Treesearch

This is the sixth annual report on the pulpwood harvest in the Lakes States counties. The 1964 harvest of pulpwood in the Lakes States amounted to approximately 3.628,000 cords, 1 percent less than the all-time high in 1963. Ninety-six percent of the pulpwood production was roundwood, while the remaining 4 percent was wood residue supplied by local primary wood-using plants.

The use of artificial lights to grow tree seedlings for research and even for commercial uses is becoming common. With this has come an increasing awareness that not all types of artificial lights produce the same results (2, 3, 5). The presence or absence of particular wavelengths in the light source may cause large differences in height growth and morphological development that are separate from the effects of light intensity.

Various portions of the root systems of bigtooth aspen (Populus grandidentata) suckers were severed, and the subsequent height and radial growth of stems were measured. Aspen vegetative regeneration is heavily dependent on the parent roots for at least 25 years following initial suckering. The distal portion of the parent root contributes more to sucker growth than does the proximal. New roots at the base of suckers contribute little during the first 6 years, then become progressively more important with age, and by 25 years account for about half of annual stem growth.

The upland northern hardwoods represent a forest type of great economic, biotic and aesthetic value throughout northeastern and northcentral United States and in southeastern Canada. Sugar maple, Acer saccharum Marsh., is usually the leading dominant in these stands in terms of numbers of trees and in size. Often the economy of the areas depends largely on the lumber produced from maple. For instance, in 1954, over 54,000,000 board feet of maple were cut from 2,663,000 acres of northern hardwoods in Wisconsin alone (Horn, 1957; Stone and Thorne, 1961). In recent years, a slow decline in...

Single or repeated spring prescribed fires and single summer fires easily kill aerial stems of hazel (Corylus spp.). Although vigorous and abundant resprouting follows spring fires, resprouting is less vigorous after summer fire. Repeated summer fires destroy the ability of hazel to resprout by (1) exposing and destroying underground stem systems and (2) probably exhausting stored food reserves. A single fire may eliminate hazel if humus is sufficiently dry to be completely consumed. This drying may occur in the summer or fall, but rarely if ever in the spring.

Portions of the lower bole of occasional sugar maples (Acer saccharum Marsh.) in Lake States northern hardwood stands are sooty black in sharp contrast to the normal gray. The blackened areas may encircle the entire stem or be confined to a narrow band; they have been observed as high as 25 feet but generally extend about 15 feet above the ground. Preliminary investigations indicated that nearly all such trees had been heavily and repeatedly attacked by sapsuckers. The possibility of using the black bark as an external indicator of bird peck defect in sugar maple prompted this investigation.

Water storage characteristics of the various horizons in a northern Minnesota bog were found to vary considerably with peat type. Surface horizons of sphagnum moss contain 0.020 g. per cc. of dry material and 95 to nearly 100% water by volume at saturation. Its total porosity consisted primarily of large pores which released 0.80 cc. of water per cc. between saturation and 0.1 bar suction. Decomposed and herbaceous peats from horizons below 25 cm. had water-holding properties strikingly different from those of the moss peats. These materials had bulk densities of 0.24 and 0.14 g. per cc.,...

Most of the stream-discharge records for our experimental watersheds are taken by continuous measurements. But the question arises: are continuous measurements necessary to determine effects of forest treatments? Or could treatment effects be determined by measurement of discharge at intervals, say, once a day or once a week?

Many studies, using various methods, have been made of dew deposition to determine its importance as a source of moisture. For example, Duvdevani (1947) used an optical method in which dew collected on a wooden block was compared with a set of standardized photographs of dew. Potvin (1949) exposed diamond-shaped glass plates at 45º to ground level, so that condensed dew ran into a graduate. Lloyd (1961) studied amount and duration of dew by using polystyrene blocks mounted on a balance linked to a 7-day continuous recorder. Craddock (1951) devised a sub-groundlevel balance and recorder to...