Corresponding author: Hallie Seiler ( hallie.seiler@zhaw.ch ) Academic editor: Monika Janišová
© 2021 Hallie Seiler, Daniel Küry, Regula Billeter, Jürgen Dengler.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Seiler H, Küry D, Billeter R, Dengler J (2021) Regional typology of spring vegetation in Parc Ela (Grisons, Switzerland). Vegetation Classification and Survey 2: 257-274. https://doi.org/10.3897/VCS/2021/69101
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Aims: The spring habitats of Central Europe are insular biotopes of high ecological value. Although subject to severe exploitation pressures, they do not yet have a comprehensive protection status in Switzerland. Contributing to this challenge is the controversy involved with their syntaxonomic classification. In the context of the development of a regional conservation strategy and the establishment of a national inventory of Swiss springs, we carried out a regional survey of spring vegetation and aimed to translate this into a classification system. Study area: Montane and subalpine zones of Parc Ela (Grisons, Switzerland). Methods: We selected 20 springs to cover different regions, elevations and bedrock types within the park. In each of them we recorded complete vascular plant and bryophyte composition as well as a range of environmental variables in three 1-m² plots that were placed to reflect the heterogeneity within the spring. After running an unsupervised classification with modified TWINSPAN, the distinguished vegetation units were characterized in terms of diagnostic species, species richness and environmental variables and placed within the syntaxonomic system. Results: Species richness was high (total species 264, mean 21.7 species in 1 m2). The two most important environmental gradients of the ordination were elevation/water conductivity and insolation/water pH/soil reaction EIV. We distinguished seven communities within two main groups. Conclusions: All unshaded springs, including those over siliceous bedrock, could be assigned to a broadly defined Cratoneurion. The petrifying springs were not strongly distinguishable floristically from other base-rich springs. The forest springs, although often not clearly differentiated from their unshaded counterparts, could be provisionally divided into the alliances Caricion remotae and Lycopodo europaei-Cratoneurion commutati. As there is a certain threat to these habitats in the park due to anthropogenic influence, protection measures are recommended, most importantly the appropriate management of alpine pastures.
Taxonomic reference:
Abbreviations: ANOVA = analysis of variance; DCA = detrended correspondence analysis; EIV = ecological indicator value; FOEN = Federal Office of the Environment (Switzerland); NCHO = Ordinance on the Protection of Nature and Cultural Heritage; SD = standard deviation; TWINSPAN = Two Way Indicator Species Analysis; WPA = Federal Act on the Protection of Waters.
bryophyte, helocrene, montane, Montio-Cardaminetea, Parc Ela, phytosociology, regional typology, rheocrene, spring vegetation, subalpine, Switzerland, unsupervised classification
Central European springs are small but complex island biotopes. Their unique environmental conditions exert great influence on the vegetation and allow colonization by many highly specialized organisms, including glacial relicts (
Because of these conditions, as well as their small size and relative isolation (
In order to develop a differentiated conservation strategy for springs, it would be useful to put spring habitats into a universal scheme. Although phytocoenoses are particularly useful as reference units for conservation (
Switzerland, unlike many other European countries or regions (e.g.
In general, the distinction between springs and their contact associations is often ambiguous because of their strong spatial variation and interlock with adjacent habitats (
Due to these difficulties, there is a need for a Europe-wide systematic review of the class Montio-Cardaminetea, based on a comprehensive data basis. Hájek et al. started a project to this end in 2020 (pers. comm.). The data of this study will be included in Hájek’s project.
Springs of the Swiss Alps have been the subject of various vegetation surveys, mostly in the context of regional studies of alpine vegetation in Grisons (
Parc Ela’s plan to develop a conservation concept for their spring habitats, as well as the commission of a national inventory of spring habitats by the Federal Office for the Environment FOEN (
As the largest nature park in Switzerland, Parc Ela covers 548 km2 in the canton of Grisons (Figure
The park is located on the Pennine and Eastern Alpine nappes, with the Surses valley lying in the middle. A large part of the park lies on basic bedrock, mainly biogenic sediments and evaporites (Federal Office of Topography swisstopo 2020). To the south, around the Albula, Septimer and Julier passes, sedimentary and crystalline rocks (granodiorite, gneiss) alternate on a small scale. In the valleys, especially in the Surses valley, alluvial debris and landslide deposits occur over large areas. The mountain landscape is glacially influenced, its soils shallow and young (ibid.). The springs of this study are located between 956 and 2,115 m a.s.l, as shown in Figure
The park is only sparsely populated. Agricultural use consists mainly of alpine pasture. Park habitats include moorlands, heathland, mountain grasslands, and richly structured landscapes which had been historically cultivated for subsistence agriculture. Tourism is of great importance for the local economy and regional development.
