Soaproot Saddle - SOAP

Site Type

Relocatable Terrestrial


California, D17, Pacific Southwest

Site Host

U.S. Forest Service

Map Legend
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NEON Sampling Boundaries
Tower Airshed Boundary
Tower Location

This map depicts the spatial layout of this field site. Please note that some locations may have moved over time due to logistics, safety and science requirements. This map was updated on July 11, 2018

Construction Status for this Site

Civil Construction Sensor Installation Field Sampling Data Status
Partially Available


The site encompasses 582 hectares (1,438 acres) of mixed conifer forest, ranging in elevation from 998 m to 1383 m (3,274 – 4,537ft). The terrain is relatively complex, with coarse hills, steep slopes, and narrow drainages. NEON has designated SOAP as one of two relocatable terrestrial sites for Domain 17 - Pacific Southwest. The domain’s relocatable aquatic site, Upper Big Creek, is just north of the terrestrial site boundaries.


The climate is typical of the Sierra Nevada, with hot, dry summers and fairly mild, wet winters. Precipitation occurs primarily in the form of rain during the winter and early spring, with limited snowfall. Temperatures in December through February range from 1 to 12 °C (34 to 54 °F), with an average of 6 °C (43 °F). Frost is common beginning in mid-November through early March. Spring is mild, with average temperatures around 10 °C (50 °F). The summer months of June through August range from 15 to 28 °C (59 to 82 °F), with an average of 22 °C (72 °F), though temperatures often reach or exceed 32 °C (90 °F) during the day.

Site History and Management

Soaproot Saddle is part of the Sierra National Forest, federal public land administered by the U.S. Forest Service. The land is managed for multiple uses and benefits, ranging from renewable resources, such as timber and forage, to recreation and research. Targeted research addresses a range of concerns and provides much of the direction in resource management. Wildland fire is of particular concern at SOAP, where foresters use a combination of prescribed fire and mechanical fuel treatment to minimize damage while maintaining a healthy fire regime.

Site-specific Topics SOAP is home to a flux tower associated with the Southern Sierra Critical Zone Observatory (CZO), which collects data on water, carbon and nutrient cycling across the rain-snow transition in the southern Sierra Nevada. CZO eddy covariance flux towers also operate at the Pacific Southwest core site, San Joaquin Experimental Range (SJER) and Lower Teakettle (TEAK), the other relocatable site.


The National Land Cover Database (NLCD) characterizes SOAP as a mix of evergreen forest and shrub scrub vegetation types. Ponderosa pine (Pinus ponderosa) and incense cedar (Calocedrus decurrens) dominate the overstory, with co-dominant canyon live oak (Quercus chrysolepis) and California black oak (Quercus kelloggii). However, the interaction of long-term drought and warming has exacerbated the outbreak of pine bark beetles, leading to high Ponderosa pine mortality and a potential shift in the forest community. Mariposa manzanita

(Arctostaphylos viscida ssp. mariposa) are interspersed throughout the understory and often form dense thickets in open areas, whereas deerbrush (Ceanothus integerrimus) and poison oak (Toxicodendron diversilobum) are common in the shaded understory. Mountain misery (Chamaebatia foliolosa) provides dense groundcover throughout much of the site. Herbaceous plants include annual and perennial grasses, as well as a range of native forbs.


Soils are weathered from granite or granodiorite, primarily from the Holland and Chaix series, and to a lesser extent, the Chawankee and Tollhouse series. Soils are moderately deep and well-drained on mountain slopes, with shallower and excessively drained soils on steeper slopes. Exposed bedrock punctuates the landscape. Intermittent streams of the watershed drain into Big Creek, just north of the site boundary and home to the domain’s relocatable aquatic site.

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