Rising temperature modulates pH niches of fen species

Abstract

Rising temperatures may endanger fragile ecosystems because their character and key species show different habitat affinities under different climates. This assumption has only been tested in limited geographical scales. In fens, one of the most endangered ecosystems in Europe, broader pH niches have been reported from cold areas and are expected for colder past periods. We used the largest European-scale vegetation database from fens to test the hypothesis that pH interacts with macroclimate temperature in forming realized niches of fen moss and vascular plant species. We calibrated the data set (29,885 plots after heterogeneity-constrained resampling) with temperature, using two macroclimate variables, and with the adjusted pH, a variable combining pH and calcium richness. We modelled temperature, pH and water level niches for one hundred species best characterizing European fens using generalized additive models and tested the interaction between pH and temperature. Fifty-five fen species showed a statistically significant interaction between pH and temperature (adj p ˂ .01). Forty-six of them (84%) showed a positive interaction manifested

Will climate change cause the global peatland to expand or contract? Evidence from the habitat shift pattern of Sphagnum mosses

“…In addition, the habitat suitability and richness of Sphagnum in high latitudes (north of 50°N) would increase over a large area with global warming. Warmer climate, elevated precipitation, longer growing seasons and permafrost thaw are expected to increase the growth and productivity of Sphagnum in northern high‐latitude peatlands (Bengtsson et al, 2021; Hájek et al, 2021; Küttim et al, 2019; Magnan et al, 2018). The fast‐growing Sphagnum mosses can suppress competitively inferior non‐ Sphagnum bryophytes and seedlings of vascular plants, and expand in rich fens (Granath et al, 2010; Singh et al, 2019; Udd et al, 2016; van Breemen, 1995; Vicherová et al, 2017).…”

“…As a result of climate‐driven fen‐bog transitions, peat accumulation would increase (Loisel & Yu, 2013; Magnan et al, 2021; Taillardat et al, 2020) but threaten fen specialized species. To protect the threatened species, many disturbance strategies have recently been proposed to prevent the invasion of Sphagnum species (Hájek et al, 2021; Singh et al, 2019, 2021). Here we reported the importance to reconsider the disturbance strategies that control the natural transformation of fens into bogs in the peatland ecosystem and reassess its global impact.…”

Can Sphagnum removal reverse the undesired succession of rich fens under different alkalinity and fertility levels?

“…Temperature may increase the decomposition rate and nutrient availability and strengthen competitive relationships in the moss layer, thereby promoting the prevalence of Sphagnum over brown mosses (Hájek et al, 2022; Kolari et al, 2021). Similarly, a humid climate facilitates Sphagnum expansion to alkaline fens (Vicherová et al, 2017).…”

“…The long‐term persistence of rich fens in nature has been perpetuated by allogenic factors, such as regular disturbances and continuous initiations of new fens, with the exception of some extremely calcareous fens, where this natural succession hardly occurs (Hájek et al, 2020). Changes in macroclimate temperature also play a role in natural succession by promoting Sphagnum growth and its competitive superiority over brown mosses across Europe, including high‐altitude or high‐latitude rich fens (Hájek et al, 2022; Kolari et al, 2021). On the other hand, increasing precipitation may intensify flooding by calcareous water and reverse the succession process (Granath et al, 2010).…”

Inference of future bog succession trajectory from spatial chronosequence of changing aapa mires

“…papillosum (Säippäsuo W, Figure 2 ). Rich fens are not safe from vegetation changes under warming (Hájek et al, 2022 ; Kolari et al, 2021 ; Küttim et al, 2019 ) and their development may deviate significantly from trajectories of weakly minerotrophic poor fens.…”