Oak Woodland Restoration in the Ventura Hillsides

Project Details

Permanent preservation of the Ventura Hillsides is a first crucial step towards providing a theatre to protect and restore habitat. Oak savanna (20-30% canopy cover) and oak woodland (30-60% canopy cover) are highly ecologically important habitat types in Ventura County. Statewide, oak habitat supports one of the highest amounts biodiversity than any other terrestrial ecosystem. Over 300 vertebrate species rely on oak forest for habitat and food including 60 species of mammals and over 110 species of birds (CDFW). This habitat type also supports over 1,110 species of plants, 370 species of fungi and over 5000 arthropod species. Oak woodland also plays crucial roles in erosion control, protection from landslides and are proven to increase water quality in drainages (Bernhardt & Swiecki, 2001).

Sadly, local area degradation of Oak woodland has been continuous since the 18th Century. Many of the oaks that used to be common on windward sides of the hills and along drainages are thought to have been harvested by settlers for firewood, charcoal and cleared to make room for agriculture, grazing and urban development. This highly important habit type has been reduced to a fraction of its original size statewide.

The goals of the Rancho Ventura Conservation Trust Oak Woodland Restoration Project are to restore coastal live oak woodland, improve the overall ecological habitat value in the Ventura hillsides, improve carrying capacity of native plants and animals, protect and expand existing oak woodland and create a successful and cost-effective habitat restoration system. Careful planning, financial support and a dedicated staff and community will be critical to long tern success of the project.

In October of 2017 the Rancho Ventura Conservation Trust began planning a habitat restoration pilot project in Barlow Canyon, an area in the northwest part of the Trust. 30 Coast Live Oak Trees (Quercus agrifolia) will be planted irrigated and monitored over time. This location was chosen because the area is representative of similar areas that support an existing population of oak woodland and/or oak savannah habitat type both on the Trust and in the local area. Cost live oak, which make up the majority of oak forest Ventura county (62%) are likely to have success growing in this location (Ventura County Planning Division Resource Management Agency, 2007). The woodlands typically occur within a 50 mile radius of the coast in well-drained soil, low to medium fertility soil on all different slope types. Additionally, there is an ephemeral watercourse adjacent to the pilot project area that drains quickly after rains and will provide a natural source of water to established oaks (Cal Poly Land).

By nature, all restoration projects are experimental. This project will allow the Trust to gather data in a controlled area and demonstrate the success of the project by meeting the aforementioned objectives. It will also encourage the development of adaptive management strategies that allow managers to adjust for variables and make decisions that produce positive results.

The pilot project will ultimately be considered successful in the near term (first 5-10 years) If the following conditions are met.  The juvenile oaks be successfully planted, irrigated, protected from herbivory (cattle and native animals) and competition from invasive weeds. Protection of the plants will continue until they are sufficiently large enough to resist adverse environmental conditions. Trees will be monitored after protections are removed to study growth, use by wildlife and acorn production etc. Native plants commonly associated with local oaks will be planted or seeded seasonally to replicate and add value to the local ecosystem. Should the methodology implemented for establishment be proven replicable then the Pilot project will be deemed a success. The long term success of the project is a different matter. Oaks are relatively simple to plant and establish, however they are a slow growing, long lived species taking up to 60-80 years to grow into a large tree (CDFW). Since most oak habitat restoration projects are in their infancy being under 10 years old it is impossible to set certain long-term goals. Preferred management practices will be developed over time with more data, research and field experience by RVCT staff.

References

Bernhardt, E. A., & Swiecki, T. T. (2001). Phytosphere Research. Retrieved from Restoring Oak Woodlands in California: Theory and Practice: http://phytosphere.com/restoringoakwoodlands/oakrestoration.htm

De Rome, D. (1997, March). Plant Communities: Coastal Live Oak Woodlands. Retrieved from Cal Poly Land: http://polyland.calpoly.edu/overview/archives/derome/woodlands.html

Holland, V. (2005). Coastal Oak Woodland. California Wildlife Habitat Relationships System, California Department of Fish & Game, California Interagency Wildlife Task Group. Retrieved from https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=2037

Ventura County Planning Division Resource Management Agency. (2007). Ventura County Oak Woodlands Management Plan. Retrieved from California National Plant Society: https://www.cnps.org/cnps/conservation/forestry/pdf/oaks-2007_ventura_county_oak_woodlands_mgmt.pdf