Date of Award
Doctor of Philosophy (PhD)
College of Science and Mathematics
Earth and Environmental Studies
Thesis Sponsor/Dissertation Chair/Project Chair
Jennifer A. Krumins
Michael A. Kruge
Several factors can influence soil function, including biotic and abiotic. Biotic factors are those that are living, like microorganisms. Abiotic factors are those that are non-living, and include heavy metals, organic contaminants, pH, and nutrients. Liberty State Park in Jersey City (N.J., U.S.A), is a 100-ha brownfield was once a major rail yard that was restricted public access in 1969. The site without any intervention of humans grew a forest. The primary objective of this dissertation is to understand the impacts of both inorganic and organic contaminants on soil function in addition to provide strategies that can override the negative impacts of these abiotic factors. Several studies were completed in order to attain the primary objective, which included 1) characterizing both organic and inorganic compounds present in Liberty State Park and understand relationship with soil function, 2) further characterize coal particles that abundant in the soil, 3) provide a potential strategy of improving soil function despite the presence of organic and inorganic contaminants by adding different combinations of artificial root exudates on soil enzymatic activities, 4) understand the influence of a gradient of abiotic factors on both soil function and microbial communities. A variety of elevated heavy metals and organic contaminants derived from fossil fuels, like polycyclic aromatic compounds were present in all studied soils. Within Liberty State Park, soils from several vegetated sites within Liberty State Park (43, 146 and 25F) had higher enzyme activities compared to the barren site 25R, which is below detection limit. Optical microscopy analyses revealed bituminous and anthracite coal, coke, tar/pitch, and ash particles were present in all soil samples. Upon further investigation using density separation, pyrolysis gas chromatography confirmed the majority of coal present are anthracite and higher rank (medium volatile) bituminous. An inoculation with 25F soil into an experimentally created gradient of 25F and 25R soils provided insights into the barren nature of 25R. Some fungal classes decreased while others increased with increasing amounts of 25R soils. One possible strategy of improving soil function is with the addition of artificial exudates, which included sugars, organic acids, and amino acids. The combination of sugars, organic acids, and amino acids, greatly increased phosphatase, cellobiohydrolase, and L-leucine aminopeptidase activity over time in poorly-functioning, barren soil 25R. Phosphatase fold change was the highest compared to the cellobiohydrolase and L-leucine aminopeptidase when artificial exudates were added. The site provides a unique opportunity to understand the impact of abiotic factors, such as inorganic and organic contaminants in the presence or absence of vegetation on soil health. These data can provide a deeper understanding of the chemistry and biochemistry, which can help to inform future remediation efforts in the public interest. These data can also provide a possible strategy to improve soil function within contaminated brownfield soils.
Hagmann, Diane, "Effect of Abiotic Factors on Enzyme Activity in Brownfield Soils" (2021). Theses, Dissertations and Culminating Projects. 711.
Available for download on Wednesday, May 24, 2023