Date of Award
Master of Science (MS)
School of Biological Sciences
Victoria A Borowicz
Root hemiparasites are green plants that tap into a neighboring plant’s water-filled xylem to acquire inorganic nutrients, which can lead to an accumulation of nutrients in hemiparasite biomass. I performed an observational field study at Nachusa Grasslands and Franklin Creek State Natural Area (Lee County, IL) in 2019 to investigate how the presence of five root hemiparasites (Aureolaria grandiflora (Benth.) Pennell, Agalinis tenuifolia (Vahl) Raf., Castilleja sessiliflora (Pursh), Dasistoma macrophylla (Nutt.) Raf., Pedicularis canadensis L.) affects their communities through the (a)keystone species hypothesis, that hemiparasites will increase measures of diversity by altering competition among surrounding plant species, (b) ecological engineer hypothesis, in that hemiparasites redistribute nutrients via the hemiparasite’s biomass, and (c) the life history hypothesis, in that annual and perennial hemiparasites differ in the quality of their leaf litter. If the hemiparasites do have a community effect, I predict (a) in areas where hemiparasites are present, plant diversity will be higher, (b) the soil nutrient content will be higher in the immediate presence of hemiparasite leaf litter than in hemiparasite absence, and (c) annual hemiparasite leaf litter will have higher nitrogen content than that of perennial hemiparasites’. C. sessiliflora was associated with higher plant diversity (a) and higher soil phosphate levels (b). Total number of plant species present in the plots was curvilinearly related to the percent abundance of C. sessiliflora. Other soil nutrient level differences can be tied to the site of each hemiparasite population, not the presence of the hemiparasites. Not enough material was collected to test hypothesis (c).
Scheidel, Anna Marie, "Evaluating the Multi-level Community Effects of Root Hemiparasites in Northern Illinois" (2021). Theses and Dissertations. 1410.