Geography, School of Natural and Built Environment, Queen's University Belfast, UK; Ottawa-Carleton Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Canada.
Geography, College of Life and Environmental Sciences, University of Exeter, UK.
Eur J Protistol. 2020 Jun;74:125693. doi: 10.1016/j.ejop.2020.125693. Epub 2020 Mar 18.
Testate amoebae are a widely-used tool for palaeohydrological reconstruction from peatlands. However, it has been observed that weak idiosomic siliceous tests (WISTs) are common in uppermost peats, but very rarely found as subfossils deeper in the peat profile. This taphonomic problem has been noted widely and it has been established that WISTs disaggregate and/or dissolve in the low pH condition of ombrotrophic peatlands. Here we investigate the effect of this taphonomic problem on water-table reconstructions from thirty European peatlands through the comparison of reconstructions based on all taxa and those with WISTs removed. In almost all cases the decomposition of WISTs does not introduce discernible bias to peatland water-table reconstructions. However, some discrepancy is apparent when large abundances of Corythion-Trinema type are present (9-12 cm deviation with 50-60% abundance of this particular taxon). We recommend that WISTs should be removed before carrying out water-table reconstructions, and that the minimum count of testate amoebae per sample should exclude WISTs to ensure the development of robust reconstructions.
有孔虫是一种广泛应用于泥炭地古水文学重建的工具。然而，人们已经观察到，在上层泥炭中，弱个体硅质外壳（WISTs）很常见，但在泥炭剖面的更深层作为亚化石却很少发现。这个埋藏学问题已经被广泛注意到，并且已经确定 WISTs 在寡营养泥炭地的低 pH 值条件下会分散和/或溶解。在这里，我们通过比较基于所有分类群的重建和去除 WISTs 的重建，研究了这种埋藏学问题对来自 30 个欧洲泥炭地的地下水位重建的影响。在几乎所有情况下，WISTs 的分解不会对泥炭地地下水位重建引入明显的偏差。然而，当 Corythion-Trinema 型大量存在时，就会出现一些差异（在该特定分类群的 50-60%丰度下，存在 9-12 厘米的偏差）。我们建议在进行地下水位重建之前应去除 WISTs，并且每个样本的有孔虫最小计数应排除 WISTs，以确保建立稳健的重建。
