity Index value at 1.05 (table 8). The reference site was significantly3
similar to the grid site (figure 24). The grid site had the second highest Shannon Diversity Index4
value at 0.90 (table 8). The grid site was significantly similar to the 2004 zig zag site (figure 24).5
The 2004 zig zag site had the third highest Shannon Diversity Index value at 0.81 (table 8). The6
2004 zig zag site was significantly similar to the grid site, the sinusoidal site, and the beneficial7
uses site (figure 24). The sinusoidal site had the fourth highest Shannon Diversity Index value8
at 0.73 (table 8). The sinusoidal site was significantly similar to the 2004 zig zag site and the9
beneficial uses site (figure 24). The beneficial uses site had the fifth highest Shannon Diversity10
Index value at 0.67 (table 8). The beneficial uses site was significantly similar to the 2004 zig11
zag site, the sinusoidal site, and the 2009 zig zag site (figure 24). The 2009 zig zag site had the12
lowest Shannon Diversity Index at 0.55 (table 8). The 2009 zig zag site was significantly similar13
to the beneficial uses site (figure 24).14
When comparing the age of the restored sites to the Shannon Diversity Index values, the15
grid site, the oldest site, had the highest Shannon Diversity Index value, 0.90. The sinusoidal16
site, the second oldest site, had the third highest Shannon Diversity Index value, 0.73. The 200417
zig zag site had the second highest Shannon Diversity Index value, 0.81. The beneficial uses18
site, built in 2005, had the fourth highest Shannon Diversity Index value, 0.67. The 2009 zig zag19
site, the newest site, had the lowest Shannon Diversity Index value, 0.55 (figure 25).20
21
22

42 | P a g e
H'
PRC 2 Zig Zag 2004 0.81
PRC 3 Grid 0.90
PRC 6 Zig Zag 2009 0.55
Site
Shannon Diversity Index 2013
Table 8: Comparing Shannon Diversity Index among the six sites at Pierce Marsh. 2013. Pierce1
Marsh.2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Figure 24: Comparing the Shannon Diversity Index among the six sites at Pierce Marsh. 2013.21
22
23

43 | P a g e
1
2
3
4
5
6
7
8
Figure 25: Comparing Shannon Diversity Index values among the five constructed sites by year9
built at Pierce Marsh. 2013.10
11
12
Shannon Diversity Index 2008 to 2013:13
When the Shannon Diversity Index values for 2008 and 2013 are compared, the14
reference site’s Shannon Diversity Index value was 0.98 in 2008 and 1.05 in 2013 (table 9). This15
was an increase of 0.07. The reference site was significantly similar to the grid and the16
sinusoidal sites in 2008. However, in 2013 it wasn’t similar to any of the other sites (figure 26).17
The 2004 zig zag site had a Shannon Diversity Index value of 0.57 in 2008 and 0.81 in 201318
(table 9). This was an increase of 0.24. The 2004 zig zag site was similar only to the beneficial19
uses site in 2008. However, in 2013 it was similar to the sinusoidal site (figure 26). The20
beneficial uses site had a Shannon Diversity Index value of 0.35 in 2008 and 0.67 in 2013 (table21
9). This was an increase of 0.33. This was the highest increase of the sites. In 2008, the22

44 | P a g e
PRC 2 Zig Zag 2004 0.57 0.81 0.24
PRC 3 Grid 1.18 0.90 -0.28
PRC 4 Sinusoidal 1.05 0.73 -0.31
Site
Shannon Diversity Index
beneficial uses site was significantly similar to the 2004 zig zag site. However, in 2013 it was1
similar to the sinusoidal site (figure 26).2
The grid site had a Shannon Diversity Index value of 1.18 in 2008 and 0.90 in 2013 (table3
9). This was a decrease of 0.28. This was the second highest decrease of the sites. The grid site4
was significantly similar to the reference site and the sinusoidal site in 2008. However, in 20135
it was significantly similar to only the 2004 zig zag site (figure 26). The sinusoidal site had a6
Shannon Diversity Index value of 1.05 in 2008 and 0.73 in 2013 (table 9). This was a decrease of7
0.31. This was the highest decrease of the sites. The sinusoidal site was significantly similar to8
the reference and grid sites in 2008. However, in 2013 it was significantly similar to only the9
2004 zig zag site (figure 26).10
The Shannon Diversity Index values could not be compared for the 2009 zig zag site as it11
was built after the 2008 data was obtained.12
13
14
Table 9: Comparing Shannon Diversity Index in years 2008 and 2013. Pierce Marsh.15
16
17
18
19
20
21
22

45 | P a g e
1
2
3
4
5
6
7
8
9
Figure 26: Comparing the Shannon Diversity Index among the six sites at Pierce Marsh for the10
years 2008 and 2013.11
12
13
Pielou’s Index of Evenness 2013:14
When comparing the Pielou’s Index of Evenness values for 2013, the 2009 zig zag site15
had the highest Pielou’s Index of Evenness value at 0.79 (table 10). The reference site had the16
second highest Pielou’s Index of Evenness value at 0.76 (table 10). The reference site and the17
2009 zig zag site were significantly similar to one another (figure 27). The beneficial uses site18
had the third highest Pielou’s Index of Evenness value at 0.61 (table 10). The 2004 zig zag site19
had the fourth highest Pielou’s Index of Evenness value at 0.59 (table 10). The beneficial uses20
site and the 2004 zig zag sites were significantly similar to one another (figure 27). The grid site21
had the fifth highest Pielou’s Index of Evenness value at 0.50 (table 10). The grid site was22

