Effects of management and altitude on bryophyte species diversity and composition in montane calcareous fens

Flora (2001) 196, 180-193 http://www.urbanfischer.de/journa\s/flora

© by Urban & Fischer VerLag

Effects of management and altitude on bryophyte species diversity and composition in montane calcareous fens ARIEL BERGAMINI*I, MARKUS PEINTINGER2 , BERNHARD SCHMID2 , EDWIN URMI 1 1

2

*

Institut fUr Systematische Botanik, UniversiUit Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland ([email protected]; [email protected]) Institut fUr Umweltwissenschaften, Universitat Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland ([email protected]; [email protected]) Corresponding author

Accepted: July 12,2000

Summary We examined patterns of bryophyte species richness and communities in 36 montane calcareous fens in Switzerland. Sites differed in management regime (grazing vs. mowing) and altitude. In addition, several environmental variables were measured. Bryophyte diversity was determined as species density (mean of 5 plots per site), as species richness (number of all species of a site) and as f3-diversity. Species richness was 20% higher at grazed than at mown sites. We interpret this as the result of higher environmental heterogeneity at grazed sites. This could also be the cause for the significantly higher f3-diversity at grazed sites. However, there was a significant management x altitude interaction caused by species-poor sites at low altitudes under grazing. This interaction might be caused by more intensive grazing at low altitude. Grazed sites contained the higher overall species richness (117 vs. 79), more exclusive species (47 vs. 9), and more Red List-species (12 vs. 6). Altitude had only an effect on the number of exclusive species, which was highest at high-altitude sites. No differences could be found for species densities both between management regimes and between altitude classes. This result indicates no differences in habitat heterogeneity at the within-plot scale. For analysis of effects of environmental variables on bryophyte communities, we used a direct ordination technique (CCA). The variables pH, amount of total carbon in the soil and management turned out to be the most important in explaining variation in the species data. However, variation explained by total carbon could also be explained in terms of total nitrogen or moisture. For preserving bryophyte diversity in montane wet meadows, extensive grazing by cattle is crucial. Due to slightly different bryophyte communities under the different management regimes, however, bryophyte diversity at the landscape level will be highest when both types of management are maintained. Key words: biodiversity, bryophytes, calcareous fens, grazing, conservation, f3-diversity

1. Introduction In many of the world's so called developed countries, the greater part of the original wetland area has been destroyed (MALTBY 1988). In Switzerland, in the last 100 years, more than 90% of the wetlands have vanished (BUWAL 1990). Major causes of this loss are drainage, intensified agricultural activities and the expansion of the built-up area (BUWAL 1990). Consequently, a great part of the wetland vascular plants and bryophytes are now endangered in Switzerland (LANDOLT 1991, URMI et al. 1992). Calcareous fens, 180

FLORA (2001) 196

dominated by communities belonging to the Caricion davallianae alliance (vegetation classification: ELLENBERG 1996), are especially rich in vascular plants. (BRAUN 1968, KLOTZLI 1969, DIETL 1975, GORS 1977). Therefore, they have been primary objects in nature conservation for a long time (KAULE 1991, LANDOLT 1991). The bryophyte layer of calcareous fens is usually well developed (KLOTZLI 1969, GIUGINI 1991) and bryophyte species richness tends to be high (BRAUN 1970, ECCB 1995). Traditionally, in the lowlands calcareous fens were mown once a year between late August and October, 0367-2530/011196/03-180

$ 15.0010

whereas in the montane region, where livestock farming is more frequent, extensive grazing by cattle is very common (MUHLETHALER 1992, VON WYL et al. 1995). Grazing and mowing can influence vegetation in very different ways (CRAWLEY 1983). The main processes by which grazing animals influence plant communities are (selective) defoliation, trampling and deposition of dung and urine, which all cause increased habitat heterogeneity (HARPER 1977, VAN WIEREN 1995). At low grazing pressure, diversity is often enhanced (e.g. SCHLAPFER et al. 1998), but high grazing pressure can also decrease diversity (ANDRESEN et al. 1990, VAN WIERDEN 1995). In calcareous fens in Switzerland and Bavaria, however, species richness of vascular plants is lower on grazed than on mown sites (BRUDI 1995, PLATTNER 1996, PEINTINGER 1999, see also WENGER 1995). So far, little is known about the influence of the different management regimes in montane wetlands on bryophyte diversity. Further, there is only sparse literature about the effects of grazing by large herbivores on bryophyte communities and bryophyte diversity in other habitats. VAN To OREN et al. (1990) found enhanced bryophyte species richness in Dutch chalk grassland after introduction of grazing by sheep. RAWES (1983) observed decreasing diversity of bryophytes associated with bare peat in formerly grazed areas on blanket bogs. DURING & WILLEMS (1986) assume that mowing, at least in chalk grasslands and applied late in the year, leads to a decrease in bryophyte diversity. Generally, one can state that management regime influences bryophyte communities and that grazed sites in general exhibit a more diverse bryophyte layer than mown sites. A noteable exception to this pattern was found by ZAMFIR (1999) in Alvar grasslands, where bryophyte diversity was greater in mown sites. Calcareous fens belonging to the Caricion davallianae alliance occur in Central Europe from the lowlands to the subalpine belt (GORS 1977), and altitude is thought to be one of the prime factors influencing species composition in these communities (GIUGINI 1991). Examining recent vertical plant distribution patterns is one way to predict future species ranges under global warming scenarios. Enhanced temperatures affect various physiological processes in plants (LARCHER 1994), which leads to altered performance (e.g. HOBBIE et al. 1999). Altered performance may finally result in changes of various traits of communities, e.g. dominance structure (HARTE & SHAW 1995). Both vascular plants and bryophytes often show clear restrictions in their vertical distribution (AMANN 1928). Diversity patterns for bryophytes and vascular plants, however, do not have to coincide along elevational gradients (e.g. SLACK 1977). In this study we examine the influence of management type (mowing vs. grazing), altitude, and the

interaction of these two factors on bryophyte species diversity and on bryophyte community composition of calcareous fens. It is for the first time that bryophytes in calcareous fens in montane Switzerland are examined. The study presented here is part of a larger project describing and explaining species diversity of various taxonomic groups in Swiss montane wetlands (PLATTNER 1996, DI GULlO 1996, PAULI 1998, PEINTINGER 1999, WETTSTEIN & SCHMID 1999).

2. Materials and Methods 2.1. Study area For this study, we used 36 fen sites scattered over an area of approx. 3500 km2 in the north-eastern part of Switzerland (cantons of Schwyz, St. Gallen, Glarus and AppenzellAusserrhoden; Fig. 1). The study area is part of the pre-Alps, which are especially rich in fen sites (BUWAL 1990). Annual rainfall is rather high and varies between 1500-2800 mm (UTTINGER 1967). Bedrock is mainly composed of various calcareous sediments of tertiary and mesozoican age (SPICHER 1972). Typical vascular plant species of the sites are Primula farinosa L., Carex davalliana Sm, Molinia caerulea (L.) Moench, Carex panicea L., Succisa pratensis Moench, Swertia perennis L., and various orchids. More nutrient-rich parts of the sites, however, are often dominated by taller species like Filipendula ulmaria (L.) Maxim., Cirsium oleraceum (L.) Scop., and Trollius europaeus L.

