Treesearch

Striking genetic variation in susceptibility to fusiform rust was observed among SS controlled-pollinated (CP) and 48 wind-pollinated (WP) families from parent trees of loblolly pine selected at random in a natural forest stand in southwest Georgia. The mating design permitted statistical tests for estimating both additive and total genetic variance. WP families were planted on two different sites, CP families on four sites, including one where a deliberate attempt was made to increase the hazard of fusiform-rust infection. Susceptibility to rust was measured as the percentage of trees...

Map users must refer to an appropriate scale in interpreting wildland resource maps. Length and area equivalents for nine map scales commonly used have been computed. For each scale a 1-page table consists of map-to-ground equivalents, buffer strip or road widths, and cell dimensions required for a specified acreage. The conversion factors are stored in a Fortran program. It can be easily modified to compute equivalents for other map scales.

Precommercial thinning in ponderosa pine stands in the Western United States is a growing practice. Thinning slash can, however, be a serious fire hazard in dry areas. Crushing and compacting this slash may be one way of reducing the hazard. Three types of mechanical crushers were tested on the Deschutes National Forest, Oregon. Results indicate that at least one of these methods of mechanical crushing is effective for lessening the fire hazard in thinning slash, and can be done at reasonable costs.

The cross-section analyses of the 3 days of weak Santa Ana conditions reveal how rapid changes in windspeed and direction may occur under these conditions. The analyses indicate the significant dip of the wind field down the lee side of the range even under relatively light wind conditions, and show how opposing wind systems interact on the lee side to allow rapidly changing surface winds. The well-defined convergence zone and the vertical wind field are obvious.

INFORMAP (Information Necessary for Optimum Resource Management and Protection) is a computerized system under development for storing, manipulating, retrieving, and displaying data for fire planning and fire control. A prototype for planning applications has been developed and tested. It is programed in Fortran IV for the IBM 7040 computer, and displays information in tabular, narrative, or graphic form. It uses card input of data and programs. Output, also requested by punchcards, is produced by highspeed line printers. Data are coded for input, and stored on magnetic tape.

A gas chromatographic analysis of the mono-terpenes of 927 ponderosa pines, representing to some degree a major portion of the species' range, showed considerable local and regional diversity in composition. Five major monoterpenes— α-pinene, β-pinene, 3-carene, myrcene, and limonene—were analyzed. There is some evidence to support the establishment of at least eight regional types of ponderosa pine, and a further breakdown of these into four major and four minor ones on the basis of greater differences. More meaningful than regional types may be individual tree variants; at least 25 of...

The natural hybrid between rock chestnut oak, Q. prinus, and white oak, Q. alba, was named Q. x saulii by Schneider (1904). The nomenclature used herein follows that of Little (1953). Q. x saulii is frequently identified throughout the area of sympatry of the parental species. It has occurred in Vermont, Massachusetts, Rhode Island, New Jersey, Pennsylvania, the District of Columbia, North Carolina, Illinois, and Alabama according to Sargent's Manual (1922) and in Virginia according to Allard (1949).

Soil moisture was measured around an isolated mature sugar pine tree (Pinus lambertiana Dougl.) in the mixed conifer forest type of the north central Sierra Nevada, California, from November 1965 to October 1966. From a sequence of measurements, horizontal and vertical soil moisture profiles were developed. Estimated soil moisture depletion from the 61-foot radius plot for the 1966 summer depletion season was 22.57 inches.