1. Little evidence that decreases in Apis mellifera
collection of Prunus serotina pollen driven by
increasing temperatures
Group 2: Taylor
Hoinash, Mohammed
Huzien, Kayla Knights,
July Reyes,
Sr. Anne Weis
2. The Issue: Climate Change Affects Physiology
● Different species of organisms have different thermal tolerance
windows - temperature ranges at which they can function and
survive
○ Genetic adaptations can account for changes in thermal tolerance.
(Somero, 2010)
● Thermal safety margin and warming tolerance for ectotherms
(Chown et al, 2010)
○ Thermal safety margin = [optimal temperature] - [mean body
temperature]
○ Warming tolerance = [critical thermal maximum] - [mean body
temperature]
3. Pollinators and
Environmental Stress
● Pollinators are a key component of
global biodiversity.
● Climate changes can alter pollinators’
circadian rhythm and reduce the body
size and lifespan of adults (Scaven &
Rafferty, 2013).
● Warming temperatures can affect plant
physiology (Scaven & Rafferty, 2013)
○ Cause changes in flower production,
time of flower opening, flower scent,
nectar production, pollen composition,
and plant/flower height
4. Relevant Honey Bee (Apis mellifera) Biology
● Honey bees are ectotherms (Guo et al., 2018)
○ Facultative endotherms- can generate heat with their flight muscles
● They are social insects that live in a hive, have a caste system,
and carry out different tasks to contribute to the communal well-
being. (Johnson, 2010)
○ Ex. Resource foraging (water, nectar, and pollen) which is used for hive health,
hygiene, and nutrition (Wright et al., 2018)
● Their critical thermal maximum is about 49.1°C, which is 120°F
(Burdine & McCluney, 2019)
○ Warming tolerance = 49.1 - 35.3 = 13.8°C (Stabentheiner et al., 2021)
● Pollen is an important source of nutrition (Wright et al., 2018)
○ Macronutrients: carbohydrates and lipids
○ Micronutrients: minerals, vitamins, and essential sterols
○ Honey bees forage from multiple sources in order to get necessary nutrients.
6. Background and Biology
- Native to eastern North America, Mexico and Central
America
- Invasive species in Europe. Only 25 species are native to
N. America (Maynard et. al, 1991)
- Thrives in warmer temperatures; can survive extreme
temperatures
- This species blooms around May with flowers that ripen
to black cherries by August to September.
- Fast-growing forest tree
- Growth ranges between 49 and 79 feet tall
- Life span: 150 to 200 years old
7. Flowers of Prunus Serotina
● Andrenid (Miner) bees are likely essential
pollinators. (McLaughlin et. al, 2022)
○ No significant relationship found between other
taxa and production of viable seeds.
● Seed production is heavily altered by
presence of insect pollinators.
○ Andrenid bees most abundantly found on
forest edges.
● Incapable of self-pollination.
8. Annual Cycle of Prunus Serotina
● White flowers start to bloom
around mid-May
● Fruits ripen in August and
September
● Frost-free growing season lasts
about 120 - 155 days
(Marquis, 1990)
Pollen Composition
Cherry* pollen has been found to have the
following composition (Vegh et al, 2022):
● 63% carbohydrates
● 24.4% protein
● 1.9% fats
● And 6.5% moisture and 3.2% ash
*Black cherry pollen may differ from regular cherry pollen
9. Black Cherry in
Temperate Climates
● P. serotina is distributed in
more humid and cold
environments (Guzman et. al,
2018)
● Adapts well to temperate-cold
climates (Segura et. al, 2018)
● Northern New Jersey →
Continental climate with
minimal influence from Atlantic
Ocean (Rutgers, 1983-1985)
10. Thermal Tolerances
● Growth and survival of black cherry in the
understory depends on the complex interaction of
environmental factors.
○ Tree overstory basal area and soil available
water were the most significant factors
controlling its vigor.
