Treesearch

Includes 66 papers presented at the US/FRG research symposium: effects of atmospheric pollutants on the spruce-fir forests of the Eastern United States and the Federal Republic of Germany, which was held October 19-23, 1987, in Burlington, Vermont.

To properly classify qr grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its develqpment for black walnut. It illustrates and describes 10 types of external defqct indicators and associated defects that are particularly difficult to evaluate.

The natural processes responsible for the origin and maintenance of native grasslands must be understood in order to restore North American prairies effectively. Grasslands historically have predominated where the climate ranged from semiarid to mesic but with periodic droughts, and where fires repeatedly removed dead aboveground biomass and retarded encroachment of woody invaders. As in most North American ecosystems, however, the particular assemblage of species naturally found at a site is frequently of recent origin and is not necessarily a stable combination. The establishment and...

Prolonged suppression of cambial growth has apparently caused a decline in radial growth in many mature red spruce, Picea rubens. Surveys indicate that this decline occurs in trees throughout the natural range of red spruce and is independent of elevation, tree size, and age class. In addition, crowns of mature red spruce at high elevations across the northeastern United States have been dying back. Understanding the physiological basis for the growth decline is essential for the judicious management of the red spruce resource. A sequence of events is inferred through which an imbalance of...

Four types of spruce budworm pheromone lures were field-tested in sparse spruce budworm populations in Maine. BioLures® with constant pheromone emission rates less than 1.0, ca. 1.0-1.5, and ca. 15.0 micrograms of pheromone per day were compared to polyvinyl chloride (PVC) lures with rapidly decreasing pheromone emission rates. Mean trap catch was roughly proportional to lure emission rates. All lures continued to catch moths over the entire flight period but moth catches with the three lowest emission-rate lures were judged to be too low. BioLures with the highest emission rate (15.0...

Cuttings from two clonally propagated elm hybrids ('Pioneer' and 'Homestead') were treated with ozone (03), sulfur dioxide (S02), simulated acid rain or left untreated. Fumigants were applied 7 hours per day, 5 days per week for 9 weeks in open-top chambers. Fumigation treatments were: 0.1 ppm 03, 0.2 ppm S02, 0.1 ppm 03 plus 0.2 ppm SO2, and charcoal filtered air. An acid rain treatment (pH 4.0) of ca. 1.27 cm was made weekly in rain simulation chambers. Elm leaf beetle, Xanthogaleruca luteola (Muller), were fed foliage harvested from trees subjected to the treatment combinations....

Males of acorn-infesting Cydia latiferreana are attracted to an equilibrium mixture of the four isomers of 8, I10-dodecadien-1-ol acetate, the virgin female-produced pheromone. Trap height relative to the height of trees in which traps are placed seems to be a significant factor influencing moth catches at attractant-baited traps. In an oak woodlot and in an oak nursery, catches of male moths were greater in traps placed near the upper periphery of the canopy than at traps deployed at lower levels in the tree. Practical application of pheromone-baited traps in a forest situation will...

The technique for constructing a montage of large wood sections cut on a sliding microtome is discussed. Briefly, the technique involves photographing many serial micrographs in a pattern under a light microscope similar to the way flight lines are run in aerial photography. Assembly of the resulting overlapping photographs requires careful trimming. A composite of many low power micrographs allows for a resolution of the sample that could not be obtained from a single photograph. A barrier zone in sugar maple (Acer saccharum) is used as an example of a 'macro-microscopic' montage. The...

This proceedings will provide field foresters and landowners with an update of current available information for regenerating Appalachian hardwood stands. We wanted a "state-of-the-art" proceedings for regenerating Appalachian hardwood stands. We asked the authors to make recommendations based on the current literature, their knowledge, and experience. Though many of these papers do provide current information and ideas, landowners and foresters will still have to decide what is best for their situations. From the practical sense, use what information you can and modify,what you cannot.

The "nominal group" process is a proven technique to systematically arrive at a consensus about critical information needs in recreation planning and management. Using this process, 41 managers who attended a 1983 conference on river management identified 114 specific information needs grouped under 11 general questions. Clearly, some concerns of administrators are researchable; many are not.