Preliminary data on the epigeic beetle fauna (Coleoptera) of the Golczewskie Uroczysko Nature Reserve

A study was conducted in May–August 2006 in the Golczewskie Uroczysko Nature Reserve, UTM WV06, using 10 Barber traps containing ethylene glycol. A total of 2,141 beetles were collected, belonging to 58 species from 7 families. The epigeic beetle fauna of the reserve comprised mainly forest, grassland and peatland species. Stable populations of three ground beetle species under partial protection, Carabus convexus, Carabus coriaceus and Carabus glabratus, are present in the forest habitats. The most ecologically valuable species include hygrophilous peatland species: Agonum ericeti (VU), Pterostichus rhaeticus, Agonum hypocrita, Limodromus krynickii, Oodes helopioides (VU), and the rare click beetle Paraphotistus impressus, all of which have poorly known ecological preferences. Wstępne dane do poznania fauny chrząszczy epigeicznych (Coleoptera) Rezerwatu przyrody „Golczewskie Uroczysko” Słowa kluczowe chrząszcze epigeiczne, Coleoptera: Catopidae, Carabidae, Elateridae, Geotrupidae, Silphidae, Staphylinidae, Tenebrionidae, Rezerwat przyrody „Golczewskie Uroczysko” Streszczenie Badania były prowadzone w maju–sierpniu 2006 roku na terenie Rezerwatu przyrody „Golczewskie Uroczysko”, UTM WV06, za pomocą 10 pułapek ziemnych z glikolem etylenowym. Zebrano 2178 chrząszczy, należących do 71 gatunków z 15 rodzin. Fauna chrząszczy epigeicznych rezerwatu ukształtowana główne przez gatunki leśne, łąkowe i torfowiskowe, W siedliskach leśnych występują stabilne populacje 3 gatunków biegaczy objętych ochroną częściową: Carabus convexus, Carabus coriaceus oraz Carabus glabratus. Do najcenniejszych #0#


Introduction
Raised peat bogs in their natural state are currently still found in Ireland, Great Britain, Scandinavia, countries of the former Soviet Union, and Poland (Sjörs, 1983). Marshland and swamps are characteristic of northern and north-eastern Poland. They occupy about 4% of the area of the country, and raised peat bogs make up 0.2% (Ilnicki, 2002). According the European Union Natura 2000 directive, raised bogs and marshland are especially valuable habitats (Council Directive 92/43/EEC).
Marshes are destroyed during agricultural practices, drainage and peat extraction. Particularly dangerous for peatlands is the decline in the groundwater level, this is a consequence of dehydration. In Poland it is the main cause of the disappearance of peatlands (Żurek, 1987). For this reason there is a need for intensive research on the fauna of these rare and threatened habitats.
In Poland, the epigeic beetles of raised peat bogs are little known; only the ground beetles (Carabidae) of the "Torfiaki" peatland complex in the vicinity of Olsztyn have been studied (Aleksandrowicz et al., 2017).

Study area
The Golczewskie Uroczysko nature reserve was established on 5 May 2004 to protect the raised peat bog and the dystrophic Lake Żabie with its surrounding transitional bog and adjacent forest complexes containing valuable plants. It is located on the Gryfice Plain, near the village of Rokita, in a moraine upland area in the Kamień Pomorski anticline, and occupies two shallow depressions in the ground moraine landscape, separated by a small hill, and a flat moraine plain in the northern part of the reserve, with a moraine kame at 40 m a.s.l. situated on the north-western border of the reserve (Kondracki, 2004).
The southern depression is occupied by Lake Żabie, a small dystrophic lake located in a transitional, topogenous peat bog. The depression occupying the central part of the reserve is entirely filled with peat. In the eastern part it is a transitional, topogenous bog, while in the western part it is a raised, ombrogenous bog.
The research area was divided into eight sites, to more fully show the species richness of the entire reserve. The sites were classified as follows: sphagnum phytocoenoses with fragments of pine forest, Sphagno squarrosi-Alnetum, Ribeso nigri-Alnetum, ash and alder riparian forest, sphagnum peat bog, Vaccinio uliginosi-Betuletum pubescentis, phytocoenoses mainly dominated by sub-Atlantic lowland oak and hornbeam forest, phytocoenoses mainly dominated by Vaccinio uliginosi-Betuletum pubescentis.

