The vegetation community at Soaproot Saddle is a mix of Ponderosa Pine (Pinus ponderosa) with oak (Quercus kelloggii).Goulden et al., 2012.
This site is part of an elevational transect that increases in altitude from west to east: SJER (400 m), Soaproot Saddle (1100 m), Providence Creek Headwater Catchments (P301, 2000 m), and Short Hair Creek (2700 m).
Along this transect, bedrock lithology is generally constant (intrusive felsic plutons) while air temperature, precipitation phase, vegetation species diversity and abundance, and subsurface properties vary. A series of eddy-covariance gas flux towers are installed at these sites. Transect-length work has included soil depth, chemistry, and moisture characterizations; vegetation surveys; forest water balance and usage research; and wind-blown dust geochemistry and microbiology studies.
Soaproot Saddle and areas with similar elevations in the southern Sierra experienced unprecedented tree mortality due to recent beetle infestation and drought from fall 2011 to summer 2015. The USDA Forest Service Pacific Southwest Research Station (USFS PSW) is continuously monitoring tree mortality conditions in the Sierra National Forest and other lands within Region 5. Over 100 million trees have died in California's national forests since 2010. More information is availble on USFS PSW's tree mortaility webpage.
Panorama of Soaproot Saddle. July 2014, shortly before major mortality event. Photo by Erin Stacy.
A full size image is available at the Sierra Nevda / San Joaquin Hydrologic Observatory digital library (external link).
To fully zoom into a small area, you may need to visit the "Map" button and uncheck "Terrain" view.
Flux Tower Transect, Soaproot Saddle - Flux Tower, Meteorology (2009-2016)
7 components • Soaproot Saddle (1160 m elevation) • Biology / Ecology, Climatology / Meteorology • Mike Goulden, Anne Kelly
National - Flux Tower - AmeriFlux Network data (2007-2018)
13 components • Boulder Creek Watershed, Jemez River Basin, Reynolds Creek Experimental Watershed, Susquehanna Shale Hills Critical Zone Observatory, San Joaquin Experimental Range (405 m elevation), Soaproot Saddle (1160 m elevation), P301 Flux Tower (2015 m elevation), Short Hair Creek (2700 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.
Soaproot Saddle, 1100 m elevation
Quad: Shaver Lake
Bass Lake Tonalite (Kbl, formerly Tonalite of Blue Canyon)
“Medium-grained biotite-hornblende tonalite facies characterized by large euhedral hornblende prisms” (Lockwood and Bateman 1976). “Typical Bass Lake Tonalite is medium-gray, medium-grained, equigranular tonalite with a conspicuous foliation that is shown both by the preferred orientation of minerals, chiefly hornblended and biotite, and by crudely lens-shaped mafic inclusions… The color index … for most samples is 10 to 30” (Bateman 1992).
For more detail on the other flux towers, refer to each page:
SJER, 400 m elevation
Quad: Millerton Lake
Ward Mountain Trondhjemite (Kw) (formerly Leucotonalite of Ward Mountain)
P301, 2000 m elevation
Quad: Huntington Lake
Dinkey Creek Granodiorite (Kdc, formerly Granodiorite of Dinkey Creek)
Short Hair Creek, 2700 m elevation
Quad: Blackcap Mountain
Aplite and felsic quartz monzonite dikes (Kap)
Granodiorite of Dinkey Creek (Kdc, see description for P301)