>Since I have been watching the oaks and other speices of trees die on my >own land and in the forests I previously managed, I was intrigued to find a >web site ( http://www.efi.joensuu.fi/features/oak_decline.html ) outlining >the serious oak decline occurring in Europe. Excerpts from the web page >are below. >- Gerry Hawkes > Woodstock, Vermont >**************************** I looked at the web site and while it might properly address conditions it Europe, it cannot begin to address the issue of oak decline in North America. It is somewhat misleading in suggesting that oak wilt causes a decline in oaks. It causes death in oaks if left untreated. For a thorough briefing on oak wilt in the U.S., including counties affected by oak wilt, chekc out the U. S. Forest Service N.E. Experiment Station site at: http://willow.ncfes.umn.edu/fidl-oakwilt/oakwilt.html. For information on oakwilt in the southern U. S., try http://cygnus.tamu.edu/Texlab/oakwilt.html. As to the topic of oak decline in the U. S., this has been researched by many, including researchers at the University of Missouri-Columbia-most notably Drs. S. G. Pallardy and John Dwyer. One notable "cause" (and I use the term loosely) for oak decline in the western range of the oak hickory association is the limiting of weather and human-caused fire which kept down regeneration of shade tolerant sugar maple. Fire suppression over the past century coupled with changes in Native American populations and their lifestyles has lead to an increase in Sugar Maple population at the expense of Oak Regeneration in that region. Of course that may not be the case in the Northeastern U. S. Here in Minnesota, a similar phenomenom takes place as European and glossy buckthorn invade the understory and limit oak regeneration. Of course, oak wilt kills thousands of oaks each year in Minnesota and Wisconsin. The nature of "Oak Decline" in the U. S. is a very complicated and often regionally specific issue. Oak Decline Oak decline causes serious economic problems in Europe. A review of the literature dealing with the latest incidence of oak decline in Europe shows a chronological and geographical progression. In the last 15 years the incidence of oak decline has shown a dramatic increase all over Europe, and by 1989 was reported in every European country. This situation has prompted many investigations in Europe. Oaks in the United States infected by the fungus Ceratocystis fagacearum are also declining and a parallel research programme is going on there. Oak forests are important for the forest economies of many European countries. Are the oak forests generally going to follow parts of the coniferous forest in Europe in suffering from, for example, air pollution or the new oak disease vascular mycosis which is spreading within the European continent? In parts of Europe oak decline is already causing severe losses. Further information: Dr Tomasz Oszako (E-mail Tomasz.Oszako@efi.joensuu.fi) and http://www.efi.joensuu.fi/projects/ Dr Oszako is spending one year at EFI studying the health of European oak forests.
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