Southern New Hampshire University Vernal Pools Discussion

PLEASE READ ALL BEFORE U BID. AND FOLLOW EVERYTHING I STATED. I have attached my rough draft with corrections suggested by my professor. Black ink is me and red ink is my professor. Please make the suggested changes. The article I attached “restoration ecology” is the article that I used as a reference and to help with the research, it’s the method that I followed for research. For reference you may use couple other articles as long as u cite them. Please do whatever the red ink says since it’s the suggested corrections from thm

Background information:

– my professor and I went on Palmer Park to take samples in Detroit Vernal Pool A. In one bottle, we took the sample of vernal pool A. We went back to campus and checked those samples under microscope on a slide. And found small little species on some sample slides under microscope. not that many

– 2nd time, I went by myself to Palmer Park and took samples of vernal pool B in 3 small bottles. Only found one species, on one slide under microscope

– 3rd time, I went by myself to park again to measure and sample the width and and the canopy cover of the vernal pool. Please include and explain how that’s done , from the article I provided.

RESEARCH ARTICLE
Comparing amphibian habitat quality and functional
success among natural, restored, and created
vernal pools
Megan B. Rothenberger2,3 , Mariuxi K. Vera2 , Dru Germanoski4 , Emily Ramirez1
The fact that several vernal pool restoration and creation attempts in eastern Pennsylvania and New Jersey have been paired
with conservation of natural pools in the same area provided a valuable research opportunity to compare amphibian habitat
quality between project sites and natural reference pools. To measure desired outcomes, we used successful reproduction
and metamorphosis of two vernal pool indicator species, the wood frog and spotted salamander. Although many previous
studies indicate that restored and created pools rarely replace function lost in the destruction of natural pools, success of
vernal pool indicator species was not necessarily related to pool type in this study. Results indicate a strong correlation
between reproductive success for both species and vernal pool size (i.e. mean depth and volume), regardless of pool type.
Although overall survival rates of wood frog larvae were significantly higher in natural pools with hydroperiods between 12
and 35 weeks, wood frogs were also successful in one restored and one created vernal pool. Salamander survival rates were
highest in two natural and two created pools, which had in common both greater volumes and higher proportions of forest
land cover in the surrounding 1,000 m. The documented success of vernal pool indicator species in two well-established created
pools demonstrates that pool creation can sometimes restore communities and ecological functions lost, especially when nearby
natural pools are degraded or destroyed.
Key words: amphibian, conservation, creation, habitat quality, restoration, vernal pool
Implications for Practice
• Success of amphibian breeding and metamorphosis in
vernal pools is not necessarily related to pool type, but
quality of mitigation attempts is highly variable.
• Well-established created vernal pools with high-quality
postbreeding habitat can be beneficial to amphibian populations in the long term.
• Practitioners aiming to restore functional habitat for vernal pool species should focus on the relationship between
pool volume and hydroperiod, surrounding forest cover,
and proximity to natural pools, as these factors appear to
be more closely related to amphibian success than others.
• Vernal pool restoration and creation projects should be
accompanied by extensive monitoring studies that include
measures of success beyond amphibian egg mass counts
since vernal pools with abundant egg masses do not
always have high overall survival rates.
specialized fauna. Fairy shrimp (Eubranchipus spp.), wood
frogs (Lithobates sylvaticus), and ambystomatid salamanders
(Ambystoma spp.) are all examples of obligate vernal pool
species that exploit the reduced predation pressure that comes
with pool transience to complete their life cycle (Semlitsch &
Skelley 2008). Vernal pools are of special concern for amphibians in northeastern North America where approximately 56%
of frog, toad, and salamander species frequent vernal pools for
breeding, development, foraging, or hibernation (deMaynadier
& Houlahan 2008). Vernal pools are also important sources of
food and water for reptiles, birds, and mammals, contributing
to overall landscape biodiversity by providing unique habitat
(Hunter 2008).
Author contributions: MBR, MKV conceived and designed overall research concept;
DG designed methods for soil and pool slope analysis; MBR, ER designed methods
for estimating amphibian reproductive success; all authors conducted field and
laboratory work and data analysis; MBR wrote and edited the manuscript with
contributions from MKV, DG.
1 Biology Department, Lafayette College, Kunkel Hall, Easton, PA 18042, U.S.A.
Introduction
Vernal pools are temporary to semipermanent wetlands occurring in shallow depressions, and in northeastern North America, they are associated with forested landscapes (Calhoun &
deMaynadier 2008). The seasonal hydrology of vernal pool
ecosystems creates vital, fishless habitat for a unique and
July 2019
Restoration Ecology Vol. 27, No. 4, pp. 881–891
2 Environmental Science and Studies Program, Lafayette College, Pardee Hall, Easton,
PA 18042, U.S.A.