The climate at Arosa (1,878 m, left) and Davos (1,594 m, right) is taken as representative for central Grisons. The climate diagrams show mean values for the standard period 1981–2010. Annual precipitation Arosa 1,365 mm; annual mean temperature Arosa 3.6°C; annual precipitation Davos 1,022 mm; annual mean temperature Davos 3.5°C (Federal Office of Meteorology and Climatology MeteoSwiss 2020).
Sites were selected in accordance with the presumed main environmental gradients of shading, elevation, and spring water chemistry. The cantonal spring inventory (
Vegetation surveys were conducted in July and August 2020. Three plots (relevés) of 1 m2 were recorded per spring site, arranged to best cover the variability evident in the field. Although single plots were intended to be as homogeneous as possible, neither ostensibly “fragmentary” nor “atypical” sites were excluded from the surveys in order to capture the real situation as completely as possible (
A variety of structural and physico-chemical parameters were included as possible explanatory variables for species composition (Table
Parameter | Unit | Comment |
---|---|---|
Coordinates | ° | World Geodetic System WGS 1984 |
Topography | ||
Elevation | m | Values extracted from the Swiss topographical model TLM25 |
Slope | ° | |
Maximum microrelief | cm | Perpendicular deviation of the surface from the plane |
Hydrology | ||
Spring size | m² | Area of open water immediately around the spring outlet ( |
Discharge | l/s | Field approximation ( |
Maximum water depth | cm | |
Vegetation | ||
Vegetation cover | % | Total vegetation; tree, shrub, herb, and cryptogam layers (shoot presence) |
Canopy cover | % | App. % cover |
Maximum height of herb layer | cm | |
Substrate | ||
Coverage values | % | Open water, litter, dead wood, stones / rocks, gravel / coarse sand, fine soil |
Carbonate content of soil | - | Ordinal scale (HCl test) ( |
Spring water | ||
Water temperature at outlet | °C | Multiprobe HQ40d (Hach) |
Water conductivity | µS/cm | Multiprobe HQ40d (Hach) |
Water pH | - | Multiprobe HQ40d (Hach) |
Oxygen content | mg/l | Multiprobe HQ40d (Hach) |
Oxygen saturation | % | Multiprobe HQ40d (Hach) |
The structural surveys followed the method developed on behalf of the FOEN for the national inventory of spring habitats (
Unsupervised classification was performed using the modified TWINSPAN (Two Way Indicator Species Analysis) algorithm (
The data were managed using Vegedaz (
In Vegedaz, the square root-weighted means of ecological indicator values (EIV) for moisture, soil reaction, temperature, light, soil aeration, nutrient content (hereafter “nutrient EIV”), and humus content were calculated for each relevé (
Detrended correspondence analysis (DCA) was performed on the vegetation data using the R package “vegan” (v.2.5), with rare species downweighted (
A total of 95 bryophytes and 164 vascular plant species were recorded. The mean species richness was 21.7 species in 1 m2. The most species-rich plot was located on a large helocrene system used as summer pasture, characterized by 31 vascular plant and 10 bryophyte species in 1 m2. The most common species were Bryum pseudotriquetrum aggr. (occurring in 70% of the relevés) and Aster bellidiastrum (62%). Palustriella commutata was recorded in about half of the plots, over both limestone and silicate. Seven species in the vegetation plots are endangered or potentially endangered in Switzerland, including Tofieldia pusilla, Bryoerythrophyllum alpigenum and Catoscopium nigritum.