46 | P a g e
E
PRC 2 Zig Zag 2004 0.59
PRC 3 Grid 0.50
PRC 6 Zig Zag 2009 0.79
Site
Pielou's Index of Evenness 2013
significantly similar to the 2004 zig zag site and the sinusoidal site (figure 27). The sinusoidal1
site built in 2009 had the lowest Pielou’s Index of Evenness at 0.46 (table 10). The sinusoidal2
site was significantly similar to the grid site (figure 27).3
When comparing the age of the restored sites to the Pielou’s Index of Evenness values,4
the grid site, the oldest site, had the second to the lowest Pielou’s Index of Evenness value,5
0.50. The sinusoidal site, the second oldest site, had the lowest Pielou’s Index of Evenness6
value, 0.46. The 2004 zig zag site had the third lowest Pielou’s Index of Evenness value, 0.59.7
The beneficial uses site, built in 2005, had the fourth lowest Pielou’s Index of Evenness value,8
0.61. The 2009 zig zag site, the newest site, had the highest Pielou’s Index of Evenness value,9
0.79 (figure 28).10
11
12
13
14
15
16
Table 10: Comparing Pielou’s Index of Evenness between the reference site and the restored17
sites. 2013. Pierce Marsh.18
19
20
21
22
23
24
25

47 | P a g e
1
2
3
4
5
6
7
8
9
10
Figure 27: Comparing Pielou’s Index of Evenness among the six sites at Pierce Marsh. 2013.11
12
13
14
15
16
17
18
19
20
21
Figure 28: Comparing Pielou’s Index of Evenness values among the five constructed sites by22
year built at Pierce Marsh. 2013.23
24

48 | P a g e
Pielou’s Index of Evenness 2008 to 2013:1
When the Pielou’s Index of Evenness values for 2008 and 2013 are compared, the2
sinusoidal site had a Pielou’s Index of Evenness value of 0.54 in 2008 and 0.46 in 2013 (table3
11). This was a decrease of 0.08. This was the only decrease of the sites. The sinusoidal site4
was significantly similar to the reference and grid sites in 2008. However, in 2013 it was5
significantly similar to only the grid site (figure 29). The beneficial uses site had a Pielou’s Index6
of Evenness value of 0.00 in 2008 and 0.61 in 2013 (table 11). This was an increase of 0.61.7
This was the highest increase of the sites. The beneficial uses site was not significantly similar8
to any other site in 2008. However, it was significantly similar to the 2004 zig zag site (figure9
29). The 2004 zig zag site had a Pielou’s Index of Evenness value of 0.36 in 2008 and 0.59 in10
2013 (table 11). This was an increase of 0.23. This was the second highest increase of the sites.11
The 2004 zig zag site was similar grid and the sinusoidal sites in 2008. However, in 2013 it was12
similar to the grid and the beneficial uses site (figure 29). The reference site had a Pielou’s13
Index of Evenness value of 0.61 in 2008 and 0.76 in 2013 (table 11). This was an increase of14
0.15. This was the third highest increase of the sites. The reference site was significantly15
similar to the grid and the sinusoidal sites in 2008. However, in 2013 it was similar only to the16
2009 zig zag site (figure 29). The grid site had a Pielou’s Index of Evenness value of 0.49 in 200817
and 0.50 in 2013 (table 11). This was an increase of 0.01. This was the lowest increase of the18
sites. The grid site was significantly similar to the reference site, the 2004 zig zag site and the19
sinusoidal site in 2008. However, in 2013 it was significantly similar to the 2004 zig zag site and20
the sinusoidal site (figure 29). The Pielou’s Index of Evenness values could not be compared for21
the 2009 zig zag site as it was built after the 2008 data was obtained.22

49 | P a g e
PRC 2 Zig Zag 2004 0.36 0.59 0.23
PRC 3 Grid 0.49 0.50 0.01
PRC 4 Sinusoidal 0.54 0.46 -0.08
Site
Pielou's Index of Evenness
Table 11: Comparing Pielou’s Index of Evenness in years 2008 and 2013. Pierce Marsh.1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Figure 29: Comparing the Pielou’s Index of Evenness among the six sites at Pierce Marsh for the21
years 2008 and 2013.22
23
24
25

50 | P a g e
Jaccard’s Coefficient of Community Similarity 2013:1
When comparing the Jaccard’s Coefficient of Community Similarity values for 2013, the2
reference site the 2004 zig zag site had the highest Jaccard’s Coefficient of Community3
Similarity at 1.0. The reference site and the beneficial uses site had the second highest4
Jaccard’s Coefficient of Community Similarity at 0.75. The reference site and the grid site, the5
sinusoidal site and the 2009 zig zag site had a Jaccard’s Coefficient of Community Similarity of6
0.50 each.7
When comparing the restored sites, the 2004 zig zag site the beneficial uses site built in8
2005 had the highest Jaccard’s Coefficient of Community Similarity at 0.75. Two site9
comparisons had a Jaccard’s Coefficient of Community Similarity of 0.67; the grid site and the10
sinusoidal site; as well as the beneficial uses site and the 2009 zig zag site. Two site11
comparisons had a Jaccard’s Coefficient of Community Similarity of 0.60; the grid site and the12
beneficial uses site; as well as the sinusoidal site and the beneficial uses site. Three13
comparisons of sites had a Jaccard’s Coefficient of Community Similarity of 0.50; the 2004 zig14
zag site and the grid site; the 2004 zig zag site and the sinusoidal site; as well as the 2004 zig zag15
site and the 2009 zig zag site. Two comparisons of sites had a Jaccard’s Coefficient of16
Community Similarity of 0.40; the grid site, and the 2009 zig zag site, as well as the sinusoidal17
site, and the 2009 zig zag site (table 12).18
19
20
21
22

51 | P a g e
Sites Jaccard's
PRC 1 vs PRC 2 1.00
PRC 1 vs PRC 3 0.50
PRC 1 vs PRC 4 0.50
PRC 1 vs PRC 5 0.75
PRC 1 vs PRC 6 0.50
PRC 2 vs PRC 3 0.50
PRC 2 vs PRC 4 0.50
PRC 2 vs PRC 5 0.75
PRC 2 vs PRC 6 0.50
PRC 3 vs PRC 4 0.67
PRC 3 vs PRC 5 0.60
PRC 3 vs PRC 6 0.40
PRC 4 vs PRC 5 0.60
PRC 4 vs PRC 6 0.40
PRC 5 vs PRC 6 0.67
Jaccard’s Coefficient of
Community Similarity 2013
Table 12: Comparing Jaccard’s Coefficient of Community Similarity between the restored sites.1
2013. Pierce Marsh.2
3
4
5
6
7
8
9
10
11
12
13
14
Jaccard’s Coefficient of Community Similarity 2008 to 2013:15
When the Jaccard’s Coefficient of Community Similarity values for 2008 and 2013 are16
compared, the reference site and the 2004 zig zag site had a Jaccard’s Coefficient of Community17
Similarity of 1.0 in 2008 and 2013. The reference site and the grid site had a Jaccard’s18
Coefficient of Community Similarity of 0.56 in 2008 and 0.50 in 2013. This is a decrease of 0.06.19
The reference site and the sinusoidal site had a Jaccard’s Coefficient of Community Similarity of20
0.50 in 2008 and 2013. The reference site and the beneficial uses site had a Jaccard’s21
Coefficient of Community Similarity of 0.20 in 2008 and 0.75 in 2013. This is an increase of22
0.55.23

