Diplopoda and Chilopoda from a special protection area in the Huy mountain range in Saxony-Anhalt, Germany

In the Natura 2000 Habitats Directive site “Huy nördlich Halberstadt” in Saxony-Anhalt, Germany, 11 sites with typical regional plant associations (2 rupicolous calcareous or basophilic grasslands of the Alysso-Sedion albi, 2 semi-natural dry grasslands and scrubland facies on calcareous substrates, 3 Asperulo-Fagetum beech forests, 1 Medio-European limestone beech forest of the Cephalanthero-Fagion and 3 Galio-Carpinetum oak-hornbeam forests) were sampled for millipedes and centipedes using pitfall traps over a period of one and a half years. In addition 11 further sites and different microhabitats were investigated using hand sampling, soil cores and sieving. With a total of 30 diplopod and 17 chilopod species, the Huy can be classified as markedly species rich. The community structures and species compositions were of special importance and characteristic for all sites. Ecologically notable species were Ophiodesmus albonanus (Latzel, 1895), Megaphyllum unilineatum (C.L. Koch 1838), Brachyiulus pusillus (Leach, 1814), Mycogona germanica (Verhoeff, 1892), Polyxenus lagurus Linne, 1758, Geophilus electricus (Linné, 1758), Lithobius nodulipes Latzel, 1880 and Lithobius pelidnus Haase, 1880.


INTRODUCTION
The Natura 2000 site (Habitats Directive, Fauna Flora Habitat -FFH) "Huy nördlich Halberstadt" is a mountain range located 12 km northwest of Halberstadt within the protected landscape area "Huy" (Fig. 1).It has an east-west length of 12 km and a north-south width of about 3 km with a total area of 2,005 ha.The altitude of this largely closed and insular woodland area ranges from 190 to 310 m above sea level.
The Huy consists primarily of limestone layers, bunter and siltstone.The predominant soil types are Lessivés and Pararendzina.Woodruff-beech woods and oak-hornbeam coppices are typical.Shrub and coppice forests are preserved particularly on exposed hilltops and slopes, They clearly represent the transition to warmer and more open areas.Hillsides are often covered by dry and mesoxeric meadows.
Because of its high nature protection value, very intensive investigations of many animal taxa ranging from higher vertebrates to insects and many other invertebrates have been carried out by the State Office for Environmental Protection Saxony-Anhalt over several years (Landesamt für Umweltschutz Sachsen-Anhalt 2014 -LAU, in press).In the context of this initiative, the dipolopod and chilopod faunas were also studied.Since the 1990s both groups have been part of the standard investigation program initiated by the LAU.

INVESTIGATION SITES
In the Huy area, 11 different sites for investigation with plant associations typical of this mountain range were selected for pitfall trapping (Fig. 1).A detailed description of these sites can be found in LAU (in press).
Summary of the characteristics of the sites studied (coordinates as WGS84 decimal degrees): Huy 1: Rupicolous calcareous or basophilic grasslands of the Alysso-Sedion albi, 51.954834° N 11.059753° E; 215 ma.s.l.Huy 2: Rupicolous calcareous or basophilic grasslands of the Alysso-Sedion albi, 51.957301° N 11.053472° E; 220 m a.s.l.Huy 3: Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia), 51.949935° N 10.974578° E; 220 ma.s.l.In the study sites of Huy 1-11, six pitfall traps, filled with 4 % formalin, were installed at a distance of 8 to 10 m to each other.The trapping took place from March to December 2009 and from March until the end of June 2010 and the traps were emptied monthly.Due to closed snow cover it was not possible to empty the traps on the dates 02.01.2010, 01.02.2010 and 01.03.2010.Ignoring destroyed traps, a total of 840 sets of trap contents were available for analysis.

Germany
To complete the record of the species spectmm, as well as the pitfall trap sites (Huy 1-11) 11 additional sites (S 1-11) were sampled on one occasion on August 16th, 2011: o 12 woodland sites: trees were "beaten" by hand and two sievings (each 20 min) of the leaf litter were carried out in each site with material subsequently sorted in the laboratory, o 10 open sites (without deciduous layer): two soil cores (ca. 25 cm2 up to approx.3 cm depth) were taken in each site and subsequently sorted by hand in the laboratory.Additional hand samples (appr.20 min.)were also taken in each site.
For the evaluation of dominance ratios (after Engelmann 1978) and activity abundances only pitfall trap data was used.

