Testing and implementing methods for managing Phytophthora root diseases in California native habitats and restoration sites

Abstract

Over the past 14 years, a variety of native plant communities in northern California have been identified where introduced root-rotting Phytophthora species, most notably Phytophthora cinnamomi, P. cambivora, and P. cactorum, are causing decline and mortality of native species. In many older infested sites, the source(s) of the original Phytophthora introductions are not clear. Movement of contaminated soil is the most likely source in some sites that are located along roads and trails. In other cases, introductions are associated with plantings of nursery stock. In one site, a multi-species infestation (P. cambivora, P. cactorum, P.’kelmania’, and P. syringae) extending over more than 2 ha was associated with the planting of 30 to 50 or more nursery-grown Ceanothus plants as part of a restoration effort. Once Phytophthora infestations become established, they have typically spread along roads and trails and downslope with surface water flow.

Parent Publication

• Proceedings of the sudden oak death sixth science symposium

Citation

Swiecki, Tedmund J.; Bernhardt, Elizabeth A. 2017. Testing and implementing methods for managing Phytophthora root diseases in California native habitats and restoration sites. In: Frankel, Susan J.; Harrell, Katharine M., tech. coords. Proceedings of the sudden oak death sixth science symposium. Gen. Tech. Rep. GTR-PSW-255. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 53-55.