52 | P a g e
When comparing the restored sites, the 2004 zig zag site and the grid site had a1
Jaccard’s Coefficient of Community Similarity of 0.56 in 2008 and 0.50 in 2013. This is a2
decrease of 0.06. The 2004 zig zag site and the sinusoidal site had a Jaccard’s Coefficient of3
Community Similarity of 0.50 in 2008 and 2013. The 2004 zig zag site and the beneficial uses4
site had a Jaccard’s Coefficient of Community Similarity of 0.20 in 2008 and 0.75 in 2013. This is5
an increase of 0.55. The grid site and the sinusoidal site had a Jaccard’s Coefficient of6
Community Similarity of 0.60 in 2008 and 0.67 in 2013. This is an increase of 0.07. The grid site7
and the beneficial uses site had a Jaccard’s Coefficient of Community Similarity of 0.11 in 20088
and 0.60 in 2013. This is an increase of 0.49. The sinusoidal site and the beneficial uses site9
had a Jaccard’s Coefficient of Community Similarity of 0.14 in 2008 and 0.60 in 2013. This is an10
increase of 0.46. The 2009 zig zag site could not be compared as it was built after the 200811
data was obtained (table 13).12
13
14
15
16
17
18
19
20
21
22
23

53 | P a g e
Sites 2008 2013 Difference
PRC 1 vs PRC 2 1.00 1.00 0.00
PRC 1 vs PRC 3 0.56 0.50 -0.06
PRC 1 vs PRC 4 0.50 0.50 0.00
PRC 1 vs PRC 5 0.20 0.75 0.55
PRC 1 vs PRC 6 n/a 0.50 n/a
PRC 2 vs PRC 3 0.56 0.50 -0.06
PRC 2 vs PRC 4 0.50 0.50 0.00
PRC 2 vs PRC 5 0.20 0.75 0.55
PRC 3 vs PRC 4 0.60 0.67 0.07
PRC 3 vs PRC 5 0.11 0.60 0.49
PRC 4 vs PRC 5 0.14 0.60 0.46
Jaccard’s Coefficient of Community Similarity 2008 & 2013
Table 13: Comparing Jaccard’s Coefficient of Community Similarity in years 2008 and 2013 by1
site. Pierce Marsh.2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
DISCUSSION17
The reference site had a high Spartina alterniflora importance value, a moderate species18
richness value, a high Shannon Diversity Index, and a high Pielou’s Index of Evenness in 2013. It19
also demonstrated stability of these values over time. The data comparing 2008 and 201320
showed that all of the above mentioned parameters were significantly similar over this time21
period. The Spartina alterniflora importance value decreased only 0.90%, the species richness22
was unchanged, the Shannon Diversity Index increased by 0.07, and the Pielou’s Index of23

54 | P a g e
Evenness increased by 0.15. This data indicates that the reference site was healthy and stable,1
which provided an excellent comparison site.2
Overall, the five restored sites fell short of showing significant similarities to the3
reference site over the majority of the compared parameters; Spartina alterniflora importance4
value, species richness, Shannon Diversity Index, and Pielou’s Index of Evenness. In fact, each5
parameter had only one site that showed significant similarities to the reference site.6
Additionally, some sites showed trends overtime that if continued, will result in the degradation7
of the sites.8
The two sites of most concern are the grid site, built in 1999, and the sinusoidal site9
built in 2001. The grid site had a Spartina alterniflora importance value significantly lower than10
the reference site. It was significantly lower in 2008 as well and dropped even further in 2013.11
Its relative frequency was significantly lower as well; however, its relative coverage was12
extremely low. As the Spartina alterniflora decreased at this site, sea-ox-eye-daisy, Borrichia13
frutescens, and saltwort, Batis maritina, colonized the site and became the species’ of14
importance. Its mean species richness value and Shannon Diversity Index were significantly15
similar to the reference site; however, it had significantly fallen from 2008 to 2013. The site’s16
Pielou’s Index of Evenness was significantly lower than the reference site’s. Its value was stable17
over time; however, the reference site’s evenness value increased, creating a significant gap.18
The Jaccard’s Coefficient of Community Similarity between the reference site and the grid site19
showed a moderate similarity between the two sites; this similarity fell slightly from 2008.20
Empirically, this site’s berms were visibly thinner than the other sites and their elevation21
appeared to be lower, although measurements were not taken, so they were being inundated22

55 | P a g e
with water for longer periods than the other sites. The significant differences between the grid1
site and the reference site in 2013, the trend of the values dropping and the differences2
becoming greater between 2008 and 2013, along with the empirical data, point to a trend that3
this site was degrading over time.4
The sinusoidal site, two years younger than the grid site, also had a Spartina alterniflora5
importance value significantly lower than the reference site. It was significantly lower in 20086
as well and dropped even further in 2013. Its relative frequency was significantly lower as well;7
however, its relative coverage was extremely low. As the Spartina alterniflora decreased at this8
site, saltwort, Batis maritina, colonized the site and became the species of importance. Its9
mean species richness value was significantly higher than the reference site and was stable over10
time. The Shannon Diversity Index was significantly lower than the reference site’s and had11
significantly fallen from 2008 to 2013. The site’s Pielou’s Index of Evenness was significantly12
lower than the reference site’s and had decreased significantly over time. The Jaccard’s13
Coefficient of Community Similarity between the reference site and the sinusoidal site showed14
a moderate similarity between the two sites and was stable from 2008. The Jaccard’s15
Coefficient of Community Similarity between the grid site and the sinusoidal site increased16
slightly over time. These were the only sites that showed and increase during this time with the17
exception of the beneficial uses site which showed and increase to all of the sites and will be18
discussed later. Empirically, this site’s berms were visibly thinner than the other sites, including19
the grid site, although measurements were not taken. The berms were so thin and fragile that20
extra caution had to be used when collecting data as to no further damage the berms. Their21
elevation appeared to be lower, although measurements were not taken, so they were being22

