Treesearch

In 1975-1976, pine trees killed by the southern pine beetle Dendroctonus frontalis Zimm.) in a 2l70-hectare (5362-acre) area at the William B. Umstead State Park in central North Carolina, were monitored by sequential color infrared aerial photography. From 1973 through summer 1975, beetles in 350 infestation spots killed more than 20,500 pines on 137 hectares (339 acres). From October 1975 to July 1976, an additional 301 dead pines were detected at 146 tree mortality centers. Southern pine beetles were associated with 98 percent of these dead trees. Pine mortality dropped rapidly from 248...

Two components of fire management programs were analyzed at these Forests: Francis Marion (South Carolina), Huron-Manistee (Michigan), San Bernardino (California), Tonto (Arizona), and Deschutes and Willamette (Oregon). Initial attack and aviation operations were evaluated by the criterion of minimizing the program cost plus the net value change of resource outputs and structures resulting from fire (C + NVC). Four alternative program or budget levels were investigated at each Forest for each of 3 years of varying fire severity. The program levels ranged from 20 percent below the 1979...

To assess the influence of road building and logging on storm flow response, a pair of watersheds were studied at Caspar Creek near Fort Bragg in northern California from 1963 to 1975. Selection cutting and tractor yarding of 85-year-old second-growth redwood and Douglas-fir forest did not significantly affect large peak streamflows. The first streamflow peaks in the fall, however, were increased about 300% after logging. These early fall storms produced small peaks, which had little, if any, hydraulic consequence. The effect of logging on peak flow was best predicted by a variable...

For 18 years Jackson Demonstration State Forest, managed by the California Department of Forestry, has been the site of a comprehensive watershed experiment. This experiment, on Caspar Creek five miles south of Fort Bragg on the Mendocino coast (fig. L), is a cooperative project between the California Department of Forestry and the U. S. Forest Service, Pacific Southwest Forest and Range Experiment Station. The Department of Forestry provides the project area, conducts the treatment and collects much of the field data. The Station provides technical assistance, some funding and much of the...

Water repellency in soils was first described by Schreiner and Shorey (1910), who found that some soils in California could not be wetted and thereby were not suitable for agriculture. Waxy organic substances were responsible for the water repellency. Other studies in the early 1900's on the fairy ring phenomenon suggested that water repellency could be caused by fungi. These fairy rings created unsightly, circular shaped areas in otherwise healthy turf and lawn. Bayliss (1911) reported on such water repellency and referred to earlier work in 1875 by Gilbert and Laws at Rothamsted which...

Abstract - The following properties of the Hugo, Mendocino, and Caspar soil series were analyzed at the 10 cm, 20 cm, 30 cm, 50 cm, 100 cm, and 150 cm depths: bulk density; porosity; particle density; saturated and unsaturated hydraulic conductivity; particle-size distribution; pore-size distribution; and water retention characteristics. The Hugo soil series exhibits great variation in its hydrologic properties from location to location. This series differs from the Mendocino and Caspar series by having a higher gravel content, a greater proportion of large diameter pores, and a lower...

Abstract - Erosion and site conditions were measured at 102 logged plots in northwestern California. Erosion averaged 26.8 m 3 /ha. A log-normal distribution was a better fit to the data. The antilog of the mean of the logarithms of erosion was 3.2 m 3 /ha. The Coast District Erosion Hazard Rating was a poor predictor of erosion related to logging. In a new equation that ""explained"" about 40 percent of the variability in erosion, yarding method was associated with a 3.7-fold difference in erosion, aspect with a 4.3-fold difference, geologic type with a 13.5-fold difference, and slope...

Techniques to calculate 1000-hour timelag fuel moistures were developed from theory of water movement in wood. The 1000-hour timelag fuel moisture is computed from mean daily temperatures and humidities and precipitation duration. Comparison of calculated and observed fuel moistures showed good agreement. Techniques to determine the seasonal starting value of the 1000-hour timelag fuel moisture are based on monthly climatological summaries. The seasonal starting value calculation was made from a least squares regression equation.

Before the telling of this tale could take place, there had to be an Experimental Forest and sorre events. Reasons for the establishment of the area will be covered later, but some of the records of establishment have been found. Blacks Mountain Experimental Forest, about 10,000 acres in size, was withdrawn from lands of Lassen National Forest and designated as an experimental forest by F. A. Silcox, (Chief) Forester, United States Forest Service, on March 28, 1934. This action fallowed a search by an Experiment Station committee for a suitable experimental area east of the Sierra Nevada...

Emergence of mamane (Sophora chrysophylla) was best when seeds were sanded or soaked in sulfuric acid and then sown at 3.8 or 6.4 cm. Soil moisture content and soil temperature were among the factors governing emergence from different sowing depths. End-of-test seedling survival was low-16 percent during a spring test and 2 percent during a summer test; it was significantly affected by type of seedcoat treatment, but not by sowing depth. Low rainfall and extreme soil surface temperatures appeared to account for most seedling mortality. In both tests, some seedlings which had died back to...