3 Address correspondence to M. B. Rothenberger, email rothenbm@lafayette.edu
4 Department of Geology and Environmental Geosciences, Lafayette College, Van
Wickle Hall, Easton, PA 18042, U.S.A.
© 2019 Society for Ecological Restoration
doi: 10.1111/rec.12922
Supporting information at:
http://onlinelibrary.wiley.com/doi/10.1111/rec.12922/suppinfo
881
The value of vernal pools has been expressed not only in
terms of their unique breeding environment but also their role as
small natural features (i.e. small ecosystems with big impacts)
and the ecosystem and social services that they deliver (e.g.
aquifer recharge, water filtration, education; Hunter 2008; Calhoun et al. 2017; Hunter 2017). Yet, a growing body of literature
provides evidence that vernal pools are still inadequately protected due to their small size and temporary hydrology. They
are especially vulnerable to loss and degradation due to urbanization, agriculture, invasive species, and climate change (e.g.
Windmiller & Calhoun 2008; Calhoun et al. 2017). Therefore,
it is not surprising that vernal pools have been a focal point for
research in conservation biology, a field that aims to develop
practical interdisciplinary approaches for protecting and restoring biodiversity.
Conservationists have long emphasized that preservation of
intact natural vernal pools should be our primary goal because
vernal pools are among the most difficult wetlands to create
given their seasonal water regime (NRC 2001; Calhoun et al.
2014). Creation of new pools is further complicated by the
fact that they must be accompanied by adjacent intact, largely
forested postbreeding habitat for biphasic amphibians (Lichko
& Calhoun 2003). Nevertheless, continued loss and degradation
of existing pools has led to mitigation efforts that often rely
on vernal pool creation (i.e. construction of vernal pools where
they did not formerly exist) or restoration (i.e. rehabilitation of
existing vernal pools; Calhoun et al. 2014; Schlatter et al. 2016).
A review of vernal pool creation in central and northeastern
North America by Calhoun et al. (2014) indicates that created
pools often do not replace function lost in the destruction of
natural pools. The failure of created pools to provide breeding
habitat to vernal pool-associated amphibians is most frequently
associated with improper hydrology (e.g. Vasconcelos & Calhoun 2006; Gamble & Mitsch 2009; Denton & Richter 2013) or
absence of high-quality migration corridors of natural vegetation between adjacent ponds (Semlitsch 1998). Problems have
also been associated with differences in water chemistry (Korfel et al. 2010) and steep inundation gradients in created pools
that limit vegetation establishment and therefore basking and
predator avoidance habitat for amphibians (Porej & Hetherington 2005). Similarly, peer-reviewed papers on the functioning of
restored vernal pools report ambiguous results because projects
either were not guided by clear conservation-oriented goals or
involved practitioners with different goals from conservationists
(Schlatter et al. 2016). These are challenges that are common to
ecological restoration in general (Palmer 2016).
Previous studies comparing created and restored pools to
natural pools can certainly be used to refine our approach to
creation and restoration, yet there is still room for significant progress to be made. For example, most regulatory agencies require 3–5 years of monitoring following creation or
restoration of vernal pools, but short-term monitoring results
may not be indicative of long-term success (Schlatter et al.
2016). There is less information on the effectiveness of more
well-established created and restored vernal pools (i.e. those
>5 years old) in comparison with reference natural pools, especially in northeastern North America. Comparison studies are
882
sometimes limited when created and natural reference pools are
in different locations since variations in ecological function may
be due to differences in soil and topography rather than pool type
(Gamble & Mitsch 2009; Korfel et al. 2010). True reference
sites that minimize confounding factors and act as paired controls are crucial for quantitatively measuring performance variation and project success (Calhoun et al. 2014; Schlatter et al.
2016). Additional comparison studies that examine correlations
between biological function and a variety of pool design parameters, including soil texture, substrate structure, and landscape
context, are needed in multiple regions (Calhoun et al. 2014).
Whether restored and created vernal pools can successfully
replace the function of natural vernal pools remains an important
question in the area of vernal pool conservation. If we can identify functionally successful created and restored vernal pools
and those environmental parameters that best predict amphibian reproductive success, we can improve ecological restoration
practices. Therefore, the overall goal of this research was to
compare hydrology, slope, water quality, within-pool vegetation, canopy cover, land use, and soil characteristics among pool
types and evaluate correlations between these parameters and
reproductive success of the wood frog and spotted salamander
(Ambystoma maculatum), both obligate vernal pool-breeding
amphibians. In order to isolate factors that are most important
for native species success, our comparison study includes multiple vernal pool sites with created or restored and natural reference pools in the same area. The created and restored pools
also represented a variety of ages and habitat characteristics. As
these methods enabled us to evaluate the effectiveness of different vernal pool creation and restoration strategies in comparison
with natural pools that establish a reference range for species
and processes (Palmer 2016), our results provide practitioners
with additional information to guide future projects and inform
adaptive management of vernal pools.
