不同生态类型富营养化湖泊沉积物中有机质赋存形态

以藻型湖泊(太湖)、草藻型湖泊(南四湖)、草型湖泊(白洋淀)湖泊沉积物为研究对象,采集了11个表层沉积物样品,测定沉积物中总氮(TN)和总磷(TP)含量并利用物理分组方法,研究了3种不同生态型湖及同一湖泊不同区域沉积物中总有机质(OM)、轻组有机质(LFOM)和重组有机质(HFOM)的赋存特征.结果表明,南四湖沉积物中总氮、总磷和总有机质含量显著高于太湖和白洋淀;尽管太湖、南四湖和白洋淀沉积物中总有机质含量较高,但是轻组有机质(LFOM)含量较低,分别占总有机质的0.95%—1.08%、0.21%—1.37%和1.4%—1.78%;重组有机质(HFOM)含量较高,分别占总有机质的83.83%—87.4%、94%—98.98%和88.2%—98.3%,表明3种不同生态型湖泊沉积物中所含有机质绝大部分为难分解的重组有机质,轻组有机质基本矿化分解.相关性分析表明,轻组有机质(LFOM)、重组有机质(HFOM)与总有机质(OM)之间均呈现显著正相关关系.

Distribution of organic matter species in the sediments of three ecological characteristics eutrophic lakes in China

Distribution of total organic matter(OM),light fraction organic matter(LFOM),and heavy fraction organic matter(HFOM) in the sediments from 3 different shallow lakes(Taihu Lake,Nansihu Lake and Baiyangdian Lake)were investigated by using physical separation methods.The results show that the content of total organic matter,total nitrogen(TN) and total phosphorus(TP) are significantly higher in Nansihu Lake sediments as compared with Taihu Lake and Baiyangdian Lake.Regardless of the high content of total organic matter,the light fraction organic matter(LFOM) is significantly low in all the sediments.Heavy fraction organic matter(HFOM) is the dominant class among the organic matter compositions in Taihu Lake,Nansihu Lake and Baiyangdian Lake sediments,contributing to 83.83%—87.4%,94%—98.98% and 88.2%—98.3%,respectively.These suggest the persistent organic compounds account for most of the organic matters,and light fraction organic matter was completely decomposed.Correlation analysis show that there is remarkable positive correlation among the contents of LFOM,HFOM and OM of the studied samples.