The objectives achieved in this thesis are: (1) to develop a new method for measuring the most important acid buffering mechanism within a soil ecosystem-mineral weathering and (2) to test a soil acidification simulation model against actual field data to determine which soil acidifying or buffering mechanisms seem to be understood and which mechanisms need more detailed analysis. First, a new method was developed that allows for quantification of H$ sp+$ consumption due to weathering and H$ sp+$ consumption due to cation exchange. Initial results yield mineral weathering rates that are well within the range of results obtained by other workers. This technique permits the analysis of multiple soil samples in a relatively short time, allowing for better quantification of spatial variability of mineral weathering within a soil ecosystem. Secondly, it was demonstrated that the acid simulation model generally underestimates soil chemistry values for pH, base cation saturation and soil solution base cations, and overestimates soil solution nitrate concentrations. Problems with obtaining accurate measurements of atmospheric dry deposition, a lack of data on cycling of nutrient elements and the absence of a sub-model to deal with the accumulation and mineralization of organic matter are reasons thought to explain the differences between model and field results.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68218 |
| Date | January 1993 |
| Creators | McCourt, George H. |
| Contributors | Hendershot, W. H. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Renewable Resources.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001386325, proquestno: AAIMM94476, Theses scanned by UMI/ProQuest. |
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