Comparing different divisions, seven was the highest number of types for which each of the terminal groups yielded a well floristically defined unit of more than five relevés (Figure
Abbreviated synoptic table from the numerical classification. Constancies are given as percentages; diagnostic (> 0.25) phi values are marked with (*), highly diagnostic (> 0.5) values with (**). Significant values are marked in light grey, highly significant values in dark grey. Diagnostic species (upper part of the table) passed Fisher’s exact test, companion species did not pass the test. No diagnostic species are marked for Type 1 because it consists of a single relevé.
Type | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
No. relevés | 1 | 5 | 9 | 21 | 5 | 6 | 13 | ||||||
Taxon | |||||||||||||
Rhizomnium magnifolium | - | 100 | ** | 22 | 10 | - | - | - | |||||
Geranium sylvaticum | - | 60 | ** | - | - | - | - | - | |||||
Calamagrostis villosa | 100 | 80 | ** | - | - | - | - | - | |||||
Epilobium alsinifolium | - | 20 | 78 | ** | - | - | - | - | |||||
Saxifraga stellaris | - | - | 67 | ** | 14 | - | - | - | |||||
Brachythecium rivulare | - | 80 | 100 | * | 14 | 20 | - | 15 | |||||
Chaerophyllum hirsutum | - | 80 | 67 | * | - | - | - | - | |||||
Pinguicula alpina | - | - | - | 71 | ** | - | - | - | |||||
Selaginella selaginoides | - | - | - | 67 | ** | - | - | 15 | |||||
Salix foetida | - | - | - | 52 | ** | - | - | - | |||||
Palustriella falcata | - | 20 | - | 52 | ** | - | - | - | |||||
Arabis subcoriacea | - | - | 22 | 52 | ** | - | - | - | |||||
Juncus alpinoarticulatus | - | - | - | 52 | * | 20 | - | 15 | |||||
Philonotis tomentella | - | - | 22 | 43 | * | - | - | - | |||||
Fissidens dubius | - | - | - | 5 | 80 | ** | - | 15 | |||||
Platydictya jungermannioides | - | - | - | - | 60 | ** | - | - | |||||
Plagiochila asplenioides | - | - | - | - | 80 | ** | 33 | 8 | |||||
Knautia dipsacifolia | - | 20 | - | - | 80 | ** | 33 | 8 | |||||
Brachythecium glareosum | - | - | - | 5 | - | 83 | ** | - | |||||
Plagiomnium medium | - | - | - | - | - | 50 | ** | - | |||||
Carex davalliana | - | - | - | 24 | 20 | - | 69 | ** | |||||
Cephalozia spec. | - | - | - | 5 | - | - | - | ||||||
Amblystegium serpens | - | - | - | - | - | - | 8 | ||||||
Agrostis stolonifera | - | - | 56 | 5 | 40 | - | 38 | ||||||
Alchemilla alpina aggr. | - | - | - | 14 | - | - | - | ||||||
Equisetum variegatum | - | - | 11 | 43 | - | - | 31 | ||||||
Aneura pinguis | - | - | 33 | 57 | 20 | 67 | 46 | ||||||
Aster bellidiastrum | - | 40 | 33 | 76 | 100 | 67 | 54 | ||||||
Anastrophyllum minutum | 100 | - | - | - | - | - | - | ||||||
Achillea millefolium aggr. | - | - | - | 5 | - | - | - | ||||||
Amblystegium tenax | - | 20 | 11 | - | - | - | - | ||||||
Amblystegium fluviatile | - | 40 | 44 | - | - | - | - | ||||||
Adenostyles alliariae | - | 20 | 11 | - | - | - | - | ||||||
Blindia acuta | - | - | - | 29 | - | - | - | ||||||
Alchemilla conjuncta aggr. | - | - | 11 | - | - | - | - | ||||||
Bartsia alpina | - | - | - | 19 | - | - | - | ||||||
Adenostyles alpina | - | - | - | 5 | - | 33 | - | ||||||
Alnus viridis | - | - | - | 10 | - | - | - | ||||||
Cephaloziella varians | - | - | 11 | - | - | - | - | ||||||
Carex sempervirens | - | - | - | 14 | - | - | - | ||||||
Angelica sylvestris | - | - | - | - | - | - | 8 | ||||||
Caltha palustris | - | 20 | - | 5 | - | - | 15 | ||||||
Briza media | - | - | - | - | - | - | 8 | ||||||
Brachypodium rupestre | - | - | - | - | 20 | - | 8 | ||||||
Aulacomnium palustre | - | - | 11 | - | - | - | - | ||||||
Avenella flexuosa | - | - | - | 5 | - | - | - | ||||||
Blepharostoma trichophyllum | 100 | 20 | - | 5 | - | - | - | ||||||
Calypogeia azurea | - | 20 | - | 5 | - | - | - | ||||||
Cardamine amara | - | - | - | - | - | - | 15 |
Water pH differed little between vegetation types (mean 7.5–7.9) and oxygen content was mostly high (Suppl. material
Representative photographs of each vegetation type. A Type 2, mineral-poor springs in subalpine forest clearings; B Type 3, mineral-poor, cold-stenothermic, unshaded springs; C Type 4, mineral-poor springs in alpine pastures; D Type 5, mineral-rich, montane forest springs; E Type 6, mineral-rich forest springs; F Type 7, montane rich-fen springs. Photographs by Hallie Seiler (A–E) and Jürgen Dengler (F).
