Document: MAR-3-60-6
Litterfall mass and nutrient dynamics in a northern hardwood forest successional sequence.
ARTHUR, M.A.* 1, R.D.YANAI 2 and T.G.SICCAMA 3
University of Kentucky, Lexington, KY 40546 USA 1
SUNY-ESF, NY USA 2
Yale University 3
Abstract:
Nutrient availability changes over the course of forest succession, and changes in litterfall chemistry are thought to be an important contributor to this pattern. Early successional species are thought to have higher concentrations of nutrients than do the species that dominate older stands, but there have been few studies capable of testing this generalization. We collected litterfall in a chronosequence of 13 northern hardwood forest stands in New Hampshire, ranging in age from 16 to >120 years of age. Because year-to-year variation in mass and nutrient concentration can be very high, we collected litterfall for mass and nutrient analysis for 4 years. We tested for differences in litter mass and chemistry among stands of different ages, among species of differing successional status, and within species across stand age. Total litterfall mass was lowest in stands between 12 and 25 years of age (1040 kg/ha/yr), rising to a peak in stands 30 to 85 years of age (1290 kg/ha/yr), and declining to 1145 kg/ha/yr in the oldest stands (>120 years). A quadratic equation described this pattern very well (R2 = 0.81, P = 0.0003). Average nutrient concentrations in litterfall decreased with increasing stand age for Ca (R2 = 0.32, P = 0.045) and Mg (R2 = 0.27, P = 0.067). Differences between species were not significant for these elements, suggesting that the availability of nutrients may control changes in litter chemistry to a greater extent than does species composition.
Keywords: nutrient availability, forest chronosequence, calcium, magnesium
This abstract is being presented at: 10:30 AM in session:
Poster Session #13: Decomposition and Soil Respiration.