STIMULATIVE EFFECTS OF ARTHROPODS ON ENDOMYCORRHIZAS OF SUGAR MAPLE IN THE PRESENCE OF DECAYING LITTER

1. We examined how Acer saccharum Marsh seedlings respond in terms of biomass and mycorrhizal colonization levels to the addition of (1) soil microarthropods and (2) decaying Litter, under microcosm conditions. 2. The addition of fauna was associated with decreased arbuscular (-38%) and hyphal (-30%) colonization, and increased vesicular colonization (+112%), with no effect on plant biomass. 3. The addition of decaying litter was associated with decreased arbuscular colonization (-51%), increased hyphal (+24%) and vesicular (+117%) colonization, and extra-radical hyphal length (+38%), and decreased shoot (-43%) and root (-23%) biomass. 4. However, there was a strong synergistic interaction between decaying litter and soil fauna and the addition of both was associated with enhanced arbuscular colonization (+59%), vesicular colonization (+85%) and increased shoot biomass (+32%), and shoot/root biomass ratio (+25%). 5. Understanding the dynamics involved in such interactions between soil organisms can have profound implications for soil management practices in agriculture, forestry and areas requiring revegetation.