Fig. 1. The location of studied fen sites (montane wetlands) in northeastern and central Switzerland. Symbols: 'V = mown sites at low altitude (800-1000 m a.s.l.), 0 = mown sites at intermediate altitude (1000-1200 m a.s.l.), 6 = mown sites at high altitude (1200-1400 m a.s.l.), .. = grazed sites at low altitude (800-1000 m a.s.l.), • = grazed sites at intermediate altitude (1000-1200 m a.s.l.), .. =grazed sites at high altitude (1200-1400 m a.s.l.). FLORA (2001) 196

181

2.2. Study design

2.4. Taxonomy

According to the inventory of the fenlands (BUWAL 1990), over 600 fens exist in the study area. Out of these, we randomly selected 36 sites. The selection was restricted to sites with the greater part of their area belonging to the Caricion davallianae alliance. We established a two-way factorial design with the factors management (grazing vs. mowing) and altitude (three classes: low: 800-1000, intermediate: 1000-1200, high: 1200-1400 m a.s.l.). For each of the 6 factor combinations there were 6 replicates. A further proviso was that the distribution of site area within each of the six factor combinations was as similar as possible. Therefore, 'effects' of the design factors on site area were not significant (F 5,30 = 1.03, P =0.420).

The nomenclature follows CORLEY et al. (1981) and CORLEY & CRUNDWELL (1991) for mosses and GROLLE (1983) for liverworts, with the exception of Palustriella Jalcata (Brid.) Hedenas and Scapania paludosa (K. Miill.) K. Miill., which are treated as separate species. The following taxa are treated as collective because they are in dried or sterile form difficult to distinguish: Calypogeia muelleriana s.l. (c. muelleriana and C. azurea), Chiloscyphus polyanthos s.l. (Ch. polyanthos and Ch. pallescens), Marchantia polymorpha s.l. (M. polymorpha and M. alpestris), Pellia epiphylla s.l. (P. epiphylla and P. neesiana), Plagiochila asplenioides s.l. (P. asplenioides, P. porelloides and P. britannica) and Sphagnum recurvum s.l. (S. Jallax, S. angustifolium and S. flexuosum). Specimens sampled for determination are deposited at the herbarium of the University of Zurich (Z).

2.3. Sampling of bryophytes and environmental variables Field work was carried out between May and July 1997. In each of the 36 sites 5 plots of 2 m 2 (1 x 2 m) were randomly selected in the following way: We divided each site in four sectors. In each sector one plot was established randomly. One additional plot was placed in the center of each site. To avoid large heterogeneity, only plots with Carex davalliana were investigated. If there was no C. davalliana in a selected plot, this plot was replaced by a randomly selected plot of the same sector. Carex davalliana is one of the typical species of the Caricion davallianae alliance. In each plot, all bryophyte species were noted. In addition, cover of vascular plant vegetation, bryophyte vegetation, and bare ground were estimated in percentages of plot area. Also on the level of plots, we measured slope and aspect. Because of the restriction in placing the plots in the Caricion davallianae alliance, only a part of the bryophyte flora of each site was sampled. To overcome this limitation, the whole site was searched for additional species after the work on the plots was finished. Additional searching was done for at least 30 minutes and for a maximum of 1 hour. Occasionally trees and rocks occurred in the fen sites. These were not searched for bryophytes, i.e. all bryophytes sampled had grown either on earth, peat, plant litter, on other bryophytes or on dung from cattle. Additionally, three soil cores of approx. 3 x 3 x 3 cm were collected in each plot. We mixed the three soil cores per plot and dried them as soon as possible at 40°C for several days. After sieving (2 mm mesh) the soil samples to remove roots and stones, we pulverized the soil with an electronic mill. Total nitrogen (N) and total carbon (C) were determined with a CHNS-Analyser (CHNS-932, Leco USA). These values, inst~ad of organic carbon and nitrogen, were later directly used for calculating CIN ratios. This was possible, because the amount of organic carbon and nitrogen were only slightly smaller than the totals (M. PEINTINGER, unpubl.). For determining soil pH, one part pulverized soil (approx. 1 g) and three parts deionized water were thoroughly mixed in test tubes. After leaving the test tubes untouched for 24 hours, they were shaken again and immediately afterwards pH was measured in suspension by an electronic pH meter (Crison pH/mY-meter digit 501). 182

FLORA (2001) 196

2.5. Data analysis We analysed effects of management and altitude on total species diversity of the sites by two-way analysis of variance. We tested for three levels of diversity: species richness (= number of species of the five plots plus the additionally sampled species), species density (= mean number of species per plot at a site) and beta-diversity after WHITTAKER (1972). Beta-diversity was calculated as f3 = (SIS) - 1 where St is total number of species in the five plots per site and S is species density. Beta-diversity measures the degree of community turnover and is therefore an indirect measurement of habitat diversity. For examinig effects of main factors on the various diversity measures, all analyses were also done with site area as covariable (results not shown). Since analyses with and without the covariable revealed the same results, area was not further considered and analyses and results are presented without area as covariable. Because seperate analyses for mosses and liverworts revealed only small differences, only results for all bryophytes are presented. Effects of management and altitude on the environmental variables (cf. Table 1) were analysed by two-way analysis of variance (ANOVA). For this, means of values for the environmental variables of the 5 plots per site were used. Because cover of vascular plants and cover of bryophytes did not satisfy the assumptions ANOVA, we used a nonparametric test (Scheirer-Ray-Hare extension of the Kruskal-Wallis test, see SOKAL & ROHLF 1995). The values of the variables CIN, total N, total C, and bare ground were log-transformed prior analy~ sis. For analysis of bryophyte communities, we used direct and indirect ordination methods (JONGMAN et al. 1995). We used frequency values (number of occupied plots, ranging from 1 to 5) as original species scores. To test for effects of management and altitude on bryophyte communities, detrended correspondence analysis (DCA) with subsequent two-way ANOVA on the site scores was applied. However, management and altitude were not significantly related to site scores of the first three axes of DCA (results not presented here).

Therefore, we used canonical correspondence analysis (CCA) to search for main environmental gradients in the species data. For this, all environmental variables, including management and altitude, were employed. The number of environmental variables was reduced by the CANOCO (TER BRAAK & SMILAUER 1998) procedure of 'forward selection of environmental variables', and their statistical significance was tested by subsequent Monte Carlo permutation test (999 unrestricted permutations). The forward selection is stopped when the additional effect of the variable last selected is not significant (conventional 5% significance level, sequential Bonferroni correction). To avoid giving undue weight in the analysis to rare taxa, data of bryophytes recorded only once during the whole study were removed. DCA and CCA were carried out with the statistical software CANOCO 4.0 (TER BRAAK & SMILAUER 1998). AllANOVAs were carried out with the GENSTAT 5.0 program, release 3.2 (PAYNE et al. 1993).

