Water Resources Professional Project Reports

Betsy Shafer

Document Type

Technical Report

Publication Date

6-7-2013

Abstract

Warming temperatures, reduced precipitation, and earlier snowmelt are predicted for the mountains of the southwestern U.S due to climate change. In addition, interannual variability in precipitation, partially linked to the El Niño-Southern Oscillation phenomenon (ENSO), also will impact stream-flow and ecosystem processes. Wholestream metabolism was modeled using continuous data for selected time periods ranging from 2005 to 2012. This eight-year study explores temporal trends in whole-stream metabolism parameters; as well, it links the potential impact of climate variability on these temporal trends. Gross primary production (GPP) and community respiration (CR) rates were comparable to other open-canopy lotic systems, and remained predominantly autotrophic with P/R > 1 with a few exceptions where P/R < 1. GPP ranged from 2.35 to 18.54 (g O2 m-2 d-1). CR ranged from 2.63 to 16.29 (g O2 m-2 d-1). GPP and CR rates were significantly greater in the summer (July) compared to spring (May) and fall (September) time periods for all years analyzed. Seasonal trends were strongly apparent. Statistical differences between spring and fall rates among years studied were not significant. Similarly, overall inter-annual rates showed no clear trend amongst years. Total snowmelt discharge (TSQ) as a proxy for effects from the El Niño-Southern Oscillation (ENSO) phenomenon explained 74% of the variation in GPP and 68% of the variation in CR during peak production periods, defined as the maximum diurnal amplitude of dissolved oxygen for a year. The negative linear relationship was statistically significant, suggesting a link between ecosystem function and global scale climate patterns. This research builds upon known large-scale environmental relationships to relate ENSO influenced climate patterns with rates of whole-stream metabolism.

Language (ISO)

English

Keywords

Biological productivity--New Mexico--Jemez River, East Fork., Freshwater organisms--Climatic factors--New Mexico--Jemez River, East Fork., Stream ecology--New Mexico--Jemez River, East Fork., Freshwater ecology--New Mexico--Jemez River, East Fork., Meltwater--New Mexico--Jemez River, East Fork., Ecophysiology--New Mexico--Jemez River, East Fork.

Comments

A Professional Project report submitted in partial fulfillment of the requirements for the degree of Master of Water Resources, Water Resources Program, University of New Mexico.

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