Port Orford Cedar Management Plan

RNSP

Introduction Port-Orford-cedar (POC) is an ecologically and economically valuable native conifer growing only in northern California and southern Oregon. POC is threatened by a root disease caused by a non-native pathogen, Phytophthora lateralis (PL). The root disease is almost always fatal, although a small percentage of POC appear to be naturally resistant. The disease threatens the long-term survival of POC in some areas because it has a limited range and spotty distribution. In Redwood National and State Parks (Figure 1), some POC are infected with the disease and are dead or dying. POC root disease is caused by PL spores that are carried in water. Movement of the disease into new watersheds is most frequently caused by disease-infested mud adhering to heavy equipment or other vehicles, and falling off in uninfested areas under conditions favorable to the disease (availability of moisture and host trees). Footwear and animals can also carry disease-infested mud. The pathogen has existed in the Little Bald Hills area of the parks since at least 1981. Currently there are at least six more infestations known in Redwood National and State Parks (RNSP), most of which are scattered individual trees along Mill Creek, Cedar Creek, and the main Smith River (Figure 2). It is likely that infestations in the parks and on adjoining privately and publicly held land will grow in number since the main forks of the Smith River upstream of the parks are infested. In RNSP, POC occurs primarily in the Smith River watershed in the northern part of the parks in Del Norte County, with some POC occurring farther south in the Klamath River watershed. Prior to the establishment and expansion of the national park in 1968 and 1978, POC was included in post-timber harvest seed mixtures that were aerially distributed in what is now the southern part of the parks in and near the Redwood Creek drainage in Humboldt County. These planted trees are considered to be an exotic plant and are not included in the management proposals presented in this plan. The National Park Service (NPS) proposes to manage POC in RNSP to slow the spread of the disease within the parks and onto adjacent lands, particularly those managed by the US Forest Service (USFS) in northwestern California and southwestern Oregon where POC plays an important ecological role in addition to its economic value.

Port Orford Cedar Management Plan

Collections