3. Results 3.1 Overall species richness and Red List taxa Sites.' A total of 126 bryophyte species was found at the 36 surveyed sites: 96 mosses (including 18 sphagna) and 30 liverworts (see Appendix). Species number in each site varied from 23-48 (mean 33.0), number of liverworts from 0-12 and number of mosses from 20-39. Fifty-five species (43.6%) were found at one or two sites only. Eleven species were very common, i.e. occuring at 30 or more sites. Four of these species, namely Calliergonella cuspidata, Campylium stella tum, Plagiomnium elatum, and Rhytidiadelphus squarrosus were found at all sites. The most common liverworts were Pellia endiviifolia (21 sites), Aneura pinguis (17), Lophozia bantriensis (16), and Chiloscyphus polyanthos (14). There was no significant correlation between number of liverworts and number of mosses (r = 0.236, n = 36).

Plots.' Within 180 plots, a total of 99 bryophyte species were found (78 mosses, 21 liverworts). Species number per plot varied from 4 - 22, number of liverworts from 0-6 and number of mosses from 4-18. Thirtynine species (39.4%) appeared in one or two plots only. Only seven species were found in more than half of the plots, namely Calliergonella cuspidata (169), Campylium stellatum (148), Plagiomnium elatum (140), Climadum dendroides (130), Fissidens adianthoides (120), Thuidium philibertii (99), Rhytidiadelphus squarrosus (92). Again, liverworts were less frequent than mosses. Most frequent on the level of plots were Aneura pinguis (29), Pellia endiviifolia (21), Chiloscyphus polyanthos (20), and Lophozia batriensis (19). On the level of plots, there was a weak but nevertheless significant correlation between number of liverworts and number of mosses (r = 0.156, P < 0.05, n = 180). Endangered species.' 13 of the 126 species are included in the Red List of endangered and rare bryophytes of Switzerland (URMI et al. 1992). Two of these species, namely Splachnum ampullaceum and Calypogeia sphagnicola, are supposed to be in danger of vanishing in Switzerland (Red List-Status: E), four species are considered rare (Red List-Status: R), and seven species belong to the category V (= vulnerable). Only three of the Red List-species were found in more than two sites; these were Hypnum pratense (13 sites), Sphagnum centrale (11 sites) and Sphagnum contortum (5 sites). These three species are considered to be vulnerable in Switzerland. With the exception of Meesia triquetra, which was restricted to one mown fen site, all Red List-species occurred at grazed sites. Five species occurred at both mown and grazed sites. On a European level, none of the previously mentioned Red List species are in danger (ECCB 1995). However, Hamatocaulis vernicosus will be included in the next edition of the Red Data Book of European bryophytes with the status VU (= vulnerable).

Table 1. Effects of management (mown vs. grazed) and altitude (800-1000, 1000-1200, 1200-1400 m a.s.l.) on environmental variables. s.e.d.: standard error of differences of means; n = 36; significance levels: *: p < 0.05; ***: p < 0.001

altitude low total N (g/kg) total C (g/kg)

15.3 227.6 CIN 15.2 pH 6.1 slope (degrees) 7.4 cover of vascular plants (%) 98.4 cover of bryophytes (%) 91.2 bare ground (%) 1.2

management intermediate

high

s.e.d.

15.0 220.4 14.8 6.1 10.6 97.7 90.7 3.0

15.0 223.3 14.9 6.1 12.3 98.2 90.0 3.6

1.63 26.2 0.52 0.19 1.86 1.10 3.58 l.32

ns ns ns ns

* ns ns ns

mown

grazed

s.e.d.

14.6 214.9 15.0 6.2 10.6 99.8 93.9 0.4

15.5 232.7 14.9 6.0 9.6 96.4 87.4 4.8

l.33 2l.4 0.43 0.15 l.52 0.90 2.92 1.07

FLORA (2001) 196

ns ns ns ns ns

*** *** *** 183

3.2. Effects of management and altitude

species density

Neither altitude nor management had any influence on the measured chemical soil characteristics. Slope, however, significantly increased with altitude. Cover of vascular plants and cover of bryophytes were significantly lower and amount of bare ground significantly higher at grazed sites (Table 1). Total species number at grazed sites was markedly higher than at mown sites (117 vs. 79 species). 47 species occurred exclusively on grazed sites, whereas this was true for only 9 species on mown sites. Most of the exclusive species occurred only at one or two sites. Some genera like Riccardia (3 species), Calypogeia (2 species), Cephalozia (2 species) and Splachnum (2 species) were restricted to grazed sites. Distribution of exclusive species in relation to altitude classes was less pronounced, but also showed a distinct pattern (low: 9, intermediate: 15, high: 24 exclusive species). Significance of these differences could be confirmed by a X2 test (X2 = 7.125 > X20.05(2) = 5.991). The same pattern was found for species numbers (low: 76, intermediate: 89, high: 96 species). However, these differences were not significant (X 2 = 2.368 < X20.05(2) = 5.991). Species richness was higher at grazed than at mown sites (36.1 vs. 30.0), whereas altitude again had no effect (Table 2, Fig. 2). The interaction between management and altitude, however, was significant. This meant that the relationship between management type and species richness was not the same for all altitude classes. There is hardly any effect of management type on species richness of low altitude sites (Fig. 2); species richness is

14 13.5 13

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species richness

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beta-diversity Table 2. ANOVA for the effects of management (mown vs. grazed) and altitude (800-1000, 1000-1200, 1200-1400 m a.s.l.) on species richness, species density, and beta-diversity of bryophytes in montane wetlands. Significance levels: *: p < 0.05; **: p < 0.01. Dependent variable

Source of variation

df

SS

10.22** 0.09 3.32*

Management Altitude Interaction Residual

1 2 2 30

0.538 6.507 18.409 73.547

0.22 1.33 3.75*

Management Altitude Interaction Residual

1 2 2 30

0.279 0.042 0.045 1.295

6.46* 0.48 0.52

FLORA (2001) 196

1.1

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0.052 0.001 0.034 0.154

184

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Beta -diversity

1.2

F

Species richness Management (log-transformed) Altitude Interaction Residual Species density

1.3

.~

'?

