黑河下游不同生境胡杨(Populus euphratica)叶片碳同位素组成特征  

Characteristics of Foliar Stable Carbon Isotope Composition of Populus euphraticafor Different Niche in the Lower Reach of the Heihe River

作　　者：袁亚鹏[1] 赵阳[1] 赵传燕[1] 李文娟[1] 

机构地区：[1]兰州大学草地农业生态系统国家重点实验室,甘肃兰州730000

出　　处：《中国沙漠》2015年第6期1505-1511,共7页Journal of Desert Research

基　　金：兰州大学旱区流域科学与水资源研究中心开放基金项目(lzujbky-2013-m02)

摘　　要：植物中稳定碳同位素组成不但与植物的水分利用效率密切相关,而且反映环境因子对植物的影响。选择黑河下游额济纳旗为研究区,以优势物种胡杨(Populus euphratica)为研究对象,利用稳定碳同位素组成分析研究区胡杨受干旱胁迫程度。结果表明:胡杨叶稳定碳同位素组成(δ13 C)处于-25.51‰^-30.21‰,平均值为-28.28‰。随干旱胁迫程度增加,δ13 C值有明显偏正趋势,植物(叶片)碳同位素组成对胡杨成熟木长期适应不同水分胁迫程度有明显的体现。分析δ13 C与胡杨生长状态发现,δ13 C与种群密度相关性不明显,与枯枝比呈显著正相关关系,枯枝比可成为碳同位素组成的替代指标,指示胡杨受干旱胁迫的程度。Foliar stable carbon isotope composition can response the effect of water stress on plant growth and is thus an important demonstrator to the niche where plant grows,especially in arid environments.Therefore,it has become key parameter to be used among researches of relationship between plant growth state and the environmental stress.This study selects Populus euphratica growing in the lower reach of the Heihe River as an object.The niche is poor for P.euphratica.It suffers from drought stress in the form of water and salt stress in the studied area.We analyze the state of drought stress by foliar stable carbon isotope composition(δ13C).The results shows thatδ13C ranges from-25.51‰ to-30.21‰ with a mean value of-28.28‰.Comparingδ13C with that in other niche where no water stress happens,we found thatδ13C value in our study is higher.δ13C increases with the increase of drought stress.It has significant relative to the ratio of died branches to total branches,but no significant relative to the population density.From the results,we can draw conclusion thatδ13C can dictate the state of water stress for P.euphratica.The ratio of died branches to total branches can be an importantδ13C proxy to indicate the niche of P.euphratica.

关 键 词：黑河 胡杨(Populus euphratica) 稳定碳同位素组成 生长态势 枯枝比 

分 类 号：S792.11[农业科学—林木遗传育种]