Ecology of the Sierra Nevada gooseberry in relation to blister rust control
| Authors: | Clarence R. Quick |
| Year: | 1954 |
| Type: | Circular |
| Station: | Pacific Southwest Research Station |
| Source: | Circular No. 937 |
Abstract
Ecological studies of the genus Ribes have been in progress in northern California for more than 20 years. A thorough under- standing of the ecology of native ribes in general, and of the Sierra Nevada gooseberry (Ribes roezli Regel) in particular, is necessary in connection with the control of the white pine blister rust in California. This disease of five-needled pines, caused by the fungus Cronartium ribicola Fischer growing on ribes as its alternate host, threatens to destroy sugar pine (Pinus lamberliana Dougi.) on about a million and a half acres of forest land that supports sufficient sugar pine to make rust control economical.
Some of the conclusions from these studies are based on extensive field observations. For the most part, however, they are related directly to analyses of field data collected from several series of plots in California from 1936 to 1949. These plots, selected for sampling the main geographic range of Ribes roezli, are distributed from Shaver Lake (Fresno County, Sierra National Forest) on the south to Lake Almanor (Plumas County, Lassen National Forest) on the north.
About 35 species and varieties of the genus Ribes L., here construed to include the genus Grossularia (Tourn.) Mill., occur in California. A recent taxonomic treatment of gooseberries and currants is given by McMinn (11)} Several species are commonly associated with sugar pine in the acreages of greatest interest to public and private agencies in California that are in blister rust control units. Approximately 175 million ribes plants were destroyed from 1926 through 1948 for the protection of sugar pine, and of the time and money spent on ribes eradication, perhaps 90 percent was expended on the removal and suppression of one species, the Sierra Nevada gooseberry. In the mixed-conifer forests of the middle altitudes of the Sierra Nevada, on areas suited ecologically to its growth, roezli may be found almost everywhere. In favorable sites there may be 3,000 to 5,000 plants per acre.