Methods
Study Site Descriptions
Although the pools included in this study demonstrate a high
degree of variability in terms of the timing and duration of flooding, they all fall within the definition for vernal pools most
commonly used in northeastern North America. This definition
includes any small, fluctuating water body that reaches its maximum size in spring, lacks fish, and provides breeding habitat
for certain species of woodland amphibians (Colburn 2004).
We used a total of four natural, four restored, and six created
pools distributed over four sites in a 290-km2 area of eastern
Pennsylvania and Warren County, New Jersey (Table 1; Fig. 1),
all mapped to areas classified as having hydric soils (USDA
NRCS 2017). The first site, Jacobsburg State Park, is a 4.73-km2
state park situated approximately 11 km northwest of Easton,
Pennsylvania in Northampton County. This site included two
natural and three created vernal pools distributed into two locations. A natural pool (JSP1) and two unlined pools created in
2011 and 2008, respectively (JSP2 and JSP3), were situated in
the first location, which is more than 1,000 m from the closest
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Success of vernal pool restoration projects
Table 1. Summary of vernal pool characteristics. Hydrological parameters were measured on a weekly basis from March 2014 through April 2018 at
Jacobsburg State Park and from March 2017 through May 2018 at the other three sites. Values are means (SE).
Site
Pool Abbreviation
Pool Type
Depth (cm)
Volume (m3 )
Hydroperiod (weeks)
Jacobsburg State Park, PA
JSP1
JSP2
JSP3
JSP4
JSP5
MCR1
MCR2
MCR3
GA1
GA2
GA3
GA4
GA5
HE1
Natural
Created
Created
Created
Natural
Created
Natural
Restored
Restored
Created
Restored
Natural
Restored
Created
26.9 (2.73)
12.2 (2.37)
24.1 (1.44)
31.4 (4.10)
56.7 (3.40)
47.9 (4.62)
7.42 (1.78)
11.48 (1.38)
36.8 (4.17)
8.51 (1.05)
18.7 (1.26)
60.2 (5.10)
17.4 (1.03)
35.9 (5.99)
67.7 (11.1)
4.61 (1.04)
6.22 (0.67)
52.9 (11.6)
193 (21.2)
52.6 (8.24)
1.18 (0.26)
59.8 (6.19)
136 (26.1)
2.14 (0.41)
7.76 (1.51)
342 (52.5)
26.8 (5.87)
68.3 (16.5)
16.0 (2.3)
10.8 (2.1)
21.7 (3.8)
14.4 (1.2)
17.8 (1.6)
52 (0)
11.5 (3.5)
33.0 (1.0)
35.5 (2.5)
23.0 (1.0)
32.5 (1.5)
52 (0)
33.5 (0.5)
24.5 (0.5)
Merrill Creek Reservoir, NJ
Graver Arboretum, PA
Hellertown, PA
Location 2
(JSP 4 -5)
Field Sites
Pennsylvania
Major City
Graver
Arboretum Sites
GA 1-5
Location 1
(JSP 1-3)
Jacobsburg
State Park
Sites
Protected
Area
Easton
Location 1
(MCR1-2)
Merrill Creek
Reservoir Sites
Location 2
(MCR 3)
Bethlehem
Hellertown
Site
HE 1
Figure 1. Map of the study area, which included a total of four natural, four restored, and six created vernal pools distributed over four sites in a 290-km2
area of eastern Pennsylvania and Warren County, New Jersey.
vehicle-accessible road. These three pools are within 100 m
of one another with no obstacles between them. The second
location within Jacobsburg State Park was near a residential
community and included a synthetically lined pool created in
2008 (JSP4) and a natural pool (JSP5) positioned approximately
175 m from one another and less than 100 m from two asphalted
roads.
Merrill Creek Reservoir Environmental Preserve, located in
Washington, New Jersey, contains a 2.6-km2 reservoir surrounded by a 1.2-km2 environmental preserve and an additional
8.1 km2 of woods and fields. This site included one natural, one
restored, and one created vernal pool distributed into two locations. The first location included a created pool constructed in
July 2019
Restoration Ecology
approximately 1980 (MCR1) and a natural pool (MCR2) situated directly adjacent to one another and approximately 100 m
from an asphalted road. The second location included a natural
pool with water derived from a spring located to the southeast.
