Rapid tufa deposition and bryophyte growth rates in Irish petrifying springs. (3rd April 2021)

• Record Type: Journal Article
• Authors: Lyons, Melinda D.; Kelly, Daniel L.
• Is Part Of: Journal of bryology. Volume 43:Part 2(2021)
• Page Start: 162
• Page End: 174
• Publication Date: 2021-04-03
• Subjects: Bryophyte growth rate -- colonisation cycle -- limestone-precipitating spring -- Palustriella commutata -- petrifying spring -- tufa deposition rate; Bryology -- Periodicals; Bryophytes -- Periodicals; Bryology -- Great Britain -- Periodicals; Bryophytes -- Great Britain -- Periodicals; 588
• DOI: 10.1080/03736687.2020.1844990
• Languages: English
• ISSNs: 0373-6687

Abstract

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.