This type consisted of a single plot in sparse mountain forest: a deep outlet of very cold water (3.8°C) under a massive rock overhang with mostly saxicolous vegetation. Many of the species present were unique in the survey (e.g. Sphagnum capillifolium, Bryoerythrophyllum alpigenum). In the ordination, this relevé lies more than 2 SD (standard deviation) away from its nearest neighbor (DCA axis 1). This type was excluded post-hoc from classification and final ordination for these reasons. The other relevés of this heterogeneous spring area belong to Types 2 and 3.
Diagnostic species: Calamagrostis villosa, Geranium sylvaticum, Rhizomnium magnifolium
This type was composed of many species that prefer sheltered sites. Brachythecium rivulare occurred frequently, while Palustriella commutata was absent. Litter cover was high, and the herb layer was vigorous (mean cover 58%, mean maximum height 88 cm). The spring water had low conductivity, was often oxygen-rich and very cold (mean water temperature at outlet 5.2°C). The type mostly consisted of rheocrenes with moderate to strong flow (mean discharge 6.2 l/s). The average maximum microrelief was 48.2 cm, significantly greater than in many other types (Figure
This type is difficult to classify. According to
Arithmetic mean, minimum, and maximum values of environmental variables over the entire survey. Significant differences are noted as follows: (***), highly significant (p < 0.001); (**), moderately significant (0.001 ≤ p < 0.01); (*), significant (0.01 ≤ p < 0.05); (n.s.), not significant. The ordinal scale of the carbonate content of the soil should be interpreted as follows: 0, no carbonate present; 1, only traces of carbonate; 2, < 2% carbonate; 3, 2–10% carbonate; 4, > 10% carbonate (
Topography | Mean | Min. | Max. | Test, Transformation | p-value | Significance |
---|---|---|---|---|---|---|
Elevation (m) | 1,575 | 964 | 2,122 | Welch’s ANOVA | < 0.001 | *** |
Slope (°) | 19 | 4 | 46 | ANOVA | 0.911 | n.s. |
Maximum microrelief (cm) | 22 | 4 | 77 | ANOVA, log10 | 0.010 | * |
Hydrology | ||||||
Spring size (m²) | 7 | 1 | 20 | Welch’s ANOVA | 0.183 | n.s. |
Discharge (l/s) | 5 | 0.03 | 25 | Welch’s ANOVA | 0.005 | ** |
Maximum water depth (cm) | 5 | 0 | 26 | ANOVA, log10 | 0.005 | ** |
Vegetation | ||||||
Canopy cover (%) | 28 | 0 | 82 | ANOVA | 0.415 | n.s. |
Maximum height of herb layer (cm) | 54 | 16 | 150 | ANOVA | 0.559 | n.s. |
Coverage herb layer (%) | 46 | 0.2 | 92 | ANOVA | 0.574 | n.s. |
Coverage moss layer (%) | 50 | 5 | 96 | Welch’s ANOVA | 0.503 | n.s. |
Species richness | 21.7 | 10 | 41 | ANOVA | 0.845 | *** |
Vascular plant species richness | 13.6 | 5 | 31 | Welch’s ANOVA | < 0.001 | |
Bryophyte species richness | 7.3 | 1 | 17 | ANOVA | 0.130 | n.s. |
Substrate | ||||||
Open water (%) | 22 | 0 | 69 | ANOVA | 0.103 | n.s. |
Litter (%) | 17 | 0.1 | 95 | Welch’s ANOVA | 0.047 | * |
Dead wood (%) | 3 | 0 | 20 | Welch’s ANOVA | 0.792 | n.s. |
Stone, rock (%) | 29 | 0 | 95 | Welch’s ANOVA | < 0.001 | *** |
Gravel, coarse sand (%) | 22 | 0 | 85 | ANOVA | 0.531 | n.s. |
Fine soil (%) | 49 | 0 | 100 | ANOVA | 0.006 | ** |
Carbonate content of soil | 1.6 | 0 | 4 | ANOVA | < 0.001 | *** |
Spring water | ||||||
Water temperature at outlet (°C) | 8.5 | 3.7 | 13.0 | Welch’s ANOVA | < 0.001 | *** |
Water conductivity (µS/cm) | 487 | 131 | 1299 | Welch’s ANOVA | < 0.001 | *** |
Water pH | 7.7 | 6.8 | 8.6 | Welch’s ANOVA | 0.046 | * |
Oxygen content (mg/l) | 7.37 | 0.17 | 10.81 | Welch’s ANOVA | < 0.001 | *** |
Oxygen saturation (%) | 78.7 | 1.9 | 108.6 | Welch’s ANOVA | < 0.001 | *** |
Diagnostic species: Brachythecium rivulare, Chaerophyllum hirsutum, Epilobium alsinifolium, Saxifraga stellaris
This vegetation developed around rheocrenes of the subalpine zone under the influence of oxygen-rich, cold spring water (mean water temperature at outlet 5.1°C). Compared to other unshaded springs in the study, the water was significantly richer in oxygen (mean oxygen content 10.2 mg/l) (Figure
This vegetation type shares a diagnostic species (Epilobium alsinifolium) with the Cratoneuro-Philonotidetum seriatae
Diagnostic species: Arabis subcoriacea, Juncus alpinoarticulatus, Palustriella falcata, Philonotis tomentella, Pinguicula alpina, Salix foetida, Selaginella selaginoides
These relevés included oligotrophic springs on pastures in the subalpine to alpine zones. The plots were evenly divided between rheo- and helocrenes. The most species-rich relevés in the survey belonged to this type (mean 24.3 species in 1 m2). These springs were mostly fully insolated or were only lightly shaded. In some cases, very high water temperatures were recorded in shallow pools. Water was significantly shallower than in Types 2 and 3 (Figure
The records of this type are similar to Philonoto fontanae-Montietum rivularis Büker et Tx. 1941. This community is found in moderately warm alpine springs over siliceous bedrock and is associated with grazing. The character species Philonotis tomentella is also diagnostic here, and the calcifuge Diobelonella palustris occurs sporadically. Compared to Pinguicula vulgaris, the diagnostic species P. alpina is more likely to occur in high mountains and is less bound to limestone (
Diagnostic species: Fissidens dubius, Knautia dipsacifolia, Plagiochila asplenioides, Platydictya jungermannioides
These helocrenes were found in forests of the montane zone. The substrate was basic (soil reaction EIV), nutrient-rich (nutrient EIV), and fine. The oxygen content of the spring water was significantly lower than many other types (mean 3.1 mg/l) (Figure
The alliance Lycopodo europaei-Cratoneurion commutati Hadač 1983 could be considered here. These calcareous forest springs, although mostly associated with the colline and montane zones, occur almost to the timberline according to
Diagnostic species: Brachythecium glareosum, Plagiomnium medium
These records were superficially similar to Type 5: they were also base-rich, shaded springs of the montane stage. The springs were either rheocrenes or linear springs. Half of the relevés were tufaceous, and the relevés were species-poor on average (mean 18.3 species in 1 m2). Water was better oxygenated in contrast to type 5 (Figure
The relevés of this type belong to two forest springs with very different environmental conditions: a linear spring without tufa formation and a very large, complex rheocrene system with cascade tufa. The question arises as to why they were combined in the classification. There are only a few species that can persist under strong tufa formation; however, these can often occur on other base-rich, wet sites, so they are usually not strictly tied to petrifying springs (