Results of trapping
From the pitfall traps 3,736 specimens of millipedes from 26 species and 7 families were recorded (Table 1).For centipedes 588 specimens from 15 species were caught (Table 2), 5 geophilomorphs and 10 lithobiomorphs.The over-representation of Lithobiomorpha is a consequence of the method of collection used (pitfall traps).
Table 1 shows the dominances of the 26 diplopod species caught by pitfall traps.These are very different.There is a large number of subrecedent species, which occured only in between one or four of the investigation sites (C.punctatus, G. tetrasticha, L. belgicus, N. varicorne, Ophioclesmus albonanus and Ophyiulus pilosus).G. marginata is the only diplopod species which occured eudominantly or at least dominantly at all sites.C. caeruleocinctus was also found at all sites, but only eudominant or dominant on the calcareous grasslands.
In contrast to the diplopods, the dominance structure of the chilopods was relatively balanced (Table 2).Only a few species occurred subdominantly or recedently (/.. erythrocephalus, G. electricus, G. flavus, S. acuminata and S. crassipes).Subrecedent species were not found.Only L. mutabilis was found eudominantly at almost all study sites.
The activity abundances of diplopods were different between the sites investigated, especially the basophilic grasslands and semi-natural dry grasslands which showed outstandingly high values (Fig. 2).The highest activity abundance was found at site Huy 4 (Festuco-Brometalia).At the oak-hombeam woods (with exception of Huy 11) as well as the beech forests of the Cephalanthero-Fagion (Huy 7), they were relatively similiar.
The activity abundances of the chilopods were much lower than those of the diplopods and were not particularly different as between the sites studied (Fig. 2).

