Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime

This study presents the results of 15 months of intensive sampling of the upper San Pedro River at the Boquillas ranch research site. Sampling identified patterns in surface water chemistry associated with seasonal changes in flow regime. The source of organic matter shifted from highly aquatic to h...

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Main Author: Haas, Peter Andrew.
Other Authors: Brooks, Paul D.
Language:en
Published: The University of Arizona. 2003
Online Access:http://hdl.handle.net/10150/191372
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spelling ndltd-arizona.edu-oai-arizona.openrepository.com-10150-1913722015-10-23T04:37:08Z Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime Haas, Peter Andrew. Brooks, Paul D. This study presents the results of 15 months of intensive sampling of the upper San Pedro River at the Boquillas ranch research site. Sampling identified patterns in surface water chemistry associated with seasonal changes in flow regime. The source of organic matter shifted from highly aquatic to highly terrestrial during the monsoon season. Concentrations of Dissolved Organic Carbon (DOC) increased from a nonmonsoon baseflow median of 2.7 ± 0.1 mg/I to a median monsoon baseflow concentration of 3.3 ± 0.2 mg/l. DOC concentrations during flow events were significantly higher (p < 0.05) with a median peak concentration of 7.2 ± 0.4 mg/l. Concentrations of Dissolved Organic Nitrogen (DON) increased from a non-monsoon baseflow median of 0.10 ± 0.01 mg/1 to a median monsoon baseflow concentration of 0.16 ± 0.01 mg/l. DON concentrations during flow events were significantly higher (p < 0.05) with a median peak concentration of 0.48 ± 0.02 mg/l. The 59-day 2002 monsoon contributed 40% of the water volume while transporting nearly 50% of the Dissolved Organic Matter (DOM) and 99% of the Particulate Organic Matter (POM) for the 2002 water year. Annual rates of production were estimated for DOC between 0.008 and 0.0012 g C m^-2yr^-1 and Particulate Organic Carbon (POC) between 0.07 and 0.11 g C m^2 yr^-1 , as well as, DON between 0.00024 and 0.00036 g N m^-2 yr^-1 and Particulate Organic Nitrogen (PON) between 0.004 and 0.006 g N m^-2 yr^-1 . Flux rates were much lower than that of mesic systems and likely reflects the lower terrestrial net primary productivity of the desert environment and below average precipitation during the 2002 water year. 2003 Thesis-Reproduction (electronic) text http://hdl.handle.net/10150/191372 219665266 en Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. The University of Arizona.
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language en
sources NDLTD
description This study presents the results of 15 months of intensive sampling of the upper San Pedro River at the Boquillas ranch research site. Sampling identified patterns in surface water chemistry associated with seasonal changes in flow regime. The source of organic matter shifted from highly aquatic to highly terrestrial during the monsoon season. Concentrations of Dissolved Organic Carbon (DOC) increased from a nonmonsoon baseflow median of 2.7 ± 0.1 mg/I to a median monsoon baseflow concentration of 3.3 ± 0.2 mg/l. DOC concentrations during flow events were significantly higher (p < 0.05) with a median peak concentration of 7.2 ± 0.4 mg/l. Concentrations of Dissolved Organic Nitrogen (DON) increased from a non-monsoon baseflow median of 0.10 ± 0.01 mg/1 to a median monsoon baseflow concentration of 0.16 ± 0.01 mg/l. DON concentrations during flow events were significantly higher (p < 0.05) with a median peak concentration of 0.48 ± 0.02 mg/l. The 59-day 2002 monsoon contributed 40% of the water volume while transporting nearly 50% of the Dissolved Organic Matter (DOM) and 99% of the Particulate Organic Matter (POM) for the 2002 water year. Annual rates of production were estimated for DOC between 0.008 and 0.0012 g C m^-2yr^-1 and Particulate Organic Carbon (POC) between 0.07 and 0.11 g C m^2 yr^-1 , as well as, DON between 0.00024 and 0.00036 g N m^-2 yr^-1 and Particulate Organic Nitrogen (PON) between 0.004 and 0.006 g N m^-2 yr^-1 . Flux rates were much lower than that of mesic systems and likely reflects the lower terrestrial net primary productivity of the desert environment and below average precipitation during the 2002 water year.
author2 Brooks, Paul D.
author_facet Brooks, Paul D.
Haas, Peter Andrew.
author Haas, Peter Andrew.
spellingShingle Haas, Peter Andrew.
Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime
author_sort Haas, Peter Andrew.
title Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime
title_short Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime
title_full Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime
title_fullStr Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime
title_full_unstemmed Changes in concentration and composition of dissolved and particulate organic matter in the upper San Pedro River, Arizona, in response to changes in flow regime
title_sort changes in concentration and composition of dissolved and particulate organic matter in the upper san pedro river, arizona, in response to changes in flow regime
publisher The University of Arizona.
publishDate 2003
url http://hdl.handle.net/10150/191372
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