Differences of Nitrogen Mineralization in Larix decidua, Pinus strobus and Thuja occidentalis Plantations of the Kwangeneung Experimental Forest, Kyonggi Province

경기도 광릉시험림의 구주낙엽송, 스트로브잣나무, 서양측백 조림지 토양내 질소 무기화 비교

Species effects on soil nitrogen mineralization and nitrification in the top 15 cm of soil were evaluated using the buried-bag incubation method in three coniferous plantations in the Kwangneung Experimental Forest, Kyonggi Province. The plantations were established on a similar soil in 1927, and included Larix decidua, Pinus strobus, and Thuja occidentalis. Ten soil samples within each plantation were taken during an entire growing season (May 2~Oct. 30, 1994). Mean daily nitrogen mineralization rates during 45-day in situ soil incubations were significantly different among species and incubation dates. Growing season nitrogen mineralization also differed significantly among species and ranged from 47.7 mg N/kg soil for Larix decidua to 21.5 ma N/kg soil for Thuja occidentalis. Growing season nitrification differed significantly among species and comprised from 93% to 100% of the total growing season nitrogen mineralized. We speculated that organic matter contents and quality might control nitrogen mineralization and nitrification in these soils.