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作 者 ：刘德燕^1，2;宋长春¹

期 刊 ：应用生态学报 2008年 19卷 12期 页码：2599-2604

关键词：小叶章；

摘 要 ：选取三江平原典型沼泽湿地植物小叶章为对象，通过野外控制试验（2004—2007年）,研究了4个不同氮素输入水平［0（对照,CK）、6（N₆）、12（N₁₂）和24（N₂₄） g·m^-2·a^-1］对小叶章叶片形态、叶绿素和生物量累积等的影响.结果表明：不同氮处理间小叶章叶长和叶宽未出现显著差异,比叶面积在N₁₂处理时最小［（149.54±18.27） cm²·g^-1］，即此氮处理水平下叶片的厚度最大.叶片的叶绿素含量均呈单峰型变化，峰前,随着氮输入量的增大而增大，且N₁₂和N₂₄处理下峰值出现的时间早于N₆和CK处理；峰后，N₂₄处理下叶绿素含量迅速降低，N₆处理则降低缓慢，说明适量的氮输入延缓了叶片衰老.连续的高氮（N₂₄）输入使小叶章的生长发育有所提前，在成熟后叶片出现早衰现象.2005和2007年生长季末，小叶章地上部分生物量均随着外源氮输入量的增加而增大，但是经过4年 (2007年) 连续高氮（N₂₄）处理的小叶章地上部分生物量较输入2年 (2005年) 时降低了53.72％.

Abstract:Taking the typical marsh wetland plant Calamagrostis angustifolia in Sanjiang Plain of Northeast China as test material, a field control experiment was conducted to study its leaf morphological characters, chlorophyll content,
and aboveground biomass under effects of different levels of exogenous nitrogen input in 2004—2007. Four nitrogen (N) fertilization treatments, i.e., 0 (CK), 6 g·m^-2·a^-1 (N₆), 12 g·m^-2·a^-1 (N₁₂) and 24 g·m^-2·a^-1 (N₂₄), were installed. The results showed that there were no significant differences in the leaf length and width among different N fertilization treatments, but the specific leaf area was the smallest (149.54±18.27 cm²·g^-1) under N₁₂, which indicated that the leaves of C. angustifolia were thicker under this N treatment. The leaf chlorophyll content showed a unimodal distribution over the growth season, which increased with the amount of N input before the peak. The peak occurred earlier under N₁₂ and N₂₄ than under N₆ and CK. After the peak, the chlorophyll content declined sharply under N₂₄ but slowly under N₆, indicating that moderate N input could delay leaf senescence. Continuous high N (N₂₄) input might advance plant growth, while leaf senescence would occur earlier. By the end of growth season both in 2005 and in 2007, the aboveground biomass of C. angustifolia increased with increasing N input, but declined by 53.72% after 4 years continuous
high N (N₂₄) input (in 2007), compared with that after 2 years treatment
(in 2005).

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