DIVISION S-7—FOREST & RANGE SOILS Influence of Edaphic Factors on Sugar Maple Nutrition and Health on the Allegheny Plateau

nce County, Wisconsin was the first to receive systematic study (Giese et al., 1964; Westing, 1966; Millers et al., Sugar maple (Acer saccharum Marsh.) decline has been a problem 1989). Since then, well-documented sugar maple deon the Allegheny Plateau for the last two decades. Previous work found that sugar maple is predisposed to decline by poor nutrition clines have occurred in Massachusetts in the 1960s and incited to decline by severe insect defoliation. Nutritional diagno(Mader and Thompson, 1969), Ontario in the 1970s ses have been based on foliar chemistry; there is little information on (Hendershot and Jones, 1989; Gross, 1991), Quebec, soil attributes that influence susceptibility. We evaluated relationships New York, and Vermont in the 1980s (Bernier and among soil characteristics, foliar chemistry, and sugar maple decline Brazeau, 1988a,b,c; Kelley, 1988; Bernier et al., 1989; for 43 stands on the Allegheny Plateau in New York and Pennsylvania Hendershot and Jones, 1989; Bauce and Allen, 1992; using correlation and stepwise regression techniques. Foliar Ca and Cote et al., 1995; Ouimet and Camire, 1995; Wilmot et Mg concentrations correlated with soil exchangeable cations exal., 1995), and Pennsylvania in the 1980s and 1990s (Kolb pressed on a concentration or site capital basis. Expression of base and McCormick, 1993; Long et al., 1997; Horsley et al., cation availability as a saturation value, or in ratio with Al, slightly 2000). Stress events such as defoliations, droughts, and improved the relationships, suggesting that antagonistic cations are important to sugar maple nutrition. The best predictions of foliar extreme weather events (late spring frosts, mid-winter chemistry were made by regressions that considered soil chemistry thaw/freeze cycles) have been common themes in all of across the depth of the B horizon, suggesting the importance of looking these declines. at more than one depth to assess nutrition. Landscape position and Studies of sugar maple declines have suggested that glacial history determined whether weathering products were effecpoor nutrition of base cation elements, including Ca, tively delivered to the rooting zone, resulting in the observed landMg, and K, was a predisposing factor to decline (Mader scape gradients. All declining stands were on unglaciated upper landand Thompson, 1969; Bernier and Brazeau, 1988a,b,c; scape positions where soils had lower Ca and Mg levels compared Hendershot and Jones, 1989; Adams and Hutchinson, with other landscape positions. Declining stands had 2% Ca satura1992; Kolb and McCormick, 1993; Cote et al., 1995; tion and 0.5% Mg saturation in the upper B and 4% Ca saturation Wilmot et al., 1995; Long et al., 1997; Horsley et al., and 0.6% Mg saturation in the lower B. These thresholds may be useful in predicting susceptibility to sugar maple decline. 2000). Evidence for this assertion is based primarily on chemical analysis of foliage and surficial ( 10 cm) soils from declining and nondeclining stands containing dominant and codominant sugar maple trees. Little research T concept of tree decline addresses situations has been conducted on aspects of site quality such as where dieback—the loss of a portion of the crown— the contribution of deeper soil horizons, the role of or mortality cannot be attributed to a single agent. Manphysiographic position or history of pedon development ion (1991) defines decline as, “an interaction of interin the landscape on sugar maple nutrition or the relachangeable, specifically ordered abiotic and biotic factionship between soil nutrition and sugar maple health tors to produce a gradual general deterioration, often (or growth). Due to its location at the boundary of the ending in death of trees.” Several factors, including minWisconsin glacial advances of 12 000 to 21 000 yr ago on eral nutrition, insects, diseases, and climatic factors, may the northern Allegheny Plateau in western Pennsylvania interact to produce the final outcome, and these factors and New York, the most recent decline of sugar maple may be different in different situations. Manion (1991) in Pennsylvania provides an opportunity for insight into used the terms “predisposing,” “inciting” (or “triggerthese questions. ing”), and “contributing” to describe the factors inIn the early to mid 1980s, forest land managers in the volved in tree decline. northwestern and north central Pennsylvania portions Declines of sugar maple have been noted throughout of the Allegheny Plateau began to notice unusual levels the twentieth century, though the 1957 episode in Floreof crown dieback and mortality of sugar maple in stands S.W. Bailey, USDA Forest Service, Northeastern Research Station, on unglaciated sites on upper slopes above about 550 m 234 Mirror Lake Rd, Campton, NH 03223; S.B. Horsley, USDA Forest elevation; stands on lower slopes did not decline (Kolb Service, Northeastern Research Station, Irvine, PA 16365; R.P. Long, and McCormick, 1993; Horsley et al., 2000). Affected USDA Forest Service, Northeastern Research Station, Delaware, OH areas lay just south of the terminal moraine of the Wis43015; and R.A. Hallett, USDA Forest Service, Northeastern Reconsin glacial incursions. Unglaciated sites typically search Station, Durham, NH 03824. Received 4 Nov. 2002. *Corresponding author ([email protected]). have highly weathered Ultisols with low base saturation, Published in Soil Sci. Soc. Am. J. 68:243–252 (2004).  Soil Science Society of America Abbreviations: defsev10, defoliation severity index; PDEADSM, percentage of dead sugar maple basal area. 677 S. Segoe Rd., Madison, WI 53711 USA