Nick Herdeg Winter Ecology: Spring 2014 Mountain Research Station, University of Colorado, Boulder

Introduction Mountain streams collect groundwater and snowmelt, feeding downstream rivers The Front Range is an arid environment, making streams the main water supply for many ecosystems Water quality can vary drastically, having major effects on ecosystems which rely on that water.

Introduction The Como Creek flows through the MRS, and feeds into the Boulder Creek Few studies have examined elevation gradients In ,000 people drink water which came from the Boulder Creek (US Census)

Introduction- question of interest How does the water quality change along the elevation descent of the Boulder-Como Creek system? Hypothesis: Water closer to the source at high elevations will be more “pure” than water at lowland levels which will contain runoff and inputs from many terrestrial ecosystems.

Methods Water samples from 10 different sites along system were analyzed for physical and chemical characteristics Quantitative measures: air temp, water temp, dissolved oxygen saturation, nitrate content Qualitative recordings: stream flow, water exposure, amount of aquatic biota, possible ecosystem inputs including anthropogenic effects

Methods- Site Descriptions Subalpine High Montane Urban Plains Elevation: 9500 ft Elevation: ft Elevation: 4300 ft

Results Temperature Gradient Degrees Celsius High elevation  Low elevation

Results

Oxygen Percent Saturation: 37% in downtown Boulder creek, only minimal amounts recorded elsewhere Nitrate content: no traces found anywhere except for in urban lowland runoff ditch Snowpacks of 1.0m and.92m had no observable effect on water quality Observations of turbulence, flow speed, and amount of aquatic biota showed no effect, but did vary by elevation

High Subalpine The stream is covered with snowpack in most places, but forms exposed pools in others.

Dissolved Oxygen

Discussion-findings The creek DOES vary substantially along the elevation gradient. Trends were evident for temperature and pH Runoff hypothesis is not supported by data Anthropogenic influences matter

Discussion-explanations Previous studies confirm the lack of nitrates in near- source water (Murphy)&(Williams & Seibold et. Al. 2009) Biological sequestration or nitrogen metabolism by soil microbes is a likely cause (Williams & Grant 1980) Dissolved Oxygen should have been more present in headwaters (Murphy). This measure is affected by partial pressure at altitude and by water temperature. (Jacobsen, 2000)

Literature Cited Murphy, Sheila F. State of the watershed : water quality of Boulder Creek, Colorado / by Sheila Murphy. p. cm. – (USGS Circular ; 1284) Gill size of trichopteran larvae and oxygen supply in streams along a 4000-m gradient of altitude Dean Jacobsen Journal of the North American Benthological Society, Vol. 19, No. 2 (June 2000), pp Published by: Society for Freshwater Science Article DOI: / Article Stable URL: for Freshwater Sciencehttp://0- Boulder City Water Quality Management Williams, M. W., Seibold, C., & Chowanski, K. (2009). Storage and release of solutes from a subalpine seasonal snowpack: Soil and stream water response, niwot ridge, colorado. Biogeochemistry, 95(1), doi: Relationships between Snow Cover and Winter Losses of Dissolved Substances from a Mountain Watershed. William M. Lewis, Jr. and Michael C. Grant Arctic and Alpine Research, Vol. 12, No. 1 (Feb., 1980), pp Published by: INSTAAR, University of Colorado Article DOI: / Article Stable URL: INSTAAR, University of Colorado