Comparison of the abundance, diversity, and composition of epiphytic bryophytes on sugar
maple trees (Acer saccharum March.) between Central New York and the Adirondack
Region
Photo: M. Garmendia/ Species: Porella platyphylla
Miguel Garmendia Z.
M.S. Candidate
Environmental and Forest Biology
College of Environmental Science and Forestry
State University of New York
Final Report on Internship
Edna Bailey Sussman Foundation
December 2014
SUMMARY
The main objective of this research was to compare the abundance, diversity, and species composition of
epiphytic bryophytes between Central New York (CNY) and the Adirondacks (ADK). This comparison
included the determination of the relationship between the abundance of each species with the climate
variables temperature and relative humidity. A survey of epiphytic bryophytes was conducted in three
state forests in Central New York (Bear Swamp State Forest, Cuyler Hill State Forest, and Long Pond
State Forest), and three wild forest in the Adirondacks (Saranac Lake Wild Forest, Horseshoe Lake Wild
Forest, and Jessup River Wild Forest). Additionally, six iButton Temperature & Humidity Loggers were
set up for four months (June to October) in each site. In total, 32 species were identified in the study area
including, 27 in ADK and 21 in CNY. The percent cover per species was higher in ADK (13.19%)
compared to CNY (10.52%). The species composition was different due to the number of species unique
for each region and the difference in percent cover of the most abundant species from one region to the
other. The most abundant and frequently found species were Anomodon attenuatus, Brachythecium
oxycladon, and Plagiomnium ciliare. The temperature was significantly different between regions, on the
contrary, humidity was not significantly different. On average, the temperature for CNY was 16.79oC,
and 15.10oC for ADK. The average humidity was around 88% for both regions. The species whose
abundance had a significant relationship with temperature were Neckera pennata and Ulota crispa. The
abundance of N. pennata had a significant negative relationship with temperature, while the abundance
of U. crispa had a significant positive relationship with temperature. Although some species showed
some slight negative or positive relationships with humidity, none of them were significant.
METHOD
The study area for this research was the upland forests of in Northern and Central New York. Six sites
were selected in order to conduct this study. Saranac Lake Wild Forest, Horseshoe Lake Wild Forest, and
Jessup River Wild Forest in the Adirondack Region (ADK), and Bear Swamp State Forest, Cuyler Hill
State Forest, and Long Pond State Forest in Central New York (CNY). The activity consisted on
conducting a survey of epiphytic bryophytes on 30 sugar maple trees per site. The criteria for selecting the
trees were (a) the trees must had a ≥ 50 cm diameter at the breast height, (b) ≤ 10o of inclination, (c) had
to be at the top of a hill, and (d) had to be far from canopy gaps. Line-intercepts were established on each
tree at 10, 20, 50, 100, and 150 cm above the ground, following McGee and Kimmerer (2002), to estimate
percent cover of each bryophyte species on each host tree. Temperature and humidity were recorded using
iButton Temperature & Humidity Loggers. Six devices were placed on trees in which the survey was
conducted at each site. The iButtons were set up from June to October 2014.
The Simpson Diversity Index, Jaccard Coefficient, and Morisita Coefficient were calculated to compare
the species composition between both regions. The index and the coefficients were calculated according
to procedures and equations described by Magurran (2004). Statistical analysis included descriptive
statistics, mean comparison (ANOVA, T-test), correlation (Pearson Coefficient), regression, frequency
analysis, and multivariate analysis (Cluster Analysis). A significance level of 0.05 was used in all tests.
The normality assumption was assessed with Shapiro-Wilks test.
RESULTS
Comparison of abundance, frequency, and species diversity
The number of species in CNY was 27 and the number of species in ADK was 21. The difference in the
number of species was not significant (t=1.55, p>0.20). The percent cover for all species in ADK
(13.19±17.01% cover) was higher compare to CNY (10.52±15.33% cover) (t=2.40, p<0.018). The
expected number of species calculated with the Chao1 Estimator was the same as the number of observed
species for each region (CNY=27 species, ADK=21 species). Therefore, there is little chance of finding
new species in subsequent samplings. The structure of the community in terms of equitability (equal
distribution of the abundance per species) according to the Simpson Diversity Index was more equitable
in CNY (0.94) than in ADK (0.92). The difference between large and small bryophyte mats was higher in
ADK. In terms of species composition calculated by the Jaccard Coefficient, both regions were 50%
similar. The species composition calculated by the Morisita Coefficient (combining the type of species
with the abundance) showed a similarity of 66% for both regions.
The low similarity between both regions according to the Jaccard Coefficient, was a result of the high
number of unique species. 11 species were found only in CNY and five species were found only in ADK.
The species found only in CNY were Anomodon rostratus, Brachythecium reflexum, Callicladium
haldanianum, Dicranum montanum, Entodon cladorrhizans, Callicladium haldanianum, Leskea
gracilescens, Plagiomnium cuspidatum, Plagiothecium laetum, Rhynchostegium serrulatum, and
Thuidium delicatulum. The species found only in ADK were Rhodobryum ontariense, Dicranum
scoparium, Leucodon brachypus, Neckera pennata, and Anomodon rugelii. The absence of one species in
one region does not mean that the species in not actually there, it means that it was not found during this
survey. Increasing the sampling effort could reveal whether the absence of the species is due to dispersal
limitations or if the species is present as a rare species.
The 34% difference in species composition according to the Morisita Coefficient was a result of the
difference in abundance per species in each region. The most abundant species in one region were not the
most abundant species in the other. For example, only three species (Anomodon attenuatus,
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Brachythecium oxycladon, and Plagiomnium ciliare) out of nine (>15% cover only) were abundant in
both regions. A. attenuatus was the most abundant species in ADK, while Brachythecium salebrosum and
Pylaisia selwynii in addition to A. attenuatus were the most abundant species in CNY.
