Treesearch

Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and Ganoderma root rot.

Pines that occur naturally in parts of the region, as well as those that do not, have been introduced throughout. Pines usually produce greater volumes of wood faster than hardwoods, but in many parts of the region there is no market for pine stumpage or logs. Aside from wood production, pines are established for Christmas trees, windbreaks, landscaping, erosion control, and habitat diversity. Often a rotation of pine will build up a poor old field site so that it will once again support quality hardwoods.

Trunk decays are major causes of low quality wood-wood with little or no economic value. As a forest practitioner you should be able to recognize trees at high risk for decay and remove them if timber production is your primary objective. Remember, however, that decayed trees often develop into den trees or nesting sites and provide essential habitat for wildlife.

Yield and quality of central hardwoods depend greatly on the site. So, first off you should determine the site quality of your land for a variety of tree species. This information will allow you to compare yield and value so you can favor the species best suited for each site. Knowing site quality will help you determine what levels of management intensity and investment your land will support.

Aggressive black walnut plantation management will produce rapid growth, good form, and marketable products much faster than plantations allowed to grow without intensive culture.

The canker stain disease, one of several fungi that cause cankers of sycamore, can cause serious loss of sycamores in natural stands, plantations, and urban areas. As many as 35 percent of the trees in some stands may be diseased. Affected trees develop thin crowns, twig dieback, small leaves and epicormic branches. The narrow, elongate, bark covered, flat, spiraling stem cankers may be obscure (fig 1A). Probing the edge of a suspected canker with a knife will expose both bright-colored healthy and darkened diseased tissues. The "wedge" of wood beneath cankers will be dark stained.

Diverse problems confront the forest manager when planting bottomland hardwoods. Bottomland vegetation types and sites are complex and differ markedly from uplands. There are different and more numerous hardwood species that grow faster in denser stands. Sites are subject to varying intensities and duration of flooding and the action of overflow river currents that deposit and erode soil. Added to these natural differences are the man-made influences of drainage ditches, borrow pits, levees, dams, dredging, and cultivation. Entirely different soils occur over very short distances. One or...

Dutch elm disease was found in Cleveland, Ohio, in 1930, and is now in most of the contiguous 48 states. The disease is caused by a fungus that has killed millions of wild and planted elms. Losses have been the greatest in the eastern United States. The fungus attacks all elms, but our native species, American, slippery, and rock elm have little or no resistance to the disease. The most important and common of these, the American elm, is found on a wide range of forest sites and old fields.

Oaks can be planted or seeded in uplands to: (1) afforest old fields, strip-mined areas, or other areas devoid of trees, and (2) supplement natural reproduction within existing forests. Planting is usually more successful than direct seeding. But even under good conditions survival and growth of planted oak has been considerably poorer than with conifers and other hardwoods.

Oak wilt, a major disease of oak trees in North America, is caused by a fungus. It infects the sapwood and stops sap flow to the branches, twigs, and leaves. When sap flow is restricted during the growing season, trees wilt and soon die. In addition to killing trees, oak wilt makes it more difficult to export oak logs to other countries. Logs must be free of oak wilt before shipment. However, our knowledge of oak wilt makes it possible to safely export oak logs to other countries without the risk of transmitting the fungus.