Results of additional catches
Tables 3 & 4 give an overview of the species and the individual numbers that were recorded by the additional sampling methods at the trapping sites Huy 1-11.With these methods 158 individuals of diplopods and 130 of chilopods were captured and determined; a further 32 specimens were juveniles and could not assigned to species level.On this basis the beech forests Huy 5 and Huy 6 were those most densely colonized by myriapods.Most specimens were found in litter and dead wood (Table 5) and sieving of these substrates was the most effective method.Using hand sampling one additional species, Proteroiulus fuscus (Am Stein, 1857), was found (at Huy 10).At the additional study sites S 1-11, in total 92 millipedes and 60 centipedes were found.The species and individual numbers are shown in Tables 3 & 4. The steppe meadow (S 6), beech wood (S 3) and the wet area at the bottom of a slope (S 4) were particularly well populated the first especially for diplopods (G.marginata).As at the pitfall trapping sites, sieving of litter was an effective sampling method (Table 5).
With the additional sampling at the sites Huy 1-11 and S 1-11, four diplopod species were found that had not been recorded previously (.Enantiulus nanus, Polyxenus lagurus, Proteroiulus fuscus and Strongylosoma stigmatosummarked with * in Table 3).Including these increased the total number of diplopod species to 30 in 10 families.G. marginata occurred continuously at nearly all sites and with all methods used (Tables 1 & 3).
For chilopods, two additional species were found (,Lithobius pelidnus and Cryptops hortensismarked with * in Table 3) increasing the total number of species to 17.For Europe 1,529 Diplopoda species are known (www.faunaeuropea.org).Of these only 133 are known to occur in Germany (Voigtlander et al. 2011, Reip et al. in press) and only 46 in Saxony-Anhalt (Voigtlander 2009a).The myriapod fauna of the FFH area "Huy" thus indicates, with 30 species (65 % of the myriapod fauna of Saxony-Anhalt), a very rich diplopod assemblage.
The Chilopoda show a similar pattern.According to Voigtlander (2009b), 507 species of Chilopoda are known in Europe; most of these belong to the Lithobiomorpha.For Germany 61 species are known at present (Voigtlander et al. 2011, Spelda et al. in press), 31 of these in Saxony-Anhalt (Voigtlander 2003b).With its 17 Chilopoda species (i.e.55 % of those known for Saxony-Anlialt) the FFH area "Huy" can also be considered to be very species-rich for tins group.
To obtain a complete species spectrum the study shows once again that different sampling methods have to be used.Some species are not active enough to be adequately sampled by pitfall traps.Tins is especially true for the "bark-dwellers" (P.fuscus, P. lagurus, L. pelidnus) as well as E. nanus (Voigtlander 1987, Spelda 1999b).Among the chilopods especially the contrast between the number of individuals caught with pitfall traps and by other methods is particularly striking with L. crassipes (32 and 92 individuals, respectively).Tins species also seems to be little "trap-agile".Notable also is the total number of L. forficatus in the beechwood (S 10).Presumably, the species was introduced with wood waste deposited here from the village.The study sites in the Huy showed a wide species spectrum (Tables 2 & 4), not only in their combined numbers, but also for each site.As well as eurytopic species, especially open-land species, many typical woodland species also occurred.Community structure and characteristic species composition are of special importance for evaluation of the condition of a habitat (Rombke et al. 1997, Spelda 1999b, Voigtlander & Diiker 2001, Voigtlander 2009b).This was tme for all sites.With respect to their Diplopoda assemblage, the rupicolous calcareous or basophilic grasslands of the Alysso-Sedion albi have to be classified as especially valuable from a nature conservation viewpoint.They not only have a high proportion of open-land species, such as O. sabulosus, M. unilineatum, and C. caeruleocinctus, but have also a very typical xerothermic community for this type of biotope (see Voigtlander & Diiker 2001).
In contrast, the Chilopoda assemblage is very sparse.Only two species occur, L. calcaratus and L. microps, both known as inhabitants of open sites.The combination of these two species is characteristic for dry and mesoxeric meadows (Voigtlander 2003a).
The semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) were, with 19 millipede species, the most diverse sites.They were characterized by a combination of eurytopic, open-land and woodland species.Such a combination of species can be also found in the Chilopoda, which together result in the high species richness of this area (12 species).
Of the woodland sites studied, the Galio-Carpinetum oak-hombeam woods Huy 9-11 are the most species-rich sites with 19 species (18 from traps and 1 from additional sampling).The Medio-European limestone beech forests of the Cephalanthero-Fagion with 16 species of Diplopoda and 8 of Chilopoda seems to be the most species-poor site.However, only one site was studied there as against three sites as usual.In the beechwoods, euryecious and stenoecious woodland species dominated.
