不同藻类生态参数在反演沉积物环境中的应用比较

Comparison of ecological parameters in the sediment using multi-proxy approaches to indicate environmental changes

海洋沉积物中残留的硅壳、甲藻孢囊、类脂类化合物及生物硅等生态参数被广泛应用于反演和指示海洋古环境特征。本研究通过测定烟台四十里湾表层沉积物中的硅藻化石、甲藻孢囊、菜籽甾醇、甲藻甾醇及生物硅5种生态参数,比较不同生态参数的相关性及它们在反演海洋环境中的功能差异,建立了多参数综合应用的研究方法。研究发现,沉积物中的硅壳丰度与菜籽甾醇含量及生物硅含量存在明显正相关关系(P<0.05),菜籽甾醇含量与生物硅含量可以较好的佐证与提高沉积物中硅壳对硅藻生物量指示的准确性;甲藻孢囊与甲藻甾醇含量相关性不明显(P>0.05),相较而言,甲藻甾醇可以更准确的反演甲藻的生物量。因此,生物与化学参数的结合应用不仅可以提高生物量指示的精确性,而且有助于从物种组成角度更好的了解藻类对环境变化的响应特征。

Diatom frustules, dinoflagellate cysts, lipids and biogenic silica （BSi） have been widely used to reconstruct and indicate the marine paleo-environmental changes. In this study, five biological and chemical proxies including fossil diatoms, dinoflagellage cysts, brassicasterol, dinosterol and biogenic silica, were analyzed in the surface sediment of the Sishili Bay for the comparison of their ecological roles. Based on the results of correlation analysis and indicative capability of the five proxies, a multi-proxy approach was suggested. Diatom frustules showed obviously positive correlation with the brassicasterol and BSi values, respectively （P〈0.05）; the brassicasterol and BSi value performed well in the corrections and improvement for the accuracy of indication from fossil diatom. However, no significant correlations were found between dinoflagellate cysts and dinosterol values; and in a comparison, dinosteral displayed a better capability to indicate the biomass of dinoflagellate than cysts. A combination of using biological and chemical parameters can not only improve the accuracy of biomass indication but also provide the species composition for a better understanding of how algae response to changed environment.