Leaching and decomposition of mountain beech litter (Nothofagus solandri: Fagaceae) in a mountain stream

Results of field and laboratory experiments on the decomposition of leaves and twigs of N. solandri: cliffortioides submerged in stream water are presented. Litter released up to 6% of its initial dry wt. as leachate within 11 days of immersion. Litter in 0.2 and 1.0 mm mesh bags kept in a mountain stream lost up to 65% of initial dry wt. in one year. This loss rate is slower than that of any species reported to date but was partly due to the inclusion of twigs in the present study. Macrofauna colonizing the bags did not affect weight loss. N increases in litter of up to 0.5% are attributed to microbial colonization. Although weight losses conformed to linear, positive and negative exponential, and logistic models, consideration of possible mechanisms of weight loss suggest that the logistic model represents the most accurate interpretation