Treesearch

Yellow birch (Betula alleghaniensis Britton) is one of the commercially important species now under study in the hardwood tree-improvement program at our Research center at Burlington, Vt. A preliminary step in this program is to acquire information about vegetative propagation.

The International Union of Forest Research Organizations (IUFRO) has sponsored several international provenance tests. This is a report on the practical aspects of an IUFRO provenance test with Scotch pine in New York.

Light is one of the most important factors that influence the growth and development of forest trees. Not only is light necessary for the basic process of photosynthesis; light also regulates and modifies other factors of the environment such as temperature and moisture. Yet despite the importance of light, few investigators have succeeded in measuring it adequately in the forest. The primary reason for this failure is the lack of suitable instruments or methods for measuring and summating light over a period of time.

A loblolly pine or Virginia pine tree that shows visible symptoms of nutrient deficiency is sick. This means that the life processes of the tree are malfunctioning and that, among other things, the growth rate is probably less than normal, and the life of the tree may be threatened. However, if the deficiency can be identified, treatment with the proper fertilizer may correct the ailment. The preliminary identification of nutrient deficiencies can often be made by visual examination of the tree, once the symptoms characteristic of each essential element are known.

A dieback condition among our ash trees is causing great concern among foresters and forest industries in the northeastern United States. There is good cause for concern. For example, a recent survey made by the New York Conservation Department in 18 eastern counties of the State revealed that about 70 percent of the woodland ash trees are dead or dying.

The fungus Fomes annosus has caused a great deal of damage to coniferous forests and plantations in Europe. The disease caused by this fungus is now widespread in the United States. In the past few years we have become increasingly aware of its threat in the Northeast. It is particularly damaging to 20- to 30-year-old conifer plantations on formerly cultivated lands, especially those that have been thinned once or twice.

Red maple (Acer rubrum L.) is also known as Carolina red maple, scarlet maple, soft maple, swamp maple, water maple, and white maple. Taxonomists recognize several varieties of red maple. The most common is Drummond red maple (Acer rubrum var. drummondii (Hook, & Arn.) Sarg.).

Paper birch (Betula papyrifera Marsh) is commonly known also as white birch. The bark, which gives not only name but also unique character to this tree, is distinguishable from the white bark of other species by its pearly surface, its creamy cast, and its chalky whiteness that rubs off onto clothing. This bark separates easily into papery thin layers. Its smooth whiteness is marked with elongated horizontal lenticels.

The fact that trees grow makes the extraction of logs and bolts from a forest different from the extraction of ore from a mine. Every mine has a limit, and sooner or later it must be abandoned, either because the vein has run out or because the mine has become too costly to operate. But a properly managed forest - one where cutting maintains production - never becomes exhausted by harvesting operations alone.

In forest genetics work, an important method for evaluating selected trees is clonal testing.