CAJ | 학술논문

δ15 N空间垂直分异特征可以有效指示森林生态系统土壤氮保留能力. 以中国亚热带典型林分 (天然林、格氏栲人工林、杉木人工林、闽粤栲人工林、闽楠人工林) 为对象, 通过对比其当年生叶片、凋落物及不同深度的土壤氮稳定同位素, 研究林分类型对植物、土壤氮稳定同位素的影响及森林生态系统垂直空间氮稳定同位素分异特征, 并探讨了不同林分土壤氮保留能力的差异. 结果表明: 不同林分当年生叶片、凋落物及0~10 cm和10~20 cm土壤δ15N均具有显著差异, 其中杉木人工林中这些 δ15 N 值显著高于其他 4 种林分类型, δ15 N 在0~40 cm土层随深度的增加而显著增加, 40~100 cm各土层δ15N差异均不显著. 另外, 不同林分叶片15N富集指数 ( EF) 存在显著差异, 呈现出杉木人工林的EF值较接近于0 的趋势.研究表明, 与阔叶人工林相比, 杉木人工林由于较高的土壤净硝化速率、硝态氮含量及叶片、凋落物、土壤δ15N值和较接近于0的叶片15N富集指数, 其土壤氮保留能力较阔叶人工林和天然林更差.
δ15 N공간수직분이특정가이유효지시삼림생태계통토양담보류능력. 이중국아열대전형림분 (천연림、 격씨고인공림、 삼목인공림、 민월고인공림、 민남인공림) 위대상, 통과대비기당년생협편、 조락물급불동심도적토양담은정동위소, 연구림분류형대식물、 토양담은정동위소적영향급삼림생태계통수직공간담은정동위소분이특정, 병탐토료불동림분토양담보류능력적차이. 결과표명: 불동림분당년생협편、 조락물급0~10 cm화10~20 cm토양δ15N균구유현저차이, 기중삼목인공림중저사 δ15 N 치현저고우기타 4 충림분류형, δ15 N 재0~40 cm토층수심도적증가이현저증가, 40~100 cm각토층δ15N차이균불현저. 령외, 불동림분협편15N부집지수 ( EF) 존재현저차이, 정현출삼목인공림적EF치교접근우0 적추세.연구표명, 여활협인공림상비, 삼목인공림유우교고적토양정초화속솔、 초태담함량급협편、조락물、 토양δ15N치화교접근우0적협편15N부집지수, 기토양담보류능력교활협인공림화천연림경차.
Spatial heterogeneity of nitrogen isotope (δ15 N ) is an effective indicator of soil nitrogen retention. We analyzed the δ15N in foliage, litter and soils in plantations of Castanopsis kawakamii, Cunninghamia lanceolata, Castanopsis fissa and Phoebe bournei and a natural forest, in order to explore the spatial characteristics ofδ15 N and compare nitrogen retention abilities among different forest types in subtropical China. The results showed that δ15N in foliage, litter and soil (0~20 cm depth) differed significantly among forest types and theδ15N was significantly higher in Cunninghamia lanceolate compared with the other four forests. The δ15N in the 0~40 cm soil depth significantly increases with soil depth but show no significant differences in δ15N of 40 ~100 cm soil depth. The 15N enrichment factor ( EF) in foliage of Cunninghamia lanceolata tends to be closer to zero than the other four forests. The net nitrification rate and net mineralization rate in Cunninghamia were significantly higher than plantations of Castanopsis kawakamii Castanopsis fissa and Phoebe bournei. Overall, our results indi-cate that soil nitrogen retention in Cunninghamia lanceolata was significantly lower than natural forest and broadleaved plantations in subtropical China.