STUDY AREAS

San Luis Obispo has a Mediterranean climate characterized by cool, wet winters and relatively warm, dry summers with strong maritime influences.  Mean annual precipitation is 24 inches, most of which occurs during the winter months, and mean annual temperatures range between 16 and 25°C (Garwood 1996).  Daily early morning humidity has a maximum mean of 90%, while the daily mid-afternoon humidity has a minimum mean of 55% (Ryan 1994).

Cheda Ranch

Cheda Ranch is a 496 acre property, of which 366 acres are owned by Cal Poly and managed by the College of Agriculture.  The ranch lies within the Chorro Valley approximately 2.5 miles northwest of San Luis Obispo on Highway 1.  It is bordered by the Cal Poly Main Campus to the southeast and the California Men’s Colony to the northwest (Figure 2).  Cheda Ranch is within the San Luis watershed, and Stenner Creek is the main waterway traversing the ranch from northeast to southeast.  Two smaller tributaries of Stenner Creek flow into two large reservoirs, Middlecamp and Nelson.  Middlecamp Reservoir receives most of its water from Whale Rock and Santa Margarita, while Nelson Reservoir receives it primarily from Middlecamp Reservoir.  A third smaller reservoir, Frog Pond, located about 400 yards northwest of Nelson Reservoir, is fed by runoff and drainage water (Figure 3).  All three reservoirs are used for stock water and irrigation.  When full, Middlecamp Reservoir is approximately 11 acre feet.  Nelson holds approximately 20 acre feet and Frog Pond holds about 2 acre feet.

Cheda Ranch has been used in the past for agriculture, cattle and sheep ranging, military purposes and the subsistence of Native Americans.  The majority of Cheda Ranch  today (387 acres) is open rangeland with the remainder divided as follows: 17 acres of permanent pasture, 14 acres of vineyard, 11 acres of Christmas tree farm (managed by the Natural Resources Department), 57 acres of miscellaneous farming and 10 acres of buildings.

Although it is the smallest ranch, Cheda Ranch has four different habitat types:  grassland, riparian, reservoirs and agricultural fields. Grasslands cover most of the ranch and include a mix of mostly grasses and forbs introduced during the Spanish colonial period, along with native California forbs.  The riparian zone along Stenner Creek is dominated by sycamore (Platanus racemosa) and willows (Salix spp.).  This zone is narrow and the tree canopy is open.  The two larger reservoirs on the ranch, Nelson and Middlecamp, are surrounded predominantly by tules, and Nelson reservoir also has eucalyptus trees growing around it.  The agricultural fields include a vineyard and rangeland used for student sheep enterprise projects.

Figure 2.  Geographical location of Cheda Ranch, Cal Poly Main Campus, Peterson Ranch and Serrano Ranch (Adapted from Stechman 1985).

Figure 3.  Cal Poly’s Cheda Ranch property. (not available)

Main Campus

            The Cal Poly Main Campus is located on the north side of the city of San Luis Obispo (Figure 2).  It covers approximately 1,150 acres and ranges in elevation from 300 to 1,185 feet.  The campus is bordered to the south by the town of San Luis Obispo, to the west by Highway 1, and to the north and east by the Santa Lucia Mountains of the Coastal Range.  Two creeks flow through the campus; Brizzolari Creek from the northeast and Stenner Creek from the northwest.  The two creeks meet at the southern end of campus and flow south to San Luis Obispo Creek (Figure 4).

There are nine reservoirs on the campus initially constructed for agriculturalThere are nine reservoirs on the campus initially constructed for agricultural use, which have become important to wildlife.  Four of the reservoirs are surrounded mainly by grasses or farmland and have only small patches of bulrush (Scirpus sp.) or cattail (Typha sp.).  Two of the reservoirs are almost completely surrounded by bulrush with some arroyo willow (Salix lasiolepis) on their borders.  Finally, one reservoir is overgrown by dense arroyo willow, bulrush, and a few oak trees, which provide habitat for species that prefer dense cover.

Urban development and farmland cover over half of the campus (Table 2). The eastern Campus Core or Academic Campus comprises 400 acres. The western side includes areas dedicated to irrigated crops, dry land crops, livestock grazing, feed mill, feed lot, dairy unit, poultry unit, swine unit, beef unit, and horse unit (Figure 4).  Poly Canyon, north of campus, is dedicated to various outdoor studies, architectural projects, and a botanical garden with native plants.

Table 2.  Acreage of various enterprises within Cal Poly Main Campus

Peterson Ranch

Peterson Ranch is managed by the College of Agriculture for livestock grazing.  The ranch is a 650 acre parcel 3 miles east of the city of San Luis Obispo (Figure 2).  The ranch is located north of the Main Campus area, at the headwaters of Brizzolari Creek and Poly Canyon.  It extends eastward to the Southern Pacific Railroad tracks, on the first ridge of the Santa Lucia Range.  The main waterway is Brizzolari Creek which runs its course in a southwesterly direction.  Several unnamed tributaries flow into Brizzolari Creek, which eventually drains into Stenner Creek (Figure 5).

Although the ranch is managed and used mainly for livestock grazing, a small area near the southwest entrance is used by students from the Physics Department, Architecture Department and College of Engineering for construction designs.

Figure 4.  Cal Poly’s Main Campus property. (not available)

Figure 5.  Cal Poly’s Peterson Ranch property. (not available)

Serrano Ranch

Serrano Ranch is managed by Cal Poly’s College of Agriculture for livestock grazing. The ranch encompasses approximately 754 acres of land in the western foothills of the Santa Lucia Mountain Range, approximately 4.5 miles north of the City of San Luis Obispo (Figure 2). The ranch is bordered by the Los Padres National Forest to the north, the Southern Pacific Railroad tracks to the east and west, and by the Peterson Ranch to the southeast.  The elevation over the property boundaries ranges from 600 feet in the southwest corner of the ranch to 1,600 feet in the northeast corner.

Two main creeks run through the ranch: Stenner Creek in the western portion of the ranch and Brizzolari Creek in the eastern side (Figure 6).  Both of these waterways eventually join with San Luis Creek outside of the ranch boundaries.