摘要
以杉木纯林为对照 ,探讨了福建三明莘口教学林场 2 7年生的杉木观光木混交林凋落物的养分特征及其动态变化。结果表明 ,各树种、各组分凋落物中N、P、K平均质量分数大小基本上为N >K >P。混交林凋落物N、K平均质量分数大于纯林 ,P质量分数略低于纯林。观光木的N、P质量分数高于混交林和纯林杉木 ;K质量分数高于纯林杉木 ,低于混交林杉木。不同树种、不同组分间N、P、K质量分数的月份动态不同。混交林全年通过凋落物归还土壤的N、P、K量分别为 4 8.5 2 8、2 .32 4、19.84 3kg·hm-2 ,纯林为 37.16 3、2 .339、18.4 0 6kg·hm-2 。混交林和纯林全年凋落物养分归还量在 3月份、8月份和 12月份出现峰值 ,N、P归还量以 3月份最高 ,K归还量以 12月份为最高 ;混交林归还土壤的N量明显高于纯林 ,K量也高于纯林 ,这对保持林地的长期肥力具有重要意义。混交林中N总归还量的季节变化模式为冬季或春季 >夏季 >秋季 ;P总归还量季节变化为 :冬季、春季 >夏季和秋季 ;K总归还量季节变化为 :冬季 >秋季 >春季 >夏季 。
This paper deals with nutrient characteristics and dynamics of litterfall in a 27-year-old mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum , compared with a pure stand of Cunninghamia lanceolata , located in Xinkou Teaching Forest Farm, Sanming of Fujian province. The results show that mean concentrations of N, P and K elements of litterfall were almost in the order of N>K>P both species and fractions. The mean concentrations of N and K of litterfall in the mixed stand were higher but P slightly lower than those in the pure stand, and the mean concentrations of N and P of litterfall of Tsoongiodendron odorum were higher than those of Cunninghamia lanceolata in both stands, with the concentration of K higher than that of the pure stand but lower than that of the mixed stand. The monthly dynamics of concentration of N, P and K of litterfall were different in all fractions of different species. The annual nutrient return through litterfall amounted to 48.528 kg·hm -2 N, 2.324 kg·hm -2 P and 19.843 kg·hm -2 K in the mixed stand and 37.163 kg·hm -2 N, 2.339 kg·hm -2 P and 18.406 kg·hm -2 K in the pure stand. Nutrient return peaked in March, August and December in both stands with N and P highest in March and K highest in December. Total return of N in the mixed stand was obviously higher than that in pure stand, which benefitted the maintenance of long-stand, which benefitted the maintenance of long-term site fertility in mixed stand. Seasonal dynamics of total N, P and K return of the mixed stand litterfall, which in the order of winter>spring>summer>autumn, winter or spring>summer>autumn and winter>autumn>spring>summer, respectively, agreed with the dynamics of nutrient return of Cunninghamia lanceolata litterfall in the mixed stand.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2002年第1期17-23,共7页
Journal of Northeast Forestry University
基金
福建省科委重大基础研究项目 (2 0 0 -F -0 0 4)
高等学校骨干教师资助计划资助