Diagnostic species: Carex davalliana
This vegetation type was influenced by warm, base-rich spring water, sometimes with tufa formation. With the exception of one plot, this type was located in helocrenes (69%) or linear springs. Canopy cover varied from 14 to 68%, but species mostly had moderately high light EIVs (mean 3.34). The water temperatures at the outlet were significantly higher than in Type 3 (Figure
This type shares many species with rich fens, including Carex davalliana (diagnostic), Carex lepidocarpa (constant), and Tofieldia calyculata. However, character species of the Cratoneurion (Palustriella commutata and Aneura pinguis) occur frequently, and Hymenostylium recurvirostrum (character species) and Pinguicula vulgaris (companion species) are also present. The Cratoneuretum commutati Aichinger 1913 could be considered: this vegetation occurs in calcareous springs of the montane stage and possesses the character species Cratoneuron filicinum aggr., present in the relevés, a rather nitrophilous species that tolerates desiccation better than Palustriella commutata (
DCA axes 1 and 2 explain much of the variation in species composition (eigenvalues 0.66 and 0.54, respectively, Figure
Gradient analysis (DCA) of the dataset. Environmental variables and EIVs are projected over the ordination. The vectors shown correlate with at least |r| = 0.80 with one of the two axes. Above – vegetation types; below – the 20 most common species in the relevés, as well as the diagnostic species of the numerical classification, are shown: “Arabsubc” – Arabis subcoriacea; “Agrogiga” – Agrostis gigantea; “Aneuping” – Aneura pinguis; “Astebell” – Aster bellidiastrum; “Bracglar” – Brachythecium glareosum; “Bracrivu” – Brachythecium rivulare; “Bryupseu” – Bryum pseudotriquetrum aggr.; “Caredava” – Carex davalliana; “Careflac” – Carex flacca; “Chaehirs” – Chaerophyllum hirsutum; “Cratdeci” – Cratoneuron decipiens; “Desccesp” – Deschampsia cespitosa; “Epilalsi” – Epilobium alsinifolium; “Equivari” – Equisetum variegatum: “Gerasylv” – Geranium sylvaticum; “Knauaggr” – Knautia dipsacifolia; “Palufalc” – Palustriella falcata; “Palucomm” – Palustriella commutata; “Plagaspl” – Plagiochila asplenioides; “Plagmedi” – Plagiomnium medium; “Polyvivi” – Polygonum viviparum; “Poteerec” – Potentilla erecta; “Rhizmagn” – Rhizomnium magnifolium; “Salifoet” – Salix foetida; “Saxiaizo” – Saxifraga aizoides; “Seslcaer” – Sesleria caerulea; “Toficaly”– Tofieldia calyculata.
The species richness of the records (95 moss species, 164 vascular plant species) is high compared to similar studies. In Gesäuse National Park (AT), 97 vascular plants and 60 bryophyte species were recorded in 46 plots of less than 1 m2 (
The ecological conditions of springs are generally difficult to assess because they are small habitats characterized by strong ecotones (
Vegetation types are clearly separated by elevation and water conductivity (Figure
There is an apparent gradient of shading within the main groups, but it is not statistically significant in the overall data set, although it explains much of the variability in the ordination (light EIV, |r| = 0.984 with DCA axis 1).
