Treesearch

When Virginia pine (Pinus virginiana Mill.) is logged, even in pure stands, its natural regeneration is not readily achieved. This is because the species is intolerant and commonly functions in nature as a transitory pioneer; hardwoods become established under its canopy and tend to dominate the reproduction after the pine is cut. Experience indicates that the most practicable harvesting method for perpetuation of the pine is some form of clear cutting.

The use of ammate (ammonium sulfamate) as a tree-killing agent has become widespread during recent years; it is well established as an effective and economical silvicide. The purpose of this report is to supplement present knowledge and also to present a case study on the use of ammate in practical application.

To demonstrate how deer browsing affects natural tree seedling and sprout reproduction, two groups of deer exclosures were established in the Pocono Mountains of northeastern Pennsylvania. Study of these exclosures after seven growing seasons confirms what other studies elsewhere have found: that when deer are too numerous for their natural food supply, it is impossible to achieve a balanced multiple use of forest land for both timber production and wildlife habitat.

Yellow birch, the most valuable timber tree in the northern hardwood forest, is losing ground in northern New England. Birch dieback in the late 1930s and 1940s killed millions of board-feet of yellow birch. Meanwhile, the demand for yellow birch veneer and lumber has increased by leaps and bounds. So industries that depend upon yellow birch are having increasing difficulties in finding adequate supplies of raw material.

In breeding trees for rapid growth, testing the progeny usually requires many years. To shorten the testing period, geneticists have tried to find characteristics in juvenile trees that would indicate mature-tree performance. With hybrid poplars (Populus spp.), work at the Northeastern Forest Experiment Station has shown that the thickness of bark on the roots of 1-year-old cuttings is significantly related to the growth rate of the tree.

The seed of yellow and paper birches, like that of many other species, often exhibits delayed germination, which apparently is due to embryo dormancy. Stratification is usually recommended for overcoming this dormancy before the seed is sown or before it is tested for germination. This involves a chilling treatment for 1 to 2 1/2 months, which is best done under controlled temperatures with the seeds layered in a moistened porous material such as sand or sphagnum moss. For testing germination, seeds are transferred after stratification treatment to flats or germinators held at about room...

During the summer of 1960, a series of clearcuttings in small patches were made in an old-growth stand of northern hardwoods on the Bartlett Experimental Forest, Bartlett, New Hampshire. This provided an opportunity to observe the variation in ages of a wide range of trees of different sites and species. The annual rings of over 100 stumps were counted in this stand of typical all-aged, old-growth birch, beech, and maple - which has been untouched by loggers since some light cutting took place late in the 19th century.

During a recent soil-site study of sweetgum in southern New Jersey, measurements of volume were also made on forty-six 0.1-acre plots. These plots were in pure, well-stocked, even-aged stands ranging in age from 30 to 65 years. Basal area ranged from 117 to 245 square feet per acre, with a mean of 180. Site index varied from 60 to 95 feet at 50 years. The trees were of seedling origin, with a maximum age range of about 8 years within a plot.

An outbreak of the pine sawfly, Neodiprion pratti pratti (Dyar), has existed in Maryland since 1955. By 1959 the insect had spread throughout 14 million acres in the Coastal Plain and Piedmont of Virginia and into several North Carolina counties. Because egg surveys conducted in the spring of 1960 indicated a continuation of the epidemic, an aerial survey was conducted to further evaluate the situation. This report contains a summary of this latter investigation.

The 1960 forest tree seed crop in New England was generally a medium one, according to reports received from observers in five of the six states. The crop was fairly uniform throughout the region; there were only few reports of marked differences between different sections. On the whole, the crop was somewhat better than that in 1959, and very much better for some northern hardwood species.