Decomposition of Populus tremuloides Leaf Liter Accelerated by Addition of Alnus crispa Litter

1989

S. 674-679

2 Abb., 4 Tab., 38 Lit. Ang.

Unselbständiges Werk

200039019

Decomposition of a slow-decaying litter type is expected to be faster in the presence of a nutrient-rich, fast-decaying litter type, but this effect has never been conclusively demonstrated for deciduous leaves. In a Rocky Mountain aspen forest, we followed decomposition of leaf litter of trembling aspen (Populus tremuloides), a relatively slow-decomposing, nutrient-poor species, and green alder (Alnus crispa), a nutrient-rich, faster-decomposing species, as well as a mixture of the two, for 2 years. Mass losses over the first winter were greatest for aspen alone, probably as a result of loss of soluble, but the mass loss rate overall was lowest for aspen (k = - 0.191/year) and greatest for alder (k = -0.251/year). Mass loss rate for mixed litter (k = -0.245/year) was much closer to the rate for alder than for aspen, demonstrating a marked acceleration of mass loss rates in the mixed-litter bags. At these rates, 95% mass loss would be achieved by aspen, alder, and mixed litter in 14.5, 11.5, and 11.6 years, respectively.