Impact of Natural Disturbance on the Growth and Survival of the Endangered Schweinitz’s Sunflower, Helianthus schweinitzii
Poster Number
053
College
College of Arts and Sciences
Department
Biology
Faculty Mentor
Kunsiri Grubbs, Ph.D.
Abstract
This study investigated the impact of disturbances on the growth of a rare sunflower species of the southeastern United States, Schweinitz’s sunflower. Its overall population has declined due to development and environmental degradation. We hypothesized that low levels of disturbances stimulate the growth of this sunflower. The investigation involved four sources of disturbance: herbivory, competition, soil pollution, and shading; all lasting for six months. To mimic herbivory, the plants were cut and allowed to retain few nodes. The control showed the highest growth and formed the highest number of lateral shoots. In contrast, the plants with the most damage produced the most lateral stems, which formed from the tuberous rhizome. To examine the effect of competition on growth, grasses were planted along with the sunflowers. The growth of the sunflowers was highest in the areas that had 50% grass coverage, the highest competition treatment. To simulate soil pollution along the roadside, we applied used motor oil to the soil around the sunflowers weekly. Some of the plants treated with the highest concentration (0.75%) died, but later formed lateral stems. To examine the effect of shading on growth, a shade cloth was placed above them. The plants that were kept under a 70% shading cloth grew the least but formed the highest number of flowers. Overall, our results suggest that Schweinitz’s sunflower could survive when it is impacted by disturbances. Of all the tested disturbances, shading was the factor that negatively affected the growth of this sunflower the most.
Previously Presented/Performed?
Association of Southeastern Biologists (ASB) Annual Meeting, Myrtle Beach, South Carolina, March 2018
Grant Support?
Supported by a grant from the Winthrop University Research Council
Start Date
20-4-2018 2:15 PM
End Date
20-4-2018 4:15 PM
Impact of Natural Disturbance on the Growth and Survival of the Endangered Schweinitz’s Sunflower, Helianthus schweinitzii
Richardson Ballroom (DIGS)
This study investigated the impact of disturbances on the growth of a rare sunflower species of the southeastern United States, Schweinitz’s sunflower. Its overall population has declined due to development and environmental degradation. We hypothesized that low levels of disturbances stimulate the growth of this sunflower. The investigation involved four sources of disturbance: herbivory, competition, soil pollution, and shading; all lasting for six months. To mimic herbivory, the plants were cut and allowed to retain few nodes. The control showed the highest growth and formed the highest number of lateral shoots. In contrast, the plants with the most damage produced the most lateral stems, which formed from the tuberous rhizome. To examine the effect of competition on growth, grasses were planted along with the sunflowers. The growth of the sunflowers was highest in the areas that had 50% grass coverage, the highest competition treatment. To simulate soil pollution along the roadside, we applied used motor oil to the soil around the sunflowers weekly. Some of the plants treated with the highest concentration (0.75%) died, but later formed lateral stems. To examine the effect of shading on growth, a shade cloth was placed above them. The plants that were kept under a 70% shading cloth grew the least but formed the highest number of flowers. Overall, our results suggest that Schweinitz’s sunflower could survive when it is impacted by disturbances. Of all the tested disturbances, shading was the factor that negatively affected the growth of this sunflower the most.