B. oxycladon, Brachythecium sp, Frullania eboracensis, and P. ciliare were found more frequently
(frequency defined as the number of trees were the species was observed divided by the total number of
trees) in both regions. Porella platyphylla was more frequently observed in ADK, while Platygyrium
repens, Ulota crispa, and Dicranum viride in CNY.
Relationship abundance-climate
The temperature in both regions was significantly different (t=-20, p<0.0001). In average, the temperature
was higher in CNY (16.79oC) than ADK (15.10oC). The relative humidity did not differ significantly
from one region to the other (t=1.05m, p>0.29). The average humidity was around 88% for both regions.
The total abundance of bryophytes showed a significant negative correlation with temperature (r=-0.07,
p<0.04) and humidity (r=-0.08, p<0.02). The species were grouped according to the variables temperature
and humidity separately using cluster analysis. Four group were defined in the temperature's cluster
(Figure 1).
Figure 1. Cluster analysis grouping the species according to the variable temperature using the Euclidea
distance and the Ward Method. Four groups were defined and named 1, 2, 3, and 4 from top to
bottom.
An analysis of variance was conducted to test whether the groups differed in term of the temperature
values to which each one was associated. As a result, each group was associated with different
temperature values (F=70.99, p<0.0001). The species in Group 2 were associated with the highest
temperature (Table 1), while the species in Group 3 were found in places where temperature was lower.
Group 1 and 4 were associated with middle temperature values. The relationship between the species
abundance and the temperature was significant only in Group 2 and Group 3 (Table 1). The species
abundance in Group 2 (R2= 0.21) showed a positive relationship with temperature, while the species
abundance in Group 3 (R2= 0.47) showed a negative relationship with temperature (Table 1).
Correlation analysis were apply to Group 2 and Group 3 in order to determine the specific species which
abundance were corrlated with temperature. As a result, for Group 2 the abundance of U. crispa had a
significant positive relationship with temperature (r=0.35, p<0.03; R2= 0.74). The remaining species in
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Group 2 had not significant relationship with temperature. For Group 3 the abundance of N. pennata had
a significant negative relationship with temperature (r=-0.60, p<0.0001; R2= 0.50). The remaining species
in Group 3 had not significant relationship.
Table 1. Mean temperature and humidity to which each group was associated as a result of the cluster
analysis. Additionally, Pearson Correlation Coefficient for the relationships Cover-Temperature,
and Cover-Humidity per group.
Group
Group 1
Group 2
Group 3
Group 4
Temperature
Mean
Correlation with
temperature
abundance
o
C
16.23
r=-0.07, p>0.27
16.72
r=0.40, p<6.0E-4
15.07
r=-0.26, p<0.02
15.86
r=-0.02, p>0.78
Humidity
Mean
Correlation
humidity %
with
abundance
90.48
r=0.58, p>0.43
98.15
r=0.05, p>0.65
88.40
r=-0.07, p>0.11
87.57
r=-0.06, p>0.48
Four groups were defined using the humidity as a grouping factor (Figure 2). Each group was associated
with significant different relative humidity (F=28.85, p<0.0001). The species in Group 2 were associated
with the highest humidity values (Table 1), while the species in Group 3 were associated with places
where humidity was lower. However, the relationship between the individual species abundance and
humidity within each group was not significant for any of them.
Figure 2. Cluster analysis grouping the species according to the variable humidity using the Euclidea
distance and the Ward Method. Four groups were defined and named 1, 2, 3, and 4 from top to
bottom.
CONCLUSION
There was no significant difference in the number of species for both regions; however, there was for the
abundance. The percent cover of epiphytic bryophytes in ADK was higher than CNY.
The species composition was different. The difference was due to the high number of species that were
unique for each area. This reduced the composition similarity between regions. Additionally, only A.
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attenuatus, B. oxycladon, and P. ciliare were abundant and frequently found in both regions. The
abundance and frequency of the remaining species varied from region to region.
As expected, temperature was significantly different between regions; however, humidity was not. The
non-significant difference in terms of humidity might be a result of the season (Summer) in which the
study was conducted.
Two groups of species with contrasting relationship with temperature were determined. In the group
associated with high temperature, only the abundance of U. crispa had a significant positive relationship
with temperature. On the contrary, in the group associated with low temperature, only the abundance of
N. pennata had a significant negative relationship with temperature.
ACKNOWLEDGEMENTS
I would like to acknowledge the Edna Bailey Sussman Foundation, who made this contribution to the
science possible. At the same time, I would like to express my gratitude to my major professor Dr.
Gregory McGee, and my committee members Dr. Martin Dovciak, and Dr. Robin Kimmerer, thanks for
your valuable advices. I want to thank my internship supervisor Dave Sinclair, regional forester at the
New York State Department of Environmental Conservation, Division of Lands and Forests, Region 7.
This research was partially funded by the Grober Graduate Research Fellowship to whom I extend this
acknowledgement. I would like to say thanks to all people who contributed in different ways to this
research, especially to Monica Berdugo, Jay Wason III, Veronica González, and Samouel Beguin.
REFERENCES
Magurran, A. E. 2004. Measuring biological diversity. Blackwell Science Ltd., Oxford, UK.
McGee, G. and W. Kimmerer, (2002). Forest age and management effects on epiphytic bryophyte
communities in Adirondack northern hardwood forests, New York, U.S.A. Can. J. For. Res. 32:
1562-1576.
Tuba, Z.; N. G. Slack and L. R. Stark. Bryophyte Ecology and Climate Change. Cambridge University
Press. 506 pp.
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