This natural pool was restored in 1989 (MCR3) with the goal
of restoring habitat for the bog turtle (Clemmys muhlenbergii
Schoepff), a species that is federally listed as threatened under
the Endangered Species Act. Creation methods and monitoring were documented in a wildlife management plan for the
restored pool.
The Lee and Virginia Graver Arboretum in Bushkill Township, Pennsylvania is a 0.25-km2 arboretum maintained and utilized by Muhlenberg College. This site included one natural
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Success of vernal pool restoration projects
(GA4), three restored (GA1, 3, and 5), and one created vernal
pool (GA2) with an unknown year of construction. All pools are
between 150 and 250 m from the nearest asphalted road. The
fourth site, located in Hellertown, Pennsylvania, included a single unlined created pool with an unknown year of construction
(HE1) located 270 m from the nearest asphalted road. No documentation of creation or restoration objectives, design criteria,
or monitoring was available for Graver Arboretum or Hellertown pools.
Amphibians
We initiated egg mass counting approximately 1 week before
typical initiation of oviposition in this area (i.e. first week
of March) and continued on a weekly basis until all eggs hatched
and decomposed in order to capture the period immediately
after the eggs were deposited and ensure that sampling encompassed the entire potential egg-laying period. We collected data
on egg mass abundance from Jacobsburg State Park vernal pools
from 2014 to 2018 and from the other nine vernal pools from
2017 to 2018. Egg mass counts were conducted by a single
observer and verified by at least one other observer using methods described in Crouch and Paton (2000). Egg mass counts for
each pool were used to determine the mean egg mass density
per cubic meter of water and maximum egg mass abundance
per pool.
Recognizing that egg mass density is a metric of pool use
for breeding by wood frogs and spotted salamanders but not
necessarily embryonic survival, we estimated larval abundance
immediately after hatching and during metamorphosis in all
pools in 2018. Measurements of larval abundance were taken
within 2 weeks after greater than 95% of the egg masses had
hatched in a pool (Petranka et al. 2003). A 114-L open-bottomed
sampler (area of sampler opening approximately 0.20 m2 ) was
pushed into the pool substrate to trap larvae, which were captured and counted. We stratified sampling sites by depth (i.e.
shallow 60 cm), and
replicate sites within each depth stratum were chosen randomly
along a transect (Heyer et al. 1994). We estimated premetamorphic larval abundance (PLA) and standard error for each pool
and species using the number of larvae per sample (i.e. based
on 2–12 samples per pool depending on pool size), the number
of sampling units in a depth stratum, and pool volume and area
at the time of sampling (Heyer et al. 1994). When larvae began
to metamorphose (i.e. as indicated by emergence of front legs),
dip nets were used to quantify larval abundance with capture
standardized among pools by using a 1-m sweep length and timing for 1 minute for the first 25 m2 and an additional minute for
each doubling in area (Heyer et al. 1994). We calculated a final
estimate of larval abundance for each pool using the number
of larvae per sweep, water volume sampled per sweep, number of sweeps completed during the sampling time, and pool
volume and area at the time of sampling (Heyer et al. 1994).
We quantified larval success, or survival from hatching to metamorphosis, as a proportion using estimates of larval population
size before and during metamorphosis. Finally, we estimated
overall survival for each species as a proportion by dividing
884
the number of metamorphosing individuals by the number of
eggs in each pool. As egg masses, but not individual eggs,
were counted, overall survival was indirectly determined using
published estimates of the number of eggs per mass for each
species. Methods for larval sampling were approved by the Institutional Animal Care and Use Committee (IACUC) at Lafayette
College.
Hydrology and Water Chemistry
We collected physical and chemical data on a weekly basis
concurrent with egg mass counts. Physical data were collected
on pool depth, area (width and length measured to water level
and calculated for area of an oval), and hydroperiod (i.e. continuous duration of time that water is ponded). We used depth
and area of each pool to calculate volume throughout the season
(i.e. volume [m3 ] = area [m2 ] × maximum depth [m] × 0.3135;
Gamble et al. 2007). While pools held water, we used a YSI
6820 V2 multiparameter meter on an approximately weekly
basis to determine water temperature, pH, conductivity, and
dissolved oxygen (DO). Data from each pool were gathered
approximately 1 m from the shoreline and at mid-depth. We
also recorded approximate dry-down dates for each pool, and we
define “dry” as a pool with no visible ponded water. To assess
the ease or difficulty that amphibians might experience when
moving to and from the pools, we measured the pool-edge slope
from the edge of the pool to complete transition to the forest
floor using total station surveying equipment along four transects in the smaller pools and along eight transects in the larger
pools.
