Taphonomic bias in the transition from life to death assemblages of marine phytoplanktor

海洋浮游植物从生到死组合转变的埋藏学偏差

基本信息

批准号：
07640628
负责人：
TANIMURA Yoshihiro
金额：
$ 1.28万
依托单位：
National Science Museum
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640628/
关键词：
plankton sediment traps taphonomic bias

项目摘要

Four sets of a time-series of thirteen consecutive 27 to 28 days-long samples representing one sediment trapping interval (Mar. 5,1991-Mar. 2,1992) were collected from four deferent depths in the northwest Pacific at station JT (34ﾟ9.802'N,141ﾟ59.268'E ; 916m, 3422m, 5429m and 8430m), and provided material to evaluate information loss in the transition from life to death assemblages of diatoms. Two sediment samples also provided material to evaluate the loss on sediment-water interface. Comparison in flux records among the four sets of trap samples distinguishes one high flux period found in two different dephts as conspicuous flux peaks ; 3442m and 5429m. A sinking velocity of diatom flux is calculated from a time lag between the two peaks ; more than 71m/day. Differences in diatom assemblages among the two peaks and the underlying sediments suggest that dissolution on sediment-water interface appears to be the prime factor in determining diatom assemblages preserved in sediments, and the following three diatom groups are distinguished as most susceptible forms to value dissolution in the Kuroshio water ; Nitzschia bicapitata-bifulcata complex, Neodelphineis indica, Chaetoceros species. These forms together comprise 55% to 60% of total sediment-trap floras which suggests that information loss from water column to sediments is at least 50%.

Four sets of a time-series of thirteen consecutive 27 to 28 days-long samples representing one sediment trapping interval (Mar. 5,1991-Mar. 2,1992) were collected from four defined depths in the northwest Pacific at station JT (34ﾟ9.802'N,141ﾟ59.268'E ; 916m, 3422m, 5429m and 8430m），并提供了评估从硅藻过渡到死亡组合过渡的信息损失的材料。两个沉积物样品还提供了评估沉积物 - 水界面损失的材料。在四组陷阱样品中的通量记录中的比较可以区分两个在两个不同的DEPHT中发现的高通量时期，为显着的通量峰。 3442m和54.29m。硅藻通量的下沉速度是根据两个峰之间的时间滞后计算的。超过71m/天。两个峰和潜在的沉积物之间的硅藻组合的差异表明，在沉积物 - 水界面上的溶解似乎是确定在沉积物中保留的硅藻组合的主要因素，并且以下三个硅藻基被区分为对库鲁希奥水中溶解的最敏感形式。 nitzschia bicapitata-fifulcata复合体，新层菌Indica，Chaetoceros物种。这些形式共同完成了总沉积物陷阱菌群的55％至60％，这表明从水柱到沉积物的信息损失至少为50％。