Response of young ponderosa pines, shrubs, and grasses to two release treatments

Abstract

To release a young pine plantation on a medium site in central California, herbicides and mulches were applied soon after planting to study their effectiveness. Bearclover is an aggressive shrub species that resprouts from rhizomes after disturbance, and must be controlled if young conifer seedlings are to become established. After 4 years, resprouting bearclover plants numbered 282,000 per acre in the control, but less than 4,000 per acre in the plots treated by herbicides. Mean foliar cover was 63 percent versus 1 percent for control and herbicide plots, respectively. Ponderosa pine seedlings were significantly taller, had larger mean diameters, and survived better in the herbicide treatment than counterparts in mulched plots and control. The 5-foot square mulches were ineffective for controlling bearclover. Cheatgrass invaded the plantation in the second year, and after 2 more years became abundant in herbicide plots (743,667 plants per acre) and plentiful in the control (130,300 plants per acre).

Citation

McDonald, Philip M.; Everest, Glen A. 1996. Response of young ponderosa pines, shrubs, and grasses to two release treatments. Res. Note PSW-RN-419. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 8 p