~

0.9

.a

0.8 0.7 0.6

mown

grazed

Fig. 2. Effects of management (mown vs. grazed) and altitude (low: 800-1000, intermediate: 1000-1200, high: 1200-1400) m a.s.l. on species richness, species density and beta-diversity ofbryophytes. Vertical bars indicate s.e.d. (standard error of differences of means).

even slightly higher on mown sites of low altitude than on grazed sites of low altitude. No significant differences could be found between species densities for management type and altitude classes (Table 2, Fig. 2). The interaction of the design factors, however, was significant. There was no correlation between species density of mosses and liverworts (r = 0.04, n = 36). Beta-diversity was significantly higher on grazed sites than on mown sites (1.17 vs. 0.99, p < 0.05). Betadiversities for the three altitude classes were very similar and there were no significant differences (Table 2, Fig. 2).

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3.3 Species composition By forward selection and associated Monte Carlo permutation test, the variables pH, C, and management turned out to be statistically significant in explaining variation in the species data. Therefore, CCA was performed with these three statistically significant variables. Percentage of variance accounted for by the three canonical axes was 21.0%. The eigenvalue of CCA axis I was markedly higher than the eigenvalues of axes 2 and 3 (axis 1: 0.156, axis 2: 0.089, axis 3: 0.061). This reflects the relative importance of axis 1 in explaining variation in the species data. The first axis accounted for 10.7% of the total variance. Intra-set correlations of environmental variables with the canonical axes showed a very simple pattern and axes were therefore quite easy to interpret (Table 3). Axis 1 very strongly reflects the effect of pH on the distribution pattern of bryophytes. Amount of organic and inorganic carbon (C) is very strongly related to axis 2 and management type is related to axis 3 (Fig. 3). However, because total C and total N are very closely related (correlation coefficient r = 0.967), axis 2 could also be interpreted in terms of total N. Species associated with low pH values were e.g., Sphagnum spp., Breutelia chrysocoma, Pleurozium schreberi, Hamatocaulis vernicosus, and Warnstorfia exannulata whereas Philonotis calcarea, Palustriella spp., Conocephalum conicum, Table 3. Eigenvalues A and intra-set correlations of environmental variables with the first three axes of CCA. axis 1

axis 2

axis 3

Eigenvalues A

0.156

0.089

0.061

pH

0.926

0.043

-0.338

-0.204

0.944

0.224

0.129

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185

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and Tortella tortuosa were restricted to sites with higher pH values (Fig. 4). Soil with a high amount of carbon was preferred by species like Sphagnum platyphyllum, Sphagnum contortum, Tomentypnum nitens, and Hamatocaulis vernicosus. Associated with grazing were species like Hamatocaulis vernicosus, Sphagnum platyphyllum, Warnstorfia exannulata, Drepanocladus aduncus, Tortella tortuosa and Calliergon stramineum (Fig. 4).

+0.4

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4. Discussion 4.1. Overall species richness The bryophyte richness lies within the reported range for peatlands and fens. VITT et al. (1995) reported 109 species for peatlands in western Canada, JANSSENS (1992) 164 species of mosses in peatlands for central North America and WHEELER (1993) 189 species of bryophytes for fens in Britain. However, the 126 species found in this study are quite remarkable considering the very limited habitat types studied, the low altitudinal range of the sites and the comparatively small geographical area. A high proportion of the reported species can be considered rare (occurring at only one or two sites) in the studied wet meadows. This pattern of rarity seems to be quite normal for most ecosystems (VITT 1991, SCHMID & MATTHIES 1994, VITT et al. 1995) and is supposed to be the result of a combination of species having specialized habitat requirements and rareness of habitats (VITT 1991).

Ham ver Sph pia War exa Ore adu

4.2. Effects of management and altitude on species diversity

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axis 1

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Fig. 4. CCA ordination diagram based on frequency of species within sites. Distribution of species in relation to A: axis 1 and 2, and B: axis 1 and 3. For abbreviations of species see appendix.

186

FLORA (2001) 196

It has been shown that species richness on grazed sites

is significantly higher than on mown sites. Because none of the measured chemical factors varied significantly between management types, we interpret the higher species diversity at grazed sites as the result of higher environmental heterogeneity caused by different activities of cattle like trampling, dung deposition, and selective defoliation. The presence of these disturbances and the higher environmental heterogeneity is indirectly confirmed by the significant effect of grazing on the coefficients of variation between plots for the variable·s bare ground, cover of vascular plants and cover of bryophytes (Table 4) which were all higher at grazed sites. The higher variation of these variables at grazed sites is also likely to be the result of non-random habitat use of grazing animals (see ERZINGER 1996). This enhanced environmental heterogeneity could be responsible for the higher beta-diversity and species richness at grazed sites. However, the almost constant species density for

Table 4. ANOVA for the effects of management (mown vs. grazed) on the coefficients of variation (CV) for the variables bare ground, cover of vascular plants, and cover ofbryophytes. Significance levels: *: p < 0.05; ***: p < 0.001 dependent variate source of variation

df

CV - bare ground Management 1 Residual 34

SS

F

32785 4.64* 240131

CV -cover of vascular plants (log-transformed)

Management 1 Residual 34

2.788 2.514

37.70***

CV -cover of bryophytes (log-transformed)

Management 1 Residual 34

0.856 6.286

4.63*

ever, there was a significant management x altitude interaction due to species poor sites at low altitudes under grazing. As PLATTNER (1996) and PEINTINGER (1999) supposed, it seems most likely that grazing was more intensive at low altitudes and that various impacts of nearby intensive agricultural land, like input of nutrients, are more severe at low altitudes (see also WETTSTEIN & SCHMID 1999). This also corresponds to the findings of MORTON (1977, cited in DURING 1990) who found only few bryophytes in heavily grazed grasslands.

