Effects of light, temperature, water and meatworks effluent irrigation on eucalypt leaf litter decomposition under controlled environmental conditions

Effects of light, temperature, water and meatworks effluent irrigation on the decomposition of Eucalyptus globulus leaf litter were examined in a pot trial under controlled conditions in three growth cabinets. All four factors had significant effects on the rate of litter decomposition, and interacted with each other. More dry mass loss occurred from the bagged litter under light than under shaded conditions. There was little difference between water and effluent irrigation under shaded conditions, but more loss from the litter irrigated with effluent under light. Differences between water and effluent irrigation occurred mainly at the lowest temperature regime (5 degreesC). The greater the irrigation rate, the more the litter dry mass loss in most cases under light. However, irrigation rate only had a small effect under shaded conditions. A large range of instantaneous decay constants (k) was found, from 0.01 to 1.34 per year, comparable with those reported in field studies. Hence, these environmental factors should be considered when managing litter in forests to give sustainable biomass production and land use, particularly for short rotation forests linked with effluent land treatment. (C) 2001 Elsevier Science B.V. All rights reserved.