Treesearch

The effect of thinning on growth rate and quality of a 6-year-old Eucalyptus saligna Sm. stand on Maui, Hawaii, was studied by testing three levels of thinning from below: 100, 85, and 70 sq ft per acre (23, 19.5, and 16 sq m/ha). The stand had an average basal area of 102 sq ft per acre (23 sq m/ha). Initial spacing was about 10 by 10 feet. During the next 6 years, no significant differences in growth response were found among the three treatments. Basal area increased to an average of 144 sq ft per acre (33 sq m/ha) at age 12, and the average height of dominant and codominant trees...

In a two-stage stratified procedure for sampling herbage yield, plots are stratified by a pin frame in stage one, and clipped. In stage two, clippings from selected plots are sorted, dried, and weighed. Sample size and distribution of plots between the two stages are determined by equations. A way to compute the effect of number of pins on the variance of estimated herbage yield has been developed. It was tested by using a sampling budget and a simulated population of Bromus mollis (soft chess), and worked reasonably well with other annual plant populations. But application to other plant...

The effects of clipping California-poppy (Eschscholzia californica Cham.) at various growth stages on plant survival, flowering, herbage yield, and root production were studied at the San Joaquin Experimental Range, in central California. Plants were clipped once to a 2-cm stubble at one of six stages. Through the early reproductive stage, a single clipping had little effect, but clipping at either the start or peak of vernal flowering reduced the display of spring flowers. Other factors studied were not significantly affected.

A tripod-supported boom sprayer was developed and used to spray herbicides on shrubs up to 15 feet tall on experimental plots where use of other spray equipment was not feasible. A pneumatic pressurized sprayer with 10 diaphragm nozzles, geometrically spaced along the outer 20 feet (6.1 m) of a 25-foot (7.6-m) boom, distributed the spray uniformly. Brush leaves were well covered with droplets of relatively uniform size at low dosages. The volume of spray applied per acre could be readily changed from plot to plot by varying the number of revolutions of the boom over the circular plot. Each...

Redwood Creek drains a 280 square mile basin which is located in a region of high winter rainfall and high natural rates of erosion. Forests of commercial quality formerly covered about 238 square miles of the basin. Parklands, including a portion of Redwood National Park, occupy approximately 10% of the lower basin and include, amount other values, several of the world's tallest trees.

This user's guide provides detailed information about how to use the computer programs of WRIS, a computer system for storing and manipulating data about land areas. Instructions explain how to prepare maps, digitize by automatic scanners or by hand, produce polygon maps, and combine map layers. Support programs plot maps, store them on tapes, produce summaries, and perform housekeeping tasks.

This user's guide provides instructions for using VIEWIT--a computerized technique for delineating the terrain visible from a single point or from multiple observer points, and for doing slope and aspect analyses. Results are in tabular or in overlay map form. VIEWIT can do individual view-area, slope, or aspect analyses or combined analyses, and can produce elevation profile charts between any two points in a study area. The guide explains how to prepare data, select available options, and interpret results. VIEWIT is designed to operate on a Univac 1108 computer with Exec-8 operation...