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  

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

作　　者：吕朋 左小安 孙珊珊 张晶 赵生龙 程清平 胡亚 LYU Peng;ZUO Xiao-an;SUN Shan-shan;ZHANG Jing;ZHAO Sheng-long;CHENG Qing-ping;HU Ya(Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences,Lanzhou 730000, Gansu, China;Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences, Lanzhou 730000, Gansu, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[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730000 [2]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730000 [3]中国科学院大学,北京100049

出　　处：《干旱区地理》2019年第3期606-614,共9页Arid Land Geography

基　　金：国家自然科学基金项目(41571106,41622103);国家重点研发计划重点专项课题(2016YFC0500506)共同资助

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2015年8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C、N含量及C/N比波动变化,土壤(0~10 cm)C和N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C、N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C、N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。In this paper,the carbon and nitrogen stoichiometric amounts of plant-soil 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 carbon-nitrogen stoichiometric amounts of plant-soil system in the restoration of degraded vegetation and quantify the relationship between carbon-nitrogen 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,semi-fixed 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 mid-August of 2011,2013 and 2015.Then the C and N contents of plant-soil 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(0~10 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 semi-fixed dune were relatively lower than other habitats,which led to the higher C/N ratios of litter and root in semi-fixed 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(P<0.01).(3) The C/N ratio of aboveground

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 

分 类 号：X171.4[环境科学与工程—环境科学]