56 | P a g e
inundated with water for longer periods than the other sites. The significant differences1
between the grid site and the reference site in 2013, the trend of the values dropping and the2
differences becoming greater between 2008 and 2013, along with the empirical data, point to a3
trend that this site was degrading over time as well.4
The 2004 zig zag site, five years younger than the grid site, also had a Spartina5
alterniflora importance value significantly lower than the reference site. It was significantly6
similar in 2008; however, it dropped significantly since 2013. Its relative frequency was7
significantly similar; however, its relative coverage was extremely low. As the Spartina8
alterniflora has decreased in numbers at this site, saltwort, Batis maritina, has increased and9
has a slightly higher importance value than Spartina alterniflora. Its mean species richness10
value was significantly similar to the reference site and had increased slightly over time. The11
Shannon Diversity Index was significantly lower than the reference site’s but had significantly12
increased from 2008 to 2013. The site’s Pielou’s Index of Evenness was significantly lower than13
the reference site’s but had also significantly increased over time. The Jaccard’s Coefficient of14
Community Similarity between the reference site and the 2004 zig zag site was extremely high15
in 2008 and 2013. The 1.0 Jaccard’s Coefficient of Community Similarity between the16
reference site and the 2004 zig zag site could be deceiving as it was only measuring the17
existence or nonexistence of species. The two sites had species in common but the significant18
difference in Spartina alterniflora relative coverage, and therefore importance value, as well as19
the significant difference in diversity and evenness measures, assured that these sites are not20
entirely similar. The Jaccard’s Coefficient of Community Similarity between the 2004 zig zag21
and the gird site showed a moderate similarity between the two sites; this similarity fell slightly22

57 | P a g e
from 2008, just as it did between the reference site and the grid site. The Jaccard’s Coefficient1
of Community Similarity between the 2004 zig zag and the sinusoidal site also showed a2
moderate similarity between the two sites; this similarity was stable over time. Empirically, this3
site’s berms were visibly wider than the grid and sinusoidal berms, although measurements4
were not taken. Their elevation appeared to be higher as well, although measurements were5
not taken, allowing the higher areas of the berm more opportunity to dry out between high6
tides. The significant differences between the 2004 zig zag site and the reference site in 20137
were not positive signs for this site; however, the trend of the mean species richness, Shannon8
Diversity Index and the Pielou’s Index of Evenness values increasing between 2008 and 2013,9
along with the positive Jaccard’s Coefficient of Community Similarity between this site and the10
reference site as well as the empirical data, indicate that this site was healthier than the grid11
and sinusoidal sites and may continue the trend. If the Spartina alterniflora coverage begins to12
increase at this site, it will be on its way to replicating the reference site.13
The beneficial uses site, built in 2005, was six years younger than the grid site, and is the14
only site built in a large area from dredge material rather than in terraced berms. It was the15
only site that had a Spartina alterniflora importance value significantly similar to the reference16
site. Its relative frequency and relative coverage were significantly similar as well. It was17
significantly higher in 2008; however, it dropped significantly since 2013 to bring it in line with18
the reference site. Its mean species richness value was slightly lower than the reference site19
but had increased significantly over time. The Shannon Diversity Index was significantly lower20
than the reference site’s but had also significantly increased from 2008 to 2013. The site’s21
Pielou’s Index of Evenness was slightly lower than the reference site’s but had dramatically22

58 | P a g e
increased over time. The Jaccard’s Coefficient of Community Similarity between the reference1
site and the beneficial uses site was low in 2008, 0.20, and high, 0.75, in 2013. The Jaccard’s2
Coefficient of Community Similarity between this site and all of the other sites had increases as3
well, ranging between 0.46 and 0.55. The beneficial uses site had only Spartina alterniflora as4
an inhabitant in 2008, so the addition of creeping glasswort, Salicornia virginica, and saltwort,5
Batis maritima, over the five-year-period increased its similarity to all of the sites. Empirically,6
this site looked much like the reference site. It had much more surface area than the other7
sites and was high enough to dry out between high tides. There were significant differences8
between the beneficial uses site and the reference site in 2013; however, it was the one site9
that had a significantly similar Spartina alterniflora importance value, along with significantly10
similar relative coverage and frequency values. The trend of the mean species richness,11
Shannon Diversity Index and the Pielou’s Index of Evenness values increasing significantly12
between 2008 and 2013, along with the positive Jaccard’s Coefficient of Community Similarity13
between this site and the reference site as well as the empirical data, indicate that this site was14
healthier than the grid and sinusoidal sites and may continue the trend. The beneficial uses site15
had a significantly higher Spartina alterniflora importance value and was significantly similar in16
mean species richness, Shannon Diversity Index and Pielou’s Index of Evenness when compared17
to the 2004 zig zag site. This indicates that this site was healthier than the 2004 zig zag site and18
most closely replicated the reference site.19
The 2009 zig zag site, ten years younger than the grid site, also had a Spartina20
alterniflora importance value significantly lower than the reference site. Its relative frequency21
was significantly similar; however, its relative coverage was extremely low. This site was built a22

