Interception by eastern white pine

Measurements of gross rainfall, throughfall, stemflow, and litter interception in three eastern white pine stands, age 10, 35, and 60 years, in the Southern Appalachians of western North Carolina, were used to derive regression equations for estimating throughfall, stemflow, and the sum of throughfall and stemflow from measurements of gross rainfall. Initiations for total interception loss were derived by algebraically combining losses from the canopy and litter. These equations were used to predict total seasonal interception loss (/) Irom measurements of total seasonal rainfall (2/') and number of storms (A"). Equations for the 10-, 35-, and 60-year-old stands are / = 0.05(A7) + 0.08 (2P), / = 0.05(A'') + 0.12(2P), and / = 0.06(.V) + 0.18(2P), respectively. Total interception loss in white pine increased with stand age, and total loss from all pine stands studied exceeded losses calculated for mature hardwoods. During the dormant season, calculated monthly inter- ception loss from mature hardwoods and white pine exceeded potential evapotranspiralion calculated by the Thornthwaite method. (Key words: Interception; vegetation; water balance; evapotranspiration)