PARENT SESSION
Poster Session #19: Nutrient Cycling.
Tuesday, August 7, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall
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Land-use change and soil C and N concentrations, soil respiration, and N availability.
Son, Yowhan1, Lee, Sook-Hee1, Yang, Soo-Young1, Hwang, Jung-Ok1, Kim, Jong-Sung1, 1
ABSTRACT- We compared total soil C and N concentrations, soil respiration, and N availability under three land-use types in central Korea; conversion of old rice field to natural willow-maple (Salix-Acer) forest, conversion of old field to artificial Korean pine (Pinus koraiensis) forest, and indigenous oak (Quercus spp.) forest. After 20 years of fallow the area of rice field conversion to forest had higher soil C and N concentrations in the soil depth of 0-10cm and 10-20cm than the areas of field conversion to Korean pine forest and indigenous forest. In general, soil C and N concentrations decreased with soil depth. Organic matter accumulation as a balance of input and decomposition seemed to be higher in the soil of previous rice field, and C and N accumulation was largely confined to the topsoil. Soil respiration rates were greatest at the area of rice field conversion to forest, and appeared to be related to soil C and soil moisture. Soil N availability measured by the ion exchange resin bag method differed significantly among land-use types; soil inorganic N and ammonium availability were highest in the soil under indigenous oak forest followed by conversion of old field to artificial Korean pine forest and conversion of old field to natural willow-maple forest.
KEY WORDS: land-use change, soil respiration, N availability, carbon