Vegetation and Canopy Cover
We compared within-pool vegetation among pool types using
vegetation surveys at each of the vernal pools in July 2016 during the growing season. We used a stratified random sampling
design to identify locations within each pool where absolute
plant cover was quantified using a 1-m2 quadrat. Since both
whole plants and fine and course woody material that falls into
vernal pools from nearby trees can serve as potential amphibian
egg attachment sites, refugia from danger, and shade (Calhoun
et al. 2014), we quantified the cover of plant species and plant
material (i.e. woody debris and leaf litter) within each quadrat
using a seven-degree Braun-Blanquet scale (Westhoff & van
der Maarel 1978). Vegetation cover estimates were made by
the same person to maintain a consistent protocol and minimize
sampling bias, and sampling continued until approximately 10%
of each pool was surveyed.
We measured canopy coverage in July 2016 during the growing season using a convex spherical crown densiometer. Readings were taken in the center of each pool and at distances of
10, 65, and 120 m in each of the cardinal directions leading
away from the pool. At each of those locations, four densiometer
readings were taken in the cardinal directions surrounding that
location. We estimated over-story density for a particular pool
by averaging these 13 readings (i.e. 1 pool center + 4 cardinal
directions × 3 distances).
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Success of vernal pool restoration projects
Land Use
Statistical Analyses
We used Geographic Information Systems (GIS) to classify
and compare land use surrounding each of the 14 vernal pools.
Land Use Land Cover (LULC) data for this analysis were
taken from the United States Geological Survey (U.S.GS) 2011
National Land Cover Database. The LULC grid was imported
into the GIS interface and reclassified using the Reclassify tool
available in Spatial Analyst to include just five general categories: (1) developed; (2) forested; (3) wetland; (4) agriculture;
and (5) water. We used the Spatial Analyst “tabulate area” function to calculate the area of each land use category within polygons with a radial distance of 1,000 m of each pool. This size
was chosen because studies have shown that juvenile wood frogs
can disperse as far as 1,000 m from their birth site, and this area
includes the three habitat types utilized by vernal pool-breeding
amphibians: the pool for breeding, forested wetlands, or hillside seeps for summer refugia, and well-drained upland forests
for hibernation (Baldwin et al. 2006). We then compared the
proportion of each land cover type within the polygon among
natural, restored, and created pools.
We used one-way analysis of variance (ANOVA) and Tukey’s
multiple comparison test to compare variables among sites (i.e.
Jacobsburg State Park [n = 5], Merrill Creek [n = 3], Graver
Arboretum [n = 5], and Hellertown [n = 1]) and pool types (i.e.
natural pools [n = 4], restored pools [n = 4], and created pools
[n = 6]). A separate model was run for each dependent variable,
and pool was included as a random effect for the egg mass and
water chemistry models to account for repeated samples within
the same pools for these parameters.
We used ordination techniques to investigate differences in
vegetation cover among pool sites and types. We established
differences in vegetation among pools using nonmetric multidimensional scaling (NMDS), considered the most effective
ordination method for ecological data (McCune & Grace 2002).
All NMDS ordinations were carried out using PC-ORD version
5.0 software in the “slow and thorough” autopilot mode using
a Sørensen distance matrix (MjM software 2010, Gleneden
Beach, OR, U.S.A.). To prepare the monitoring dataset for ordination, vegetation data were compiled into a matrix of absolute
plant cover for each plant taxon by vernal pool. To reduce the
“noise” (variability) in the vegetation dataset and enhance detection of assemblage patterns in relation to environmental parameters, rare plant taxa (defined as present in 5 m3 in volume) with mean hydroperiods shorter than 12 weeks and dry-down dates occurring in
May and sometimes earlier. Next, both indicator species were
generally more successful in pools with short- to long-cycle
hydroperiods with mean dry-down dates in early July. Although
all pools included in this study were mapped in areas classified as having hydric soils, pools with hydroperiods having
discrete drying episodes in early summer (e.g. JSP1, JSP5,
HE1, and GA1) had high concentrations of low permeability
silt, clay, and fragipans in the soil that further contributed to
water retention and interflow that sustained them until evapotranspiration and reduction in effective precipitation reduced
water levels. This finding emphasizes the importance of situating future created pools in landscapes with hydric soils with
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Success of vernal pool restoration projects
Figure 4. Nonmetric multidimensional scaling was used to establish differences in amphibian success by vernal pool hydroperiod category. Each point on the
diagram represents egg mass abundance, larval abundance, and survival for each species from a given pool and year (the same points are shown in both
panels). The relative distance between points reflects similarity or differences in biotic parameters and amphibian success rates. (A) Vectors indicate strength
and direction of biotic parameters (r2 cutoff value = 0.60; WF, wood frog; SS, spotted salamander; OS, overall survival; LS, larval survival; PLA,
premetamorphic larval abundance; EMA, egg mass abundance) and (B) vectors indicate strength and direction of environmental parameters (r2 cutoff
value = 0.50).
significant silt and clay content or fragipans to facilitate water
retention.
