Seasonal Dynamics of Litter in a Headwater Stream of Riparian Forest in Xiangxi River Catchment

Based on the litter collection of riparian forest in a headwater stream during one year,annual litterfall at the site was 438.72 g/m².Leaves are chief component,and it accounted for 84% of annual litterfall.Temporal pattern of litter inputs are clearly seasonal:75% of the annual litterfall occurred in autumn (September to November),6.2% in spring(March to May),13.6% in summer (June to August),and 5.5% in winter (December to February) .The production of leaves,flowers and fruits litter also show a seasonal trend in litter composition.There was no seasonal trend in that of branches.The high peak period of leaves litter in autumn accounting for 83% of the annual amount of leaves,and 29% of the annual amount of branches.And that of flowers and fruits in summer accounting for 63% of the annual amount of flowers and fruits.The density of epilithic algae showed a significant difference during one year.The highest peak appeared in November,and was 72 individuals cm^-2 .The lowest peak in January was 7 individuals cm^-2 .The changes of epilithic algae had a significant relationship with the dynamic of litter and leaf litter (r= 0.57,P<0.05).