4.3. Species composition

Management and altitude were not major determinants of bryophyte species composition. However, the weak the two management types (Fig. 2) indicates that at the but significant correlation of management to axis 3 of within-plot scale (2 m 2) there were no differences in CCA shows that management practice has an influence habitat heterogeneity between management types. Our on species composition. Altitude showed no significant correlation to axes of CCA, i.e. species composition of results agree with those of VAN TOOREN et al. (1990), who also found no differences in species density at the the three altitude classes were not different. This stands 1 m2 scale between grazed and mown sites in chalk in contradiction to the findings of PEINTINGER (1999) grasslands. However, species richness (at the site scale) for vascular plants and to phytosociological studies was markedly higher at grazed than at mown sites. This (GORS 1977, GIUGINI 1991). Therefore, the altitudinal could be a consequence of the more open vascular plant zonation of moss vegetation in these habitats is much layer under grazing regimes. Similar conclusions were weaker than that of vascular plants. This is likely to be also reached by WATSON (1960). She found a wider a consequence of the wide vertical distribution of most range of bryophyte species in more open chalk grass- bryophytes in this study (AMANN & MEYLAN 1918). lands, provided that other factors were favourable. Although we were working in calcareous fens, mean Similar effects were reported by SUMMERHAYES (1941), pH varied between 5.3 and 7.2. It is therefore not surwho observed bryophytes benefitting from the grazing . prising that pH turned out to be the prime factor in deterand tunelling activities of voles. This is further confirm- mining bryophyte species distribution as reflected by ed by VITT et al. (1995) who found species richness the strong correlation of CCA axis 1 and pH. The highly correlated with habitat heterogeneity at the site importance of soil acidity in determining bryophyte scale. species distribution is well-known (see WATSON 1918, However, effects of grazing are not independent of AMANN 1928, RICHARDS 1932) and has been confirmed the taxonomic group studied. PLATTNER (1996) and in various studies of bryophytes in wetlands (recent PEINTINGER (1999), working with vascular plant spe- studies by VAN BAAREN et al. 1988, GIGNAC et al. 1991, cies at the same sites, found markedly lower species VITT & CHEE 1990, GERDOL 1995, ANDERSON et al. densities under grazing regimes. Our data do therefore 1995, ALBINSSON 1997). The pH is often correlated with not confirm the existence of 'diversity hotspots', i.e. chemical variables such as electrical conductivity, sites that are species rich for bryophytes are not auto- alkalinity, and base cations (see review by VITT 1994). matically species rich for vascular plants and vice versa. One would expect that low pH values are often correThe different reaction of bryophytes and vascular lated with the formation of peat. Therefore it is surprisplants on grazing is likely to be caused by the non-pala- ing that the variable C was so strongly correlated with· the second CCA axis while pH was correlated with the tabil~ty of bryophytes to large herbivores and the very high capacity of vegetative regeneration of bryophytes first one. That is, pH and C influence species composiin contrast to most vascular plants, i.e. bryophytes have tion independently. Therefore we assume that pH of our the potential to reestablish very fast after disturbances sites was not determined by the amount of peat but by like trampling. In addition, some bryophytes (members the pH or ionic content of the ground water. Such an of the family Splachnaceae) are dependent on cattle effect of the ground water was shown by BOEYE & dung as substrate. VERHEYEN (1994) for Belgian discharge fens. AccumuIn contrast to management practice, altitude had no lation of peat is only possible under wet, anaerobic consignificant influence on species richness of sites. How- ditions. As soon as the hydrology of the fen sites is FLORA (2001) 196

187

disturbed and they become drier, e.g. through drainage, peat is mineralized (Succow 1988). Therefore it is possible to interpret CCA axis 2 as a moisture gradient. This gradient is confirmed by a significant linear regression (p = 0.005, F = 8.45, n = 62) of the species scores of CCA axis 2 on the indicator values for moisture (DULL 1992). This interpretation, however, is complicated by the very high correlation of total C and total N. Therefore, the C or moisture gradient could also be interpreted as a nitrogen gradient. This correlation is frequently found (e.g. ELLENBERG 1992) and, of course, it is not possible to separate the effects of moisture and nitrogen without experimental work.

4.4. Implications for nature conservation Considering bryophytes only, grazing is clearly to be favoured over mowing, because grazed sites contain the higher overall species richness, the higher mean species richness, more exclusive species and genera, and more Red List-species. However, it seems to be very important that grazing intensity is rather low (WENGER 1995, PLATTNER 1996). The poor bryophyte flora of the grazed sites at low altitude may be the direct cause of too high grazing pressure. Therefore, grazing pressure at higher altitudes should not be enhanced and at lower altitudes, if possible, reduced. Longer vegetation periods as cause of global change could lead to longer grazing periods and therefore to loss of species. Including other groups of organisms into the consideration, one cannot favour a certain management type. Vascular plant species richness was higher at mown sites (PEINTINGER 1999, PLATTNER 1996) and WETTSTEIN & SCHMID (1999) found higher richness of day-active butterflies at mown sites. Grasshoppers, however, were richer on grazed sites. This, together with the fact that several endangered species of bryophytes, vascular plants, day-active butterflies, and grasshoppers are restricted to one of the two management types, suggests that both types of management should be maintained.

Zusammenfassung Der Einfluss der Bewirtschaftung und der Hohenlage auf die Vielfalt der Moosflora und Moosvegetation in montanen Kalkflachmooren Wir untersuchten in 36 Streuwiesen und Feuchtweiden unterschiedlicher Hohenlage der montanen Stufe der Nordalpen in der Schweiz die Vielfalt der Moosflora und -vegetation. Zusatzlich wurden verschiedene Umweltparameter gemessen. Drei GroBen dienten als Mass fur die Diversitat der Moose: Die Artendichte (Mittel wert aus 5 Aufnahmeflachen pro Untersuchungsobjekt), die Artenvielfalt (Zahl aller Taxa in einem Objekt) und die B-Diversitat. Die Artenvielfalt ist in den Weiden urn 20% grosser als in den Streuwiesen. Wir betrachten diesen Befund als Folge der groBeren Vielfalt an Kleinstandorten in Weiden. Diese konnte auch der Grund sein fUr die signifikant groBere ~-Diversitat in den Weiden. Die beobachtete Artenarmut der Weiden in tieferen Lagen ist wahrscheinlich auf intensivere Beweidung dort zuriickzufUhren. Die totale Artenvielfalt uber aBe Weiden ist groBer als bei den Streuwiesen (117 vs. 79), auBerdem enthalten die Weiden mehr Arten der Roten Liste (12 vs. 6) und mehr Arten, die im anderen Bewirtschaftungstyp nicht vorkommen. Nur die Zahl dieser exklusiven Arten ist von der Hohenlage abhangig, wobei sie in hohen Lagen am groBten ist. Bei der Artendichte konnte keine Abhangigkeit gefunden werden, weder von der Hohenlage noch von der Bewirtschaftung. Dieser Befund deutet darauf hin, daB es innerhalb der einzelnen Aufnahmeflachen keine Unterschiede der standortlichen Diversitat gibt. Fur die Analyse der Auswirkungen der Umwelt-Variablen auf die Moosgemeinschaften verwendeten wir eine Methode der direkten Ordination (CCA). Dabei zeigte sich, dass pH, Gesamtkohlenstoff im Boden und Bewirtschaftungsweise die wichtigsten Faktoren sind, urn die Variabilitat des Artenspektrums zu erklaren. Allerdings konnten der Gesamtstickstoff oder die Bodenfeuchtigkeit den gleichen Anteil der Variabilitat erklaren wie der Gesamtkohlenstoff. Fur den Schutz der Vielfalt an Moosen ist die extensive Beweidung durch Grossvieh von zentraler Bedeutung. Wegen der leicht verschiedenen Moosgemeinschaften von Streuwiesen und Feuchtweiden wird die Vielfalt der Moose am groBten sein, wenn beide Bewirtschaftungsformen aufrechterhalten werden.

