Dwarf mistletoe had no noticeable effect on trunk taper of young, dominant and codominant red firs 4 to 22 inches (10.2 to 55.9 cm) d.b.h. Also, taper was not influenced by live crown ratio of infected and uninfected trees. Trees less than 7 inches d.b.h. had significantly more taper than larger trees, irrespective of dwarf mistletoe.
In direct-seeding trials on the Challenge Experimental Forest, Yuba County, California, 27 combinations of seeding rates, aspect, and site treatment were tested. The best results were obtained on northerly aspects on unburned mechanically disturbed seedbeds with a high proportion of exposed mineral soil when seed application rates were high. Sowing at least 1 pound of seed per acre (1.12 kg per ha) consistently resulted in 400 or more seedlings per acre (988 seedlings per ha). Baiting for rodent control and attempted seed covering by "dragging" did not improve results. If regeneration requirements will be met by 400 seedlings per acre, these procedures for operational testing are suggested: (1) prepare 100 percent of the site by piling and burning slash and residual vegetation; (2) use seed that has had the standard endrin-arasanaluminum- dust pest repellent treatment, or equivalent; and (3) apply at least 1.5 pounds of seed (10,000 to 12,000 viable seed) per acre (1.7 kg, or 24,710 to 29,650 seed, per ha).
Blowdown in shelterwood, sanitation cuts, and other partial cuts on the Kings River Ranger District, Sierra National Forest, are due to Mono winds. Both winter storm and Mono winds were considered as causes of winter blowdown. All evidence, e.g., direction of tree-fall and occurrence of high wind events, point to Mono wind events as the cause of blowdown. Only 12 percent of Mono wind events cause blowdown. Windspeed during a Mono wind (northeast winds) blowdown averages 50 mi/h with gusts to 100 milh. The probability of a blowdown occurring is about once per year, with some years having multiple blowdowns and other years having none.
Tree diameter outside bark at an earlier period of growth can be estimated from the linear relationship of present inside bark and outside bark diameters at breast height. This note presents equations for estimating inside bark diameters, outside bark diameters, and past outside bark diameters for each of the mixed-conifer species in the central Sierra Nevada.