Treesearch

Density of embedded scars resulting from old fir engraver (Scolytus ventralis Lec.) attacks was assessed in 3,430 bole cross sections cut from 603 white firs growing in both cutover and in virgin old-growth stands in northern California. Mean scar density was directly related to percentage of mature stand removed by logging and was higher in suppressed and intermediate, compared to dominant, fir. Inverse relationships were found between scar density and site quality, tree diameter, height, age, volume, and mean growth rate. A risk rating system based on tree and stand characteristics...

About a mile north of Gasquet there is a very small flat drainage which flows toward the south with a slope of about 25 percent. Extensive stands of Darlingtonia can be found in the minute creek in an area extending about 1/3 mile in length and 10 to 50 yards in width. Growing amongst the Darlingtonia are scattered Pinguicula.

Drosera anglica abound, growing in all moist areas where water at this time of the year was less than tout two inches deep and continuing up to perhaps one inch above the water line, forming a reddish-green carpet. Many Drosera thus were submerged by two inches but thriving nevertheless

A planning model in which social, economic, and environmental constraints are specified--especially in mathematical form--can be helpful in decisionmaking. The general structure of a land-use decision model approached through systems analysis is described. The proposed procedures emphasize the quantification of interrelationships between uses and the specification of preferences and goals. The complexity of land-use planning is illustrated by an account of how the model might be applied on a Forest Service Ranger District of a National Forest in Colorado.

To quantify production rates for small trees, this study examined the components of log-making and tractor yarding at the Challenge Experimental Forest, Yuba County, California. Rates were calculated over a range of 12 to 40 inches d.b.h. The rate for incense-cedar was lowest; for ponderosa pine it was intermediate; and for Douglas-fir, white fir, and sugar pine combined, it was highest. Log size strongly influenced production. For log-making, production for 38-inch d.b.h. trees was two and a half times that for 14-inch d.b.h. trees; for yarding, production for a turn of logs averaging 22...

A 34-year study of the condition of unburned logging slash in two mixed conifer sites in northern California showed that breakdown and decay occurs at a much slower rate than has been reported elsewhere. The long-term studies were made on the Lassen and Stanislaus National Forests. Correlative weather data for an 18-year period suggested that high summer temperatures and low summer and fall precipitation were vital in retarding slash decay. Most prevalent and active decay fungi were Polyporus abietinus, Fomes pinicola, and Lenzites saepiaria.

Abstract - The effects of logging and associated road construction on four California trout and salmon streams were investigated from 1966 through 1969. This study included measurements of streambed sedimentation, water quality, fish food abundance, and stream nursery capacity. Logging was found to be compatible with anadromous fish production when adequate attention was given to stream protection and channel clearance. The carrying capacities for juvenile salmonids of some stream sections were increased when high temperatures, low dissolved oxygen concentrations, and adverse sedimentation...