59 | P a g e
year after the 2008 data was collected so data for trends was not available. Its mean species1
richness value and Shannon Diversity Index were significantly lower than the reference site. The2
site’s Pielou’s Index of Evenness was significantly similar to the reference sites. The Jaccard’s3
Coefficient of Community Similarity between the reference site and the 2009 zig zag site was4
moderate, 0.50. The two zig zag sites had a moderate Jaccard’s Coefficient of Community5
Similarity as well, 0.50. However, it had lower similarity values when compared to the grid and6
sinusoidal sites. Empirically, this site’s berms were visibly similar to the 2004 zig zag berms in7
width and height, although measurements were not taken. One visible difference was the8
highest section of the berms had not become completely vegetated yet; however, overall, the9
bare ground values for the zig zag sites were similar. The significant differences between the10
2009 zig zag site and the reference site in 2013 were not positive signs for this site. However,11
this site shows some strong similarities to the 2004 zig zag site. Its Spartina alterniflora12
importance value, relative frequency and coverage are all significantly similar. The 2004 site13
showed positive trends between 2008 and 2013 in mean species richness, Shannon Diversity14
Index and the Pielou’s Index of Evenness values. Additionally, the 2009 zig zag site had a higher15
Jaccard’s Coefficient of Community Similarity when compared to the reference site and the16
2004 site than when compared to the grid and sinusoidal sites. This information as well as the17
empirical data, indicate that this site was similar to the 2004 zig zag site and was healthier than18
the grid and sinusoidal sites and may continue the trend. Like the 2004 zig zag site, if the19
Spartina alterniflora coverage begins to increase at this site, it will be on its way to replicating20
the reference site.21

60 | P a g e
If reconstructed marshes develop as expected, the older reconstructed marshes will1
have higher Spartina alterniflora coverage and importance values. In 2008, Howard and2
Dobberstine found that restoration design affected the Spartina alterniflora coverage more3
than the age of the site. However, the 2013 data suggested as the sites got older their Spartina4
alterniflora coverages decreased. This was the opposite of what would be expected if the5
reconstructed marshes were performing better over time. These trends could be pointing to6
the older sites degrading, as was the case with the grid and sinusoidal sites. Both zig zag sites7
and the beneficial uses site are clearly out-performing the older sites. It was impossible with8
the available data to determine if these differences are due to their designs or their age. The9
data collected at these sites in 2018 will give further information about the trajectory of these10
sites. It will be interesting to know how the zig zag sites and the beneficial uses sites perform11
and whether the grid and sinusoidal sites will be there at all.12
A few words about error: Using an estimation of percent coverage to obtain importance13
values could be somewhat unreliable when comparing years. A different person determined14
the percent coverage in 2008 than did in 2013. While the principal investigators remained the15
same and therefore aided in identifying the plant species with consistence and gave consistent16
instructions on how to determine plant coverage, the estimation of coverage could still be a17
cause of error. The fact that the data obtained in 2008 and 2013 for the reference site18
remained stable and consistent for all parameters; Spartina alterniflora importance values,19
species richness, Shannon Diversity Index, and Pielou’s Index of Evenness was an excellent20
indicator that this error did not occur. Additionally, the percent of detritus material was not21

61 | P a g e
estimated for the 2008 data but was included in the 2013 data. The change in technique could1
have an impact on the coverage values and therefore the importance values.2
Data will be collected at Pierce Marsh next in 2018. Keeping the overall techniques3
consistent with those used in 2013 will be vital in assuring the data will be reliable to compare4
the sites throughout the years. Adding the measurement of berm widths would be a valuable5
addition to the data. Smaller terraced berms could be measured manually in the field. Larger6
terraced berms or the dredge material sites could be measured using geographic information7
system, GIS, technology.8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

62 | P a g e
Literature Cited1
Brower, J.E., J,H. Zar, C.N. von Ende. 1998. Field and Laboratory Methods for General Ecology.2
4th
Edition. McGraw Hill, Massachusetts.3
Caldwell, P.A., G.A. Matthews, and T.J. Minello. 2004. A habitat-use model to determine4
essential fish habitat for juvenile brown shrimp (Farfantepenaeus aztecus) in Galveston5
Bay, Texas. Fishery Bulletin, April 2004.6
Costanza, R., R. de Groot, P. Sutton, S. van der Ploeg, S. J. Anderson, I. Kniszewski, S. Farber,7
R.K. Turner. 2014. Changes in the global value of ecosystem services. Global8
Environmental Change. 26: 152-158.9
Craft, C., J. Reader, J.N. Sacco, S.W. Broome. 1999. Twenty-five years of ecosystem10
development of constructed Spartina alterniflora (Loisel) marshes. Ecological11
Applications 9(4): 1405-141912
Craft, C., P. Megonigal, S. Broome, J. Stevenson, R. Freese, J. Cornell, L. Zheng, and J. Sacco.13
2003. The pace of ecosystem development of constructed Spartina alterniflora14
marshes. Ecological Applications. 13(5):1417-1432.15
Cullinan, M., N. LaBella, and M. Schott. 2004. Salt marshes – A valuable ecosystem. The16
Traprock. 3:20-2317
Davis, C. 1998. Marine Botany, Second Edition. John Wiley and Sons, NY, NY. pp 496.18
Galveston Bay Foundation. Pierce Marsh Fact Sheet. www.galvbay.org19
Gossman, B.P. 2000. Thesis: Use of terraced marsh habitats by estuarine nekton in20
Southwestern Louisiana. Louisiana State University. pp 59.21
Greenberg, R., J.E. Maldonado, S. Droege, and M.V. McDonald. 2006. Tidal Marshes: A global22

63 | P a g e
perspective on the evolution and conservation of their terrestrial vertebrates.1
Bioscience. 56(8) 675-685.2
Howard, C. L. and J.A. Dobberstine. 2008. Science based monitoring of created and restored3
habitat within the Galveston Bay system. Coastal Management Program of the Texas4
General Land Office and the National Oceanic and Atmospheric Administration.5
Contract number 07-005-11. 20 pp.6
Lester, J., and L. Gonzales (eds.). 2002. The state of the bay: Characterization of the Galveston7
Bay Ecosystem. 2nd
Edition. The Galveston Bay Estuary Program. Galveston, Texas.8
Mendelssohn, I.A., and J.T. Morris. 2002. Eco-Physiological Controls on the Productivity of9
Spartina alterniflora Loisel. Concepts and Controversies in Tidal Marsh Ecology. pp 59-10
8011
Merino, J.H., L.P. Rozas, T.J. Minello, and P.F. Sheridan. 2010. Effects of marsh terracing on12
nekton abundance at two locations in Galveston Bay, Texas. Wetlands. 30:693-704.13
Rozas, L.P. and T.J. Minello, 2001. Marsh terracing as a wetland restoration tool for creating14
fishery habitat. Wetlands. 21(3) 327-341.15
Shafer, D.J. and W.J. Streever. 2000. A comparison of 28 natural and dredged material salt16
marshes in Texas with an emphasis on geomorphological variables. Wetland Ecology17
and Management. 8:353-366.18
Stokes, B. 2014. Blue ribbon resilient communities: Texas – Challendges/Opportunities.19
Galveston Bay Foundation.20
Streeter, W.J. 2000. Spartina alterniflora marshes on dredge material: a critical review of the21
ongoing debate over success. Wetlands Ecology Management. 8: 295-316.22