Acknowledgements We thank the various landowners who permitted work on their land; M. NAGELI, S. STOFER, R. MElLE and E. GAMPERLE for helping with fieldwork; D. PAULI for various comments during the planning phase of this study and R. HUSI for help with chemical analysis of the soil samples. We are grateful to L. HEDENAS, B. BURYOVA and C. SCHUBIGER-BoSSARD for their help in identifying troublesome species of Brachythecium, Philonotis and Scapania, respectively. Financial assistance was provided by the 'Naturforschende Gesellschaft Luzern'. 188

FLORA (2001) 196

References ALBINSSON, c. (1997): Niche relations and association analysis of southern Swedish mire hepatics. - J. Bryol. 19: 409-424. AMANN, J. (1928): Bryogeographie de la Suisse. - Beitr. Kryptogamenfl. Schweiz VI: 1-453. AMANN, J. and MEYLAN, C. (1918): Flore des Mousses de la Suisse. Herbier Boissier, Geneve.

ANDERSON, D. S.; DAVIS, R. B. & JANSSENS, 1. A. (1995): Relationships of bryophytes and lichenes to environmental gradients in Maine peatlands. - Vegetatio 120: 147-159. ANDRESEN, H. ; BAKKER, J. P. ; BRONGERS, M. ; HEYDEMANN, B. & IRMLER, U. (1990): Long-term changes of salt marsh communities by cattle grazing. - Vegetatio 89: 137-148. BOEYE, D. & VERHEYEN, R. F. (1994): The relation between vegetation and soil chemistry gradients in a ground water discharge fen. - 1. Veg. Sci. 5: 553-560. BRAUN, W. (1968): Die Kalkflachmoore und ihre wichtigsten Kontaktgesellschaften im Bayrischen Alpenvorland. Diss. Bot. 1: 1-134. BRAUN, W. (1970): Bestimmungstibersicht ftir die wichtigsten Kalkflachmoore und deren wichtigsten Kontaktgesellschaften im Bayrischen Alpenvorland. - Ber. Bayer. Bot. Ges. Erforsch. heim. Flora 42: 109-138. BRUDI, M. (1995). Vergleichende Untersuchung tiber die Auswirkungen der Bewirtschaftungsformen Beweidung und Mahd auf die Vegetation von Kalkflachmooren im Alpenvorland. Diploma Thesis, Technische Universitat, Miinchen. BUWAL. (1990): Inventar der Flachmoore von nationaler Bedeutung. Entwurf flir die Vernehmlassung. CORLEY, M. F. V & CRUNDWELL, A. C. (1991): Additions and amendments to the mosses of Europe and the Azores. - J. Bryol. 16: 337 -356. CORLEY, M. F. V; CRUNDWELL, A. C. ; DULL, R. ; HILL, M. O. & SMITH, A. J. E. (1981): Mosses of Europe and the Azores; an annotated list of species with synonyms from the recent literature. - J. Bryol. 11: 609-689. CRAWLEY, M. J. (1983): Herbivory: The dynamics of animalplant interactions. Blackwell Scientific Publications, Oxford. DI GULlO, M. (1996). Die phytophage Insektengemeinschaft des Teufelsabbiss (Succisa pratensis). Diploma Thesis, Universitiit Ztirich, Ztirich. DIETL, W. (1975): Die landschaftsokologische Bedeutung der Flachmoore. Beispiel: Davallseggenrieder. - Jahrb. Vereins Schutze Bergwelt 40: 47-64. DULL, R. (1992). Zeigerwerte von Laub- und Lebermoosen. In: ELLENBERG, H. ; WEBER, H. E. ; DULL, R. ; WIRTH, V ; WERNER, W., & PAULlSSEN, D. (eds.): Zeigerwerte von Pflanzen in Mitte1europa. - Scr. Geobot. 18, Verlag Erich Goltze, Gottingen, 175-214. DURING, H. J. (1990). The bryophytes of calcareous grasslands. In: Hillier, S. H. (ed.): Calcareous grasslands - ecology and management. - Bluntisham Books, 35-40. DURING, H. J. & WILLEMS, J. H. (1986): The impoverishment of the bryophyte and lichen flora of the Dutch chalk grasslands in the thirty years 1953-1983. - BioI. Cons. 36: 143-158. ECCB. (1995): Red Data Book of European bryophytes. ECCB, Trondheim. ELLENBERG, H. (1992). Zeigerwerte derGefasspflanzen (ohne Rubus). In: ELLENBERG, H.; WEBER, H. E.; DULL, R.; WIRTH, V; WERNER, W. & PAULlSSEN, D. (eds.): Zeigerwerte von Pflanzen in Mitteleuropa. - Scr. Geobot 18, Verlag Erich Goltze, Gottingen, 175-214.

ELLENBERG, H. (1996): Vegetation Mitteleuropas mit den Alpen in okologischer, dynamischer und historischer Sicht. Ulmer, Stuttgart. ERZINGER, S. (1996): Einfluss von Schottischen Hochlandrindern auf eine montane Weide im Oberen Tosstal. Bull. Geobot. Inst. ETH 62: 47-60. GERDOL, R. (1995): Community and species-performance patterns along an alpine poor-riche mire gradient. - J. Veg. Sci. 6: 175-182. GIGNAC, L. D.; VITT, D. H.; ZOLTAI, S. C. & BAYLEY, S. E. (1991): Bryophyte response surfaces along climatic, chemical and physical gradients in peatlands of western Canada. - Nova Hedwigia 53: 27 - 71. GIUGINI, G. (1991): Etude phyto-ecologique des bas-marais de pente (caricion davallianae) des prealpes chablaisiennes (suisses et franc;aises). - Beitr. Geobot. Landesaufn. Schweiz 67: 1-289. GORS, S. (1977). Tofieldietalia. In: OBERDORFER, E. (ed.): Siiddeutsche Pflanzengesellschaften, Teil I. Gustav Fischer Verlag, Stuttgart, New York, 243-272. GROLLE, R. (1983): Hepatics of Europe including the Azores : an annotated list of species, with synonyms from the recent literature. - J. Bryol. 12: 403 -459. HARPER, J. L. (1977): Population biology of plants. Academic Press, London. HARTE, J. & SHAW, R. (1995): Shifting dominance within a montane vegetation community: results of a climatewarming experiment. - Science 267: 876-880. HOBBIE, S. E.; SHEVTSOVA, A. & CHAPIN III, S. F. (1999): Plant responses to species removal and experimental warming in Alaskan tussock tundra. - Oikos 84 : 417-434. JANSSENS, J. A. (1992). Bryophytes. In: Wright, H. E.; Coffin, B. A. & Aaseng, N. E. (eds.): The patterned peatlands of Minnesota. University of Minnesota Press, Minnesota, 43-57. JONGMAN, R. H. G.; TER BRAAK, C. J. F. & VAN TONGEREN, O. F. R. (1995): Data analysis in community and landscape ecology. Cambridge University Press, Cambridge. KAULE, G. (1991): Arten- und Biotopschutz. Ulmer, Stuttgart. KU:iTZLl, F. (1969): Die Grundwasserbeziehungen der Streuund Moorwiesen im nordlichen Schweizer Mittelland. Beitr. Geobot. Landesaufn. Schweiz 52: 1-296. LANDOLT, E. (1991): Gefiihrdung der Fam- und Bliitenpflanzen der Schweiz mit gesamtschweizerischen und regionalen roten Listen. EDMZ, Bern. LARCHER, W. (1994): Okophysiologie der Pflanzen. Ulmer, Stuttgart. MALTBY, E. (1988): Global wetlands - history, current status and future. In: Hook, D. D.; McKEE, W. H.; SMITH, H. K.; GREGORY, J.; BURRELL, V G.; DEVOE, M. R.; SOJKA, R. E.; GILBERT, S.; BANKS, R.; STOLZY, L. H.; BROOKS, C.; MATTHEWS, T. D. & SHEAR, T. H. (eds.): The ecology and management of wetlands. Timber Press, Portland, Oregon, 3-14. MORTON, M. R. (1977): Ecological studies of grassland bryophytes. Ph. D. Thesis, University of London. MUHLETHALER, E. (1992): Nutzungsgeschichte der Flachmoore in der Schweiz. In: BUWAL (ed.): Handbuch Moorschutz in der Schweiz. Teil 1. EDMZ, Bern. FLORA (2001) 196

