白令海陆架区柱样沉积物脂类分子特征及其气候变化响应

为探究全球变暖对于高纬度海洋生态环境的影响，对中国第5次北极科学考察在白令海陆架区采集的BL16柱样沉积物中的脂类进行了研究.沉积物中检测到丰富的饱和烃和脂肪酸等化合物，其组成和分布显示，该沉积柱中有机质为陆源和海源混合输入.其中长链正构烷烃和长链饱和正构脂肪酸主要来源于陆源高等植物，饱和异构和反异构脂肪酸主要来源于海洋自生细菌，短碳链正构烷烃、反异构烷烃和烷基环戊烷烃的浓度相互间有较好的相关性，表明其来源较为一致，主要来源于海洋浮游藻类和细菌.海源短链正构烷烃与陆源长链正构烷烃的比值∑C_15-21/∑C_23-33在0.14~0.90之间，表明该沉积柱中正构烷烃主要以陆源输入为主.沉积柱中短链正构烷烃、反异构烷烃和烷基环戊烷浓度，以及脂肪酸中异构、反异构脂肪酸组分与长链饱和正构脂肪酸组分的相对变化与总有机碳含量（TOC）、总氮含量（TN）变化一致，尤其在20世纪70年代以来明显升高，可能反映了海洋初级生产力持续增加的趋势，并且对全球变暖做出了灵敏的响应. 

Characteristics of Lipid Biomakers and Their Response to Climate Change in Column Sediments from Bering Sea Shelf

In order to study the impact of global warming on the ecological environments of high latitude ocean, the lipid biomarkers of a sediment core called BL16 were studied, which was collected during the Fifth Chinese National Arctic Expedition Cruise at the Bering Sea shelf. These compounds, including saturated hydrocarbons and fatty acids; show that the organic matter in the sediments is the mixed input of terrigenous and marine sources. The long chain n-alkanes and long chain saturated fatty acids are mainly derived from terrestrial higher plants, while saturated iso- and anteiso-fatty acids mainly originate from marine autotrophic bacteria. Two of the concentrations of short chain n-alkanes, anteiso-alkanes and alkylcyclopentanes are well interrelated, suggesting that these compounds share the same source and are mainly from phytoplankton and microbes. The relative ratios of the short to long chain n-alkanes (∑C_15-21/∑C_23-33) vary from 0.14 to 0.90 in sediments, indicating that the n-alkanes are primarily derived from terrestrial sources. The concentrations of short chain n-alkanes, anteiso-alkanes and alkylcyclopentanes, and the relative abundances of saturated iso-, anteiso-fatty acids to saturated long chain fatty acids are consistent with total organic carbon (TOC) and total nitrogen (TN) in the sediment core and show an apparent increase since the 1970s, which may reflect the continuously increasing trend of marine primary productivity and a sensitive response to global warming.