64 | P a g e
Whaley, S.D. and T.J. Minello. 2002. The distribution of bethic infauna of a Texas salt marsh in1
relation to marsh edge. Wetlands. 22(4):753-766.2
White, W.A., T.A. Tremblay, E.G. Wermund Jr., and L.R. Handley. 1993. Trends and status of3
wetland and aquatic habitats in the Galveston Bay System, Texas. Galveston Bay4
National Estuary Program, Report GBEP-31. 225 pp.5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

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Appendices1
Appendix I: Importance values calculations by site for 2008. Pierce Marsh.2
3
4
5
6
PRC 1 - Reference Site
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 18 18 1.000 0.310 0.308 0.619
Detritis
Spartina alterniflora 18 18 1.000 0.310 0.411 0.721
Salicornia virginica 18 6 0.333 0.103 0.044 0.148
Salicornia bigelovii 18 0 0.000 0.000 0.000 0.000
Batis maritima 18 11 0.611 0.190 0.189 0.379
Aster tenuifolius 18 4 0.222 0.069 0.042 0.111
Borrichia frutescens 18 0 0.000 0.000 0.000 0.000
Distichlis spicata 18 1 0.056 0.017 0.006 0.023
Cuscuta salina 18 0 0.000 0.000 0.000 0.000
Iva frutescens 18 0 0.000 0.000 0.000 0.000
Lycium carolinianum 18 0 0.000 0.000 0.000 0.000
Sesuvium portulacastrum 18 0 0.000 0.000 0.000 0.000
Solidago sempervirens 18 0 0.000 0.000 0.000 0.000
Suaeda linearis 18 0 0.000 0.000 0.000 0.000
Totals 3.22 1.00 1.00 2.00
Ʃf=3.22 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0
Importance Value Calculations 2008
Not measured

66 | P a g e
1
2
3
4
5
6
PRC 2 - Zig Zag 2004
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 18 18 1.000 0.375 0.647 1.022
Detritis
Batis maritima 18 2 0.111 0.042 0.016 0.057
Cuscuta salina 18 0 0.000 0.000 0.000 0.000
Iva frutescens 18 0 0.000 0.000 0.000 0.000
Suaeda linearis 18 0 0.000 0.000 0.000 0.000
Totals 2.67 1.00 1.00 2.00
Ʃf=2.67 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0
Not measured

67 | P a g e
1
2
3
4
5
6
PRC 3 - Grid 1999
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 18 18 1.000 0.234 0.542 0.776
Detritis
Batis maritima 18 9 0.500 0.117 0.043 0.160
Cuscuta salina 18 1 0.056 0.013 0.006 0.019
Iva frutescens 18 4 0.222 0.052 0.025 0.077
Suaeda linearis 18 2 0.111 0.026 0.014 0.040
Totals 4.28 1.00 0.99 1.99
Ʃf=4.28 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0
Not measured

68 | P a g e
1
2
3
4
5
6
PRC 4 - Sinusoidal 2001
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 18 18 1.000 0.273 0.509 0.782
Detritis
Batis maritima 18 4 0.222 0.061 0.022 0.083
Cuscuta salina 18 0 0.000 0.000 0.000 0.000
Iva frutescens 18 0 0.000 0.000 0.000 0.000
Suaeda linearis 18 2 0.111 0.030 0.017 0.047
Totals 3.67 1.00 1.00 2.00
Ʃf=3.67 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0
Not measured

69 | P a g e
1
2
3
4
5
6
PRC 5 - Beneficial Uses 2005
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 12 12 1.000 0.500 0.500 1.000
Detritis
Batis maritima 12 0 0.000 0.000 0.000 0.000
Cuscuta salina 12 0 0.000 0.000 0.000 0.000
Iva frutescens 12 0 0.000 0.000 0.000 0.000
Suaeda linearis 12 0 0.000 0.000 0.000 0.000
Totals 2.00 1.00 1.00 2.00
Ʃf=2.00 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0
Not measured

70 | P a g e
Appendix II: Importance values calculations by site for 2013. Pierce Marsh.1
2
3
4
5
6
PRC 1 - Reference Site
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 9 9 1.000 0.243 0.071 0.314
Detritis 9 8 0.889 0.216 0.039 0.255
Batis maritima 9 6 0.667 0.162 0.281 0.443
Cuscuta salina 9 0 0.000 0.000 0.000 0.000
Iva frutescens 9 0 0.000 0.000 0.000 0.000
Suaeda linearis 9 0 0.000 0.000 0.000 0.000
Totals 4.11 1.00 1.00 2.00
Ʃf=4.11 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0

71 | P a g e
1
2
3
4
5
6
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 9 9 1.000 0.243 0.494 0.738
Detritis 9 9 1.000 0.243 0.114 0.358
Batis maritima 9 6 0.667 0.162 0.208 0.370
Cuscuta salina 9 0 0.000 0.000 0.000 0.000
Iva frutescens 9 0 0.000 0.000 0.000 0.000
Suaeda linearis 9 0 0.000 0.000 0.000 0.000
Totals 4.11 1.00 1.00 2.00
Ʃf=4.11 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0

