植物生态学报 ›› 1999, Vol. 23 ›› Issue (199901): 77-83.

• 论文 • 上一篇    下一篇

马占相思与大叶相思人工林氮素营养特性研究

李志安,林永标,沈承德,孙彦敏,陈庆强   

  • 发布日期:1999-07-10
  • 通讯作者: 李志安

Characteristics in Nitrogen Nutrition of Acacia mangium and Acacia auriculaeformis Man-Made Forests

LI Zhi-An, LIN Yong-Biao, SHEN Cheng-De, SUN Yan-Min and CHEN Qing-Qiang   

  • Published:1999-07-10
  • Contact: LI Zhong-Pei

摘要: 以中国科学院鹤山丘陵综合试验站马占相思与大叶相思人工林为材料,报道两种人工林氮素营养特征,结果表明:1)马占相思与大叶相思改土效应显著,12年林龄时,表层土壤(10cm)有机质含量在30g·kg-1以上,含氮量大于1.6g·kg-1,但马占相思的肥土效应显著高于大叶相思,在30cm以下,大叶相思林土壤的含氮量约只有马占相思林土壤的一半。2)两种叶子含氮量全年变幅不大,但有一定的起伏,马占相思绿叶与落叶内含氮量显著高于大叶相思,它是林下土壤获得更快改良的主要原因。两个种均从落叶中大量转移利用氮素,马占相思的转移率在24%~58%之间,大叶相思转移率高于马占相思,在37%~60%之间。3)当土壤受到干扰时,土壤中的氮矿化数倍高于未受干扰的土壤,30d土柱培养后土壤的总矿质氮量为马占相思15.04mg·kg-1,大叶相思20.81mg·kg-1,而相应的碎土培养结果为马占相思46.17mg·kg-1,大叶相思44.53mg·kg-1。这两种林下土壤的矿质氮以硝态氮为主。4)两个种不同部位的含氮量变化极大,叶子含氮量最高,马占相思为33.4g·kg-1,大叶相思为31.4g·kg-1;主干的含氮量最低,马占相思为5.4g·kg-1,大叶相思为3.9g·kg-1;两个种枝条与根各对应等级的含氮量极其相似,它们随径级大小而变化的格局也相同,径级越大,含氮量越低。两种叶子的C/N比较低(15~16),是培肥土壤的优质有机物质。

Abstract: This paper deals with nitrogen characteristics of two man-made forests in Heshan Inter Disciplinary Experimental Station, Academia Sinica, situated in 23˚N, l18˚E. The results show:l) A. mangium and A. auriculaeformis could improve soil significantly. Surface soil (0~10cm) contained organic matter, over 30g·kg-1, nitrogen, over 1.6g·kg-1 A. mangium had much stronger soil effect than A. auriculaeformis. In soil deeper than 30cm, nitrogen content in A. auriculaeformis had only half of that in A. mangium. 2) Nitrogen content did not change very much, but undulation could be observed. The level of nitrogen content in both live and dead leaves of A. mangium was higher than that of A. auriculaeformis, accounting for the quick improvement of soil by A. mangium. Both species largely reused the nitrogen from senesced leaves. The resorption rate of A. mangium ranged from 24 % to 58 %, while 37 % ~60 % for A. auriculaeformis. 3) Nitrogen mineralization was multiplied as the soil was disturbed. The total mineralized nitrogen of soil core incubation was 15.04 mg·kg-1 for A. mangium after 30 days’incubation, while 20.81 mg·kg-1 for A. auriculaeformis respectively. On the contrary, the total mineralized nitrogen of ground soil incubation was 46.17 mg·kg-1 for A. mangium, 44.53 mg·kg-1 for A. auriculaeformis. The nitrate was the dominant form of mineralized nitrogen. 4) The different organs of both species had rather different nitrogen content, with highest in leaf, lowest in trunk. The leaves of A. mangium contained 33.4g ·kg-1 N, while 31.4 g·kg-1 for A. auriculaeformis. The trunk of A. mangium contained 5.4g·kg-1 N, while 3.9 g·kg-1 for A. auriculaeformis. The stem and root of both species had rather similar pattern of nitrogen content. The higher the diameter class the lower the nitrogen content was the low C/N ratios of the species were beneficial to the soil amelioration.