Flanagan, C.M. (2007)

Understanding alpine watersheds in the Colorado Front Range: Phytoplankton community analysis and watershed education

Thesis (M.S.)--University of Colorado, 117 p.

Studies of the aquatic ecosystem provide a meaningful vehicle for understanding the Rocky Mountain Front Range because all life relies upon water availability. Investigations in aquatic ecology assess the interconnectedness between living and nonliving systems, emphasizing community interactions with the changing aquatic environment. This study investigates both the scientific and educational outreach components of alpine aquatic ecology, in the context of climate variability and water quality, at the Niwot Ridge Long Term Ecological Research (NWTLTER) site in the Colorado Front Range. Phytoplankton community composition was quantified and water column chemistry was characterized throughout the summers of 2000--2005 at Green Lake 4, NWTLTER, and analyzed in the context of climate variation since 1981. A Principal Components Analysis of the phytoplankton community confirmed a shift in the community composition coincident with a three-year drought (2000--2002). A Redundancy Analysis highlighted 2002 as an extreme year, depicting the importance of temperature, silica, and Synedra sp. in the variation of community composition. Increased phosphate concentrations in the post-drought period were associated with a shift in the dominance of chlorophyte and chrysophyte taxa. These results illustrate the climatic influences on alpine lake ecosystems and indicate that changes in climate, such as more frequent droughts or warmer water temperatures, may shift the phytoplankton communities