Date of Award
Ph.D. in Biological Science
J. Stephen Brewer
Clifford A. Ochs
Despite the vast array of past research focused on carnivorous plants, few studies have investigated the ecological interactions between carnivorous and non-carnivorous plant species. I addressed the following three questions: (1) does niche complementarity promote coexistence between fire-adapted carnivorous and non-carnivorous species? (2) do carnivorous plants rely on both leaf traps and arbuscular mycorrhizal fungi to access different nutrients that are in high demand after fire in nutrient poor bogs? (3) why are carnivorous plants largely absent from nutrient-rich wetlands? I addressed the first question by examining the three-way interacting effects of fire, prey-derived nutrient availability, and root competition from neighbors on sarracenia alata growth. I found no evidence of belowground competition on growth, nor did belowground competition interact with fire to influence growth. To address the second question, I used carnivorous drosera tracyi to experimentally test the effects of light availability and the availability of nutrients found in higher concentrations in prey versus nutrients found in higher concentrations in post-fire ash on relative investment in carnivory versus amf colonization. Although the addition of phosphorus and other nutrients besides nitrogen appeared to slightly reduce investment in carnivory, I found no effect of late season fire on carnivory or amf colonization in d. Tracyi. To address the third question, I compared the performance of s. Alata in a nutrient-rich marsh and a nutrient-poor bog, with and without neighbors. I also measured multiple soil characteristics potentially responsible for transplant performance. I found no evidence of competition from neighboring plants on s. Alata growing in either the nutrient rich marsh or the nutrient-poor bog. Rather, I found that s. Alata were intolerant of the low oxygen levels within the nutrient-rich marsh soils. Together, these results suggest interspecific competition between non-carnivorous and carnivorous plants may be weak in the wet pine savannas studied here. I suggest that the ability of a large number of species to tolerate the abiotic conditions present in wet pine savannas, combined with weak resource competition among herbaceous plants (carnivorous and non-carnivorous) enables species coexistence in these uniquely diverse ecosystems.
Abbott, Matthew John, "Conditions Responsible For The Success Of Carnivorous Plants In Nutrient-Poor Wetlands" (2017). Electronic Theses and Dissertations. 913.