Treesearch

In Detroit, Michigan, 12 plots, each containing about 600 American elm trees, Ulmus americana L., were subjected for 3 years to intensive and conventional sanitation treatments to control Dutch elm disease. In the intensive treatment, three disease surveys were conducted each year; each followed by tree removal within 20 working days. In the conventional treatment, one survey was conducted each year, and diseased trees were removed in late fall and winter. Results showed that the intensive sanitation treatment was significantly better than the conventional treatment each year. Arborists...

A study of the engineering and economic effects of heat exchangers in conventional maple syrup evaporators indicated that: (1) Efficiency was increased by 15 to 17 percent with heat exchangers; (2) Syrup produced in evaporators with heat exchangers was similar to syrup produced in conventional systems in flavor and in chemical and physical composition; and (3) Heat exchangers reduce per unit production costs, and can yield greater production and higher profits.

A trail transect that documents trail conditions and changes in trails has been used successfully over the past 3 years to measure soil loss, and changes in trail width and vegetation. The system also can be used to study the relationship between trail degradation and the physical characteristics of the site. Data from trail transects can be useful in determining the physical conditions favorable for trail construction.

Gaging the ability of the forest resource to satisfy future timber requirements is central to solving many problems arising from competition for use of forest land. In this study, production potentials of forest acreage in the Northeastern United States under management alternatives that range from extensive to intensive are weighed against several estimates of timber requirements for the year 2000. The different capabilities for fulfilling timber requirements in different parts of the region indicate areas likely to be affected most by further shifts toward nontimber use of forest land....

Variation in budbreak date among 37 half-sib families of white spruce in a replicated one-parent progeny test plantation in southern Maine was only 5 days. Differences in the mean date of budbreak between years were greater than those between families, but the genetic correlation between date of budbreak in different years was .661. Heritability estimates ranged from .228 to .814, depending on the year and method of calculation. In each of 2 years, heritabilities estimated for family selection were higher than those for mass selection of indilvidual trees in the plantation, but family...

We have presented prediction equations and tables for estimating the gross cubic-foot volume of sawtimber for hardwood trees, and cubic-foot yields of lumber, sawdust, and sawmill residue that are produced during the sawing process. Yields are presented for northern red oak, black oak, white oak, chestnut oak, red maple, sugar maple, yellow-poplar, yellow birch, paper birch, and basswood.

Stem characteristics, mainly height, of the tallest hardwood saplings in 10-year-old circular clearcut openings were evaluated for several Appalachian hardwoods in West Virginia. Heights of the tallest saplings were not influenced by cardinal directions on two oak sites. Saplings were taller near the center of 150-, 2OO-, and 250-foot openings than saplings in the center of the 50- and 100-foot openings. Saplings in the larger openings (150- to 250-foot) were significantly taller near the opening center compared to the tallest saplings along the border of the same size openings. For small...

SEMTAP (Serpentine End Match TApe Program) is an easy and inexpensive method of programing a numerically controlled router for the manufacture of SEM (Serpentine End Matching) joints. The SEMTAP computer program allows the user to issue commands that will accurately direct a numerically controlled router along any SEM path. The user need not be a computer programer to produce a variety of SEM patterns.

A test of vapor compression distillers for processing maple syrup revealed that: (1) vapor compression equipment tested evaporated 1 pound of water with .047 pounds of steam equivalent (electrical energy); open-pan evaporators of similar capacity required 1.5 pounds of steam equivalent (oil energy) to produce 1 pound of water; (2) vapor compression evaporation produced a syrup equal in quality to that from a conventional open-pan evaporation plant; and (3) a central plant prodrucing 8,000 gallons of syrup per year should yield a return of 16 percent on investment. Increasing annual product...

The design of fumigation chambers is described. Each chamber has individual temperature, humidity, light, and pollutant control. Temperature is variable from 15 to 35ºC and controlled within ± 1ºC. Humidity is variable from 25 to 95 percent and controlled within ± 3 percent. Seedlings have been successfully grown in these chambers for up to 3 months.