Vertical niche separation control of diversity and size disparity in planktonic foraminifera
Vertical niche separation control of diversity and size disparity in planktonic foraminifera
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DOI：
10.1016/j.marmicro.2006.11.002
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发表时间：
2007-04-30
影响因子：
1.9
通讯作者：
Schmidt, Daniela N.
中科院分区：
文献类型：
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作者：
Al-Saboui, Nadia;Kucera, Michal;Schmidt, Daniela N.
浮游有孔虫组合中的物种分布模式对于理解其生态决定因素至关重要。到目前为止，用于识别此类分布模式的数据主要是使用标准 > 150 μm 筛网尺寸获取的。然而，鉴于浮游有孔虫中的组合壳尺寸范围不是恒定的，这种数据采集实践可能会在分布数据中引入人为因素。在这里，我们通过分析横跨大西洋所有生物区的 12 个样本中的多个筛孔大小部分，研究了最近浮游有孔虫的组合壳尺寸范围和多样性之间的联系。使用覆盖群落结构各个方面的五个多样性指数，我们发现极地海洋中 > 63 μ m 部分和其他地方 > 125 μ m 部分的计数足以接近所有近期组合中的最大多样性。基于大于 150 μm 部分计数的多样性值明显低估了极地的最大多样性 - 令人惊讶的是，热带省份也是如此。尽管新方法改变了多样性/海面温度（SST）关系的形状，但其强度似乎不受影响。我们的分析表明，浮游有孔虫组合的多样性不断增加，伴随着具有独特的、偏置的壳尺寸分布的较大物种的逐渐增加。因此，先前记录的总体组合贝壳尺寸范围向低纬度地区的增加与来自同一地点的物种之间不断扩大的贝壳尺寸差异有关。这一观察结果支持这样的观点：有孔虫组合中的多样性和壳尺寸范围差异是生态位分离的结果。海表温度的增加会导致地表水分层增强，并导致垂直生态位分离，从而实现生态专业化。在地表水不稳定的区域中可以看到总体多样性和贝壳尺寸差异纬度模式的特定偏差，这表明耦合的贝壳尺寸和多样性测量可用于重建过去海洋的水柱结构。 (c) 2006 Elsevier B.V. 保留所有权利。
Species distribution patterns in planktonic foraminiferal assemblages are fundamental to the understanding of the determinants of their ecology. Until now, data used to identify such distribution patterns was mainly acquired using the standard > 150 mu m sieve size. However, given that assemblage shell size-range in planktonic foraminifera is not constant, this data acquisition practice could introduce artefacts in the distributional data. Here, we investigated the link between assemblage shell size-range and diversity in Recent planktonic foraminifera by analysing multiple sieve-size fractions in 12 samples spanning all bioprovinces of the Atlantic Ocean. Using five diversity indices covering various aspects of community structure, we found that counts from the >63 mu m fraction in polar oceans and the > 125 mu m elsewhere sufficiently approximate maximum diversity in all Recent assemblages. Diversity values based on counts from the > 150 mu m fraction significantly underestimate maximum diversity in the polar - and surprisingly also in the tropical provinces. Although the new methodology changes the shape of the diversity/sea-surface temperature (SST) relationship, its strength appears unaffected. Our analysis reveals that increasing diversity in planktonic foraminiferal assemblages is coupled with a progressive addition of larger species that have distinct, offset shell-size distributions. Thus, the previously documented increase in overall assemblage shell size-range towards lower latitudes is linked to an expanding shell-size disparity between species from the same locality. This observation supports the idea that diversity and shell size-range disparity in foraminiferal assemblages are the result of niche separation. Increasing SST leads to enhanced surface water stratification and results in vertical niche separation, which permits ecological specialisation. Specific deviations from the overall diversity and shell-size disparity latitudinal pattern are seen in regions of surface-water instability, indicating that coupled shell-size and diversity measurements could be used to reconstruct water column structures of past oceans. (c) 2006 Elsevier B.V. All rights reserved.