189

PAULI, D. (1998): Plant species diversity and productivity in wetland communities: patterns and processes. Ph. D. Thesis, Universitat Zurich, Zurich. PAYNE, R. W.; LANE, P. w.; DIGBY, P. G. N.; HARDING, S. A.; LEECH, P. K.; MORGAN, G. W. ; TODD, A. D. ; THOMPSON, R.; TuNICLIFFE WILSON, G.; WELHAM, S. J. & WHITE, R. P. (1993): Genstat 5 reference manual. Clarendon Press, Oxford. PEINTINGER, M. (1999): The effects of habitat area, management and altitude on species diversity in montane wetlands. Ph. D. Thesis, Universitat Zurich, Zurich. PLATTNER, M. (1996): Diversitat undArtenzusammensetzung der Vegetation in Flachmooren in Abhangigkeit von Nutzung, Hohenlage, Flachengrosse und verschiedenen Bodenparametern. Diploma Thesis, Universitat Basel, Basel. RAWES, M. (1983): Changes in two high altitude blanket bogs after the cessation of sheep grazing. - J. Ecol. 71: 219-235. RICHARDS, P. W. (1932): Ecology. In: VERDOORN, F. (ed.): Manual of Bryology. Martinus Nijhof, The Hague, 367-395. SCHLAPFER, M.; ZOLLER, H. & KORNER, c. (1998): Influences of mowing and grazing on plant species composition in calcareous grasslands. - Bot. Helv. 108: 57 -67. SCHMID, B. & MATTHIES, D. (1994): Seltenheit und Gefahrdung - Populationsbiologische Grundlagen des Artenschutzes. - Naturwissenschaften 81: 283-292. SLACK, N. G. (1977): Species diversity and community structure in bryophytes: New York state studies. - N. Y. State Mus. Bull. 428: 1-70. SOKAL, R. R. & ROHLF, F. J. (1995): Biometry. W. H. Freeman and Company, New York. SPICHER, A. (1972): Geologie. In: IMHOF, E. (ed.): Atlas der Schweiz. Eidgenossische Landestopographie, 19651978, Bern-Wabern. Succow, M. (1988): Landschaftsokologische Moorkunde. Gebrtider Borntraeger, Berlin. SUMMERHAYES, V. S. (1941): The effect of voles (Microtus agrestis) on vegetation. - J. Ecol. 29: 14-48. TER BRAAK, C. J. F. & SMILAUER, P. (1998): CANOCO reference manual and user's guide to CANOCO for Windows. Software for Canonical Community Ordination (version 4). Centre for Biometry, Wageningen. URMI, E.; BISANG, I.; GEISSLER, P.; HURLIMANN, H.; LIENHARD, L.; MULLER, N.; SCHMID-GROB, I.; SCHNYDER, N. & THONI, L. (1992): Die gefahrdeten und seltenen Moose der Schweiz - Rote Liste. EDMZ, Bern. UTTINGER, H. (1967). Klima und Wetter II. In: IMHOF, E.

190

FLORA (2001) 196

(ed.): Atlas der Schweiz. Eidgenossische Landestopographie, 1965 -1978, Bern-Wabern. VAN BAAREN, M.; DURING, H. & LELTZ, G. (1988): Bryophyte communities in mesotrophic fens in the Netherlands. - Holarct. Ecol. 11: 32-40. VAN TOOREN, B. F.; BAUDEWIJN, 0.; DURING, H. J. & BOBBINK, R. (1990): Regeneration of species richness in the bryophyte layer of Dutch chalk grassland. - Lindbergia 16: 153-160. VAN WIEREN, S. E. (1995): The potential role of large herbivores in nature conservation and extensive land use in Europe. - BioI. J. Linn. Soc. 56 (Suppl.): 11-23. VITT, D. H. (1991). Distributional patterns, adaptive strategies and morphological changes of mosses along elevational and latitudinal gradients on South Pacific Islands. In: NIMIS, P. L. & CROVELLO, T. J. (eds.): Quantitative approaches in phytogeography. Kluwer Academic Publishers, Dordrecht, 205 - 231. VITT, D. H. (1994): An overview of factors that influence the developement of Canadian peatlands. - Mem. Entomol. Soc. Canada 169: 7-20. VITT, D. H. & CHEE, w. L. (1990): The relationships of vegetation to surface water chemistry and peat chemistry in fens of Alberta, Canada. - Vegetatio 89: 87 -1 06. VITT, D. H.; YEN HUNG, L. & BELLAND, R. J. (1995): Patterns of bryophyte diversity in peatlands of continental Western Canada. - Bryologist 98: 218-227. VON WYL, B.; DIETL, W. & WENGER, D. (1995). Zur Beweidung von Hoch- und Flachmooren. In: BUWAL (ed.): Handbuch Moorschutz in der Schweiz. Teil 2. EDMZ, Bern. WATSON, E. V. (1960): A quantitative study of the bryophytes of chalk grassland. - J. Ecol. 48: 397 -414. WATSON, W. (1918): The bryophytes and lichens of calcareous soil. - J. Ecol. 6: 189-198. WENGER, D. (1995): Einfluss der Beweidung auf Feuchtgebiete, dargestellt anhand von Beispielen aus dem Kanton Bern. - Mitt. Naturf. Ges. Bern 52: 75-95. WETTSTEIN, W. & SCHMID, B. (1999): Conservation of arthropod diversity in montane wetlands: effect of altitude, habitat quality and habitat fragmentation on butterflies and grasshoppers. - J. Appl. Ecol. 36: 363-373. WHEELER, B. D. (1993): Botanical diversity in British mires. - Biodivers. Conserv. 2: 490-512. WHITTAKER, R. H. (1972): Evolution and measurement of species diversity. - Taxon 21: 213-251. ZAMFIR, M. (1999) : From pattern to process - studies on limestone grassland, with emphasis on the bryophyte-lichen layer and its effects on vascular plants. Uppsala University Library, Uppsala.

