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The Influence of Different Reclamation Phases on Distribution of Frogs at the Wilds
YuHyun ShinThe Ohio State University, Columbus, OH, USA, The Wilds, Cumberland, OH, USA
CONCLUSIONSRESULTS
INTRODUCTION
METHODS & MATERIALSSite Selection and Study Area
Study sites were chosen across the Wilds
property, which was divided based on phases of
reclamation and can be categorized into South,
Middle and North regions. Ten ponds or lakes
were randomly selected from each of these
divided areas, totaling thirty sites. The entire
perimeter of the study site was first
Environmental Variables
At each pond, water quality test including pH, conductivity and water temperature
were measured. Conductivity (µS), pH, and water temperature (℃) readings were
taken using Oakton™ and Eutech instruments Ltd. Some environmental variables
such as emergent vegetation, woody ground cover, rock ground cover and
canopy cover were visually estimated by the percentile based on the entire pond.
Also, distance to or from the nearest forest edge (m) and size of pond (m2) were
measured by ArcGis Online.
Statistical Analysis
All statistical analyses were conducted using R project, version 3.01. Analysis of
Similarity(ANOSIM) was separately run twice to distinguish dissimilarity or
similarity among the regions based on either environmental variables or frog
species. Non-metric Multidimensional Scaling (NMDS) was used to determine the
significant environmental variables that impact frog distribution. The two methods
together provide complementary information on distribution of frogs on three
regions based on environmental variables.
surveyed upon arrival. If any life stage was detected on any visit at a pond during the study
period we considered that species to be present and conversely, absent if no life stage was
detected. Each study site was surveyed twice. Amphibians were identified visually or by their
breeding calls.
ACKNOWLEDGEMENTSSpecial thanks to the department of Conservation Science at the Wilds especially Joe Greathouse,
Caitlin Byrne and the pond group. Figure 2. One of the sites in North region. It has pH of 6. and conductivity level of1542 µS/cm, one of the highest conductivity and lowest pH in entire sites.
RESULTS CONTINUED
Figure 5. Illustrating distributions of green frogs (Rana clamitans melanota),
bullfrogs (Rana catesbeiana) and pickerel frogs (Rana palustris) in 30 sites.
Green frogs are evenly distributed across the regions. On the other hand, bull
frogs are less evenly distributed in northern region. Also, pickerel frogs are
heavily distributed in southern region, but absent in northern region.
Figure 6. NMDS ordination illustrates the significance of environmental variables on each region. Several environmental variables show a correlation with NMDS1 and NMDS2 (p<0.05). The variables of increasing conductivity and woody ground cover are most associated with North region(3). On the other hand, the variables of increasing size of pond and distance to forest edge are most associated with South region(1). Red lines represent the level of conductivity in microsiemens and illustrate that the level of conductivity is increasing from South region(1) to North region(3).
Significance of Environmental Variables on Each Region
Figure3. A pickerel frogFigure4. Measuring the total length (mm) of the green frog by a caliper
Figure 8. ANOSIM test illustrates the similarity or dissimilarity among regions based on frogs species found. Although the grouping of samples based on frog species is not strong (R=0.033), ANOSIM test still shows that the other regions are not significantly different from one another based on distribution of frog species. Green frogs were not considered for the test, as they were found in all 30 sites.
Although regions that went through different reclamation phases have distinctly different ecological
characteristics (Figure 6), frog species were similarly distributed across the three phases of reclamation
(Figure 8). The environment of North region was significantly different than South and Middle regions
(Figure 7), however, the distribution of frogs seemed to be independent of the pond ecosystems in all
three regions.
1: South2: Middle3: North
:Presence of green frogs : Presence of bullfrogs : Presence of pickerel frogs
The Wilds, the largest conservation center for endangered species in North America, used
to be surface-mined almost entirely. The extraction of coal by different methods, including
surface mining has a significant impact on terrestrial and aquatic ecosystems (Buehler
and Percy 2012). The property went through three phases of reclamations throughout the
mid to late 1900s (Figure 1).
Frog species throughout the Wilds property are studied to
check their distribution across three phases of reclamation.
Amphibians are considered good indicators of environmental
stressors because they have unique life-history strategies
linked to terrestrial and aquatic habitats, are sensitive to
desiccation and susceptible to the effects of chemicals
in water and can absorb contaminants through their skin
(Welsh and Olivier 1998). As a result, water chemistry
potentially plays an important part in abundance and distribution of amphibians (Hecnar
and M‘Closkey 1996). pH affects many chemical and biological processes in the water
and conductivity can affect amphibian behavior, growth, development as well as survival
(Chambers 2011).
Breeding seasons for anurans vary between species; American bullfrog (Rana
catesbeiana), breed from May to July and green frogs (Rana clamitans melanota), breed
from April to August. The corresponding time periods during which the study took place
and breeding seasons made these 2 species the most commonly found. Pickerel frogs
(Rana palustris), which breed from February to late May were rarely encountered during
the surveys (Cappuccio et al. 2012).
Figure 1.The black line represents the Wilds property, 9104 acres. Blue region went through the first reclamation (1966-73 affected). Orange region went through the second reclamation (1973-76 affected). Yellow region went through the third reclamation phase (1975-02 affected). Also, red, green and purple dots indicate randomly chosen sites from North, Middle and South regions
Figure 7. ANOSIM test illustrates the similarity or dissimilarity among regions based on their environmental variables; some overlap between regions, other do not. While the characteristics based on environmental variables of South region (1) and Middle region (2) showed similarities, North region (3) has distinctly different environments compared to South and Middle region. The result is significant (p=0.004).
1: South2: Middle3: North
1: South2: Middle3: North
REFERENCEBuehler, D. A., & Percy, K. (2012). Coal mining and wildlife in the eastern United States: a literature review. Retrieved from http://www.appalachianwildlife.com/Coal%20Mining%20and%20Wildlife%20in%20the%20Eastern%20United%20States-final%20draft.pdf Cappuccio, N. E., Hagenberger, E. K., Fabis, A. L., Ferreli, A. J.,& Riaz, O. A. (2009). Effects of Water Chemistry on Anuran Species Diversity Within Huntingdon County. Journal of Ecological Research,11, 15-22). Retrieved from http://departments.juniata.edu/biology/eco/documents/Capuccio_etal.pdfChambers, D. L. (2011). Increased Conductivity Affects Corticosterone Levels and Prey Consumption in Larval Amphibians. Journal Of Herpetology, 45(2), 219-223.Hecnar, S.J., and R.T. M'Closkey. 1996. Amphibian species richness and distribution in relation to pond water chemistry in south-western Ontario, Canada. Freshwater Biology, 36, 7-15.Welsh, H. H. J. and Olivier, L. M. 1998. Stream amphibians as indicators of ecosystem stress: A case study from California Red woods. Ecological Applications. 8, 1118-1132.
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