72 | P a g e
1
2
3
4
5
6
PRC 3 - Grid 1999
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 9 9 1.000 0.220 0.321 0.541
Detritis 9 8 0.889 0.195 0.151 0.346
Batis maritima 9 5 0.556 0.122 0.167 0.289
Cuscuta salina 9 0 0.000 0.000 0.000 0.000
Iva frutescens 9 0 0.000 0.000 0.000 0.000
Suaeda linearis 9 0 0.000 0.000 0.000 0.000
Totals 4.56 1.00 1.00 2.00
Ʃf=4.56 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0

73 | P a g e
1
2
3
4
5
6
PRC 4 - Sinusoidal 2001
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 9 9 1.000 0.250 0.311 0.561
Detritis 9 5 0.556 0.139 0.026 0.164
Batis maritima 9 9 1.000 0.250 0.549 0.799
Cuscuta salina 9 0 0.000 0.000 0.000 0.000
Iva frutescens 9 0 0.000 0.000 0.000 0.000
Suaeda linearis 9 0 0.000 0.000 0.000 0.000
Totals 4.00 1.00 1.00 2.00
Ʃf=4.00 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0

74 | P a g e
1
2
3
4
5
6
PRC 5 - Beneficial Uses 2005
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 9 9 1.000 0.273 0.311 0.584
Detritis 9 9 1.000 0.273 0.236 0.508
Batis maritima 9 1 0.111 0.030 0.022 0.053
Cuscuta salina 9 0 0.000 0.000 0.000 0.000
Iva frutescens 9 0 0.000 0.000 0.000 0.000
Suaeda linearis 9 0 0.000 0.000 0.000 0.000
Totals 3.67 1.00 1.00 2.00
Ʃf=3.67 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0

75 | P a g e
1
2
3
4
5
6
Species (i)
Number
of plots
sampled
Present
in #
plots (ji)
Frequen
cy (fi)
Relative
Frequen
cy (RFi)
Relative
Coverag
e (RCi)
Importa
nce
Value
(IVi)
Bare ground 9 8 0.889 0.258 0.418 0.676
Detritis 9 9 1.000 0.290 0.206 0.496
Batis maritima 9 0 0.000 0.000 0.000 0.000
Cuscuta salina 9 0 0.000 0.000 0.000 0.000
Iva frutescens 9 0 0.000 0.000 0.000 0.000
Suaeda linearis 9 0 0.000 0.000 0.000 0.000
Totals 3.44 1.00 1.00 2.00
Ʃf=3.44 ƩRF=1.0 ƩRC=1.0 ƩIV=2.0

76 | P a g e
Appendix III: Mean species richness calculations by site. 2008. Pierce Marsh.1
2
3
4
Year
Site Code
Site
Number
Type Trans Stat spp rich
2008 PRC 1 REF A 1 2 Column1
2008 PRC 1 REF A 2 3
2008 PRC 1 REF A 3 2 Mean 2.222222222
2008 PRC 1 REF B 1 1 Standard Error 0.172553971
2008 PRC 1 REF B 2 3 Median 2
2008 PRC 1 REF B 3 2 Mode 2
2008 PRC 1 REF C 1 3 Standard Deviation 0.732084498
2008 PRC 1 REF C 2 3 Sample Variance 0.535947712
2008 PRC 1 REF C 3 2 Kurtosis -0.905621654
2008 PRC 1 REF A 1 2 Skewness -0.383135834
2008 PRC 1 REF A 2 1 Range 2
2008 PRC 1 REF A 3 1 Minimum 1
2008 PRC 1 REF B 1 3 Maximum 3
2008 PRC 1 REF B 2 3 Sum 40
2008 PRC 1 REF B 3 2 Count 18
2008 PRC 1 REF C 1 3
2008 PRC 1 REF C 2 2
2008 PRC 1 REF C 3 2
2008 PRC 2 ZIG A 1 1
2008 PRC 2 ZIG A 2 2 Column1
2008 PRC 2 ZIG A 3 1
2008 PRC 2 ZIG B 1 1 Mean 1.666666667
2008 PRC 2 ZIG B 2 1 Standard Error 0.180775382
2008 PRC 2 ZIG B 3 1 Median 1.5
2008 PRC 2 ZIG C 1 1 Mode 1
2008 PRC 2 ZIG C 2 2 Standard Deviation 0.766964989
2008 PRC 2 ZIG C 3 2 Sample Variance 0.588235294
2008 PRC 2 ZIG A 1 1 Kurtosis -0.867
2008 PRC 2 ZIG A 2 3 Skewness 0.684516253
2008 PRC 2 ZIG A 3 2 Range 2
2008 PRC 2 ZIG B 1 3 Minimum 1
2008 PRC 2 ZIG B 2 3 Maximum 3
2008 PRC 2 ZIG B 3 1 Sum 30
2008 PRC 2 ZIG C 1 1 Count 18
2008 PRC 2 ZIG C 2 2
2008 PRC 2 ZIG C 3 2
2008 PRC 3 GRD A 1 3 Column1
2008 PRC 3 GRD A 2 3
2008 PRC 3 GRD A 3 2 Mean 3.333333333
2008 PRC 3 GRD B 1 3 Standard Error 0.255654996
2008 PRC 3 GRD B 2 3 Median 3
2008 PRC 3 GRD B 3 3 Mode 3
2008 PRC 3 GRD C 1 6 Standard Deviation 1.084652289
2008 PRC 3 GRD C 2 3 Sample Variance 1.176470588
2008 PRC 3 GRD C 3 4 Kurtosis 0.99025
2008 PRC 3 GRD A 1 3 Skewness 1.106345335
2008 PRC 3 GRD A 2 4 Range 4
2008 PRC 3 GRD A 3 3 Minimum 2
2008 PRC 3 GRD B 1 2 Maximum 6
2008 PRC 3 GRD B 2 5 Sum 60
2008 PRC 3 GRD B 3 3 Count 18
2008 PRC 3 GRD C 1 2
2008 PRC 3 GRD C 2 5
2008 PRC 3 GRD C 3 3

