threat to natives

Does anyone know of any particular exotics that threaten plants of the Oak Woodland community?</p>

Well, there are a number of things to look at. Start at the UCD Herbarium. They should have some good information. Annual grasses are probably the biggest problem in oak woodlands. The biomass they produce prevents acorns from reaching the ground, and then if they reach the ground and sprout, they die from root rot. The moisture held in the biomass is the culprit on that one. Other pests include Tree of Heaven Ailanthus altissisima, once established it forms clonal stand and require great diligence to remove. Yellow star thistle Centaurea solstitialis is another nasty annual that covers millions of acres in California. Usually requires a regimented burning program or herbicide application to get rid of it. Let me know if you have any further questions, or more specific questions. Ben</p>

Algerian Ivy is a major pest. It climbs the Oaks and eventually kills them. Vinca major doesn't climb the trees, but like Algerian Ivy it chokes out the other vegetation beneath them.</p>

In San Diego I have seen Italian thistle and Cape Ivy taking over oak understory.</p>

Most species found growing in the understory of oaks are non beneficial and can be detrimental. Oaks- and species associated with oak woodlands rely heavily on microrizal activity. Alien grasses and broadleaves disturb the microbes and the service they provide to the oak woodland. I work on native habitat restoration in Central CA. Anytime i approach a situation in where grasses and alien broadleaves thrive in the understory of the oaks themselves, an aggresive weed abatement approach is the first step-- do not let weed species go to seed--either with manual removal, string line trimmer, roundup or pre-emergent or some other practical approach--anyway-- i will stop babbling-- any more questions please write--Casey</p>

Casey -- I thought Catalina Ironwoods are only grown on Catalina Island. Not Santa Monica. Although you have me intrigued Also--please excuse my ignorance, but can you please explain the detriment of planting bamboo in Santa Monica. thanks,laura</p>

Check out this book: Proceedings of a symposium on Oak woodlands: Ecology, management, and urban interface issues. March 19-22, 1996 It is a general technical report PSW-GTR-160 published by the USDA Forest Service, Pacific Southwest Research Station.</p>

We recently bought a house in Mountain View and in the back yard is arather large tree just identified as the Cat. ironwood, and we wonderabout how to assess a number of things:-its health it drops lots of brown leaves and mostly brown leafclusters daily-how much water it can tolerate there is a sprinkler that keeps theadjacent Rhododendrons, ferns, Camilia, and star jasmine happy-how brittle it may be. the tree is much taller than our 2 story houseand some of the branches extend laterally for significant distancesi.e. do we need to prune it to avoid breaking/falling limbs? [I canguestimate the height and pace off some branches if that would help]- pruning it produces many many suckers/shoots at the bottom andhigher. I hope to utilize these to create a denser sub-story to blocklate afternoon and early evening light from blinding folks eating at thekitchen table.

The sites that google provided were helpful in confirming theidentification and providing some general knowledge about the naturalhistory, but lacked the details desired. If you can point me towardsother web sites that are more informative it would be appreciated.

David