| I studied the effects of topographic attributes and vegetation types of subcatchments on streamwater chemistry in a 3165 ha forested watershed in Hokkaido Island of northern Japan. Streamwater was collected four times between June and October of 2002 from 20 locations in the watershed. The streamwater showed general characteristics of high pH and strong influence of marine aerosols. Alkalinity, pH, and concentrations of dissolved organic carbon (DOC), and some of major cations and anions showed distinctive spatial patterns across the watershed. Streamwater constituents such as nitrate, sulfate, calcium, and alkalinity had positive relationships with mean elevation and mean slope, whereas chloride, DOC, dissolved organic nitrogen (DON) had positive relationships with mean Topographic Index and the areas of conifer-dominant forests. The gradients of soil wetness and the presence of wetlands seemed to explain many of the observed spatial patterns of solutes in these surface waters. |
