Effect of Dissolved Organic Matter on Stream Water Quality in Forested Watershed

Runoff and contribution of dissolved organic matter to stream chemistry were examined in Motoki Brook draining small forested watershed in Sendai.Dissolved organic carbon and the absorbance at 260nm raised their concentrations in the brook during episodic events.It was considered that leaching components from the litter layer mainly influenced to it as a source of organic matters.From results of calculation about ion-balance, it was assumed that dissolved organic matter had a role of organic anion in the brook.Chemical aluminum fractionation indicated that dissolved organic matter directly contributed to the runoff monomeric aluminum to work as organic ligand.