Methods
The study was carried out from 28 May to 15 August 2006. Due to the fact that the studies were conducted in the nature reserve, the duration of the study and the number of traps used were limited.
The beetles were caught using Barber traps, each consisting of a plastic 500 ml container buried in the earth so that its rim did not protrude above the surface, making it much easier for insects to fall in. About 15 ml of a 10% solution of ethylene glycol was poured into the container. A plastic lid was placed about 2 cm over the trap to protect it from rain and falling leaves that could block the opening. This is a standard method that is widely used in this type of research (Thiele, 1977).
The habitat preferences of each species were based on a work by Koch (1989) and Aleksandrovich (2004).

Results
In the Golczewskie Uroczysko Nature Reserve 2,141 beetles were captured and identified, comprising 58 species from 7 families ( Table 1).
The most abundant families were Carabidae, with 34 species and 1,108 specimens, Silphidae, with 8 species and 631 specimens, Staphylinidae 4 species and 18 specimens, and Geotrupidae, with 3 species and 315 specimens (Table 1).  Three species are on the Polish Red List of endangered species (Pawłowski et al., 2002): the near threatened (NT) Carabus convexus and the vulnerable (VU) Agonum ericeti and Oodes helopioides.
The most ecologically valuable are stenobiontic hygrophilous species typical of raised bogs: ground beetles Agonum ericeti, Pterostichus diligens and Pterostichus rhaeticus and of transitional bogs and fens ground beetles Agonum hypocrita and Limodromus krynickii, the click beetle Paraphotistus impressus.
Agonum ericeti -a stenobiontic hygrophilous species of raised bogs. One species caught 1 July 2006 in a raised peat bog. Recorded the first time for West Pomerania.
Pterostichus rhaeticus -a stenobiontic hygrophilous species of raised bogs. 21 species caught on 9 August 2006 in a raised peat bog, 6 specimens in a peat bog with fragments of pine forest, and 4 in a Sphagno squarrosi-Alnetum association.
Paraphotistus impressus -rare and sporadic species associated with coniferous forests (Burakowski et al., 1985). Four specimens caught on 9 August 2006, in a peat bog with fragments of pine forest.

Discussion
Peatlands are considered very demanding, extreme environments (Främbs et al., 2002). Species strictly associated with these biotas are called tyrphobionts, while those occurring in the highest numbers, but with a broader ecological spectrum, have been classified as tyrphophiles (Peus, 1932). The tyrphobiontism of numerous taxa occurring in marshes and peatlands is the result of regional limitations. Most of these species are eurytopes which have spread in the continental regions of Eurasia, while in Central and Western Europe their occurrence is limited to oligotrophic peatlands (Thiele, 1977). In the Uroczysko Golczewskie reserve, Agonum ericeti and Pterostichus rhaeticus belong to this group.
In the study area we can observe that the species occurring in the highest numbers are representatives of the Carabidae and Silphidae families. The first of these are predatory species which actively seek prey, while the latter are scavengers (apart from the predatory Phosphuga atrata and the polyphagous Thanatophilus sinuatus). Tews et al. (2003) found that species richness is most affected by habitat structure in periodically flooded wetlands. It is likely that the mosaic character of the habitats in the Uroczysko Golczewskie reserve had a significant effect on species diversity.
Comparison of the species composition of the epigeic beetles of the Uroczysko Golczewskie reserve indicates a fairly high degree of similarity with the fauna of peatlands of NW Germany (Peus, 1932, Mossakowski, 1970, NE Poland (Aleksandrowicz et al., 2017) and northern Belarus (Sushko, 2006).

Conclusions
The study was conducted in May-August 2006 in the Golczewskie Uroczysko Nature Reserve, UTM WV06. Ten Barber traps with ethylene glycol were used to catch 2,141 beetles belonging to 58 species from 7 families.
The most abundant families were Carabidae, with 34 species and 1,108 specimens, Silphidae, with 8 species and 631 specimens, and Geotrupidae, with three species and 315 specimens.
The epigeic beetle fauna of the reserve consisted mainly of forest, grassland and peatland species.
The presence of three species of ground beetles under partial protection was established: Carabus convexus, Carabus coriaceus and Carabus glabratus (Dz.U. [Journal of Laws] of 2016, item 2183). These species are fairly abundant in forest habitats (phytocoenoses dominated by sub-Atlantic lowland oak and hornbeam forests) and their populations are not endangered.
Three species are on the Polish Red List of endangered species (Pawłowski et al., 2002): the near threatened (NT) Carabus convexus and the vulnerable (VU) Agonum ericeti and Oodes helopioides.
Comparison of the species composition of the epigeic beetles of the Uroczysko Golczewskie reserve indicates a fairly high degree of similarity with the fauna of peatlands of north-western Germany and northern Belarus.