Roe Helen M, Elliott Suzanne M, Patterson R Timothy
School of Natural and Built Environment, Queen's University Belfast, Belfast BT7 1NN, United Kingdom.
School of Natural and Built Environment, Queen's University Belfast, Belfast BT7 1NN, United Kingdom.
Eur J Protistol. 2017 Aug;60:13-27. doi: 10.1016/j.ejop.2017.03.006. Epub 2017 Apr 9.
Testate amoeba-derived transfer functions are frequently used in peatland palaeohydrological studies and involve the development of training sets from surficial peats. However, within acrotelmic peats, considerable vertical variation in assemblage composition can occur, particularly along Sphagnum stems, which may limit the representation of the associated 'contemporary' testate amoeba samples as analogues for the peatland surface. This paper presents contiguous testate amoeba assemblage data from nine monoliths collected from different peatland microforms (hummock, hollow, lawn) in three Sphagnum dominated ombrotrophic peatlands in Ontario and Quebec, eastern Canada. The aim is to: (i) gain a greater understanding of the vertical distribution of xerophilous/hygrophilous taxa along Sphagnum stems; (ii) determine the vertical extent of live/encysted taxa along this gradient; and (iii) assess the significance of this distribution on surface sampling protocols. The results show that testate amoeba communities in the uppermost acrotelmic peat layers display considerable variability. This may reflect a complex interplay of abiotic and biotic controls, including moisture, temperature, light and other characteristics, food availability, and mineral particle availability for test construction. These findings underline the complexity of testate amoeba community structure and highlight the importance of analysing both living and dead Sphagnum stem sections when developing calibration sets.
源自具壳变形虫的转移函数常用于泥炭地古水文研究，且涉及从表层泥炭构建训练集。然而，在粗腐殖质泥炭中，群落组成会出现相当大的垂直变化，尤其是沿着泥炭藓茎干，这可能会限制相关“当代”具壳变形虫样本作为泥炭地表面类似物的代表性。本文展示了从加拿大东部安大略省和魁北克省三个以泥炭藓为主的雨养泥炭地不同泥炭地微地形（丘、洼、坪）采集的九个岩芯的连续具壳变形虫群落数据。目的是：（i）更深入了解嗜旱/嗜湿类群沿泥炭藓茎干的垂直分布；（ii）确定活态/包囊态类群沿此梯度的垂直范围；（iii）评估这种分布对地表采样方案的意义。结果表明，最上层粗腐殖质泥炭层中的具壳变形虫群落表现出相当大的变异性。这可能反映了非生物和生物控制的复杂相互作用，包括湿度、温度、光照和其他特征、食物可利用性以及用于构建壳体的矿物颗粒可利用性。这些发现强调了具壳变形虫群落结构的复杂性，并突出了在构建校准集时分析活态和死亡泥炭藓茎段的重要性。
