Treesearch

Pot-culture studies have indicated that roots of yellow birch (Betula alleghaniensis Britton) develop more prolifically in humus than in sandy mineral soil (Hoyle 1965; Winget et al. 1963; Redmond 1954; and Tubbs 1963). This situation has also been observed during root-excavation studies (Redmond 1957; Spaulding and MacAloney 1931). Results of these studies generally indicated that soil temperature, soil moisture, and bulk density were not limiting factors in mineral horizons. Better root development in humus, and in mineral soil with high organic matter content, suggested that nutrient...

Atlantic white-cedar, which grows in the swamps of the New Jersey Pine Region, is a prized timber species. Most areas now growing white-cedar have been clearcut 4 or 5 times since 1700. In contrast, the associated swamp hardwoods-red maple, blackgum, and sweetbay-rarely produce wood that is valuable enough to harvest.

Decay and discoloration are the principal defects that reduce quality of northern hardwoods in New England. We need to know how to minimize these defects in young growing stock, and how to recognize them in merchantable trees. To determine accurately the amount of internal defect in trees, we must know the quantitative relationships between external signs on stems and the losses within them. The purpose of this note is to point out the defect pattern associated with dead stubs of main stems that persist on living northern hardwoods.

At present practically no wooden guardrail posts are being installed along West Virginia's highways. Neither are concrete posts. Only steel posts are being used in new highway construction despite the fact that wooden posts that have been properly treated with a decay-preventing preservative are entirely acceptable to the State Highway Department. Furthermore, treated wooden posts are reported to provide as good or better service than posts made of steel or concrete (1, 2, 3).

Procedures have recently been developed that permit economic and biological information to be integrated in making decisions about the need for control against the white-pine weevil, and in scheduling control in young white pine plantations. The procedures are based upon studies of the magnitude of economic losses that result from weevil attack in white pine and upon studies of the temporal and spatial pattern of weevil attack. The profitability of control can be determined by economic projections to maturity of values saved by control and of the costs of control.

In breeding programs designed to produce insect-resistant plants, a serious obstacle to progress often is the lack of efficient selection and testing criteria. Natural infestations of some insects are large and severe enough to allow selection of resistant plants directly from the natural plant population. However, the attacks of the white-pine weevil (Pissodes strobi Peck), the major pest of eastern white pine (Pinus strobus L.), are limited to a small proportion of the trees in a stand or plantation in any given year. Moreover, weevil attack is influenced by the interaction between...

A better understanding of the growth responses of young trees to silvicultural treatments is essential for intensive management programs for juvenile stands. At the juvenile stage, the effect of silvicultural treatment on main-stem development is much greater than it would be later.

The Northeastern Forest Experiment Station, in cooperation with Federal and State forest-pest-control agencies, undertook a survey of blister-rust infection rates in the white pine region of the East during 1962 and 1963. Those engaged in blister-rust-control activities will not be surprised at the survey's results. We found that infection rates were significantly higher in high-hazard climatic zones than elsewhere. Hazard maps prepared by Charlton (1963) were used as the basis for delineating climatic hazard zones.

In the past, uncontrolled clearcutting on many of the good to excellent hardwood sites in the Appalachians has resulted in forest stands composed of the so-called cove hardwoods, a high proportion of which are intolerant species. Characteristically these stands run heavily to yellow-poplar (Liriodendron tulipifera L.), northern red oak (Quercus rubra L.), black cherry (Prunus serotina Ehrh.), basswood (Tilia americana L. and T. heterophylla Vent.), white ash, (Fraxinus americana L.), and sugar maple (Acer saccharum Marsh.); and the first three species generally make up more than half the...

In a study at the Beltsville, Md., Experimental Forest in 1953 and 1954, the seed of Virginia pine (Pinus virginiana Mill.) became at least 45 percent viable 8 weeks before the natural opening of cones. Because seedfall in that locality usually starts during the first or second week of November, it was concluded that cone collecting could begin there safely in early September (1).