Treesearch

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...

For at least 20 years foresters have been experimenting with methods designed to reduce transpiration from planted conifers. The object is to decrease the water requirement of the plants until the root systems become adjusted to their new environments and are able to supply enough water for the trees to survive. Despite the fact that relatively few clearcut instances of success have been published, considerable enthusiasm for use of transpiration retardants exists.

The purposes of this bibliography are to enumerate and describe publications that have a bearing on the growing of sugar pine for timber production. It is intended primarily for the information of forest managers, and it includes mainly those articles which appeared to pertain rather directly to management. Although a careful search was made for titles, no claim is made that all possible informative sources of information have been included.

Ecological studies of the genus Ribes have been in progress in northern California for more than 20 years. A thorough under- standing of the ecology of native ribes in general, and of the Sierra Nevada gooseberry (Ribes roezli Regel) in particular, is necessary in connection with the control of the white pine blister rust in California. This disease of five-needled pines, caused by the fungus Cronartium ribicola Fischer growing on ribes as its alternate host, threatens to destroy sugar pine (Pinus lamberliana Dougi.) on about a million and a half acres of forest land that supports sufficien...

The transfer theory is applied to the problem of atmospheric diffusion of momentum and heat induced by line and point sources of heat on the surface of the earth. In order that the validity of the approximations of the boundary layer theory be realized, the thickness of the layer in which the temperatures and velocities differ appreciably from the values at infinity must be small compared to the height of the region of influence. Variations of four dependent variables--inflow rate, inflow velocities, maximum velocities, and maximum temperature--as a function of elevation for representative...

Thirty years of research in the ponderosa pine and mixed conifer forests of the Sierra of California by Dunning and his associates have shown that previous methods of silviculture were not providing adequate restocking of pine. Analysis of records indicated a new approach was necessary. From this work, new procedures that gave most promise of success were formulated by Duncan Dunning. These procedures are techniques for applying unit area control in the ponderosa pine and mixed conifer forests.

When the forester finds planting necessary to regenerate an area he should know which species and class of planting stock is best suited to his particular operation. He should also weigh the expected successes on various locations which could be planted. Through such a procedure the best planting locations will be given priority and the best results, measured by survival and growth, will be obtained from the efforts expended. A test conducted at the Blacks Mountain Experimental Forest, an area typical of the California eastside pine type, has shown that survival of ponderosa pine (Pinus...

Squirrels may harvest a far greater proportion of ponderosa pine cones than many foresters realize. This was evident while making a routine cone count on a number of permanent plots on the Stanislaus Experimental Forest near Pinecrest, California, in September 1952. Ponderosa and Jeffrey pines were the predominant species affected. Many ponderosa pines had more than half their total number of cones cut and destroyed.