Date of Award
Doctor of Philosophy
Natural Resource Ecology and Management
Richard B. Hall
Resource managers are challenged with waste disposal and leachate produced from its degradation. Poplar (Populus spp.) trees offer an opportunity for ecological leachate disposal as an irrigation source for managed tree systems. Information about sodium (Na+), chloride (Cl -), and nutrient uptake and distribution into tissues of Populus genotypes irrigated with landfill leachate helps to maximize biomass production and to understand impacts of leachate chemistry on tree health. However, such knowledge about the response of poplar genotypes to landfill leachate irrigation is limited, along with efficient methods for choosing genotypes based on leachate composition.;During initial greenhouse research, poplar clones were irrigated during three cycles of phyto-recurrent selection to test whether genotypes responded differently to leachate and water, and to test whether the methodology had merit as a tool for plant selection during remediation. Fifteen belowground and aboveground traits were evaluated. Of the twenty-five clones tested in cycle 1, the best 12 genotypes were used in cycles 2 and 3. These results detail the extensive variation in clonal responses to leachate irrigation, along with the need and efficacy of using phyto-recurrent selection to choose superior genotypes.;Furthermore, the top eight clones from cycles 1 to 3 were selected and subsequently tested in an in situ landfill study (cycle 4). The trees were irrigated with fertilized well water (control) (N, P, K) or municipal solid waste landfill leachate weekly during 2005 and 2006 in Rhinelander, Wisconsin, USA (45.6°N, 89.4°W). Evaluation during Aug. 2006 consisted of testing for differences in tree height, diameter, volume, and biomass of leaves, stems, branches, and roots, along with total Na, Cl, N, P, K, Ca, Mg, S, Zn, B, Mn, Fe, Cu, Al, and Pb concentration in preplanting and harvest soils, and in leaf, woody (stems + branches), and root tissue. Overall, these results document successful uptake of nutrients without detrimental impact to tree health, which validated the use of landfill leachate as an irrigation and fertilization source for Populus. In addition, these data will serve as a basis for researchers and resource managers making decisions about future leachate remediation projects.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Jill Annette Zalesny
Zalesny, Jill Annette, "Phytoremediation of landfill leachate using Populus" (2007). Retrospective Theses and Dissertations. 15554.