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林业科学 ›› 2011, Vol. 47 ›› Issue (7): 42-49.doi: 10.11707/j.1001-7488.20110707

• 论文 • 上一篇    下一篇

锦鸡儿林草带状复合系统细根空间分异特征

秦树高1, 吴斌1,2, 张宇清1,2, 张天勇3   

  1. 1. 北京林业大学水土保持学院 北京 100083;2. 国家林业局宁夏盐池荒漠生态系统定位研究站 盐池 751500;3. 宁夏盐池县环境保护与林业局 盐池 751500
  • 收稿日期:2010-03-01 修回日期:2011-01-07 出版日期:2011-07-25 发布日期:2011-07-25
  • 通讯作者: 张宇清

Spatial Distribution of Caragana spp. Fine Root in Alley Silvopasture Systems

Qin Shugao1, Wu Bin1,2, Zhang Yuqing1,2, Zhang Tianyong3   

  1. 1. School of Soil and Water Conservation, Beijing Forestry University Beijing 100083;2. Ningxia Yanchi Desert Ecosystem Research Station of State Forestry Administration Yanchi 751500;3. Ningxia Yanchi County Environmental Protection and Forestry Bureau Yanchi 751500
  • Received:2010-03-01 Revised:2011-01-07 Online:2011-07-25 Published:2011-07-25

摘要:

以立地条件基本相同、林带完好、长势均匀的两行一带锦鸡儿林草带状复合系统(带距分别为4,6,8 m)为研究对象,采用壕沟法对锦鸡儿根系进行分层挖掘取样,研究其在不同造林带距条件下的空间分异特征。研究显示: 锦鸡儿根系生物量在水平方向上多靠近林带分布,与6 m和8 m带距系统相比,4 m带距系统林地中部锦鸡儿根系生物量密度相对较高。锦鸡儿在林地中部土体的细根根长和表面积密度随带距增大而减小; 带距分别为4,6,8 m的系统中,锦鸡儿在4 m带距系统整个样地土体中细根根长和表面积密度均处于相对较高的水平; 而随带距增大,在0~40 cm土层中,锦鸡儿平均细根根长密度、细根长度累计百分比、平均细根表面积密度和细根表面积累计百分比均呈减小趋势。因此,与4 m和6 m带距系统相比,在8 m带距系统中,锦鸡儿细根较少地分布于表土层和林地中部土体中,林草主要资源利用层发生隔离,而且林地两侧锦鸡儿根系在林地中部较少发生接触,使得林草种间竞争和锦鸡儿种内竞争较为缓和; 同时8 m带距系统仍可有效防止林地发生风蚀,所以在我国西北干旱半干旱地区进行锦鸡儿林草带状复合系统建设时,采用8 m带距较为适宜。

关键词: 林草复合系统, 锦鸡儿, 细根, 根系空间分异, 竞争

Abstract:

Our objectives were to investigate fine root spatial distribution of Caragana spp. in three alley silvopasture systems which are composed of one shrub belt and two-rows with different belt distance(4, 6, 8 m). The three systems had intact structure and uniform growth status in similar sites. The roots were sampled by the way of excavation from one soil layer to another vertically, on the woodland soil profile. The results showed that root biomass(RB)of Caragana spp. concentrated near the shrubs, Caragana spp. root biomass density(RBD)of 4 m system was markedly greater than that of 6 m and 8 m systems in central soil of woodland. The results also showed that, Caragana spp. fine root length density(FRLD)and fine root surface area density (FRSAD) in whole woodland of 4 m system were greater than that in 6 m and 8 m systems. In the three systems, average FRLD and FRSAD, cumulate percents of fine root length and surface area in 0-40 cm soil, FRLD and FRSAD in central soil, all decreased as belt distance of systems increasing. In 8 m system, root concentrated layers were separated between Caragana spp. and herbaceous, and fewer Caragana spp. roots were superposed in central soil, because of fewer fine roots of Caragana spp. in topsoil and central soil than that in other systems. Consequently, interspecies competition between Caragana spp. and herbage, and intraspecies competition of Caragana spp, were more mitigative in 8 m system, than in other systems. It suggests that Caragana spp. alley silvopasture system with 8 m belt distance is comparatively feasible, in semi-arid areas of northwestern China.

Key words: silvopasture system, Caragana spp., fine root, root spatial distribution, competition

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