凋落叶多样性对杉木幼苗生长及吸收15N标记硫铵的影响

利用15N硫铵研究了凋落叶多样性对杉木幼苗生长及养分吸收的影响 .结果表明 ,凋落叶多样性的增加有利于盆栽杉木幼苗的生长 .杉木、火力楠、红栲和刺楸 4种凋落叶混合处理后 ,杉木幼苗的生长量最大 ;杉木、火力楠、刺楸 3种凋落叶混合处理后的杉木幼苗生长量次之 ,其它依次为杉木、火力楠、红栲 3种凋落叶混合处理 >杉木和刺楸凋落叶处理 >杉木和红栲凋落叶处理 >对照 >杉木和火力楠 2种凋落叶混合处理 >杉木凋落叶处理 .就杉木幼苗对硫铵氮的吸收率而言 ,不作任何处理的杉木幼苗吸收率最高 ,其次为杉木、火力楠、红栲和刺楸 4种凋落叶混合处理 ,其它依次为杉木、火力楠、刺楸 3种凋落叶混合处理和杉木、火力楠、红栲 3种凋落叶混合处理 >杉木和刺楸凋落叶处理 >杉木和红栲凋落叶处理>杉木和火力楠 2种凋落叶混合处理 >杉木凋落叶处理 .另外 ,用凋落叶处理后 ,土壤中硫铵氮的残留量比不作凋落叶处理的土壤多 ,硫铵氮的总回收量也比不作凋落叶处理的土壤大幅增加 ,而且凋落叶多样性的增加也会增加硫铵氮的残留量 .

Effects of plant foliar litter diversity on the growth of Chinese fir seedling and the absorption of (15NH4)2SO4

Effects of plant foliar litter species composition on the growth of the potted Chinese fir seedling and the absorption of (~ 15NH 4) 2SO 4 was studied.The result showed that there were significant growth responses to foliar litter treatments. A very noticeable trend was that as the tree species of foliar litter placed on pots increases, the growth of Chinese fir seedlings increases steadily. Seedling growth in four-species mixed foliar litter were the largest and that in Cunninghamia lanceolata+Michelia macclurei+Kalooanax septemlobus foliar litter mixture were the second. The others were in order of seedlings in C.lanceolata+M.macclurei+Castanopsis carlesii foliar litter mixture >C.lanceolata+K.septemlobus foliar litter mixture >C. lanceolata+C. carlesii>control (no foliar litter) >C.lanceolata+M.macclurei foliar litter mixture >Chinese fir foliar litter treatment. The recovery of (~ 15NH 4) 2SO 4 by Chinese fir seedlings in no foliar litter treatment was maximum, and seedlings grown in four foliar litter mixture was the second, then it was in order of C. lanceolata+C. carlesii+K.septemlobus=C.lanceolata+C.carlesii+M. macclurei>C.lanceolata+K.septemlobus>C.lanceolata+C.carlesii>C.lanceolata+M. macclurei>C.lanceolata foliar litter treatment. In addition, the residue of (~ 15NH 4) 2SO 4 was greater in soil with foliar litter treatment than in no foliar litter soil. Both of the residual amount of (~ 15NH 4) 2SO 4 in soil and the total recovery of (~ 15NH 4) 2SO 4 increased with the increasing tree species of applied foliar litter.