Treesearch

This report is concerned primarily with timber. It presents figures regarding significant factors bearing on the present economics of this resource. Another purpose is to describe some of the most important considerations that bear on future development of the timber resource. Other forest values - water, recreation, and forage - are discussed briefly. Trends in use of these resources must be considered in relation to timber, because practically no forest lands are managed for timber alone.

Forage available for use by livestock varies with the season in which ranges are used. Specific precipitation patterns accounted for 87% or more of the variation in forage yields of crested wheatgrass grazed at different seasons in the Front Range of Colorado. Rainfall in April determined forage yields of ranges grazed in the spring; May and July rainfall determined forage yields for fall-grazed ranges. Expected forage yields and stocking rates can therefore be predicted from precipitation measurements.

The usual methods of marking cattle ear tags or neck chains are often unsatisfactory in livestock management and research. When obtaining birthweights of calves at the Manitou Experimental Forest in Colorado, for instance, it was nearly impossible for us to get close enough to range cows to read ear tags. We needed a large identifying number that could be applied to the cows prior to calving, and that would last several months.

Forage samples collected by freely grazing ruminal fistulated steers were analyzed chemically and botanically to ascertain the quality of the diets selected by two herds of Hereford range cows managed under separate grazing systems. The herd grazing native and seeded ranges on an integrated basis was maintained on a high plane of dietary crude protein and phosphorus for a longer period of time than was the herd grazing native ranges only. The response was attributed to earlier initiation of spring growth and lateral attainment of winter dormancy by the seeded forage species. Seasonal...

The Manitou Experimental Forest Was established in 1936 to study problems of land use as they relate to the management of all the resources. The experimental forest lies 28 miles northwest of Colorado Springs. the experimental area totals 25 square Miles, and represents the land of the Colorado Front Range within the ponderosa pine zone. The ponderosa pine zone in the Front Range of the Colorado Rocky Mountains encompasses approximately 4 million acres. An area of numerous mountain ranges and interspersed valleys with open parks and grasslands, this zone is well suited for the production...

George Fahnestock's work (1960) on logging slash was a guide for establishing the experimental plots. The purposes of his study and the present one were different. Fahnestock was interested chiefly in comparing the influences of species, loading, and aging on burning slash. He was evaluating factors that influence the burning of natural beds of logging slash. The study reported here was designed to relate flame front characteristics to a specific fuel bed. To facilitate the comparison of data from the two studies, fuel beds were loaded at the same weights per acre (7.5, 20.0, and 32.5 tons...

This study tested the feasibility of estimating snow loads on roofs from measurements of depth and water content of snow on nearby ground. The water content, and therefore the weight, of snow on the ground proved comparable to that of snow on roofs.

Seedlings of Douglas fir, grand fir, western larch, western red cedar, and western white pine were grown in modified environments for four growing seasons to see whether characteristic growth responses of roots and shoots might suggest a cause for pole blight of white pine. Environments included three soil profiles (topsoil, hardpan, and rock) and two moisture regimes (adequate and deficient). Of several variable characteristics of growth, total root weight was the only significant source of variation in diameter and height growth of white pine. Of all five species, white pine also...

A method is described for computing daily values of moisture stress on forest vegetation, or water deficits, based on the differences between Thornthwaite's potential evapotranspiration and computed soil-moisture depletion. More realistic functions are used for soil-moisture depletion on specific soil types than have been customary. These functions relate daily rates of depletion to characteristics of soil-moisture tension. Separate functions account for surface soil wetting and drying processes following rain and during dry periods. Two methods of summarizing the day-by-day distribution...

Fuel beds of ponderosa pine needles and white pine needles were burned under controlled environmental conditions to determine the effects of fuel moisture and windspeed upon the rate of fire spread. Empirical formulas are presented to show the effect of these parameters. A discussion of rate of spread and some simple experiments show how fuel may be preheated before the fire reaches the fuel. The interrelationship between unit energy release rate and rate of spread produces a fire characteristics curve. Diffusion flame analysis shows good agreement when working with 1/2-inch stick fires.