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干旱区地理 ›› 2019, Vol. 42 ›› Issue (3): 606-614.doi: 10.12118/j.issn.1000-6060.2019.03.17

• 生态与环境 • 上一篇    下一篇

科尔沁沙地退化植被恢复过程中碳氮化学计量特征的变化

吕 朋1, 2, 3, 左小安1,2, 孙珊珊1,3, 张 晶1,2,3, 赵生龙2,3,程清平2,3,胡 亚2,3   

  1. 1 中国科学院西北生态环境资源研究院奈曼沙漠化研究站,甘肃兰州 7300002 中国科学院西北生态环境资源研究院乌拉特荒漠草原研究站,甘肃兰州 7300003 中国科学院大学,北京100049

  • 收稿日期:2018-11-15 修回日期:2019-01-25 出版日期:2019-05-25 发布日期:2019-05-21
  • 通讯作者: 左小安. E-mail: zuoxa@lzb.ac.cn
  • 作者简介:吕朋(1989-),男,博士研究生,研究方向为恢复生态学. E-mail: lvpengsnake@163.com

Changes of carbon and nitrogen stoichiometry in the restoration process of degraded vegetation in Horqin Sandy Land

LYU Peng1,2,3, ZUO Xiao'an1,2, SUN Shanshan1,3, ZHANG Jing1,2,3, ZHAO Shenglong2,3,CHENG Qingping2,3, HU Ya2,3   

  1. (1 Naiman Desertification Research Station,Northwest Institute of EcoEnvironment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China; 2 Urat Desertgrassland Research Station,Northwest Institute of EcoEnvironment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China; 3 University of Chinese Academy of Sciences,Beijing 100049,China)
  • Received:2018-11-15 Revised:2019-01-25 Online:2019-05-25 Published:2019-05-21

摘要: 为研究沙地退化植被恢复过程中碳氮化学计量特征的变化,分别于2011年、2013年和20158月中旬对流动、半固定、固定沙丘和草地进行植被调查,并测定植被—土壤系统的碳氮化学计量特征。结果表明:(1) 随着沙地退化植被的恢复,地上植物、凋落物和根系的CN含量及C/N比波动变化,土壤(010 cmCN含量及C/N比显著增加(P <0.05)。(2)沙地4种生境上的地上植物、凋落物、根系、土壤的CN含量及C/N比年际间变化显著(P <0.05)。(3) 沙地退化植被恢复过程中地上植物、凋落物、土壤的C/N比与物种丰富度呈正线性关系(P <0.01)。沙地退化植被恢复过程中优势植物演替导致植被—土壤系统中CN化学计量特征的变化,植被恢复过程中植物的氮素利用效率也在逐渐增强,而封育时间的增加能够促进沙地土壤中N的积累。

 

关键词: C、N含量, C/N比, 退化植被恢复, 恢复年限, 科尔沁沙地

Abstract: In this paper,the carbon and nitrogen stoichiometric amounts of plantsoil system were investigated along with the restoration sequence of degraded vegetation in Horqin Sandy Land,Inner Mongolia,China.This would be helpful to definite the changes of carbonnitrogen stoichiometric amounts of plantsoil system in the restoration of degraded vegetation and quantify the relationship between carbonnitrogen stoichiometric amounts and species richness,which provided the theoretical foundation for the sustainable management and utilization of sandy grassland.A total of 24 plots with the size of 20 m×20 m were set up at four habitats ( mobile dune,semifixed dune,fixed dune and grassland ),each habitat had 6 replicated plots.The distance between each plot was in the range from 0.5 to 8 km.Three quadrats with the size of 1 m×1 m were selected for plant and soil sampling in each plot in midAugust of 2011,2013 and 2015.Then the C and N contents of plantsoil system were analysed by Costech Elemental Combustion System 4010,Italy.The resluts shown as follows: (1) With the restoration of degraded vegetation,the C and N contents and C/N ratios of aboveground plant,litter and root had a fluctuated change trend,while the C and N content and C/N ratio of soil (010 cm) was increased significantly (P <0.05).The N content of aboveground plant in mobile dune was the highest,thus the C/N ratio was much lower than other habitats.On the other hand,the N contents of litter and root in semifixed dune were relatively lower than other habitats,which led to the higher C/N ratios of litter and root in semifixed dune. (2) From 2011 to 2015,the average C content of above ground plant changed a little,while the N content was significantly increased (P <0.01).The C and N content and C/N ratio of litter fluctuated smoothly,while there was no significant difference of that for root between years.On the other hand,the C content and C/N ratio of soil changed undulately,but the N content was increased significantly ([WTBX]P[WTBZ]<0.01). (3) The C/N ratio of aboveground plant,litter,soil had positive linear relationship with species richness in the restoration process of degraded vegetation (P <0.01).In conclusion,the succession of dominant vegetation in the restoration process of degraded vegetation led to the changes of C and N stoichiometric amounts of plantsoil system,the N use efficiency was also increased with the restoration of degraded vegetation.Moreover,the increase of fencing time promotes the accumulation of soil N in sandy land.

Key words: C and N contents, C/N ratios, restoration of degraded vegetation, restoration ages, Horqin Sandy Land