Again, the frequent success of wood frog larvae in vernal
pools with moderate hydroperiods (i.e. neither too short nor
too long) is not new information (e.g. Vasconcelos & Calhoun
2006; Korfel et al. 2010). However, two semipermanent pools
(GA4 and MCR1) were also among the most functionally
successful pools in our study. GA4 supported successful reproduction and metamorphosis of wood frogs only, whereas MCR1
supported successful reproduction and metamorphosis for spotted salamanders only. One possible explanation for this finding
may have to do with predator density. Wood frogs may achieve
reproductive success in pools with longer hydroperiods only if
predator density is low (e.g. GA4), whereas spotted salamanders
may achieve reproductive success in semipermanent pools even
when predator density is relatively high (e.g. MCR1). Although
none of the pools contain fish, initial observations indicate a
relatively high density of green frogs (Lithobates clamitans),
eastern newts (Notophthalmus viridescens), American bullfrog
tadpoles (Lithobates catesbeianus), and various invertebrates
(e.g. dragonfly and damselfly larvae) in MCR1. Previous studies
have indicated that wood frog eggs are far more vulnerable to
predation pressure than those of spotted salamanders, which
are enclosed in protective, layered mucopolysaccharide membranes (Vasconcelos & Calhoun 2006). Since we have not yet
attempted to quantify predator densities in these pools, the
degree to which year-to-year variation in larval success can be
attributed to variation in predator densities will be an important
area for future study.
July 2019
Restoration Ecology
The final parameters that emerged as important predictors of
vernal pool-breeder success are landscape context and land use
in the surrounding 1,000 m of pools. As mentioned, all pools
included in this study were situated in landscapes with hydric
soils, and the most successful restored and created pools were
either paired with preservation of existing pools to allow for
colonization and pool-to-pool flow of amphibians within a single population (i.e. GA1 and MCR1; Vasconcelos & Calhoun
2006; Calhoun et al. 2014) or located in an area where natural
pools were lost (i.e. HE1; Calhoun et al. 2017; Hunter 2017).
Although a natural pool was once thought to exist in the Hellertown site, no natural pool was located using aerial photography
or through extensive physical searches of the area. If the natural
pool at the Hellertown site was altered or destroyed, HE1 would
be critical for maintaining populations of vernal pool amphibians within the area.
Our results also indicate an inverse relationship between
proportion of developed land cover and overall spotted salamander survival, but not necessarily with wood frog survival
rates. The Graver Arboretum site appears to be a useful case
study of this relationship. Some of the pools at the Graver
Arboretum site had high overall wood frog survival rates, but
spotted salamanders were never observed at this site, which had
a significantly lower proportion of forest and higher proportion
of developed and agricultural land cover within 1,000 m of
pools. In fact, the Graver Arboretum pools had less than 25%
forest cover in a 1,000-m radius of pools compared with an
average forest land cover of 59% for pools at the other three
sites. Homan et al. (2004) reported a critical threshold value
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Success of vernal pool restoration projects
of 51% forest cover within 1,000 m for spotted salamanders
compared with 44% for wood frogs. Despite reduced forest cover surrounding Graver Arboretum, the relatively high
canopy cover within 120 m of pools (i.e. mean canopy cover
approximately 90% at the Graver Arboretum site) appears to be
adequate to support a successful breeding population of wood
frogs. This study reinforces results of previous studies indicating that spotted salamanders are more sensitive than wood frogs
to forest loss with increasing distance from breeding pools
(Homan et al. 2004).
In conclusion, the results of our multiyear monitoring study
mostly corroborate previous research demonstrating that the
quality and success of restoration and creation attempts is
highly variable and that certain habitat parameters (i.e. water
depth, volume, hydroperiod, and landscape context) are better
predictors of successful breeding and metamorphosis of vernal
pool indicator species than others (e.g. vegetation). Our finding
that pools with very high yearly amphibian egg mass abundance
did not always have greater overall survival rates also confirms
that larval survival, rather than egg mass counts alone, should
be used to assess success of mitigation attempts (Calhoun
et al. 2014). Although we agree that conservation of natural
vernal pools should be considered a priority, we believe that
vernal pool mitigation projects are important given the reality
of continued wetland degradation and loss. Our study demonstrates that created pools with high-quality postbreeding habitat
and adequate hydroperiods can be beneficial to amphibian
populations in the long term.
