Treesearch

Direct seeding is a highly desirable method of regeneration. It is more economical and more flexible in both time and place than the planting of trees. In California, however, direct seeding generally has been an ineffective method of regeneration. Early trials by the Forest Service with broadcast sowing and spot sowing invariably failed to produce an adequate stand of reproduction primarily because forest rodents destroyed the seed or seedlings. Poisoning and trapping had little effect. Protecting seed spots with screens was judged to be effective but not economical. More recently direct...

Natural reproduction must provide future crops of timber on most of the forest land being placed under management in California. Relatively few acres will be planted or seeded in the near future because planting costs are high, facilities for undertaking large-scale planting are inadequate, and direct seeding has not yet proved satisfactory. In the pine region it is desirable that reproduction stands be adequately stocked with vigorous pine seedlings. How promising is the outlook for natural restocking. The degree of success in one important locality is the subject of this paper. It...

Instructions for establishing fire-weather stations in Region 5 have usually specified that the fuel-moisture indicator sticks be placed over a bed of ponderosa pine needles. This specification was made to insure uniform ground-cover effect for all stations. Because ponderosa pine needles are not readily available in all areas of California fire control technicians have often asked if pine needles must be used in preference to local litter types.

The literature provides limited information on the time of ignition of wood under conditions of rapid heating such as occur in forest and structure fires. An investigation was made of ease of ignition as affected by such physical properties of wood as initial temperature, size, and moisture content and by temperature of ambient gas or rate of heating. Temperature-time history curves are shown for two radii of wood specimens. With the temperature-time data and an equation for unsteady-state heat conduction, the surface temperature of wood when flame appears is calculated. With the method...

Increasing interest in the management of sugar pine (Pinus lambertiana Dougl.) in the mixed-conifer stands of the west slope of the Sierra Nevada has pointed out the need of certain silvical knowledge. One bit of required knowledge is the area that can be seeded effectively by a sugar pine tree. The forest manager must have this information in marking a stand to obtain natural reproduction of sugar pine.

The control of seed-eating rodents, combined with the proper method of cutting and site preparation, appears essential to get the maximum results of natural seeding of pine. One method of control is by treating the area to be regenerated with lethal bait prior to seedfall. This note describes such a method and costs of treatment for the westside and eastside Sierran pine types in California.

In part of the high-site-quality pine and fir types of California, stand improvement cuttings are made especially difficult by the sprouting habit of tanoak (Lithocarpus densiflora Hook. and Arn. ) and madrone (Arbutus menziesii Pursh.). The stumps of these species sprout so vigorously that release of the favored crop trees is only temporary. How to control this sprouting on areas dedicated to production of conifers was the object of a small test on the Challenge Experimental Forest.

In part of the high- site-quality pine and fir types of California, stand improvement cuttings are made especially difficult by the sprouting habit of tanoak (Lithocarpus densiflora Hook . and Arn . ) and madrone (Arbutus menziesii Pursh.). The stumps of these species sprout so vigorously that release of the favored crop trees is only temporary. How to control this sprouting on areas dedicated to production of conifers was the object of a small test on the Challenge Experimental Forest.

A modified embryo culture technique was used to facilitate germination of seed obtained after pollinating sugar pine with pollen from blister rust- resistant Armand and Korean pines. Resulting seedlings appear to be hybrids.

Trees fit into the general rule that (the plants and animals which nature gave us have not been considered quite good enough. For millions of years, it is true, nature has developed a breathtaking variety of forms, each wonderfully adapted to its surroundings. Changes in climate or the conformation of the earth's surface have caused the extinction of some forms and the development and migration of others. But during the long development of civilization man has learned to alter some of the myriad forms of life about him, making them better suited to his needs.