Abstract Dinoflagellate cyst (=dinocyst) assemblages are widely used for the reconstruction of multiple oceanographic variables through the application of transfer functions. There is evidence that the number and kind of variables driving compositional changes in dinocyst assemblages vary regionally and that the selection of driving factors and the evaluation of transfer function performances are method-specific and complicated by spatial autocorrelation. Here, we used two new modern datasets from the Northern Hemisphere Atlantic-Arctic and the Northern Hemisphere Pacific oceans to re-evaluate the impact of sea-surface properties in dinocyst assemblages. We determined the dimensionality of the dinocyst ecological response and identified the main drivers for both regions. We calibrated and evaluated transfer function methods for the prediction of these variables and estimated their performances considering spatial autocorrelation. In both datasets, multiple environmental variables mutually and independently affect assemblage compositions, but the number and kind of these variables differ between datasets. We detected spatial autocorrelation, which was often due to environmental similarity, but some variables appeared to reflect geographical closeness, implying that spatial independence between sample sites depends upon the variables. We identified different primary drivers in both areas, highlighting the merit of regional calibrations and the necessity to carry out variable selection for each region separately. The multiple gradients identified imply that potentially multiple parameters could be reconstructed from the same fossil dinocyst assemblages. However, as the multiple gradients reflect geographical structuring, we propose that regional calibrations, even at the expense of generalisation, could improve the reliability and interpretation of transfer function reconstructions.

中文翻译：

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识别恐龙囊组合中海面特性的特征：通过传递函数和模拟技术对定量古海洋学重建的影响

摘要 甲藻囊肿 (=dinocyst) 组合被广泛用于通过应用传递函数重建多个海洋变量。有证据表明，驱动 dinocyst 组合中成分变化的变量的数量和种类因区域而异，驱动因素的选择和传递函数性能的评估是特定于方法的，并且因空间自相关而变得复杂。在这里，我们使用来自北半球大西洋-北极和北半球太平洋的两个新的现代数据集来重新评估海面特性对双囊藻组合的影响。我们确定了 dinocyst 生态响应的维度，并确定了这两个区域的主要驱动因素。我们校准和评估了用于预测这些变量的传递函数方法，并在考虑空间自相关的情况下估计了它们的性能。在这两个数据集中，多个环境变量相互独立地影响组合组成，但这些变量的数量和种类因数据集而异。我们检测到空间自相关，这通常是由于环境相似性造成的，但一些变量似乎反映了地理接近度，这意味着样本点之间的空间独立性取决于变量。我们在这两个领域确定了不同的主要驱动因素，强调了区域校准的优点以及为每个区域分别进行变量选择的必要性。确定的多个梯度意味着可以从相同的化石双囊壳组合重建潜在的多个参数。然而，由于多个梯度反映了地理结构，我们建议区域校准，即使以概括为代价，也可以提高传递函数重建的可靠性和解释。