Sugarloaf Ridge State Park
Map SatelliteAt least six plant communities are found in this State Park: open savannah grassland, mixed evergreen forest, oak woodland, redwood forest, riparian association and chaparral.
The oak woodland, which together with the chaparral form the dominant communities, is composed primarily of Oregon oak, Quercus garryana, and black oak, Quercus kelloggii. Within the park boundaries nine types of oak occur: in addition to the above, canyon live, Quercus chrysolepis, coast live, Quercus agrifolia, blue, Quercus douglasii, and valley, Quercus lobata, all of which are. found in the mixed evergreen forest and in portions of the oak woodland, as well as scrub, Quercus berberidifolia, interior live, Quercus wislizenii, and leather, Quercus durata, which are found primarily in the chaparral.
Five types of Arctostaphylos are found here: Arctostaphylos canescens, Arctostaphylos glandulosa, Arctostaphylos manzanita, Arctostaphylos stanfordiana and Arctostaphylos viscida. In addition to the Arctostaphylos the chaparral includes chamise, Adenostoma fasciculatum, and Ceanothus spp. The gray pine, Pinus sabiniana, is found in the more arid sections. The rare Ceanothus sonomensis occurs here.
Along the steep north slopes are redwood forests with Sequoia sempervirens, Douglas fir, Pseudotsuga menziesii, and madrone, Arbutus menziesii. A few ponderosa pine, Pinus ponderosa, and California nutmeg, Torreya californica, occur here.
There is a riparian association along the stream beds which includes arroyo, red and yellow willows, Salix lasiolepis, Salix laevigata and Salix lasiandra, big-leaf maple, Acer macrophyllum, and white alder, Alnus rhombifolia.
The grasslands include locally abundant natives such as Festuca californica, Nassella pulchra and the non-native Aira caryophyllea.
A variety of animals inhabits the area, including Heermann kangaroo rat, Dipodomys heermanni, golden eagle, Aquila chrysaetos, Pacific giant salamander, Dicamptodon ensatus, and a substantial population of Western rattlesnakes, Crotalus viridis.
Much of the park is composed of the Sonoma volcanics of the Pliocene era; however, in the eastern portion there are some serpentine areas dating to the Mesozoic.
Integrity: There are roads and some camping sites within the park, as well as trails and other recreational facilities. Portions of the area are relatively undisturbed.
Use: Research, educational, observational, light recreation.
Ref: Wright, K. E. 1975. Sugarloaf Ridge State Park Resource Inventory. Unpub. Calif.- Dept. of Parks and Recreation, Sonoma, Calif.
August 1976
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman