Peat bogs are characterized by very wet, acidic and oligotrophic conditions, and their soil is of organic origin. They are among the most threatened habitats in Central Europe, due to dewatering, peat mineralization, land reclamation, afforestation, nutrient contamination and recently by climate change. Within the last century, over 90 % of all peat bogs in Austria were devastated or completely destroyed (Niedermair et al. 2010).

Auchenorrhyncha are among the most abundant animal groups in peatlands. The majority of species is stenoecious, specialized on both habitat conditions and host plants (Nickel et al. 2002, Nickel 2003; see Table 3). With a few exceptions (Leising 1977, Holzinger 1995, 2000, Holzinger and Novotny 1998) the Auchenorrhyncha fauna of Austrian peat bogs is poorly studied, and the hopper fauna of the granite and gneiss highlands of the Austrian Bohemian Forest is completely unknown. Here we present the first overview on the peat bog fauna of this area and give some data on the Auchenorrhyncha communities of Central European peat bogs (see also Schlosser 2012, Schlosser and Holzinger 2012).

Seven typical oligotrophic peat bog sites of the Bohemian Forest were studied in 2011. Quantitative samples were taken monthly (from May until September) by a suction sampler (“G-Vac”, see Stewart 2002). Each sample was taken by walking slowly through the sampling site and performing 100 “touchdowns” with the suction sampler nozzle (Ø 12 cm). Thus one sample represents the fauna of 1.1 m². Three samples per date and site were taken, thus the data set contains a total of (7 sites × 5 dates × 3 samples =) 105 samples.

Study sites

The study sites are located in the very north of Upper Austria, close to the German and Czech border. They are shown in Fig. 1 and characterized in Table 1 and 2.

Figure 1.

Location of the sampling sites in the Bohemian Forest (Upper Austria), overview. Samling sites: DE = Deutsches Haidl, ST = Stadlau, BA = Bayrische Au, IG = Moor am Iglbach. Map source: AMAP 3D.

Table 1.

Study sites, coordinates and sampling dates on these sites (according to the Upper Austrian environmental lawyer, unpublished).

Code	Site name	Coordinates	Altitude	Area (ha)	Site description	Sampling dates
BA	Bayrische Au	48°40'49"N, 14°03'32"E	720 m	33.8	oligotrophic peat bog of national importance (Steiner 1992)	13.5., 22.6., 27.7., 22.8., 24.9.2011
ST-1	Stadlau 1	48°42'29"N, 13°51'12"E	610 m	7.1	dewatered, partially eroded and heavily nutrient contaminated remnants of a formerly large peat bog area	17.5., 20.6., 25.7., 21.8., 23.9.2011
ST-2	Stadlau 2	48°42'23"N, 13°51'18"E	610 m
ST-3	Stadlau 3	48°42'32"N, 13°51'15"E	610 m
IG-1	Iglbach-Moor 1	48°39'10"N, 14°01'44"E	800 m	3.9	drained peat bog complex, oligotrophic to mesotrophic, partially still very wet	19.5., 22.6., 26.7., 20.8., 24.9.2011
IG-2	Iglbach-Moor 2	48°39'09"N, 14°01'30"E	800 m
DE	Deutsches Haidl	48°45'43"N, 13°51'13"E	1242 m	2.8	acidic oligotrophic peat bog of international importance (Steiner 1992); sphagnum moss–spruce forest with a large central area covered by Carex limosa and Sphagnum majus	18.5., 25.6., 27.7., 22.8., 25.9.2011

Table 2.

Vegetation and management of the study sites (according to the Upper Austrian environmental lawyer, unpublished).

Code	Site name	Vegetation	Site management
BA	Bayrische Au	Patchy mixture of Phalaridetum arundinaceae, Caricetum rostratae, Caricetum gracilis, Caricetum nigrae, Sphagnetum magellanici	parts of the peat bog formerly used for peat-ditching; no management today
ST-1	Stadlau 1	Molinion, Sphagnetum magellanici	some years grazed (cattle) but not in 2011
ST-2	Stadlau 2	Caricetum nigrae, Caricetum rostratae, Junco-Molinietum	some years grazed (cattle) but not in 2011
ST-3	Stadlau 3	Junco-Molinietum	mowing once a year (July), grazed (cattle)
IG-1	Iglbach-Moor 1	Caricetum rostratae	no management
IG-2	Iglbach-Moor 2	Caricetum rostratae	no management
DE	Deutsches Haidl	Caricetum limosae, Sphagnetum magellanici, Sphagno girgensohnii-Piceetum	no management

A total number of 93 Auchenorrhyncha species (7465 adult specimens) were collected and identified (Tables 3 and 4). The most abundant species is Conomelus anceps representing almost 17 per cent of the total number of specimens, followed by Jassargus pseudocellaris (5.5 %), Muellerianella extrusa (9.2 %), Sorhoanus xanthoneurus (7.6 %) and Macustus grisescens (5.2 %). The relative species abundance plot (Fig. 2) is not very steep; the six most abundant species represent only 50 % of the total individuals, and the 75 % mark is reached at species number 14.

Eleven species are peat bog specialists, i.e. tyrphobiontic or tyrphophilous, according to Nickel et al. (2002). Compared to other wetland areas in Central Europe (see e.g. Schiemenz 1971, 1975, 1976, 1977, Remane and Reimer 1989, Andrew and Rushton 1993, Holzinger and Novotny 1998, Szwedo et al. 1998, Nickel 2002, Nickel and Gärtner 2009, Walter and Nickel 2009, Swierczewski and Blaszczyk 2011), this is a very average number. Peat bog specialists represent 18 % of the total number of individuals collected. The majority of the individuals are hygrophilous and mesophilic grassland species (Figs 3, 5).

Seven species could be found on all sites, among them one peat bog specialist (Sorhoanus assimilis). 18 species occur in at least five of the seven sites, among them three more peat bog specialists (Kelisia vittipennis, Paradelphacodes paludosa, Oncodelphax pullula). Almost half of the species (44) were recorded only on one site (among them four peat bog specialists).

Species composition

The Auchenorrhyncha communities of the peat bogs show higher proportions of univoltine species than the total fauna of Austria. The number of species hibernating in nymphal stages is also higher in peat bogs than in the total fauna of Austria (Fig. 4). This might be caused by comparatively unsuitable conditions (low temperature, high humidity) for Auchenorrhyncha development in these habitats.

The vast majority of the Central European Auchenorrhyncha species is mono- or oligophagous, specialised on one or few host plant species or genera (see Holzinger 2009 for the fauna of Austria). Interestingly, the tyrphophilous and tyrphobiontic Auchenorrhyncha species feeding on Calamagrostis canescens and Molinia caerulea in Germany (see Nickel 2003) could not be found within this study (whereas the non-tyrphophilous monophagous species are present). These species are missing or very rare in the southern parts of Central Europe and might not (or no longer?) exist in the peat bogs of the Austrian part of the Bohemian Forest (Fig. 6).

Figure 5.

Total number of Auchenorrhyncha collected at the seven peat bog sites. Colours = ecological types (after Holzinger 2009). Abbreviations: BA = Bayrische Au, ST = Stadlau, IG = Moor am Iglbach, DE = Deutsches Haidl. ST-3 is the site with highest human impact (grazing, mowing, dehydratation); DE is a peat bog in much higher elevation than all other sites.

Figure 6.

Number of tyrphobiontic and tyrphophilous species specialised on wetland plant species (data from Nickel 2003). Most plant species are utilised by their Auchenorrhyncha hosts also in the study sites, only Calamagrostis canescens and Molinia caerulea lack their mono-/oligophagous tyrphophilous “species set”.

Saisonality and densities

The densities of adult Auchenorrhyncha in peat bogs are low in spring (about 10–60 individuals per m²), increase towards July up to 180 (±50) individuals per m² and slowly decreases afterwards (Fig. 7). Disturbed sites have higher species numbers and higher Auchenorrhyncha densities in total but lower numbers and densities in peat bog specialists. The highest proportion of peat bog specialists (almost 95 %) was found in the undisturbed site „Deutsches Haidl“ (Fig. 5).

These Auchenorrhyncha densities of peat bogs are similar to those of other Central European grassland habitats (pastures and meadows: about 50–200 adult specimens/m²; alpine meadows: about 50–100 specimens/m²; ÖKOTEAM unpublished data).

Figure 7.

Seasonal mean numbers of Auchenorrhyncha species (left) and adult hopper specimens (=individuals/m²; right) in the peat bogs of the Austrian part of the Bohemian Forest.