ABSTRACT

Introduction.

Rates of deposition of tufa in petrifying springs are complex and highly variable, and the growth rates of associated bryophytes are poorly known.

Methods.

Tufa deposition and bryophyte growth rates were measured using novel methods at six petrifying spring sites in Ireland, north-western Europe. Tufa height was measured at 293 point locations, from 2011 to 2013, using fixed bars mounted above actively growing deposits. Most samples were bryophyte-dominated and the height increments of individual species were measured. Environmental factors were recorded and the chemical composition of spring water was analysed.

Results and Conclusions.

Tufa deposits increased in height by 20.5 ± 1.1 mm.yr⁻¹ on average. The pleurocarpous moss Palustriella commutata, in particular, was associated with rapid deposition. Mixed effects modelling revealed a significant interaction between P. commutata and the presence of surface water: together, they increased annual deposition of tufa by 5.7 ± 1.9 mm. The mean height increment for bare, unvegetated tufa was only 16.5 ± 3.0 mm.yr⁻¹. Palustriella commutata can outgrow the mean rate of tufa deposition, with a mean annual increment of 27.6 ± 1.9 mm in depth of sward. The smaller acrocarpous mosses Didymodon tophaceus and Eucladium verticillatum grew in height by only 9.1 ± 1.6 mm.yr⁻¹ and 9.5 ± 1.3 mm.yr⁻¹ respectively; these two species cannot, therefore, contend with the most rapid rates of tufa deposition. A colonisation cycle was observed, involving competitive displacement of the smaller species by P. commutata. Non-intrusive methods enabled rapid deposition rates to be detected.

中文翻译：

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爱尔兰石化泉中的快速凝灰岩沉积和苔藓植物生长率

摘要

介绍。

石化泉中凝灰岩的沉积速率复杂且变化很大，相关苔藓植物的生长速率知之甚少。

方法。

使用新方法在欧洲西北部爱尔兰的六个石化泉水地点测量了石灰华沉积和苔藓植物生长率。从 2011 年到 2013 年，使用安装在活跃生长的矿床上方的固定杆在 293 个点位置测量了石灰华高度。大多数样品以苔藓植物为主，并测量了单个物种的高度增量。记录环境因素并分析泉水的化学成分。

结果和结论。

凝灰岩沉积物的高度平均增加了 20.5 ± 1.1 mm.yr ^-1。侧蒴藓Palustriella commutata，特别地，用快速沉积有关。混合效应模型揭示了P.commutata与地表水的存在之间存在显着的相互作用：它们共同使凝灰岩的年沉积量增加了 5.7 ± 1.9 毫米。裸露、无植被的凝灰岩的平均高度增量仅为 16.5 ± 3.0 mm.yr ^-1。Palustriella contata 的生长速度超过了凝灰岩沉积的平均速率，草丛深度的平均年增量为 27.6 ± 1.9 毫米。较小的顶果苔藓Didymodon tophaceus和Eucladium v​​erticillatum高度分别仅增长了 9.1 ± 1.6 mm.yr ^-1和 9.5 ± 1.3 mm.yr ^-1；因此，这两个物种无法与最快速的凝灰岩沉积相抗衡。观察到定植周期，涉及由较小物种的竞争性置换P. commutata。非侵入式方法能够检测到快速的沉积速率。