Treesearch

Creating ground conditions favorable to regeneration immediately after the final harvest cutting is basic to forest management wherever advance growth is deficient. Ponderosa (Pinus ponderosa Laws) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seeds require bare mineral soil for satisfactory germination. Pine seedlings, whether from natural seedfall or planting, survive and grow vigorously only when free from competition with other vegetation. This article describes methods used and reports the cost of site preparation in recent years at the Blacks Mountain Experimental Forest in...

Many winter deer ranges throughout the West have been steadily deteriorating as a result of overgrazing, fire, and insect depredations. Lack of winter forage has caused heavy mortality of deer. The problem has become so acute that some of the western states have started research to determine what can be done to rehabilitate these ranges, if and when the causes of deterioration can be controlled.

Residual tanoak (Lithocarpus densiflorus (Hook. & Arn.) Rehd.) trees and tanoak sprouts often are an important component of the vegetation which competes with conifer reproduction in northwestern California. Sometimes enough tanoak is present in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands to dominate the ground completely after logging. And tanoak sprouts develop vigorously after parent trees are destroyed by fire or logging (fig. 1), thereby providing severe competition to conifer reproduction. Although tanoaks generally are considered undesirable at present, someday they...

The composition and characteristics of the needle oils of western pines may provide criteria for distinguishing pine hybrids and may help explain why some needle-feeding insects select certain pine species as hosts.

Available data on the behavior of wood undergoing charring and weight loss are summarized.

Brush competition is one of the more serious obstacles to survival of both planted and naturally established trees in California. Brush has taken over many cutover and burned areas. In the western Sierra Nevada alone, 1.7 million acres of commercial forest land are classified as poorly stocked or non-stocked. All of this area is capable of producing forest trees, but brush dominates most of the ground and greatly hinders efforts by man and nature to reestablish conifers in adequate numbers. If these acres are to produce timber within a reasonable period, the brush must be either eradicated...

Evidence that immature sugar pine cones are killed by severe late spring freezes was observed for the first time on the Stanislaus Experimental Forest in 1954. Although extremely low temperatures previously were suspected to have destroyed young sugar pine cones, no definite instances are known to have been reported heretofore.

The effect of storage temperature on the viability of sugar, Jeffrey, and ponderosa pine seed was studied to determine a suitable condition for each of the three species. Barton has reported -4° C. (25° F.) as being better for ponderosa pine than either -11° C. or -18° c. (12° F. or 0° F.), but storage temperatures have not been recommended for either sugar or Jeffrey pine seed. Before 1952, all seed stored at this Experiment Station was kept in air-tight containers at 41° F. (5° C.). However, germination tests on some seed lots, particularly sugar pine, indicated that storage at 41° F....

Prediction of wind breakage and uprooting in tree stands requires information on weight of dry crown, branchwood, and foliage. This information has not been published. An experimental program started in 1951 has led to a number of generalized relations by which these crown characteristics can be determined with good accuracy over a wide range of tree diameters, species, and species groups.Crowns, their components–branchwood and foliage–and stems were analyzed for 211 conifer trees representing 13 species and 4 sites from 4 states. Diameters of stems ranged from 1 inch to 37 inches at...