● Shade-intolerant species (Paquette et. al, 2007)
● Little effect of high temperature on Prunus
serotina
● Able to withstand freezing temperatures (Teskey
et al., 2015)
11. Hypothesis and Predictions
Elevated environmental temperatures have led to a decrease
in both the abundance and variety of food sources available
to honey bees, which has resulted in physiological stress
within bee colonies (Gilley, 2023).
Predictions 3:
There has been a decrease in the abundance of pollen collected from plants
of particular nutritional importance - specifically black cherry - between 2018
and 2023.
13. Sample Information
● Quantification of pollen grains obtained via
hemocytometer and compound microscope
● We used eight data sets collected between 2017/
2018 and 2023.
○ Collected data was analyzed to compare the abundance of
pollen grains between the 2017/2018 dates and the 2023
dates.
● Independent variables: Year and Sample Date
● Dependent variables:
○ Prediction 3: Number of pollen grains of
black cherry
Sample Dates
5/24/2017
5/22/2023
6/5/2023
6/7/2018
6/19/2023
6/20/2018
7/10/2018
7/10/2023
15. Techniques
The pollen was collected on the given dates. Two hundred pellets were
selected at random from each date of pollen collection and homogenized in
glycerine. The homogenized samples were given to us for analysis, specifically
for the pollen grains of the species Prunus Serotina.
Over the course of 4 weeks, our group collected data using a microscope and
hemocytometer to count total pollen grains, number of different species
present, and the number of pollen grains of the focal species (black cherry).
As a group, we collected five sample counts for each pollen collection date, for
a total of 40 data sets.
After data collection, reliability analyses were performed on all of our group
pollen counts (total, number of species, and focal).
16. Vortexing the pollen sample Preparing the hemocytometer and inserting
the pollen sample into the well
20. Reliability
Analysis
Year Sample date Focal Reliability test Total
Reliability
test
2017 24-May 26.02% 11.97%
2023 22-May 19% 31.67%
2018 7-Jun 56.95% 15.49%
2023 5-Jun 11.72% 32.83%
2018 20-Jun 0% 28%
2023 19-Jun 78.06% 7.88%
2018 10-Jul 0% 10.10%
2023 10-Jul 0% 17%
21. Fig. 1. Higher black
cherry pollen counts
were observed during
2017/2018
compared to 2023. A
chi-square analysis of
the data was
performed, with
p=3.758x10-23,
showing the pollen
counts in the present
to be significantly
lower than the past.
22. GDD Correlation Graph
Fig. 2. There is a
negative correlation
between the total black
cherry pollen collected
and the GDD.
Regardless of year, as
the season went on
(higher GDD), there
was a decrease in the
collection of black
cherry pollen.
24. Conclusions about Prediction 3
Between 2017/2018 and 2023 there has
been a dramatic decrease in the abundance of
pollen collected from black cherry
25. Conclusions about Hypothesis
In comparing these years, there was not a significant
difference in the numbers of grow degree days (GGDs) at
the time of each sample, and so we cannot conclude that
warming temperatures have caused the reduction in
pollen collected from black cherry, though it is still a
possibility.
● The older years (2017/2018) showed a higher number of
GGDs at the time of each sample collection
26. Considerations
● Better alternative sources of nutrition
○ Black cherry pollen is only 2.4% fat content,
which is the lower end of the average range of
pollen total lipid content (2-20%) (Wright et al.,
2018)
● Possible effects of warming temperatures at other
times of the year (that were not studied) on the
physiology of the plant
○ This could be explored in future research
27. References
● “NJ Climate Overview.” (n.d.). Rutgers University. https://climate.rutgers.edu/stateclim_v1/njclimoverview.html
● Auclair, A. N., & Cottam, G. (1971). Dynamics of black cherry (Prunus serotina Erhr.) in southern Wisconsin oak forests. Ecological Monographs, 41(2), 153-177.
● Burdine, J.D. & McCluney, K.E. (2019). Differential sensitivity of bees to urbanization-driven changes in body temperature and water content. Scientific Reports, 9:1643.
● Downey, S. L., & Iezzoni, A. F. (2000). Polymorphic DNA markers in black cherry (Prunus serotina) are identified using sequences from sweet cherry, peach, and sour cherry.
Journal of the American Society for Horticultural Science, 125(1), 76-80.
● García-Aguilar, Leticia et al. “Nutritional value and volatile compounds of black cherry (Prunus serotina) seeds.” Molecules (Basel, Switzerland) vol. 20,2 3479-95. 17 Feb. 2015,
doi:10.3390/molecules20023479
● Gilley, D. (2023). Project Development.
● Guo, X., Zhang, L., Zhao, J., Zhao, E., Wei, Y., & Yan, S. (2018). Thermoregulation Capacity of Honeybee Abdomen for Adaptability to the Ambient Temperature. Journal of Bionic
Engineering. 15, 992–998.
● Guzmán, F.A., Segura, S. & Fresnedo-Ramírez, J. Morphological variation in black cherry (Prunus serotina Ehrh.) associated with environmental conditions in Mexico and the
United States. Genet Resour Crop Evol 65, 2151–2168 (2018).
● Johnson, B. R. (2010). Division of labor in honeybees: form, function, and proximate mechanisms. Behavioral ecology and sociobiology, 64, 305-316.
● Marquis, D.A (1990) prunus serotina ehrh black cherry- silvics of north north america, 2, 594-604.
● Maynard, C. A., Kavanagh, K., Fuernkranz, H., & Drew, A. P. (1991). Black cherry (Prunus serotina Ehrh.). Trees III, 3-22.
● McLaughlin, R., Keller, J., Wagner, E., Biddinger, D., Grozinger, C., & Hoover, K. (2022). Insect visitors of black cherry (Prunus serotina)(Rosales: Rosaceae) and factors affecting
viable seed production. Environmental entomology, 51(2), 471-481.
● Paquette, A., Bouchard, A., & Cogliastro, A. (2007). Morphological plasticity in seedlings of three deciduous species under shelterwood under-planting management does not
correspond to shade tolerance ranks. Forest Ecology and Management, 241(1-3), 278-287.
● Portner, H.O., & Farrell, A.P. (2008). Physiology and Climate Change. Science. 322, 690-692.
● Segura, S., Guzmán-Díaz, F. , López-Upton, J. , Mathuriau, C. and López-Medina, J. (2018) Distribution of Prunus serotina Ehrh. in North America and Its Invasion in Europe.
Journal of Geoscience and Environment Protection, 6, 111-124
● Somero, G. N. (2010). The physiology of climate change: how potentials for acclimatization and genetic adaptation will determine ‘winners’ and ‘losers’. Journal of Experimental
Biology, 213(6), 912-920.
● Stabentheiner, A., Kovac, H., Mandl, M., & Kafer, H. (2021). Coping with the cold and fighting the heat: thermal homeostasis of a superorganism, the honeybee colony. Journal of
Comparative Physiology, 207:337-351.
● Teskey, R., Wertin, T., Bauweraerts, I., Ameye, M., Mcguire, M.A., & Steppe, K. (2014). Responses of tree species to heat waves and extreme heat events. Plant, Cell &
Environment, 38(9), 1699-1712.
● Végh, R., Puter, D., Vaskó, A., Csóka, M., & Mednyánszky, Z. (2022). Examination of the nutrient content and color characteristics of honey and pollen samples. Journal of Food
Investigation, 68(1), 3793-3806.
● Wright, G.A., Nicolson, S.W., & Shafir, S. (2018). Nutritional Physiology and Ecology of Honey Bees. Annual Review of Entomology, 63:327-338.
![The Issue: Climate Change Affects Physiology
● Different species of organisms have different thermal tolerance
windows - temperature ranges at which they can function and
survive
○ Genetic adaptations can account for changes in thermal tolerance.
(Somero, 2010)
● Thermal safety margin and warming tolerance for ectotherms
(Chown et al, 2010)
○ Thermal safety margin = [optimal temperature] - [mean body
temperature]
○ Warming tolerance = [critical thermal maximum] - [mean body
temperature]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)