Black Oak Planting Project Near Grass Valley

Oaks ‘n’ Folks – Volume 11, Issue 1 – June, 1996

As part of an effort to reduce wildfire hazard at the Empire Mine State Park near Grass Valley, California, crews have been cutting and removing dense thickets of large, old manzanita. This material is subsequently placed into piles and burned. As a result of this operation, this area, as well as nearby housing tracts, have become much more “fire-safe”. Another result, however, is that there are now large areas where little woody vegetation remains, and the ground is relatively bare. The State Park ecologist Sandy Frizzell would like to see California black oak (Quercus kelloggii)- which is the primary tree species on adjacent parcels, and were sparsely distributed throughout the original thickets – planted and established on these cleared areas. Unfortunately there is a dearth of information on techniques for artificially regenerating this species, and consequently, it is difficult to design a successful black oak planting program. To provide some of this information, a cooperative study between State Parks and the UC Integrated Hardwood Range Management Program was initiated in late 1995 to evaluate several approaches for establishing black oaks.

The experimental plot consists of a little less than an acre with 360 planting spots. Treatments include factorial combinations of three types of weed control (none, vispore weed mats and scalping), and three types of above- ground protection (none, vexar tubes and treeshelters). In addition,the study is also comparing the performance of direct seeded acorns, to that of transplanted 4-month old seedlings. Locally collected, pregerminated acorns were planted in mid-December, 1995, and seedlings were planted the following April. All plants will be monitored for at least three years inthe field to determine responses to the various treatments, including survival,growth, acorn depredation and browsing damage.

While California black oak is generally not one of the oak species listed as having difficulty regenerating in the state, there are specific areas where it is not reproducing adequately. For instance, a research and restoration effort has been underway in Yosemite Valley for the past 10 years to help develop guidelines for regenerating and managing the remaining stands of large, old black oak in the Valley on a sustained basis (to be reported in the Proceedings of recent Hardwood Symposium). Also, there is considerable current interest in utilizing black oak for lumber products, but a relatively small body of information on black oak silviculture, or sustained yield management.

It is hoped that this cooperative study will provide some much- needed information about how to go about artificially regenerating this important species in areas where they are not currently growing or regenerating, including sites where vegetation has been removed for fire hazard reduction.

prepared and edited by Richard B. Standiford and Pamela Tinnin