不同地区狗尾草及其植硅体碳氮同位素研究

Study on Carbon and Nitrogen Isotopes of Setaria Viridisand its Phytolith in Different Areas

为揭示不同地区的狗尾草植硅体碳氮同位素和植物碳氮同位素之间的关系,为狗尾草碳氮同位素的研究,重建气候提供理论依据,在广东吴川、福建福州、湖北武汉、湖北襄阳、河南许昌、河南开封六个不同地区采集狗尾草植株进行分析。对野外采集的狗尾草进行湿式灰化法提取植硅体,测定植硅体和植物稳定碳(δ13C)同位素组成及稳定氮(δ15N)同素组成,并结合气象数据进行分析。结果表明:植物与植硅体碳同位素值有很好的相关性,而植物与植硅体氮同位素值相关性不明显;气候两大重要因素气温和降水量对植物和植硅体碳氮同位素关系复杂,其中植硅体氮同位素值可作为气温变化的衡量指标,而植物碳氮、植硅体碳同位素值不能很好地体现对气候的响应,不能代表一地的气候特征。

In order to reveal the difference and relationship between carbon-nitrogen isotopes and plant carbon-nitrogen isotopes in different areas,and to provide a theoretical basis for the study of carbon and nitrogen isotopes,rebuild climate,Wuchuan,Fuzhou,Kaifeng,Xuchang and Wuhan,six different areas were collected and analyzed.The phytolith was extracted by wet ashing method,and the isotopic composition ofδ13C andδ15N were determined.The meteorological data were used to analyze the isotopic composition ofδ13C and stable nitrogenδ15N.The results show that:there was a good correlation between carbon isotope value of plant and phytolith.But there was no significant correlation between nitrogen isotope value of plant and phytolith.Temperature and precipitation,have a complex relationship with carbon and nitrogen isotopes in plants and phytolith,in which the value of plant silicon nitrogen isotope can be used as a measure of temperature change,while plant carbon and nitrogen isotopes,the carbon isotope value of the phytolith can not reflect the climate well,nor can it represent the climatic characteristics of a place.