Aqueous and isotope geochemistry of the Fly River, Papua New Guinea: Coupling of the water and carbon cycles in tropical rainforest biomes [microform]
- Bib ID:
- 5036217
- Format:
- Book and Microform
- Author:
- Ferguson, Paul
- Online Version:
- http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:NR49347
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- Description:
- 203 p.
- ISBN:
- 9780494493472
- Summary:
-
Terrestrial moisture fluxes associated with plant growth represent one of the largest movements of mass and energy in the Earth's outer spheres, yet the relative contributions of abiotic water vapor fluxes and those that are regulated solely by the physiology of plants remains contentious and poorly constrained. Herein, based on the interpretation of the stable isotopes of water as tracers of evaporation, a methodology for partitioning total evaporation (ET) into its constituent fluxes is developed. This methodology enabled the separation of evaporation from soils and water bodies (Ed), canopy evaporation (I n), and plant transpiration (T) and was developed for the Fly River watershed (~76,000 km2), situated in a rainforest-dominated region of central New Guinea and then subsequently applied to thirteen other watersheds in North America, South America, Africa, and Australia.
Estimates of the annual water balances for the selected watersheds suggest that T is the dominant water vapor flux in 'water-limited' regions, comprising approximately 67% of ET and 55% of P. Moreover, these regional estimates of T co-vary with P in a manner similar to that observed for independent estimates of net primary productivity (NPP), suggesting that similar to small-scale measurements of plant water-use, water vapor and carbon dioxide fluxes are inherently coupled and the flux of water vapor to the atmosphere during photosynthesis is several orders of magnitude larger than the corresponding sequestration of atmospheric carbon. Similar estimates of a partitioned terrestrial water vapor flux are scarce beyond this study and hence the results are informative, emphasizing the inter-dependency between solar radiation and terrestrial processes and the considerable uncertainty that is currently associated with these aspects of the Earth system.
Although admittedly first-order in scale, the estimates offer a broadly conceptual perspective on the dynamics of energy exchange between terrestrial systems and the atmosphere, whereby the terrestrial carbon cycle is essentially driven by solar energy via the water cycle intermediary. In order to constrain the sources of dissolved constituents in the Fly River watershed, additional data pertaining to the carbon isotope composition of dissolved carbon in river was collected. Monthly samples were collected for a period of two years and higher-resolution data was collected over a period of several weeks in 2007. These data suggested that the dissolution of carbonate minerals in the watershed were the predominant source of dissolved constituents and that constituents related to the dissolution of silicate minerals were negligible by comparison.
- Notes:
-
- (UMI)AAINR49347
- Source: Dissertation Abstracts International, Volume: 70-07, Section: B, page: 4023.
- Thesis (Ph.D.)--University of Ottawa (Canada), 2007.
- Reproduction:
- Microfiche. Ann Arbor, Mich. : University Microfilms International.
- Subject:
- Other authors/contributors:
- University of Ottawa (Canada)
- Copyright:
-
In Copyright
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Copyright status was determined using the following information:
- Material type:
- Literary Dramatic Musical
- Published status:
- Unpublished
- Creation date:
- 2007
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