Acknowledgments
Funding support for this research was provided by the Lafayette
College Excel Scholars Program, Department of Biology,
and Environmental Science and Studies Program. We thank D.
Sunderlin in Lafayette’s Department of Geology and Environmental Geosciences and B. Cohen in Lafayette’s Department
of Engineering Studies for providing comments on earlier versions of this manuscript. P. Auerbach and K. Farrell provided
technical field support. A. Baranovic, T. Broholm, F. Demirhan,
K. Engberg, E. Lynch, J. Ventresca, and S. Woodruff all assisted
with field research.
LITERATURE CITED
Baldwin RF, Calhoun AJK, deMaynadier PG (2006) Conservation planning for
amphibian species with complex habitat requirements: a case study using
movements and habitat selection of the wood frog Rana sylvatica. Journal
of Herpetology 40:443–454
Calhoun AJK, deMaynadier PG (2008) Science and conservation of vernal pools
in northeastern North America. CRC Press, Boca Raton, Florida
Calhoun AJK, Arrigoni J, Brooks RP, Hunter ML, Richter SC (2014) Creating
successful vernal pools: a literature review and advice for practitioners.
Wetlands 34:1027–1038
Calhoun AJK, Mushet DM, Bell KP, Boix D, Fitzsimons JA, Isselin-Nondedeu F
(2017) Temporary wetlands: challenges and solutions to conserving a
disappearing ecosystem. Biological Conservation 211:3–11
Colburn EA (2004) Vernal pools natural history and conservation. The MacDonald & Woodward Publishing Company, Blacksburg, Virginia
890
Crouch WB, Paton PWC (2000) Using egg-mass counts to monitor wood frog
populations. Wildlife Society Bulletin 28:895–901
Denton RD, Richter SC (2013) Amphibian communities in natural and constructed ridge top wetlands with implications for wetland construction.
Journal of Wildlife Management 77:886–889
Egan RS, Paton PWC (2004) Within-pond parameters affecting oviposition by
wood frogs and spotted salamanders. Wetlands 24:1–13
Gamble DL, Mitsch WJ (2009) Hydroperiods of created and natural vernal
pools in central Ohio: a comparison of depth and duration of inundation.
Wetlands Ecology and Management 17:385–395
Gamble DE, Grody E, Undercoffer J, Mack JJ, Micacchion M (2007) An
ecological and functional assessment of urban wetlands in central Ohio.
Volume 2: morphometric surveys, depth-area-volume relationships and
flood storage function. Ohio EPA Technical Report WET/2007-3B, Ohio
Environmental Protection Agency, Wetland Ecology Group, Division of
Surface Water, Columbus, Ohio
Heyer RW, Donnelly MA, McDiarmid RW, Hayek LC, Foster MS (eds) (1994)
Measuring and monitoring biological diversity: standard methods for
amphibians. Smithsonian Institution Press, Washington D.C.
Homan RN, Windmiller BS, Reed JM (2004) Critical thresholds associated
with habitat loss for two vernal pool-breeding amphibians. Ecological
Applications 14:1547–1553
Hunter ML (2008) Valuing and conserving vernal pools as small scale ecosystems. Pages 1–10. In: Calhoun AJK, deMaynadier PG (eds) Science and
conservation of vernal pools in northeastern North America. CRC Press,
Boca Raton, Florida
Hunter ML (2017) Conserving small natural features with large ecological roles:
a synthetic overview. Biological Conservation 211:88–95
Korfel CA, Mitsch WJ, Hetherington TE, Mack JJ (2010) Hydrology, physiochemistry, and amphibians in natural and created vernal pool wetlands.
Restoration Ecology 18:843–854
Lichko LE, Calhoun AJK (2003) An evaluation of vernal pool creation projects
in New England: project documentation from 1991-2000. Environmental
Management 32:141–151
deMaynadier PG, Houlahan JE (2008) Conserving vernal pool amphibians in
managed forests. Pages 253–280. In: Calhoun AJK, deMaynadier PG (eds)
Science and conservation of vernal pools in northeastern North America.
CRC Press, Boca Raton, Florida
McCune B, Grace JB (2002) Analysis of ecological communities. MjM Software
Design, Gleneden Beach, Oregon
Munsell Color Company (2010) Munsell soil color charts: with genuine Munsell
color chips. Munsell Color, Grand Rapids, Michigan
NRC (National Research Council) (2001) Compensating for wetland losses under
the Clean Water Act. National Academy Press, Washington D.C.
