Blue oak woodland and savanna is one of the largest habitat types in the state of California. This habitat is threatened by land development, fire pressure, and drought. Across California, blue oak tree mortality is increasing while recruitment and regrowth is decreasing. Despite blue oak woodland and blue oak tree prevalence, these mortality and regrowth rates are not yet fully understood. Moreover, blue oak woodlands may be left vulnerable without management strategy.
Circle J-Norris ranch is mostly blue oak woodland and savanna, dominated by annual vegetation including soft chess, rip-gut brome, foxtail, and filaree. Blue oak trees represent a majority of the ranch’s tree community; other tree populations include interior live oak, valley oak, and buckeye. In a wet year forbs--including poppies, lupine, brodiaea, and milkweeds--are abundant. Common shrubs include honeysuckle, buck brush, and manzanita. Non-native, invasive plants include Italian thistle, Bermuda grass, and fiddleneck. In the ranch’s riparian zone there are willow, sycamore, cottonwood, mulefat, and deergrass. Students have planted both valley oak acorns and hundreds of interior live oak acorns in the Lower Riparian trap in spring of 2021.
Blue oak woodlands and savanna are home to hundreds of wildlife species. Keystone predators include the coyote, mountain lion, bobcat, and birds of prey like the red-tailed hawk. Common herbivores include black-tailed deer, as well as many rodent and lagomorph species such as ground squirrel, grey squirrel, cottontail rabbits, and pocket gophers. Blue oak woodlands and their riparian zones provide habitat for resident and migratory birds, including the acorn woodpecker, california quail, kingfisher, and great-horned owl.
Special Status Species and Habitats
Circle J-Norris Ranch is home to state and federally threatened species. Both the Kaweah Brodiaea and the Springville Clarkia are known to grow on the ranch, and may be impacted by improper grazing management. There are forty or more vernal pools existing on the ranch, which are often home to multiple rare or threatened species. The endangered vernal pool fairy shrimp has been found in a Circle J-Norris Ranch vernal pool. For this reason, all vernal pools on the ranch should be treated as though they may be home to rare and important species. Historically, Circle J-Norris Ranch is representative of the historic critical range for the endangered California Condor. As the California Condor makes a return to this landscape, Circle J-Norris
Ranch will play a critical role in connecting habitat to the 11,000 acre Blue Ridge Wildlife Refuge to the North
|Vernal Pool Fairy Shrimp
Figure 1. Endanagered species found at Circle J-Norris ranch