Pollinators show no preference between Goldenrod Plants and Aster Plants regardless of differences in flower length. Introduction In this experiment, we observed the pollination of various plants by various pollinators in the Binghamton University Nature Preserve. We collected data by observing various plants by the pond trail area of the nature preserve and attempted to explain why some plants were structurally more attractive to pollinators than other plants. While observing a variety of plants, it became clear that the Goldenrod Plant and the Aster plant were the most attractive.This conclusion was drawn because they attracted the most pollinators. In fact, data collected of the other plants was so scarce they were deemed insignificant. The new focus of the experiment became to determine whether the Goldenrod or Aster was more attractive to pollinators and attempt to explain why.
Previous works have classified both the Goldenrod plant and Aster plant as Composite Flowers, or plants that have “multiple flowers inserted on a flattened, broad receptacle,” (Koch 1930). This means that the flowers of both the Goldenrod and Aster are made up of similar, if not identical, internal structures.Thus, we attempted to attribute the differences in pollinator visitations between the two plants to differences in external structures. If a difference in pollinator preferences was observed, we would try to attribute that preference to differences in the external structure of the length of the flower. Previous works have determined the average flower length of Goldenrod plants to be ? of an inch (Gross &Werner 1983), and the average flower length of Aster plants to be 2 inches (Harder 1985).The analysis of the data collected in this experiment attempts to test our null hypothesis: Pollinators show no preference between Goldenrod plants and Aster plants, and our alternative or working hypothesis: Pollinators do show a preference between Goldenrod plants and Aster plants. Methods The experiment took place in the Pond Trail area of the Binghamton University Nature Preserve.
Observations and data collection were taken over a course of three days, with the approximate time of observation occurring at 1pm and the approximate temperature being 60F for each of the three days.The duration of data collection per plant was 30 minutes. In order to record pollinator data, we chose one individual plant of each species (Goldenrod, Aster, Queen Anne’s Lace, Chicory, Knapweed) and observed each plant for 30 minutes. We recorded how many pollinators and what species of pollinator (Honeybee, Bumble Bee, Butterfly, Fly, Wasp), pollinated the plant in the observed 30 minutes. A pollinator was considered pollinating a plant if the pollinator remained on the plant for at least two seconds.
This observation and data collection procedure was repeated for each of the three days at the same time of day and temperature in the same Pond Trail area of the nature preserve. At the end of the three days, we added up all the collected data to determine the total number of pollinators that pollinated all the observed plants in the Pond Trail area of the nature preserve. In order for a plant’s observed data to be considered “significant” enough to study its attractiveness to pollinators, the plant needed to have at least thirty points of data.
Meaning, the plant needed to be visited by at least thirty pollinators over the course of the three days. If a plant did not have 30 points of data, it would not be studied for its attractiveness to pollinators in this experiment. Results Data collection over the three days yielded the following results displayed above in the bar graph. The Goldenrod plant was pollinated by a total of 35 pollinators (10 wasps, 1 fly, 3 bumble bees, 2 Butterflies, 19 Honeybees). The Aster plant was pollinated by a pollinated by a total of 42 pollinators (10 wasps, 3 flies, 6 Bumble Bees, 1 Butterfly, 22 Honeybees).The Queen Anne’s lace plant was pollinated by a total of 23 pollinators (8 Wasps, 1 Fly, 2 Bumble Bees, 12 Honeybees). The Chicory was pollinated by a total of 18 pollinators (8 Wasps, 2 Bumble Bees, 8 Honeybees).
The Knapweed was pollinated by a total of 8 pollinators (6 Bumble Bees, 2 Butterflies). As discussed before, in order to study the structural attractiveness of a plant it needed to be considered “significant” or have at least 30 points of pollinator data. The above bar graph displays the only two observed plants that had 30 points of pollinator data over the course of the three days.The Goldenrod plant had 35 points of data and the Aster plant had 42 points of data, making them both significant enough to study further. Previous work by Koch classified both these plants as Composite Flowers (1930). Given their similar internal structures, we would focus on a difference in flower length, an external structure, to explain the differences in pollinator visitations. Previous work by Gross& Werner has shown the average flower length of Goldenrod plants to be ? of an inch (1983). Previous work by Harder has shown the average flower length of Aster plants to be 2 inches (1985).
Chi Square Data Goldenrod Aster Honey Bee . 0086. 0086 Butterfly . 2571. 225 Bumble Bee .
25 . 2469 Fly . 3556. 2909 Wasp . 089. 0743 2 = 1. 806 df= 4 C= 9.
5 2 C – Fail to reject null hypothesis Discussion The Chi Square analysis above shows that we fail to reject our null hypothesis, since our Chi Square value was less than the critical value at 5% and for 4 degrees of freedom. Since we failed to reject our null hypothesis, according to our experimental data we must conclude that pollinators show no preference between Goldenrod and Aster plants.It can also be concluded that the flower length of a plant did not significantly affect pollinator attraction to a plant in this experiment. Although there was a difference in observed pollinator visits (35 for Goldenrod, 42 for Aster), our analysis shows that this difference was not significant enough for us to relate flower length to pollinator-plant attraction. Our original working hypothesis was that pollinators do show a preference between Aster plants and Goldenrod plants.We attributed longer flower lengths in the Aster plant to explain the greater number of pollinator visits.
We reasoned that longer flower lengths were more attractive to pollinators because it gave pollinators more room to search for nectar inside the flower, as well as the ability for larger pollinators to spend more time pollinating a plant if it has more room to move around on. Although it seemed logical at the time, our working hypothesis has yet to be confirmed. For now we must conclude that flower length is not significant for affecting the preferences of a pollinator.
Because Goldenrod and Aster plants have similar internal structures, it can be concluded that these internal structures play a larger role in attracting pollinators that flower length. Similarly, since the differences between the number of pollinator visits was found to be insignificant it can be concluded that Goldenrods and Asters may employ similar strategies to attract pollinators such as height, bright colors, internal location of nectar and pollen and that differences in their external structures may not be as significant.Sources of error in this experiment include human error, such as not properly observing and recording the number of pollinators visiting a plant, whether recording too few or too many pollinators visiting a plant. Human error could also include not observing the same individual plant, as described in the methods section, resulting in an incorrect number recorded for an individual plant. Other sources of error could result from the environment of the plants and pollinators.
Rainy or cold mornings preceding observation and data collection time may have severely reduced the number of pollinators able to go out at 1 pm, resulting in an incorrect reflection on the number of pollinators in the nature preserve capable of pollinating plants. Regardless of the sources of error; however, it must be concluded for now that pollinators do not show a preference between Goldenrod plants and Aster plants.Literature CitedGross, Ronald S. , and Patricia A. Werner. Relationships among Flowering Phenology, Insect Visitors, and Seed-Set of Individuals: Experimental Studies on Four Co-occurring Species of Goldenrod (Solidago: Compositae). ” Ecological Monographs 53.
1 (1983): 95-117. Print. Harder, Lawrence D. “Morphology as a Predictor of Flower Choice by Bumble Bees. ” Ecology 66.
1 (1985): 198-210. Print. Koch, Minna Frotscher.
“Studies in the Anatomy and Morphology of the Composite Flower II. ” American Journal of Botany 17. 10 (1930): 995. Print.