湖北太白湖400多年来沉积硅藻记录及湖水总磷的定量重建  

Diatom records and reconstruction of epilimnetic phosphorus concentration in Lake Taibai ( Hubei Province) over the past 400 years

作　　者：董旭辉[1] 羊向东[1] 刘恩峰[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所

出　　处：《湖泊科学》2006年第6期597-604,共8页Journal of Lake Sciences

基　　金：中国科学院重大创新项目(KZCX1-SW-12);国家973项目(2002CB412300)共同资助

摘　　要：依据沉积物钻孔的高分辨率硅藻研究,利用长江中下游现代湖泊硅藻与总磷转换函数结果,定量重建了太白湖400余年来占湖水总磷浓度的变化．结果表明,约1630 AD前和1 800-1924 AD期间,湖水总磷浓度较低,在50-68μg／L之间;1630-1800 AD,总磷浓度偏高,总体上在50-160μg／L之间变化,变幅较大．1800-1924AD,总磷浓度明显下降为谷值段,且变化相对稳定(50μg／L左右);1924-1953AD,总磷浓度仍较低,但有增加趋势(50-63μg／L);20世纪50年代开始,总磷浓度出现快速增加;至1970年后,总磷浓度超过120μg／L左右.利用样品相似对比的方法发现约80％的样品具有较好的重建效果．古湖水总磷浓度值的变化揭示了该湖两次明显的富营养化过程,初步探讨了其驱动机制.根据重建结果提出:太白湖自然营养本底总磷值约为50μg／L左右,可作为该湖治理时的参考目标．The epilimnetic total phosphorous concentrations （ [ TP] ） over the past 400 years were reconstructed for Lake Taibai, based on the high resolutional fossil diatom lished regional diatom-TP transfer function. The results study from one sediment core in that lake and an estabindicated that, during 1630 AD and 1800 -1924 AD, [ TP] was low within 50- 68 μg/L; 1630- 1800 AD, [ TP] were much higher and changed dramatically, which was within 50 - 160 μg/L; 1800 - 1924 AD, [ TP] showed low values with little changes （ remained about 50 μg/ L） ; 1924 - 1953 AD, [TP] kept low values, showing slight increase （50 -63 μg/L） ; From 1950s [TP] began to increase and after 1970 [ TP] exceeded 120 μg/L. Match Analog Technique was used to estimate the validity of the reconstruction results and it showed that about eighty percent samples provided reasonable values. The changes of the reconstructed [ TP] revealed that two eutrophication stages had occurred and the causes were preliminarily discussed. Finally 50 μg/L was propounded to be the naturalness value for TP index in Lake Taibai, which could be used as the restoration target.

关 键 词：太白湖 沉积硅藻 总磷 定量重建 营养本底 

分 类 号：X524[环境科学与工程—环境工程]