Treesearch

In paired-watershed studies, the occurrence of an extreme event during the after-treatment period presents a problem: the effects of treatment must be determined by using greatly extrapolated regression statistics. Several steps are presented to help insure careful handling of extreme events during analysis and reporting of research results.

A 2-acre enclosure was built in a 40-year-old hardwood stand, and 5 to 19 gray squirrels (Sciurus carolinensis) were confined in it during 3 years. Reproductive behavior of the squirrels was the same at all population densities, but densities above 12 may have reduced productivity. For 10 to 12 squirrels, behavior was about normal and productivity was high. At population levels above 12, antagonistic behavior and fence-running increased. The enclosure was modified until escapes were reduced to less than 10 percent per year. Disease and predation were not a problem. Fence costs were $2,000...

Sweep is one of the major stem-form defects in hardwood sawtimber. Some sweep is removed during bucking. But we found sweep of 2 inches or more on 17 percent of the 4,510 logs measured at Appalachian sawmills. Volume deductions for sweep scaled at least 10 percent in 1 of every 7 sample logs and at least 15 percent in 1 of every 9 sample logs. Reduction in the severity of sweep might be obtained by applying the simple rules outlined for buckers.

A preliminary evaluation of the effectiveness of injecting solubilized benomyl into oaks for prevention or cure of oak wilt disease is presented. Symptom development was greatly reduced or prevented in trees injected with fungicide before inoculation. Symptom development was markedly arrested in diseased trees by fungicide injected before more than 10 percent of the crown was wilted, but treatment of trees with more advanced disease symptoms was not effective.

The effect of ecosystem disturbance on nutrients in the system has been receiving widespread attention. An appraisal of research results in the Northeast indicates that timber-harvest clearcutting has not increased nutrient levels sufficiently to reduce water quality below drinking water standards. Losses of nutrients from clearcuttings in New Hampshire over a 2-year period were about 85 pounds per acre for nitrate-N and 80 pounds per acre for Ca. Losses in the central and southern Appalachians were far less. There is both need and opportunity for productive research on many aspects of...

Measurement of the ages of seedlings of balsam fir (Abies balsamea (L) Mill.), red spruce (Picea rubens Sarg.), and white spruce (Picea glauca (Moench) Voss) 15 years after the first harvest of a two-cut shelterwood operation revealed that very few potential crop-tree seedlings in the sample occurred as advance regeneration in the original stand. Relationships among total height, age, and current growth of the samples are reported, as well as the variation in seedling age encountered.

A stocking chart for eastern white pine is presented and described. The chart shows basal areas and numbers of trees by mean stand diameter, representing the upper limit in stocking for practical management (A curve) and minimum stocking for full site utilization (B curve).

Soil temperatures in the Hubbard Brook Experimental Forest in central New Hampshire decline very slowly from December to March and are restricted from falling below OºC by insulation of snow and organic matter. Soil in the hardwood forest on a moderate south slope warms rapidly in the spring leafless period after snowmelt and reaches a maximum temperature in early August that averages 17.5ºC near the surface and 12.5ºC at 91-cm depth. The soil cools to nearly isothermal conditions at 11ºC in October. The mean annual cycle of soil temperature near the surface corresponds closely to that of...

During the last Forest Survey of Maine, data were collected about the four hardwood species-paper birch, yellow birch, sugar maple, and beech-that are used by turneries. Analysis of the data showed that only about 18 percent of the volume of growing stock in trees 8 inches d.b.h. and larger in these species is acceptable for turning bolts, according to the criteria used.

The cubic-foot volume equations used in the regionwide Forest Survey are presented, and their development is discussed. An example of the use of an equation is given.