Testing inter‐regional variation in pH niches of fen mosses

Abstract

Question: Mosses are important ecosystem engineers in mires. Their pH optima and tolerances presented in the literature differ between regions, even though the high dispersal ability of mosses should prevent local adaptations. Nutrient availability is sometimes suggested as a reason for local niche differentiation. Are patterns in moss niche diversification, optima and tolerance with respect to pH consistent between regions differing in nutrient availability and abundance of calcareous bedrock?Location: Western Carpathians (Slovakia, a predominantly calcareous P-and K-poor region), Bohemian Massif (Czech Republic, a predominantly crystalline, P-and K-rich region).Methods: Analyses of an original stratified data set and a large database using species response curves.Results: Although the above two regions differ in abundance of calcareous fens, species pH optima (either original or adjusted according to calcium level) were consistent between the regions and data sets. Calcium-tolerant peat mosses (Sphagnum warnstorfii, S. contortum, S. teres) showed an optimum at pH 6 and rather narrow niches. Sphagnum fallax was the most acidophilous, and both S. palustre and S. flexuosum had rather wide intermediate niches. The pH amplitudes were largely consistent between the regions (especially when adjusted pH was used), but S. fallax and Aulacomnium palustre exhibited wider niches in the Bohemian Massif. Despite no significant difference in niche optimum and width, some more nutrient demanding and more generalist species occurred at higher frequency in specific parts of the pH gradient in the Bohemian Massif, while some fen specialists showed the opposite pattern. Conclusions:The small stratified data set and the database data set yielded rather consistent results regarding fen moss niches in the Bohemian Massif and the Western Carpathians. The consistency in pH niches corresponds to the lack of large-scale genetic differentiation in moss species. The observed inter-regional differences in species response curves may thus reflect an increased frequency of competitively strong species in certain parts of the pH/Ca gradient in the nutrient-richer Bohemian Massif rather than genetically conditioned niche shifts. Expansion of these species was probably triggered by potassium enrichment that took place in the 1970s-1980s. Inter-regional differences in species response curves were observed in both data sets, but in the large database data set they were more frequently statistically significant.

A European map of groundwater pH and calcium

“…1) with Ca 2+ as a dependent variable (y) and EC as a predictor (x); the resulting equation of y = 0.153x was obtained (R 2 = 0.84). Such a relationship between Ca 2+ and EC is similar to that found in the abovementioned studies (Hem, 1985;Sjörs and Gunnarsson, 2002;Plesková et al, 2016). Based on this equation, we imputed Ca 2+ concentrations to all samples where only EC was measured.…”

“…We considered all types of shallow groundwater systems, especially spring, spring fen and stream water. The core of our data set is formed by unpublished pH and Ca 2+ or EC data sets of the co-authors (3618 sites); some of them were processed in ecological papers without having presented original pH and Ca 2+ data (Hájková et al, 2006(Hájková et al, , 2008Hájek et al, 2008;Sekulová et al, 2013;Plesková et al, 2016;Horsáková et al, 2018;Šímová et al, 2019). The second most important source were vegetation databases registered in GIVD (Global Index of Vegetation-Plot Databases; Dengler et al, 2011; Table 1) and EVA (European Vegetation Archive; Chytrý et al, 2016), from where 1160 measurements from freshwater habitats were obtained.…”

“…For imputation of Ca 2+ values based on EC, we first aimed at constructing a simple imputation equation based on the well-known correlation between EC and the Ca 2+ concentration in springs and fens (Hem, 1985;Sjörs and Gunnarsson, 2002;Plesková et al, 2016). In our data set of 2988 samples, as well as in its regional subsets, this relationship was strongly governed by EC values above ca.…”

Environmental Together With Interspecific Interactions Determine Bryophyte Distribution in a Protected Mire of Northeast China

“…Mires are usually dominated by bryophytes (mainly Sphagnum), and associated wetland vascular plants. Here, plant distribution is strongly affected by environmental variables such as WTD (Andrus, 1986;Breeuwer et al, 2008;Bu et al, 2013), shade (Gignac and Vitt, 1990), pH (Benavides and Vitt, 2014;Plesková et al, 2016), and cation concentrations (Kooijman, 1993).…”

Refugial occurrence and ecology of the land snail Vertigo lilljeborgi in fen habitats in temperate mainland Europe

“…Water pH and calcium concentration, as reflected by water electric conductivity (see Horsák, 2006), were found to have a synergistic control on vegetation structure (brown mosses vs. Sphagnum mosses; Vicherová, Hájek & Hájek, 2015) to which mollusc species respond. Therefore, we combined water pH and water conductivity (a proxy for calcium richness) into a single variable, hereafter called adjusted pH, using the formula presented in Plesková et al (2016). For each site, a set of climatic variables (i.e.…”