Changes of Inorganic Nitrogen and CO₂ Evolution Rate on the Decomposition Process of Korean White Pine Needles

잣나무엽(葉)의 초기(初期) 분해과정(分解過程)에 있어서 무기태(無機態) 질소(窒素) 및 CO₂ 방출속도(放出速度)의 변화(變化)

Forest soils mixed with organic matters (green needle, flesh needle litter and needle litter in F layer of Pinus koraiensis, and green leaf of Quercus dentata and Q. variabilis) were incubated under a constant $30^{\circ}C({\pm}1)$ for 53 days to measure the changes of inorganic nitrogen and $CO_2$ evolution rate. The results obtained were summarized as follows; 1) In the early incubation period the amounts of total inorganic nitrogen in soils by mixture of organic matters decreased rapidly because of immobilization by microbial uptake, and thereafter their amounts increased with further incubation. 2) The rate of immobilization of organic nitrogen in mixed organic matters was the highest in green needle among green needle, flesh needle litter and needle litter in F layer of P. koraiensis, but lower than that of green leaf of Q. variabilis and Q. dentata. 3) The rates of $CO_2$ evolution from soils mixed with organic matters increased sharply in the early time, and then decreased slowly with increasing time. The order of the $CO_2$ evolution rate was green leaf of Q. variabilis > green leaf of Q. dentata > green needle of P. koraiensis > flesh needle litter of P. koraiensis > needle litter of P. koraiensis in F layer from the largest to the least. 4) Nitrate nitrogen concentrations showed a tendency to increase throughout incubation time, so that their concentrations after 53 days were higher than that of ammonium nitrogen.

잣나무의 녹엽(綠葉), 낙엽(落葉), F층(層)의 엽(葉)과 떡갈 및 굴참나무의 녹엽(綠葉)을 각각 토양(土壤)에 혼합(混合)하여 53일간 $30^{\circ}C({\pm}1)$로 항온배양(恒温培養)하는 동안 토양중(土壤中)의 무기태(無機態) 질소(窒素) 및 $CO_2$ 방출속도(放出速度)의 변화(變化)를 측정(測定)하여 다음의 결과(結果)를 얻었다. 1) 배양초기(培養初期)에는 무기태(無機態) 질소(窒素)의 유기화(有機化)로 무기태(無機態) 질소량(窒素量)의 감소(減少)가 강(強)하게 일어났고, 시간(時間)의 경과(經過)에 따라 점차 증가(增加) 하였다. 2) 혼합(混合)한 엽중(葉中)의 유기태(有機態) 질소(窒素)의 유기화속도(有機化速度)는 잣나무의 엽중(葉中) 녹엽(綠葉)에서 가장 컸으나, 굴참 및 떡갈나무의 녹엽(綠葉)보다는 작았다. 3) $CO_2$ 방출속도(放出速度)의 크기는 굴참나무녹엽(綠葉), 떡갈나무녹엽(綠葉), 잣나무녹엽(綠葉), 잣나무 낙엽(落葉), F층(層)의 잣나무엽(葉)을 혼합(混合)한 토양(土壤)의 순(順)이었고, 시간의 경과(經過)에 따라 점차 감소했다. 4) 질산태(窒酸態) 질소량(窒素量)은 점차 증가(增加)하여 배양(培養) 53일 후에, 암모니아태(態應) 질소량(窒素量)을 상회(上迴)하였다.