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).
In a sampling of 32 logged areas in red fir forests of northern California, 58 plant species were found. Species corresponded with less than one-fifth of the 93 species reported in an earlier study of the virgin forest. Sampling of uncut areas adjacent to cuttings does not seem uscful for predicting the earlier successional vegetation that will appear when the areas are logged.
The technique proposed allows interpolation of data recorded at unevenly spaced sites to a regular grid or to other sites. Known data are interpolated to an initial guess field grid of unevenly spaced rows and columns by a simple distance weighting procedure. The initial guess field is then adjusted by using a parabolic leapfrog correction and the known data. The final output is then generated by use of cubic spline interpolation on the adjusted grid. Application to test and actual data showed acceptably low root-meansquare error.
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.
Fuel moisture estimates generated by the National Fire-Danger Rating System procedure were compared with actual fuel moisture measurements determined from laboratory analysis. Meteorological data required for the NFDRS procedure were collected at two heights to assess the effect of temperature and humidity lapse rates. Standard measurements gave the best results, but use of a xeric hygrometer showed promise of giving reliable fuel moisture estimates by a simple linear regression.