Treesearch

Several studies have indicated a long-term decrease in exchangeable Ca in forest soils within the northeastern Unrted States, but the regional extent of these decreases and the importance of acid deposition as a cause has not been fully resolved. Results, from two recently completed studies have provided the opportunity to further investigate the role of acid deposition in depletion of base cations in northeastern forest soils. These two studies entailed 1) a survey of soils in northeastern red spruce (Picea rubens Sarg.) stands, whtch were selected to encompass the range of environmental...

Forest health and monitoring issues have become major focus of scientists and research institutions in Europe and North America during the last decade because of wide-spread forest decline symptoms in Europe, high elevation spruce/fir decline in eastern North America and sugar maple (Acer saccharum Marsh.) decline in Quebec, and the United States.

A review of the available historical evidence provides a picture of sugar maple's site relationstiips in the presettlement forest and its changing statis over the last 300 years. Sugar maple was widely distributed throughout the Northeast during the presettlerment period. it was particularly abundant on the richer, better drained, silt-rich sites. A comparison of the eariy land survey records and more recent forest inventory data suggests that sugar maple has increased its abundance on a variety of sites, including a number of more marginal sites. The resulting off-site conditions may...

Only a few episodes of sugar maple dieback or decline were recorded during the first half of the 20th Century. In contrast, the last 50 years have provided numerous reports of both urban and forest dieback/decline. In the late 1950s, a defoliation-triggered decline, termed maple blight, that occurred in Wisconsin prompted the first comprehensive, multidisciplinary study of a sugar maple decline. That research, and other investigations since, provided the conceptual framework for a model of sequential, stress initiated cause and effect for dieback/decline disease. Many cases of urban maple...

The North American Maple Project (NAMP) monitored annual sugar maple mortality from 1988 through 1997 in Maine, Massachusetts, New Brunswick/Nova Scotia, New Hampshire, New York. Ontario, Quebec, Vermont, and Wisconsin. Annual mortality in Minnesota, Ohio and Pennsylvania was evaluated for 1992 through 1997. When data from the dominant/codominant and intermediate/suppressed crown levels were combined, average annual mortality (% trees) ranged from 1.9% (New York) to 0.3% (New Brunswick/Nova Scotia) in sugarbushes (SBs) and 1.9% (New Hampshire) to 0.49% (Wisconsin) in maple stands not...

Sugar maple decline began to affect Allegheny Plateau forests in the early to mid-1980s. The forests of the region were exposed to several stresses In the period frorn 1985- 1996, including droughts during 1988, 1991, and 1995. Additionally, both native and exotic insects reached epidemic levels during this period (see, for example, Rhoads, 1993). Other documented stresses in the region include past and present harvesting practices (Allen and others 1992), herbivory by deer (Tilghman 1989), and low soil nutrient availability (Long et al. 1997, DeWalle and Swistock 1997) possibly associated...

Mortality of sugar maple and red maple was observed throughout Pennsylvania in 1995 following an outbreak in 1994 by forest tent caterpillar and elm spanworm on sugar maple and red maple, respectively. Symptoms of leaf anthracnose caused by Discula campestris (Pass.) were observed during the refoliation period from July through September 1994: the refoliation of crowns of affected trees was extremely poor or almost non-existent. Subsequent mortality and tree condition were monitored in 15 sugar maple stands located in Bedford, Blair, Lycoming, Potter, Sullivan, Susquehanna, Tioga, and...

In 1985 a long-term study was initiated by the Pennsylvania Bureau of Forestry and the Northeastern Research Station to evaluate factors impeding regeneration of Allegheny hardwoods (Auchmoody, unpublished). The major factors suspected of limiting regeneration were high soil aluminum levels associated with low soil pH (typically 3.6 to 4.2 in surface mineral soils), deer browsing, and interfering vegetation such as hayscented fern (Dennstaedfia punctilobula (Michx.) Moore) and striped maple (Acer pensylvanicum L.). At that time, overstory sugar maple (Acer saccharum Marsh.) decline was...

Sugar maple (Acer saccharum Marsh.) seedlings often have poor survival on acidic unglaciated portions of the Allegheny Plateau. Greater survival is found after lime treatment of unglaciated sites or on glaciated areas of the Plateau. The difference in survival rate may depend in part on the acidity or chemical composition of the soil.