PARENT SESSION
Oral Session # 38: Forest Ecology II: Soils, Carbon, and Nutrient Cycling.
Presiding: B Clinton
Wednesday, August 6. 8:00 AM to 11:30 AM, SITCC Meeting Room 100.
Effects of forest liming on soil chemistry and sugar maple health in Pennsylvania from 1986-2002.
Long, Robert*,1, Horsley, Stephen 2, Lilja, Paul3, Hall, Thomas4, Bailey, Scott5, 1 USDA Forest Service, Delaware, OH2 USDA Forest Service, Irvine, PA3 Pennsylvania Bureau of Forestry, Coudersport, PA4 Pennsylvania Bureau of Forestry, Middletown, PA5 USDA Forest Service, Campton, NH
ABSTRACT- A long-term liming study was initiated in 1985 to mitigate acidic soils and has been intensively monitored at four forested sites on unglaciated soils in north central PA. Dolomitic limestone was applied (22.4 Mg ha-1) in fall 1985. Soils were sampled and analyzed for exchangeable Ca, Mg, K, P, Al, and acidity annually from 1986 to 1989 and in 1993, 1996, and 2001. Soil pH in the upper 5 cm remained elevated at 6.4 on limed plots, compared with 3.8 on unlimed plots in 2001. Elevated Ca and Mg and decreased Al were measured at all depths to 60 cm in limed plots sampled in 2001. Both P and K decreased in response to liming, but only in the upper 5 cm. Changes in sugar maple (Acer saccharum Marsh.) crown vigor have been evaluated yearly using a scale from 1 (dead) to 6 (healthy). Crown vigor was consistently higher on limed plots, but has varied considerably due to stress events that include droughts (1988, 1991, 1995, 2001), and defoliations (1993, 1994). Mean sugar maple vigor in limed plots peaked in 1998 at 5.5 while vigor in unlimed plots averaged 3.7. Subsequent drought in 2001 decreased sugar maple vigor in all plots, but by 2002 mean vigor in limed plots increased slightly from 3.9 in 2001 to 4.0 while trees in unlimed plots averaged 3.2 in both years. Sugar maple basal area increment for trees on limed plots averaged 24.5 cm2 yr-1 and trees in unlimed plots grew at a rate of 9.0 cm2 yr-1 from 1986 to 2002. Cumulative sugar maple mortality from 1986 to 2002 was 30% in unlimed plots and 13% in limed plots. These results indicate that a single lime application has long-term beneficial effects on soil chemistry and sugar maple vigor and growth.
Key words: soil chemistry/base cations, crown vigor and tree growth, forest liming, sugar maple, Acer saccharum