Date of Award
Master of Forest Resources (MFR)
Forestry and Environmental Conservation
David R Coyle
Callery pear is an invasive tree in 15 states of United States and is currently present in 37 states. Its management has challenged landowners and land managers. Despite being listed as a noxious weed in four states, its study is limited. The accurate estimation of Callery pear biomass will give a clearer picture of the level of invasion and help land managers develop different strategies to control its population. Similarly, identifying possible pollinators of Callery pear is essential to have some insights on pollinators associated with this tree. Hence, the objectives of this study are 1) to calculate total above-ground biomass and prepare allometric equation, and 2) identify the pollinator taxa and calculate diversity metrics and community composition of pollinators using Callery pear.
Forty trees from six different sites were destructively harvested. We measured diameter at breast height (DBH), total tree height, fresh weight, oven-dry weight, C:N ratio and moisture content of different tree components (i.e., leaves, fruits, stem, and branches) and examine their relationship with each other. Biomass of each tissue component was significantly related to DBH. Total wet biomass ranged from 326.75 g (1.27 cm DBH) to 160 kg (17.52 cm DBH), and total dry biomass ranged from 193.25 g to 97 kg for the same DBH. The average moisture content ranged from 39% to 42 % and the average wood density was found to be 0.88 gm/cm3. The model/equation determined for the biomass is Log linear model with 91% variation explained by the model.
Five sites in South Carolina were surveyed using yellow, blue, white colored plastic cups and sweep net methods. A total of 756 insects were collected, belonging to 15 families in three orders; Diptera (611), Hymenoptera (135), and Coleoptera (10). The most common families of insects visiting Callery pear were Syrphidae, Sarcophagidae, Anthomyiidae, and Andrenidae with common species being Toxomerus, Andrena, Apis mellifera, Osmia, and Lasioglossum. Because of being present in highest number in all sites, we propose that Toxomerus spp. from Syrphidae family are the major visitors of Callery pear’s flower whereas sweep net and yellow bowl trap are most suitable methods of collecting them.
Sharma, Prabina, "STUDY OF MORPHOLOGICAL AND PHYSIOLOGICAL PROPERTIES AND POLLINATORS OF THE INVASIVE CALLERY PEAR" (2023). All Theses. 4103.