Palmer MA (2016) Persistent and emerging themes in the linkage of theory to restoration practice. Pages 517–532. In: Palmer MA, Zedler
JB, Falk DA (eds) Foundations of restoration ecology. Island Press,
Washington D.C.
Petranka JW, Murray SS, Kennedy CA (2003) Responses of amphibians to
restoration of a southern Appalachian wetland: perturbations confound
post-restoration assessment. Wetlands 23:278–290
Porej D, Hetherington TE (2005) Designing wetlands for amphibians: importance of predatory fish and shallow littoral zones in structuring of amphibian communities. Wetlands Ecology and Management 13:445–455
Rheinhardt RD, Hollands GG (2008) Classification of vernal pools: geomorphic
setting and distribution. Pages 11–30. In: Calhoun AJK, deMaynadier
PG (eds) Science and conservation of vernal pools in northeastern North
America. CRC Press, Boca Raton, Florida
Schaetzyl R, Anderson S (2005) Soils genesis and geomorphology. Cambridge
University Press, Cambridge, United Kingdom
Schlatter KJ, Faist AM, Collinge SK (2016) Using performance standards
to guide vernal pool restoration and adaptive management. Restoration
Ecology 24:145–152
Semlitsch RD (1998) Biological delineation of terrestrial buffer zones for
pond-breeding salamanders. Conservation Biology 12:1113–1119
Restoration Ecology July 2019
1526100x, 2019, 4, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/rec.12922 by University Of Detroit – Mercy, Wiley Online Library on [19/04/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
Success of vernal pool restoration projects
Semlitsch RD, Skelley DK (2008) Ecology and conservation of pool-breeding
amphibians. Pages 127–148. In: Calhoun AJK, deMaynadier PG (eds)
Science and conservation of vernal pools in northeastern North America.
CRC Press, Boca Raton, Florida
Skidds DE, Golet FC, Paton PWC, Mitchell JC (2007) Habitat correlates of
reproductive effort in wood frogs and spotted salamanders in an urbanizing
watershed. Journal of Herpetology 41:439–450
USDA NRCS (United States Department of Agriculture Natural Resources
Conservation Service) (2017) Web soil survey. https://websoilsurvey.sc
.egov.usda.gov/App/HomePage.htm (accessed 29 Jan 2018)
Vasconcelos D, Calhoun AJK (2006) Monitoring created seasonal pools for
functional success: a six-year case study of amphibian responses, Sears
Island, Maine, USA. Wetlands 26:992–1003
Westhoff V, van der Maarel E (1978) The Braun-Blanquet approach. Pages
287–399. In: Whittaker RH (ed) Classification of plant communities. Junk,
The Hague, The Netherlands
Windmiller B, Calhoun AJK (2008) Conserving vernal pool wildlife in urbanizing landscapes. Pages 233–251. In: Calhoun AJK, deMaynadier PG (eds)
Science and conservation of vernal pools in northeastern North America.
CRC Press, Boca Raton, Florida
Supporting Information
Coordinating Editor: Siobhan Fennessy
Received: 22 September, 2018; First decision: 5 November, 2018; Revised: 22
December, 2018; Accepted: 5 January, 2019; First published online: 4 March,
2019
July 2019
Restoration Ecology
The following information may be found in the online version of this article:
Table S1. Comparison of upland and within-pool environmental parameters and
mean egg mass abundance and density of wood frogs and spotted salamanders
combined among vernal pools at Jacobsburg State Park, Merrill Creek Reservoir,
Graver Arboretum, and Hellertown.
Table S2. Comparison of upland and within-pool environmental parameters and
mean egg mass abundance and density of wood frogs and spotted salamanders
combined among natural (n = 4), restored (n = 4), and created (n = 6) vernal
pools.
Table S3. Summary statistics for repeated measures ANOVA on five-dependent
variables.
Figure S1. Monthly mean temperature (A) and precipitation (B) for the egg deposition
period compared to historical, 100-year means.
Figure S2. Chronology of wood frog (A) and spotted salamander (B) egg mass
deposition from 2014 to 2018.
Figure S3. Mean egg mass abundance (A) and density (B) over time for wood frogs
and spotted salamanders at Jacobsburg State Park, Merrill Creek Reservoir, Graver
Arboretum, and Hellertown pools.
Figure S4. Mean egg mass abundance (A) and density (B) over time for wood frogs
and spotted salamanders in natural, restored, and created pools.
891
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Success of vernal pool restoration projects