M. Komulainen et J. Mikola, SOIL PROCESSES AS INFLUENCED BY HEAVY-METALS AND THE COMPOSITION OF SOIL FAUNA, Journal of Applied Ecology, 32(1), 1995, pp. 234-241
1. The effects of heavy metals (Cu and Ni) on soil processes were stud
ied experimentally in forest microcosms as a function of the presence
of different groups of soil fauna (nematodes, microarthropods and ench
ytraeids). 2. The soil respiration rate was measured at intervals and
water leachates were analysed twice for mineral-N. At the end of the e
xperiment, the mass loss of birch leaf litter was determined. 3. The s
oil respiration and nitrification rates were significantly affected by
heavy metals, with lower rates observed in the contaminated soil (200
+ 100 mg kg(-1) Cu + Ni). In contrast, concentrations of ammonium-N w
ere higher in the leachate from the contaminated soil compared to the
control soil. There were, however, no significant differences in litte
r mass-loss among metal concentrations. 4. The soil respiration rate w
as affected only slightly by the composition of the fauna, whilst ther
e were significant differences in the amounts of mineral-N leached fro
m microcosms representing different faunal assemblages. 5. Microcosms
containing the enchytraeid Cognettia sphagnetorum (Enchytraeidae) rele
ased significantly more mineral-N than all the other units in both con
trol and contaminated soils, showing the integral role of enchytraeids
in N-dynamics.