Sites include San Joaquin Experimental Range, Soaproot Saddle, Providence Creek Headwater Catchments, and Short Hair, spanning a 2300-m elevation range that captures gradients in climate, regolith, soils, and vegetation. Along this transect, bedrock lithology is generally constant (intrusive felsic plutons). Ecosystems range from low-elevation oak savannah (rain-dominated) to high-elevation subalpine forest (snow-dominated). A series of eddy-covariance gas flux towers are installed at these sites (see below). Examples of transect-length work include soil and regolith depth, chemistry, and moisture characterizations; vegetation surveys; forest water-balance research; and wind-blown dust geochemistry and microbiology studies.
From O'Geen et al., 2018:
The subalpine forest site Short Hair is the highest-elevation site in the elevational transect, and represents a headwater catchment situated along Short Hair Creek. Mean Annual Temperature: 4.2°C. Mean Annual Precipitation: 1078 mm yr−1.
This site was glaciated in the Pleistocene resulting in hard weathered bedrock (WB) underlying soil (Gillespie and Zehfuss, 2004).
The Short Hair site has a cryic soil temperature regime and udic soil moisture regime. The site has thin patchy and rocky soils that limit moisture storage intermixed with areas of deep glacial till. Soils are mapped as the Stecum series (sandy-skeletal mixed Typic Cryorthents).
Vegetation community is mostly lodgepole pine (Pinus contorta Douglas ex Loudon) and western white pine (Pinus monticola Douglas ex D. Don).
For additional information on climate and vegetation, see also Goulden et al., 2012.
Panorama of Short Hair Creek tower site. July 2014. Photo by Erin Stacy.
A full size image is available at the Sierra Nevada / San Joaquin Hydrologic Observatory digital library (external link).
An eddy-covariance flux tower was installed at this site in October 2009. Due to harsh winter conditions and a falling tree, the flux tower was down from 2011-2014. A replacement tower was brought in by helicopter and raised by a team in August 2014. Instruments were reinstalled June 2015. Elevation of the tower is 2700 m above sea level.
The flux tower is used to analyze the carbon and water balance of the surrounding forest. Instruments on the flux tower track changes in carbon dioxide, water vapor, air temperature, relative humidity, and other atmospheric properties.
Hydrological monitoring infrastructure is located within the footprint of the eddy flux tower.
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Flux Tower Transect, Short Hair Creek - Flux Tower, Meteorology (2009-2018)
12 components • Short Hair (2670 m elevation) • Climatology / Meteorology, Biology / Ecology • Mike Goulden; Anne Kelly
National - Flux Tower - AmeriFlux Network data (2007-2018)
14 components • Boulder Creek Watershed, Jemez River Basin, Reynolds Creek Experimental Watershed, Susquehanna Shale Hills Critical Zone Observatory, San Joaquin Experimental Range (210-520 m elevation), Soaproot Saddle (1000-1500 m elevation), Short Hair (2670 m elevation) • Climatology / Meteorology • Boulder Creek Critical Zone Observatory; Catalina-Jemez Critical Zone Observatory; Reynolds Creek Critical Zone Observatory; Shale Hills Critical Zone Observatory; Southern Sierra Critical Zone Observatory
An eddy covariance flux tower is located near the top of the P301 watershed. Instruments collect data on temperature, relative humidity, and fluxes of carbon dioxide and water vapor to determine the physiological responses of the site (for example, how photosynthesis increases with light) and summed over a year to determine the carbon balance of a site (how much carbon it is gaining or losing). Three other flux towers have been instrumented at different elevations with the Sierras including the San Joaquin River, Soaproot, and Short Hair Creek.
This west-east transect spans elevation gradient from 400 m to 2700 m. The change in elevation is accompanied by a slight increase in precipitation, but the main change is a shift from rain-dominated precipitation to snow-dominated precipitation. The climatic shift plays out in other ways as well. At lower elevations, high temperatures and low water availability limit evapotranspiration by vegetation. Meanwhile, forest activity (evapotranspiration) at higher elevations is limited by cold winter temperatures. There is a sweet spot at middle elevations of yera-round evapotranspiration and forest activity.
Hundreds of instruments and sensors have been deployed in the primary SSCZO research site of the Providence Creek watershed as well as in Wolverton basin. Additional SSCZO flux towers and instruments have also been installed at the San Joaquin Experimental Range, Soaproot Saddle, and Short Hair Creek.
Explore more photos of the intstuments and sensors used by SSCZO.
Short Hair Creek, 2700 m elevation
Quad: Blackcap Mountain
This site was glaciated in the Pleistocene (Gillespie and Zehfuss 2004) and is situated on glacial till. The bedrock immediately below the tower is of unknown composition. However, two different bedrock units are exposed within 500 m of the tower (Bateman 1965).
Aplite and felsic quartz monzonite dikes (Kap)
Dinkey Creek Granodiorite (Kdc, formerly Granodiorite of Dinkey Creek, same as P301)
“Medium-grained, generally strongly foliated. Contains abundant disc-shaped mafic inclusions and mafic clots composed of hornblende, biotite, sphene, plagioclase, and opaque minerals. Intrudes the quartz diorite of Blue Canyon. Age by Rb-Sr whole-rock isochron 110 +/- 11 m.y.” (Bateman and Wones 1972). The mafic inclusions are “as much as 30 cm long and 5 cm thick. The mafic minerals are intergrown, and individual grains are anhedral” (Bateman 1992).
SJER, 400 m elevation
Quad: Millerton Lake
Ward Mountain Trondhjemite (Kw) (formerly Leucotonalite of Ward Mountain)
Soaproot Saddle, 1100 m elevation
Quad: Shaver Lake
Bass Lake Tonalite (Kbl, formerly Tonalite of Blue Canyon)
P301, 2000 m elevation
Quad: Huntington Lake
Dinkey Creek Granodiorite (Kdc, formerly Granodiorite of Dinkey Creek)