Treesearch

To learn more about the tolerance of hardwoods to herbicides, the survival and growth on nine hardwood species were compared in plots eitehr cultivated or treated with various herbicides applied at different rates, on prepared and unprepared ground, and before and after planting. Black walnut and white oak were very tolerant to all herbicides tested but American sycamore and European alder were highly susceptible to berbicide damage by all chemicals testsed except dichlobenil.

Yellow-poplar seedlings that germinated and were completely released from woody competition in 1957 (the first year after a harvest cut) were four times taller and five times larger in diameter after the 1973 growing season than seedlings that were not released.

It has been shows that a root exudate of sugar maple reduces the growth of yellow birch. A laboratory test indicated that the growth of northern conifers is also reduced in sugar maple root exudate. Allelopathy may play an important role in survival of species on sites where sugar maple is abundant.

Preliminary findings from a study to gain information on the inflection process and genetics of resistance of the Hypoxylon canker fungue (Hypoxylon mammatum) on aspen (Populus tremuloides) indicate that the poplar-gall Saperda (Saperda inornata) may be involved. This paper describes the types of wounds made by the insect and how these and resulting Hypoxylon infections in the study plantation resemble the observed pattern of infections in the field.

Transportation costs affect the marketing and utilization of pulpwood. Their impact on the procurement and utilization of pulpwood often prove difficult to measure because deriving an average annual measure of the transportation cost is difficult. This note, by means of a simple index method for measuring regional interstate pulpwood rail freight costs, illustrates that the cost for shipping pulpwood from Minnesota to Wisconsin by rail more than doubled between 1946 and 1958. In 1959 rates declined slightly and remained stable before escalating in the late 1960''s and early 1970''s to more...

Initial observations indicate belt life may be longer and belt loading less at 0.080-inch than at 0.040-inch depth of cut with other machining variables held constant.

Whole tree chipping is a productive and economical harvesting system. The resultant product, however, is barky chips. THis paper outlines a promising method for removing the bark particles from whole tree chips.

This 30th annual report shows 1975 pulpwood production by county and species group in Michigan, Minnesota, and Wisconsin. Production in these three Lake States fell to 4.1 million cords from 5.5 million cords in 1974.

Observations show that pollutants from large emission sources may cause significant air concentrations 500 to 1000 miles away. Very acid precipitation occurs in such periods. The scavenging is often intensified by the topography. Case studies will be presented, with special emphasis on acid precipitation in Scandinavia. Large scale dispersion models have been developed recently in order to estimate the long range transport of air pollutants. The models take into account chemical transformations as well as deposition of pollutants. The calculations will be compared with observations from...

We investigated the mechanism and dynamics of solid particles, emissions, and the concentrations of sulphur dioxide as integral components of the contamination of atmosphere. The only way of decontamination is the wash-out by precipitation (solid - snow, liquid - rain). We started from the items of information acquired during the studies of snow acidity in mountain regions heavily polluted by industrial exhalations (NOVÁKOVÁ and TOLLINGER 1971). It was necessary to choose a quite new methodical process, as required and enabled by the existing conditions of our investigation. The investigati...