马尾松针叶组织稳定硫同位素地球化学特征及来源示踪

Sulfur Isotopic Signatures in Leaves of Pinus massoniana Lamb. and Source Apportionment

对贵州地区(贵阳)和云南地区(昆明、曲靖)的马尾松针叶组织中的无机硫(S SO4)和总硫(S T)的含量及其δ34S值进行了测定.结果表明,贵阳地区针叶组织中的无机硫和总硫含量明显高于云南地区,各采样地大气SO2浓度和针叶无机硫含量存在较好的正相关关系,但和总硫不存在显著相关关系,说明针叶组织无机硫含量的变化相对于总硫更能可靠地反映大气硫输入.贵阳地区针叶中无机硫δ34S平均值为-7.22‰,明显低于云南地区针叶中的无机硫δ34S(3.85‰),这与贵阳地区燃煤的硫同位素组成低于云南燃煤的硫同位素组成有关.无机硫和总硫含量在昆明钢铁厂和曲靖火电厂附近针叶中都表现为与离工厂距离呈反比,而δ34S则表现为在昆明钢铁厂附近随距离变大而偏负;在曲靖火电厂附近随距离变大而偏正,这主要是由工厂燃煤来源的大气硫沉降所决定的.

This study analyzed the inorganic sulfur （Sso4 ） and total sulfur （Sr） content as well as the isotopic signatures （δ34Sso4 and 834ST） in leaves of Pinus massoniana lamb. collected from Guizhou and Yunnan areas. The results indicated that the Sso4 and ST content in leaves at Guiyang areas was significantly higher than that at Yunnan areas, and the content of inorganic sulfur in the leaves was found to be directly related to the concentration of ambient sulfur dioxide, but no correlation was seen between the ST content and the ambient sulfur dioxide, showing the Sso4 content in leaves was more reliable to reflect the ambient sulfur input. The average value of 834Sso4 in leaves at Guiyang areas （-7.22‰） was significantly lower than that at Yunnan areas（3.85‰） , which was related to the fact that the sulfur isotopic composition of coal at Guiyang areas is lower than that at Yunnan areas. The Sso4 and Sr content in leaves around Kunming steel and Qujing power plant was inversely proportional to the distance from the factories, while around Kunming steel plant the value of 834Sso4 in leaves became more negative when the distance became larger while around Qujing power plant the value of δ34Sso4 became more positive when the distance became larger, indicating that the Sso4 content and δ34Sso4 in leaves around Kunming steel and Ouiing power plant were controlled by coal sources of atmospheric sulfur deposition.