A severe May wildfire decimated an unthinned ponderosa pine stand in northern Arizona, while an adjacent thinned stand was relatively undamaged. Radial growth increased on burned trees where crown kill was less than 60% and decreased where crown kill was more than 60%. Burning initially stimulated growth of herbaceous vegetation in both stands. Herbage nutrient value was temporarily enhanced due to burning. Artificially seeded areas produced most herbage 2 years after burning.

The tendency in the past has been to assume that when wakes or non-uniform total head profiles are fed into an axial compressor then substantially constant static pressure prevails at the entry, the variations in total head appearing as variations in velocity. This variation in velocity causes variation in incidence on the early stage blade rows and thus can give rise to excitation of blade vibration. This assumption is implicit, for instance, in References 1 and 2, but we think has been a common assumption by most of the people working in this field.Where the compressor is fed by a duct of substantially parallel walls for a reasonable length ahead, such an assumption appeared justifiable. Such a duct when given an air flow test with its outlet discharging, for instance, to atmosphere instead of to the compressor, then the distribution assumed would normally be obtained and in fact many surveys of such ducts have been represented in this fashion. The object of this note is to show that, in fact, this distribution will not normally occur when the compressor is present and we may normally expect much more nearly a constant velocity into the compressor with attendant static pressure distributions to match with the total head variations ahead of the intake, with of course, the attendant curved flow to support the static pressure gradients.

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Microhistological analysis of esophageal or fecal materials provides an accurate and efficient method for evaluating botanical compositions of cattle diets on native longleaf pine-bluestem range. For practical purposes fecal analysis is the preferred method. Plant species that were most important to cattle during the present study were the bluestems and panicums. Southern pine ecosystems serve as range for livestock and wildlife. These forest ranges have potential for high production of red meat with minimum inputs (Pearson and Whitaker 1974; Pearson 1975; Sternitzke and Pearson 1975). Cattle impact on ecosystems is related to the animal's dietary needs, preferences, and available forage. The purpose of this study was to estimate cattle diets on longleaf pine-bluestem range. Specific objectives were to contrast cattle diets estimated from esophageal and fecal samples with estimates obtained from exclosures. Study Areas This study was conducted from April 1971 through March 1974 on the Palustris Experimental Forest in central Louisiana. A stand of second growth longleaf pine (Pinus palustris) (= 15-years-old) existed on the area. Predominant herbaceous vegetation was pinehill bluestem (Andropogon scoparius). Other bluestem grasses were prominent, as were the panicums (Panicum spp.) and paspalums (Paspalum spp.). Principal browse included southern waxmyrtle (Myrica ceriferu), oaks (Quercus spp.), blackberries (Rubus spp.), and blueberries (Vuccinium spp.).