Temporal patterns in the activity density and sex ratio of isopods (Oniscidea, Isopoda) along an urbanization gradient in Denmark
Urbanization effects on terrestrial isopod (Isopoda, Oniscidea) populations were studied in forested areas along a rural-to-urban gradient including a native beech forest, suburban and urban forest fragments in Sorø, Denmark. The seasonal activity patterns of the dominating species (Oniscus asellus, Philoscia muscorum and Porcellio scaber) indicated differences among the areas, but these patterns were idiosyncratic. There were more females than males in most areas. The seasonal patterns of males and non-gravid females were similar and often bimodal; gravid females showed markedly different, usually unimodal activity patterns. Temporal changes of sex ratios were — in each species — characterized by an early summer activity peak of males, followed by the activity peak of gravid females. We suggest that these trends might indicate a reproduction-driven surface activity of males. The small response of the three isopod species to urbanization may reflect their wide ecological tolerance as well as the “soft management” of the urban park.
KeywordsActivity patterns Female-dominated sex ratio Seasonal activity Urbanization
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We thank the support of the Sorø Akademi Stilftelse, the former Danish Institute for Agricultural Sciences, Flakkebjerg Research Center, the International School of Biodiversity Studies (ISOBIS) Aarhus, Denmark and the Hungarian Scholarship Board (ZE), Dr. H. Schmalfuss (Natural History Museum, Stuttgart) for taxonomic help, and Dr. E. Hornung (Szent István University, Budapest) for comments. This is publication no. 14 of the Danglobe Project. Author contributions: GL and ZE designed the study, and performed field sampling; ZE and FV sorted and identified the material, FV, ZE and GL made the analysis and wrote the paper.
- Andreev, V. 2004. Urban Climate and Air Quality – a Review. in: L. Penev et al. (eds.), Ecology of the City of Sofia. Species and Communities in an Urban Environment. Pensoft Publishers, Sofia – Moscow, pp. 55–82.Google Scholar
- Anichtchenko A. et al. 2012. Carabidae of the World. http://www.carabidae.pro; accessed: 13 July 2017
- Bogyó, D. and Z. Korsós. 2009. Effect of urbanization on diplopods – Faunistical results. Természetvédelmi Közlemények 15:412–421. (in Hungarian)Google Scholar
- Cochard, P.O., F. Vilisics and E. Séchet. 2010. Alien terrestrial crustaceans (Isopods and Amphipods). In: A. Roques, J.Y. Rasplus, W. Rabistch, C. Lopez-Vaamonde, M. Kenis, W. Nentwig and D. Roy (eds.), Terrestrial Arthropod Invasions in Europe. BioRisk 4:81–96.Google Scholar
- Dias, N. and M. Sprung. 2003. Population dynamics and production of the isopod Tylos ponticus in a Ria Formosa saltmarsh (South Portugal). In: A. Sfenthourakis, P.B. Araujo, E. Hornung, H. Schmalfuss, S. Taiti and K. Szlávecz (eds.), The Biology of Terrestrial Isopods V. (Crustaceana Monographs, 2), Brill Academic Publisher, Leiden, pp. 133–149.Google Scholar
- Elek, Z. and G.L. Lövei. 2005. Ground beetle (Coleoptera, Carabidae) assemblages along an urbanization gradient near Sorø, Zealand, Denmark. Entomol. Med. 73:115–121.Google Scholar
- Farkas, S. 1998. Population dynamics, spatial distribution, and sex ratio of Trachelipus rathkei (Brandt, 1833) (Isopoda: Oniscidea) in a wetland forest by the Drava River. Isr. J. Zool. 44:323–332.Google Scholar
- Fazekas, J., F. Kádár, M. Sárospataki and G.L. Lövei, 1997. Seasonal activity, age structure and egg production of the ground beetle Anisodactylus signatus (Coleoptera: Carabidae) in Hungary. Eur. J. Entomol. 94:473–484.Google Scholar
- Hornung, E. and M.R. Warburg. 1998. Plasticity of a Porcellio ficulneus population under extrem weather conditions (a case study). Isr. J. Zool. 44:395–398.Google Scholar
- Horváth, R., Z. Elek and G.L.Lövei. 2014. Compositional changes in spider (Araneae) assemblages along an urbanisation gradient near a Danish town. Bull. Insectology 67:255–264.Google Scholar
- Meinertz, T. 1964.The distribution of the terrestrial isopods in Denmark up to 1963. Vidensk. Medd. Dan. Naturhist. Foren. 126:465–496.Google Scholar
- Nair, G.A. 1998. Reproductive and population biology of Porcellio scaber (Isopoda, Oniscidea) in Benghazi, Libya. Isr. J. Zool. 44:399–412.Google Scholar
- O’Neill, S.L., A.A. Hoffmann and J.H. Werren, 1997. Influential Passengers: Inherited Microorganisms and Invertebrate Reproduction. Oxford University Press, Oxford, UKGoogle Scholar
- Roques, A., W. Rabitsch, J.Y. Rasplus, C. Lopez-Vaamonde, W. Nentwig and M. Kenis. 2009. Alien Terrestrial Invertebrates of Europe. Handbook of Alien Species in Europe. Invading Nature — Springer Series in Invasion Ecology 3, pp. 63–79.Google Scholar
- Sapia, M., G.L. Lövei and Z. Elek. 2006. Effects of varying sampling effort on the observed diversity of carabids (Coleoptera: Carabidae). Ent. Fenn. 17:345–350.Google Scholar
- Scharff, N. and O. Gudik-Sørensen, 2006. Catalogue of the Spiders of Denmark (Araneae), Entomol. Medd. 74:3–71.Google Scholar
- Schmalfuss, H. 2003. World catalog of terrestrial isopods (Isopoda: Oniscidea). Stuttg. Beitr. Naturk., Ser. A 654:1–341.Google Scholar
- Sutton, S.L. 1980. Woodlice. Pergamon Press, Oxford, UK.Google Scholar
- Tuf, I.H. 2003. Development of the community structure of terrestrial isopods (Crustacea, Isopoda, Oniscidea) after a summer flood. In: A. Sfenthourakis, P.B. Araujo, E. Hornung, H. Schmalfuss, S. Taiti and K. Szlávecz (eds.), The Biology of Terrestrial Isopods V. (Crustaceana Monographs, 2), Brill Academic Publisher, Leiden, pp. 231–242.Google Scholar
- Wijnhoven, H. 2000. Landpissebedden van de Ooijpolder: deel 1. verspreiding (Crustacea: Isopoda: Oniscidea). Nederl. Faunist. Med. 11:55–131.Google Scholar
- Zimmer, M. and G. Kautz. 1997. Breeding phonological strategies of the common woodlouse, Porcellio scaber (Isopoda: Oniscidea). Eur. J. Soil Biol. 33:67–73.Google Scholar
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