Among the specially investigated sites, the areas of S 4 (moist location), S 1 (quarry, open area) and S 7 (pine mixed forest) are striking with their high species numbers.The lowest species numbers were found in the beechwoods (S 5, S 10), where sampling took place from under the bark of living trees and from bark lying on the ground, and the ruderal site (S 9).R e m a r k a b l e s p e c i e s Brachyiulus pusillus (Leach, 1814) occurs only moderately frequent in Germany.The species has already been recorded from the North Harz Foreland (Voigtlander 2009a).It is known from floodplains and riverbanks as well as from fallow land and dry meadows at lower altitudes.Within the area studied here, it was only found in a basophilic grassland (Huy 2) and under adjacent Rosa and Primus shrubs.
Megaphyllum unilineatum (C.L. Koch 1838).This extremly xerothermic species occurred in the study area only at Huy 1 and 2, both basophilic grasslands.Due to the increasing intensification of agriculture and development on suitable habitats, the species is already extinct in many areas of Baden-Wurttemberg (Spelda 1999c).It is listed as endangered (category 3) on the Red List of Germany (Reip et al., in press).
Mycogona germanica (Verhoeff, 1892) is endemic to the European central uplands and has its main distribution area in Germany.The study area is located on the northern border of its area of continuous occurrence.With the exception of the basophilic grasslands (Huy 1, Huy 2) and the limestone beech forest (Huy 7), M. germanica was found in all biotope types of the present study.
Ophiodesmus albonanus (Latzel, 1895) is a thermophilic and very small species (4.5-5.0 mm) only known for Germany from a small number of (predominantly synanthropic) localities.It was found at site Huy 4 (semi-natural dry grasslands) and the limestone beech forest Huy 5, which represent its first records for Saxony-Anhalt! Polyxenus lagurus Linne, 1758 is an inhabitant of the bark of living trees and is only occasionally caught in traps.Searching by hand provides the best results.In the Huy region only sampling by hand was successful (9 specimens at Paulskopf, pine bark, 18 Apr 2010, coll.M. Jung and 1 ind.at the site S 4, Kellerloch, 16 Aug 2011, own collection).
Geophilus electricus (Linne, 1758).Up to now this species has only rarely been recorded in Germany.In Saxony-Anhalt it also shows a scattered distribution (Voigtlander 2009b); in the study area it occurred at five sites (Huy 4, 5, 7, 10 and 11) with only few specimens in each case (max.5 individuals).
Lithobius nodulipes Latzel, 1880 inhabits submontane to montane sites.The species extends in Saxony-Anhalt from the Harz mountain up to the northern Harz Foreland.With the exception of the calcareous grasslands, the species was found in high numbers at all the study sites.
Lithobius pelidnus Haase, 1880 is very rare and only very locally distributed in Germany.In Saxony-Anhalt the species had been recorded from bogs of the Hochharz as well as from the Rhin-Havel-Luch (Voigtlander 2004).However, it may be assumed that the "rareness" of this species is probably a methodological artifact.The species prefers tree trunks (Spelda 1999a) and also sometimes occurs under bark and in dead wood and sampling of such microhabitats is usually neglected.In the Huy, L. pelidnus was sporadically found in dead wood sievings and in hand sampling on dead tree trunks and stumps (1 \ 2 ) as well as in moss and leaf-litter sievings (each 1 $).Within its overall distribution area, the species is restricted to cool-humid habitats but was also recently found in Luneburg Heath in an open heathland, in pine woods and in a /icm/fl-afforcstation (Lindner et al. 2010).Also at the Huy, the species was found in two extremely different biotope types: in the open area of the quarry "Gletschertopfe" as well as in the woodlands Huy 6 and Huy 10.This morphologically very variable species obviously has a much broader ecological range than assumed before.We are very grateful to Peer Schnitter (Halle) and the State Office for Environmental Protection Saxony-Anhalt for the long-standing cooperative collaboration and the provision of myriapod material.Especially thanks we would like to give to Marlies Wiesenhiitter for compiling the data as well as David Russell (both Gorlitz) and Tony Barber (Ivybridge) for English proofreading.
Fig. 1: L ocation o f the study area Huy in Germ any and the study sites.M odified after M eyer (2011).▲ -H uy 1-11 (sites o f pitfall traps) and • S 1-11 (additional sam pling sites).
A c k n o w l e d g e m e n t s
• S 11: Sloe-wild rose shrub {Rosa canina, Prunus spinosa) at the edge of the dry meadow Huy 2. 51.955849° N 11.052249° E, 220 ma.s.l.M a t e r i a l a n d m e t h o d s

Table 1 :
Species spectrum, num ber o f individuals and dom inances o f the Diplopoda caught by pitfall traps at the investigation sites in the FFH area Huy.Preference type according to .

Table 2 .
Species spectrum, num ber o f individuals and dom inances o f the Chilopoda caught by pitfall traps in the study sites o f the FFH area Huy.A bbreviations as in Table1. http://rcin.org.pl

Table 3 .
Species spectrum and num ber o f individuals o f D iplopoda from pitfall traps (Huy 1-11) and additional sam pling sites (S 1-11).* -only found by using the additional sam pling methods.

Table 4 .
Species spectrum and num ber o f individuals o f Chilopoda from pitfall traps (Huy 1-11) and additional sam pling sites (S 1-11).* -only found by using the additional sampling methods.

Table 5 .
N um ber o f specimens o f D iplopoda and Chilopoda in different habitat types at the pifall-trap sites Huy 1-11 and the additional sam pling sites S 1-11 found by sieving, hand sam pling and soil cores.