Input, Accumulation, and Residence Times of Carbon, Nitrogen, and Phosphorus in Four Rocky Mountain Coniferous Forests

1989

S. 489-498

3 Abb., 6 Tab., 32 Lit. Ang.

Unselbständiges Werk

200038984

Canadian Journal of Forest Research 1989 ; 19(4), S. 489-498

Annual aboveground litterfall in forests of Pinus contorta Loud., Picea glauca (Moench) Voss, Picea engelmannii Parry ex Engelm., and Abies lasiocarpa (Hook.) Nutt. in southwestern Alberta ranged from 286 to 321 g.m- 2.year-1. The mass of litter accumulated on the forest floors ranged from 6.3 to 11.0 kg.m-2. Residence times of organic matter in the forest floor were 11 years in a 90-year-old P. contorta stand, 16 years in a 120-year-old P. glauca - P. contorta stand, and 23 years in a 350-year-old P. engelmannii - A. lasiocarpa stand. Residence times of litter in the L layer of the forest floor were longer in a recently clearcut area than in the older forests. Residence times of individual nutrients in the forest floors were in the order N > P > C. Litter in the pine forest had lower concentrations of both N and P than did litter inthe spruce-pine forest; litter in the spruce-fir forest had relatively high N and low P concentrations. Differences in nutrient concentrations of litter among sites reflected differences in the nutrient-use efficiency of the vegetation, suggesting that the species composition of vegetation is important in determining availability of nutrients in the floor of these forests.