Influence of seasonally deposited phytodetritus on benthic foraminiferal populations in the bathyal northeast Atlantic. the species response
Influence of seasonally deposited phytodetritus on benthic foraminiferal populations in the bathyal northeast Atlantic. the species response
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季节性沉积的植物碎屑对东北大西洋深海底栖有孔虫种群的影响。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
P. Lambshead
中科院分区：
文献类型：
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作者：
A. Gooday;P. Lambshead
1982年4月和7月，在豪猪湾的半深海（1320至1360米深）用多芯取样器获得了岩芯。在7月（但不是4月）的沉积物表面覆盖着一层植物碎屑，材料迅速sedlmented从真光区以下的春天开花。从7月岩芯中取出的样本的植物碎屑部分（0至1厘米的子岩芯层;表面积3.46平方厘米）含有密集、多样性低的底栖有孔虫种群，这些有孔虫种群类似于已经在更深（4550 m）的地方描述过的植物碎屑栖息组合。东北大西洋的BIOTRANS站点。我们的新观察结果巩固了这样一种观点，即植物碎屑是某些深海底栖有孔虫物种的微生境。半深海种群中以Weddellensis（75 '70）为主，还包括Episton~inella exigua和Tinogullmia sp. nov. 4月的采样和7月的总采样（植物碎屑加沉积物组分）产生了相似密度和物种丰富度的不同有孔虫种群。然而，在分类学上存在一些重要的差异。特别是，在7月的三个月里，植物碎屑中的8个种类明显增多，而在4月的三个月里，最常见的种类（01.dmrnina sp. nov. A）在7月完全消失。我们认为，植物碎屑的infhtence，而不是空间变异性（斑块），负责物种丰度的一些差异。然而，其他物种保持更稳定的种群密度。我们的研究结果表明，深海底栖有孔虫，像那些生活在浅水中，可能会显示出各种生活史的战略和populdtion动态。
Cores were obtained with a multiple corer at a bathyal site (1320 to 1360m depth) in the Porcupine Seabight during April and July 1982. In July (but not April) the sediment surface was overlain by a layer of phytodetritus, material rapidly sedlmented from the euphotik zone following the spring bloom. The phytodetrital fraction of samples (0 to 1 cm layer of subcores; 3.46 cm2 surface area) removed from the July cores harboured dense, low-diversity populations of benthic foraminifers which resembled the phytodetritus-dwelling assemblages already described from the much deeper (4550 m) BIOTRANS site in the northeast Atlantic. Our new observations consolidate the view that phytodetritus is a microhabitat for some deep-sea benthic foraminiferal species. The bathyal populations were dominated by Alabaminella weddellensis (75 '70 of total) and also included Episton~inella exigua and Tinogullmia sp. nov. These 3 species occurred also in the BIOTRANS phytodetrital assemblages. The April san~ples and the total July samples (phytodetritus plus sediment fractions) yielded diverse foraminiferal populations of similar density and species richness. However, there were some important taxonomic dfferences. In particular, the 8 species consistently present in the phytodetritus were significantly more abundant in the July san~ples, while the most common species in the April sanlples (01.dmrnina sp. nov. A) was entirely absent during July. We argue that the infhtence of phytodetritus, rather than spatial variability (patchiness), was responsible for some of the differences in species abundances. Other species, however, maintain more stable populat~on densities. Our results suggest that deep-sea benthic foraminifers, like those living in shallow water, probably display a variety of life-history strategies and populdtion dynamics.