77 | P a g e
1
2
3
Appendix IV: Mean species richness calculations by site. 2013. Pierce Marsh.4
5
6
7
8
2008 PRC 4 SIN A 1 2 Column1
2008 PRC 4 SIN A 2 2
2008 PRC 4 SIN A 3 3 Mean 2.777777778
2008 PRC 4 SIN B 1 4 Standard Error 0.286465451
2008 PRC 4 SIN B 2 5 Median 2.5
2008 PRC 4 SIN B 3 3 Mode 2
2008 PRC 4 SIN C 1 2 Standard Deviation 1.215369978
2008 PRC 4 SIN C 2 3 Sample Variance 1.477124183
2008 PRC 4 SIN C 3 2 Kurtosis -0.615283108
2008 PRC 4 SIN A 1 1 Skewness 0.476929683
2008 PRC 4 SIN A 2 2 Range 4
2008 PRC 4 SIN A 3 2 Minimum 1
2008 PRC 4 SIN B 1 1 Maximum 5
2008 PRC 4 SIN B 2 4 Sum 50
2008 PRC 4 SIN B 3 4 Count 18
2008 PRC 4 SIN C 1 3
2008 PRC 4 SIN C 2 5
2008 PRC 4 SIN C 3 2
2008 PRC 5 UNC A 1 1 Column1
2008 PRC 5 UNC A 2 1
2008 PRC 5 UNC A 3 1 Mean 1
2008 PRC 5 UNC B 1 1 Standard Error 0
2008 PRC 5 UNC B 2 1 Median 1
2008 PRC 5 UNC B 3 1 Mode 1
2008 PRC 5 UNC A 1 1 Minimum 1
2008 PRC 5 UNC A 2 1 Maximum 1
2008 PRC 5 UNC A 3 1 Sum 12
2008 PRC 5 UNC B 1 1 Count 12
2008 PRC 5 UNC B 2 1 Range 0
2008 PRC 5 UNC B 3 1
2013 PRC 1 REF A 1 2 Column1
2013 PRC 1 REF A 2 2
2013 PRC 1 REF A 3 2 Mean 2.222222222
2013 PRC 1 REF B 1 2 Standard Error 0.146986184
2013 PRC 1 REF B 2 2 Median 2
2013 PRC 1 REF B 3 3 Mode 2
2013 PRC 1 REF C 1 3 Standard Deviation 0.440958552
2013 PRC 1 REF C 2 2 Sample Variance 0.194444444
2013 PRC 1 REF C 3 2 Kurtosis 0.734693878
Skewness 1.619847741
Range 1
Minimum 2
Maximum 3
Sum 20
Count 9

78 | P a g e
1
2
3
4
5
6
7
2013 PRC 2 ZIG1 A 1 2 Column1
2013 PRC 2 ZIG1 A 2 2
2013 PRC 2 ZIG1 A 3 1 Mean 2.111111111
2013 PRC 2 ZIG1 B 1 2 Standard Error 0.200308404
2013 PRC 2 ZIG1 B 2 2 Median 2
2013 PRC 2 ZIG1 B 3 3 Mode 2
2013 PRC 2 ZIG1 C 1 3 Standard Deviation 0.600925213
2013 PRC 2 ZIG1 C 2 2 Sample Variance 0.361111111
2013 PRC 2 ZIG1 C 3 2 Kurtosis 1.125950972
Skewness 0.01828682
Range 2
Minimum 1
Maximum 3
Sum 19
Count 9
2013 PRC 3 GRD A 1 2 Column1
2013 PRC 3 GRD A 2 2
2013 PRC 3 GRD A 3 2 Mean 2.666666667
2013 PRC 3 GRD B 1 3 Standard Error 0.372677996
2013 PRC 3 GRD B 2 4 Median 2
2013 PRC 3 GRD B 3 4 Mode 2
2013 PRC 3 GRD C 1 4 Standard Deviation 1.118033989
2013 PRC 3 GRD C 2 1 Sample Variance 1.25
2013 PRC 3 GRD C 3 2 Kurtosis -1.485714286
Range 3
Minimum 1
Maximum 4
Sum 24
Count 9
2013 PRC 4 SIN A 1 2 Column1
2013 PRC 4 SIN A 2 3
2013 PRC 4 SIN A 3 2 Mean 2.888888889
2013 PRC 4 SIN B 1 3 Standard Error 0.200308404
2013 PRC 4 SIN B 2 3 Median 3
2013 PRC 4 SIN B 3 3 Mode 3
2013 PRC 4 SIN C 1 3 Standard Deviation 0.600925213
2013 PRC 4 SIN C 2 4 Sample Variance 0.361111111
2013 PRC 4 SIN C 3 3 Kurtosis 1.125950972
Skewness -0.01828682
Range 2
Minimum 2
Maximum 4
Sum 26
Count 9

79 | P a g e
1
2
3
4
5
6
7
8
9
10
11
12
2013 PRC 5 BEN A 1 1 Column1
2013 PRC 5 BEN A 2 1
2013 PRC 5 BEN A 3 1 Mean 1.666666667
2013 PRC 5 BEN B 1 2 Standard Error 0.23570226
2013 PRC 5 BEN B 2 2 Median 2
2013 PRC 5 BEN B 3 2 Mode 1
2013 PRC 5 BEN C 1 2 Standard Deviation 0.707106781
2013 PRC 5 BEN C 2 3 Sample Variance 0.5
2013 PRC 5 BEN C 3 1 Kurtosis -0.285714286
Range 2
Minimum 1
Maximum 3
Sum 15
Count 9
2013 PRC 6 ZIG2 A 1 2 Column1
2013 PRC 6 ZIG2 A 2 2
2013 PRC 6 ZIG2 A 3 1 Mean 1.444444444
2013 PRC 6 ZIG2 B 1 1 Standard Error 0.242161052
2013 PRC 6 ZIG2 B 2 2 Median 2
2013 PRC 6 ZIG2 B 3 1 Mode 2
2013 PRC 6 ZIG2 C 1 2 Standard Deviation 0.726483157
2013 PRC 6 ZIG2 C 2 0 Sample Variance 0.527777778
2013 PRC 6 ZIG2 C 3 2 Kurtosis 0.185199842
Skewness -1.014259034
Range 2
Minimum 0
Maximum 2
Sum 13
Count 9

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