Towards the pan-European bioindication system: Assessing and testing updated hydrological indicator values for vascular plants and bryophytes in mires

Hájek, Michal; Dítě, Daniel; Horsáková, Veronika; Mikulášková, Eva; Peterka, Tomáš; Navrátilová, Jana; Jíménez-Alfaro, Borja; Hájková, Petra; Tichý, Lubomír; Horsák, Michal

doi:10.1016/j.ecolind.2020.106527

Cited by 16 publications

(20 citation statements)

References 74 publications

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“…We further estimated a water level value for each vegetation‐plot record in the data set by averaging the tabled hydrological indicator values for all individual taxa occurring in the record. We adopted the indicator values from the pan‐European study of Hájek et al (2020) that assessed for each taxon, at the scale of 1–12, the values for species optimum to water table depth, drought intolerance, flooding tolerance and ecological tolerance to water table (niche breadth). We averaged indicator values for drought intolerance, with both the ecological tolerances and the percentage covers of individual taxa used as weights.…”

Section: Methodsmentioning

confidence: 99%

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Rising temperature modulates pH niches of fen species

Hájek

Těšitel

Tahvanainen

et al. 2021

Global Change Biology

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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

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Section: Methodsmentioning

confidence: 99%

“…We averaged indicator values for drought intolerance, with both the ecological tolerances and the percentage covers of individual taxa used as weights. Hájek et al (2020) found that these settings resulted in the strongest correlations with measured water level data in data sets containing different types of mire habitats.…”

Section: Methodsmentioning

confidence: 99%

Rising temperature modulates pH niches of fen species

Hájek

Těšitel

Tahvanainen

et al. 2021

Global Change Biology

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“…Based on geographic coordinates, climatic variables (annual precipitation, mean annual temperature and number of hot days above 30°C) from 1961 to 2010 was obtained for each site using the CARPATCLIM database (Antolović et al 2013;www.carpatclim-eu.org). To characterize the water regime, we calculated the means of updated hydrological indicator values for vascular plants and bryophytes in mires weighted by ecological tolerances (Hájek et al 2020a). The traditional Ellenberg-type ecological indicator values (EIV) were used, but means calculated by the minimum value of the tolerance range (called 'drought intolerance' in Hájek et al 2020a) highly correlated with them (r = 0.95, P < 0.001).…”

Section: Environmental Variablesmentioning

confidence: 99%

“…To characterize the water regime, we calculated the means of updated hydrological indicator values for vascular plants and bryophytes in mires weighted by ecological tolerances (Hájek et al 2020a). The traditional Ellenberg-type ecological indicator values (EIV) were used, but means calculated by the minimum value of the tolerance range (called 'drought intolerance' in Hájek et al 2020a) highly correlated with them (r = 0.95, P < 0.001). These hydrological indicator values (Hájek et al 2020a) correlate more strongly with water level than soil moisture (Hájek et al 2020a).…”

Section: Environmental Variablesmentioning

confidence: 99%

“…The traditional Ellenberg-type ecological indicator values (EIV) were used, but means calculated by the minimum value of the tolerance range (called 'drought intolerance' in Hájek et al 2020a) highly correlated with them (r = 0.95, P < 0.001). These hydrological indicator values (Hájek et al 2020a) correlate more strongly with water level than soil moisture (Hájek et al 2020a). We, therefore, refer to this variable as 'water level'.…”

Section: Environmental Variablesmentioning

confidence: 99%

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Variability and classification of Carpathian calcium-rich fens

Hájek¹,

Hájková²,

Goia³

et al. 2021

Preslia

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Calcareous and rich fens harbour the unique biodiversity of plants and invertebrates. They are extremely sensitive to landscape changes because of their island nature. In the Carpathians, they are still well-preserved, but their number has substantially decreased. Knowledge about their variability and classification into vegetation units, a baseline for efficient nature conservancy, is still insufficient in the Eastern Carpathians, where phytosociology has used different methodologies than in the Western Carpathians. It has resulted in artificial boundaries in the distribution of vegetation types and low compatibility with modern European habitat classification schemes. Here we gathered a large set of vegetation-plot records, sampled by the unified sampling protocol. The aim was to uncover the principal variation in compositional data, identify resulting clusters with the hitherto reported vegetation units, and create the unified classification system adjusted for the entire Carpathian territory. In line with previous ecological studies, the unsupervised classifications (Twinspan, beta-flexible clustering method) largely mirrored the base saturation gradient and distinguished between relict fens and younger fen grasslands. We defined formally the cores of 10 vegetation units well reproduced by unsupervised classifications and used them as prototypes in semi-supervised k-means clustering. The final 10 clusters essentially correspond with phytosociological associations, with five of them being reported for the first time for Romania. These vegetation units were well-separated in the principal coordinate analysis, whose first axis separated relict fens from younger fen grasslands, while the second axis followed the water level gradient largely. Groundwater pH and conductivity contributed to forming significant compositional gradients. Climate (temperature, precipitation, number of hot days above 30°C) and specific edaphic conditions contributed to the diversification of the vegetation types. Our analyses supported the classification of fen grasslands into both the tufa-forming and the peatforming ones, belonging to different associations and Habitat Directive units, both occurring in all countries including Romania, rather than having a single separate Eastern-Carpathian association. We provide strong evidence for distinguishing the Sphagno warnstorfii-Tomentypnetalia order and its alliances Sphagno warnstorfii-Tomentypnion nitentis, Stygio-Caricion limosae and Saxifrago hirculi-Tomentypnion in Romania, the latter missing in other Carpathian countries. The final unified classification system will make Carpathian vegetation types of rich and calcareous fens applicable to continental habitat classification schemes.

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