Treesearch

In this paper, we discuss how to collect and preserve plant specimens. Plant pressing, mounting, and labeling techniques are also outlined.

A method for deriving the weighted least squares estimators for the parameters of a multiple regression model. Confidence intervals for expected values, and prediction intervals for the means of future samples are given.

Forest land occupies 75 percent of the total land area in Vermont. Nearly one-half of this forest land is the beech-birch-maple forest type. The inventory data show volume increasing but at a lower rate than in neighboring states. This is due to large losses from cull and mortality. Total growing-stock volume is now 4.7 billion cubic feet.

Nitrogen (N) and phosphorus (P) concentrations in leaf blades and petioles obtained from three fertilized and three unfertilized yellow-poplar sample trees were determined annually during a 4-year period. Concentrations were substantially higher in blades than in petioles. Fertilization increased N and P concentrations in blades, but petioles showed only a slight increase in N and a decrease in P. Because blades were more responsive to changes in external nutrient supply than petioles, and because fertilization affected the composition of blades and whole leaves unequally, blades give a...

A radiographic technique has been developed for observing and quantifying development and mortality of Blepharipa scutellata ( Robineau-Desvoidy), Parasetigena agilis (Robineau-Desvoidy), and Compsilura concinnata (Meigen), tachinid parasites of the gypsy moth, Porthetria dispar (L.). Puparia can be examined and sorted immediately after collection and decisions on further collecting and release can be made in the fall. Healthy tachinid pupae can be placed directly in a release area eliminating the handling of adults the following spring.

A multiple-regression model is presented that reflects statistically significant correlations between defoliation by the gypsy moth, the dependent variable, and a series of biotic and physical independent variables. Both possible uses and shortcomings of this model are discussed.

To woodland owners or managers who are interested in bird-habitat improvement, the authors suggest managing for: (1) people with slight to moderate knowledge of birds; (2) high numbers of both individual birds and bird species, particularly the conspicuous species; (3) seeing and hearing birds near trails and other human-activity areas; (4) bird nesting; and (5) natural-appearing habitat. The nesting-habitat preferences of 31 representative species are listed. Guidelines are offered for trails, sites, plants, growth stages, dimensions and lay-out, and treatments.

Most of the silvicultural recommendations for reducing the hazard of gypsy moth outbreaks have been based in part on the premise that gypsy moth density levels are related closely to the proportion of favored food trees in the overstory. This premise did not prove to be true for a series of plots observed in eastern New England between 1911 and 1931.

Bark residue weights are tabulated for eight species of hardwood sawlogs according to log volume by the Doyle, International 1/4-inch, and Scribner decimal C log rules. Factors are provided for converting from weight in pounds to volume in cubic yards.

From a survey of veneer producers in the Northeast in 1972, veneer-log production and receipts by states and species, and log shipments between states and regions are presented. Comparisons are made with a similar survey made in 1968. A current list of northeastern veneer manufacturers is included.