摘要:
以原始阔叶红松林、次生林土壤NH+
4 -N 与NO-
3 -N 为研究对象,采用原位顶盖埋管法,研究2 个林地土壤矿
质氮供应水平与组成的差异动态。结果表明:观测期内原始阔叶红松林土壤NH+
4 -N 含量均高于次生林,5、6、7 月
原始阔叶红松林土壤NO-
3 -N 含量低于次生林,其他时段高于次生林;观测期内原始阔叶红松林土壤NH+
4 -N 始终
占优势,5、6、7 月次生林土壤NO-
3 -N 占优势,其他时段NH+
4 -N 占优势。以红松、白桦分别作为顶级群落优势树种
与退化演替群落先锋树种的代表植物,根据各器官氮含量动态与生长动态,对2 个树种氮素获取行为模式进行连
续研究。结果表明:红松、白桦氮吸收动态与原始阔叶红松林、次生林土壤矿质氮含量动态相似;410 月红松持续
平缓地吸收土壤氮素,58 月白桦大量吸收土壤氮素并在6 月中下旬达到吸收峰期。
Abstract:
Soil NH+
4 -N and NO-
3 -N were the research objects, and tube closed-top incubation method was
conducted to investigate the content and composition of soil mineral N in the original broadleaved Pinus
koraiensis forest and the secondary forest. The results showed that soil NH+
4 -N content of the original
broadleaved P. koraiensis forest was always more than the secondary forest from April to October, and soil
NO-
3 -N content of original broadleaved P. koraiensis forest was less than the secondary forest from May to
July. In the original broadleaved P. koraiensis forest, soil NH+
4 -N was always the dominating N form. In
the secondary forest, soil NO-
3 -N was the dominating N form from May to July, and soil NH+
4 -N was
dominated in the other months. P. koraiensis and Betula platyphylla represented respectively the
dominant tree species in the climax community and the pioneer tree species in the degenerated
community,whose N absorption pattern was studied continuously by investigating their organ N content
and growth. The results showed that N absorption trends of the two tree species were similar to soil
mineral N content trends in the original broadleaved P. koraiensis forest and the secondary forest. From
April to October, soil mineral N was absorbed gently by P. koraiensis, and it was absorbed rapidly by B.
platyphylla from May to August, and its peak period was late June.
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