Appendix Frequency of all bryophytes found in the examined fen sites. Frequencies are given for mown and grazed sites separately as well as the total frequency. Species not found in the 5 plots are indicated by 'a' (= additional). Red List status of species after URMI et al. (1992). Taxon abbreviations as used in Fig. 4. Species exclusive for grazed sites are written in bold; species exclusive for mown sites are written in italics. Liverworts

Aneura Barbilophozia Barbilophozia Blepharostoma Calypogeia Calypogeia Cephalozia Cephalozia Chiloscyphus Conocephalum Lophocolea Lophocolea Lophozia Lophozia Marchantia Pellia Pellia Plagiochila Preissia Riccardia Riccardia Riccardia Scapania a Scapania Scapania Scapania a Scapania Scapania Trichocolea Tritomaria a a a a a a a

Red List status

pinguis floerkei quadriloba trichophyllum muelleriana s. I. sphagnicola bicuspidata connivens polyanthos s. l. conic urn bidentata heterophylla bantriensis cf. collaris polymorpha s. l. endiviifolia epiphylla s. l. asplenioides s. l. quadrata chamaedryfolia incurvata multifida aequiloba irrigua paludicola paludosa uliginosa undulata tomentella quinquedentata

Ane pin

E

Chi pol Con con Lop bid Lop ban Mar pol Pel end Pel epi PIa asp R R

Sca pIa

Mosses Amblystegium Atrichum Aulacomnium a Barbula Brachythecium Brachythecium Brachythecium Brachythecium Brachythecium Breutelia Bryum a Calliergon Calliergon Calliergon Calliergon Calliergonella Campylium

Red List status

riparium undulatum palustre crocea glareosum mildeanum rivulare salebrosum turgidum chrysocoma pseudotriquetrum cordifolium giganteum sarmentosum stramineum cuspidata stellatum

Atr und Aul pal Bra gla Bra mil Bra riv Bra tur Bre chr Bry pse

Cal str Cal cus Cam ste

R V

mown

grazed

total

8 0 0 0 0 0 0 0 4 1 3 0 5 0 2 11 2 2 0 0 0 0 0 1 2 0 0 0 1 2

9 1 1 1 2 1 2 1 10 5 5 1 11 1 2 10 4 4 2 1 1 2 2 1 3 1 1 1 0 1

17 1 I 1 2 1 2 1 14 6 8 1 16 1 4 21 6 6 2 1 1 2 2 2 5 1 1 1 1 3

mown

grazed

total

1 15 l3 0 0 14 13 0 1 1 18 1 2 0 6 18 18

0 13 13 1 3 14 15 1 1 1 17 0 2 2 8 18 18

1 28 26 1 3 28 28

FLORA (2001) 196

1 2 2 35 1 4 2 14 36 36 191

Mosses a

a

a a

a

a a a

a a

a

a

Cinclidium Cirriphyllum Climacium Cratoneuron Ctenidium Dicranella Dicranella Dicranum Dicranum Dicranum Didymodon Ditrichum Drepanocladus Drepanocladus Drepanocladus Eurhynchium Eurhynchium Fissidens Fissidens Geheebia Hamatocaulis Hylocomium Hylocomium Hypnum Hypnum Meesia Palustriella Palustriella Palustriella Philonotis Philonotis Philonotis Plagiomnium Plagiomnium Plagiomnium Plagiomnium Pleurozium Pohlia Polytrichum Polytrichum Polytrichum Ptychodium Racomitrium Rhizomnium Rhizomnium Rhodobryum Rhytidiadelphus Rhytidiadelphus Rhytidiadelphus Sanionia Scleropodium Scorpidium Sphagnum Sphagnum Sphagnum Sphagnum

192

FLORA (2001) 196

Red List status stygium piliferum dendroides filicinum molluscum schreberiana varia bonjeanii polysetum scoparium ferrugineus flexicaule aduncus cossoni revolvens hians praelongum adianthoides taxifolius gigantea vemicosus pyrenaicum splendens lindbergii pratense triquetra commutata decipiens falcata calcarea fontana tomentella affine elatum ellipticum undulatum schreberi sp. commune formosum strictum plicatum elongatum pseudopunctatum punctatum roseum loreus squarrosus triquetrus uncinata purum scorpioides capillifolium centrale compactum contortum

Cir pil Cli den Cra fil Cte mol

Dic bon Dic sco Dit fie Dre adu Dre cos

Fis adi Geh gig Ham ver Hyl pyr Hyl spi Hyp lin Hyppra

V V

Pal com Pal dec Pal fal Phi cal Phifon PIa aff PIa ela PIa ell PIa und PIe sch

mown

grazed

total

0 15 18 12 13 0 1 11 2 2 1 0 0 16 0 0 0 l7 1 7 2 11 12 17 7 1 2 14 15 9 13 0 3 18 1 7

1 14 17 12 15 1 0

1 29 35 24 28 I 1 21 3 6 1 2 2 34 1 1 1 34 2 11 5 19 25 33 13 1 8 30 28 18 25 1 5' 36 3 15 21 1

10

Rw Rhi pun

Rhy squ Rhy tri San unc ScI pur

Sph cen

V

Sph con

V

1 1 3 1 0 0 0 2 1 0 18 13 1 3 0 2 5 0 3

10

1 4 0 2 2 18 1 1 1 l7 1 4 3 8 13 16 6 0 6 16 13 9 12 1 2 18 2 8 11 0 9 5 3 1 I 1 2 0 1 18 9 6 6 1 3 6 2 2

10

8 4 1 1 1 4 1 1 36 22 7 9 1 5 11 2 5

Mosses

a a a a

Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Sphagnum Splachnum Splachnum Thuidium Thuidium Thuidium Thuidium Tomentypnum Tortella Warnstorfia

cuspidatum denticulatum girgensohnii magellanieum pa1ustre papillosum platyphyllum quinquefarium reeurvum s. 1. russowii squarrosum subseeundum teres warnstorfii ampullaceum sphaericum delieatuium philibertii reeognitum tamariscinum nitens tortuosa exannulata

Red List status

mown

grazed

Vw

0 2 0 2 4 0 0 4 2 0 0 5 0 1 0 0 9 17 11 0 6 0 0

1 0 5 8 4 1 2 2 6 3 1 7 1 2 1 2 8 17 5 2 7 4 4

Sph den

Sph pal Sph pIa

V

Sph sub Sph war

E Thudel Thu phi Thu ree Tom nit Tor tor Warexa

FLORA (2001) 196

total 1 2 5 10

8 1 2 6 8 3 1 12 1 3 1 2 17 34 16 2 l3 4 4

193