Seasonal change of dung beetles in Hungarian pastures, wood-pastures and forests – knowledge for the conservation of decomposers

(Poster)

László Somay
somay.laszlo@okologia.mta.hu

MTA Centre for Ecological Research, Institute of Ecology and Botany, Alkotmány u. 2-4., H-2163 Vácrátót, Hungary MTA Centre for Ecological Research, GINOP Sustainable Ecosystem Research Group, Klebelsberg u. 3., H-8237 Tihany, Hungary Szent István University, Doctoral School of Environmental Sciences, Páter Károly u. 1., H-2100 Gödöllő, Hungary, Hungary
,
Réka Ádám
MTA Centre for Ecological Research, Institute of Ecology and Botany, Alkotmány u. 2-4., H-2163 Vácrátót, Hungary, Hungary
,
Gergely Boros
Szent István University, Departure of Zoology and Animal Ecology, Páter Károly u. 1., H-2100 Gödöllő, Hungary MTA Centre for Ecological Research, GINOP Sustainable Ecosystem Research Group, Klebelsberg u. 3., H-8237 Tihany, Hungary, Hungary
,
András Báldi
MTA Centre for Ecological Research, Institute of Ecology and Botany, Alkotmány u. 2-4., H-2163 Vácrátót, Hungary MTA Centre for Ecological Research, GINOP Sustainable Ecosystem Research Group, Klebelsberg u. 3., H-8237 Tihany, Hungary, Hungary

DOI: 10.17011/conference/eccb2018/107761

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Dung beetles (Scarabaeidae: Scarabaeinae, Aphodiinae and Geotrupidae) have an important role in several ecologically and economically valuable ecosystem functions and services through dung decomposition and by improving soil characteristics. Their number has a decreasing tendency throughout in Europe and thus, the ecosystem functions and services they provide are damaged. Main reason of decline is the change of farming practices, namely the decrease of grazing livestock and seminatural pastures. Until the second half of the 20th century wood-pastures were traditional pasture areas and grazing in forests also had great importance. However, forest grazing has now almost completely disappeared, several wood-pastures are under restoration and grazed again, primarily as conservation management. The aim of the study was to describe the structure and functional composition of the dung beetle assemblages, its seasonal changes in wood-pastures, compared to forests and pastures. Our study was carried out in three landscapes in the Északi-Középhegység (North Hungarian Mountains) and the Dunántúli-Középhegység (Transdanubian Mountains) regions. Three sampling points per area were designated in each habitat. The sampling of dung beetle assemblages was carried out in spring (May), summer (July) and autumn (October) of 2016, using pitfall traps baited with the dung of cattle, horse and sheep, the three most important livestock species in region. Pitfall traps were emptied after one week. Collected beetles were identified at species level and were categorized into functional groups. Average dry weight of each species were measured as well. In all, more than 70,000 specimens of nearly 60 species were collected and classified into four functional groups: small rollers, big tunnelers, small tunnelers and dwellers. The seasonal pattern was similar in all the three areas: the highest species richness was in spring what is gradually declined to autumn. Densities and dung preferences were significantly different in the areas. The composition and biomass of functional groups also differed between habitat types and seasons. In general, pastures were dominated by small tunneler species in spring and summer, while the forests by the big tunnelers in summer. In autumn the abundance of dwellers increased in all habitat types. The dung beetle assemblages of wood-pastures show a transition between the assemblages of forests and pastures. In these partly wooded areas the species of forests and open grasslands may occur together. Therefore, we recommend special conservation efforts to maintain and restore wood-pastures and to graze with different livestock, to secure the functioning of diverse dung beetle asssemblages.

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INTRO:
The authors studied dung beetle assemblages of wood-pastures, forests and pastures in Hungary. Especially wood-pastures had a high species richness highlighting their high relevance for nature conservation.
MERITS:
See comments above.
CRITIQUE:
The authors should mention the sample size per habitat type.
DISCUSSION:
No further recommendations.

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INTRO:
This study investigates the structural and functional composition of dung beetle assemblages in wood pastures in comaprison to forests and grassland. Furthermore, the study aims to identify seasonal shifts during the season in each of the studied habitats. This work reveals that the composition and biomass of the functional groups differed between the studied habitat types and season. Dung beetles showed a clear response to different habitat types, with each habitat type harboring a unique assemblage. As wood pastures appear to hold the highest value for biodiversity conservation, habitat management should primarily focus on the maintenance of traditional forest grazing, as well as the restoration of abandoned wood pastures.
MERITS:
Due to abandonment, wood pastures are highly threatened throughout Europe. Thus, investigations analyzing structural and functional diversity in this habitat type are urgently needed. In particular, they are an important habitat for several rare dung beetles, which are a well-suited indictaor group in analyzing the effects of grazing. It should therefore be noted that the study provides significant information for future biodiversity conservation in wood pastures.
CRITIQUE:
The field work was conducted in three different landscapes in two mountain ranges in North Hungary. In each of the landscapes, three sample points were investigated in each of the three studied habitat types. In my opinion, it could be considered even more appropriate to study the effects of different habitat or management types (e.g. abandoned wood pastures, low-intensity grazing, intensive grazing etc.) in sufficient sample size concentrated to one well-suited study area. Furthermore, there are minor linguistic flaws in the manuscript.
DISCUSSION:
Despite some minor weak points, I highly appreciate the work of the authors. I think that the study provides important insights to gain more knowledge for biodiversity conservation in wood pastures. Thus, the study is of particular interest for ecologists participating the ECCB.