This study was affected by the oft-cited paucity of diagnostic species particular to spring habitats (
Epilobium alsinifolium, listed as a class character species of Montio-Cardaminetea, appears in these records only in the Types 2 and 3, presumably due to temperature-related effects. The class character species Stellaria alsine and Bryum schleicheri (
Although the water conductivity was mostly not very low (Figure
The delimitation between spring and contact community is challenging, which complicates the selection of areas for vegetation surveys: in the literature, very different area sizes are recorded, between 0.04 to 80 m2 (
The numerical classification results in seven vegetation types which seem to occupy a rank between alliance and association. For this classification, the forest springs were neither simply split off into a separate alliance, nor were they merged with unshaded springs of similar chemistry. Although some researchers (e.g.,
The description and comparison of types results in the proposed syntaxonomy in Table
Montio-Cardaminetea Br.-Bl. et Tüxen ex Klika et Hadač 1944 |
Montio-Cardaminetalia Pawłowski et al. 1928 |
Cratoneurion commutati Koch 1928 |
Montane associations |
º Eucladietum verticillati Allorge 1922 |
º Cratoneuretum commutati Aichinger 1913 |
Subalpine-alpine associations |
º Cratoneuro-Philonotidetum calcareae |
º Cratoneuro-Philonotidetum seriatae |
Lycopodo europaei-Cratoneurion commutati Hadač 1983 |
º Brachythecio rivularis-Cratoneuretum |
Cardamino-Chrysosplenietalia |
Caricion remotae |
º Cardamino-Chrysosplenietum alternifolii |
The two visualized DCA axes show high heterogeneity along their lengths. DCA axis 1 can be interpreted as a gradient from highly insolated, oligotrophic springs to somewhat more nutrient-rich forest springs with base-rich water (Figure
In the ordination it can be clearly seen that elevation is a sum parameter which integrates diverse factors and catchment processes (
The ordination confirms that nutrient EIV is an important factor for species composition (|r| = 0.799 with DCA axis 1). Since eutrophication quickly leads to the depletion of specialized bryophytes in oligotrophic wetlands (
Parc Ela has a good ecological infrastructure which is continuously being reinforced. Spring restoration projects, rare in Switzerland to date, likely have a good chance of success within the park; however,
This study confirms the oft-cited species richness of spring habitats. For the protection of these valuable habitats, many new developments can be expected in the coming years, such as the planned European revision of the class Montio-Cardaminetea (cf. Hájek et al., pers. comm.) and completion of the national inventory of spring habitats in Switzerland. However, regional projects remain important. Since many species of bryophytes are highly specialized to springs (
In the future, a refined typology must be considered for spring conservation. This study identifies three major challenges to typifying the montane-subalpine springs of the central Alps: the complex geological and topographical conditions prevent simple division by groundwater chemistry; petrifying springs are floristically hardly distinguishable from other base-rich springs (and definition based on tufa formation is unsatisfactory;
Although the network of spring habitats is more intact in the high mountains than in the lowlands, many threats still exist. In this study, the importance of nutrient balance for plant species composition is confirmed; however, for the numerous oligotrophic springs on alpine pastures, the extent of the ecological influence of this type of land use is still unclear. Climatic conditions may also become problematic in the coming years: because high-elevation springs depend on catchment snowpack and glaciers (
As the “water castle of Europe,” Switzerland bears a strong responsibility to preserve its natural springs. Although there are many challenges facing spring conservation, renewed national scientific interest should do much to protect these valuable habitats.
The data are provided as supplementary material and also included in the GrassPlot database (https://edgg.org/databases/GrassPlot).
The project was planned jointly by H.S., J.D., and D.K.; H.S. carried out the field sampling and plant determination with support from J.D. and D.K.; H.S. performed the analyses and drafted the manuscript under the guidance of J.D.; all authors checked, improved, and approved the manuscript.
We are grateful to Regula Ott of Parc Ela for coordinating the project and sharing her insights into the studied habitats and their regional context. Daniel Hepenstrick and the Swiss Association of Bryology and Lichenology offered valuable assistance in determining bryophytes, while Beata Cykowska-Marzencka checked and revised the determinations of critical samples. Open access funding was provided by ZHAW Zurich University of Applied Sciences.
Hallie Seiler (Corresponding author, hallie.seiler@zhaw.ch), ORCID: https://orcid.org/0000-0002-9333-5226
Daniel Küry (daniel.kuery@lifescience.ch), ORCID: https://orcid.org/0000-0002-5207-9713
Regula Billeter (regula.billeter@zhaw.ch)
Jürgen Dengler (juergen.dengler@zhaw.ch), ORCID: https://orcid.org/0000-0003-3221-660X