Response of ground arthropods to effect of urbanization in southern Osaka, Japan

Ground arthropods are abundant in urban ecosystem, but our understanding of their ecological traits is limited. The aim of this study is to clarify the effect of urbanization on ground arthropod communities. Ground arthropods were monitored weekly at six sites (Site 1: Yamato River riverbank; Site 2: Daisen Park; Site 3: Oizumi Ryokuchi Park; Site 4: Osaka Prefecture University campus; Site 5: paddy field; and Site 6: town forest) from April 2005 to December 2005. A total of 221,000 individuals of ground arthropods belonging to 19 orders were identified in the dataset. Isopoda, including Porcellionidae and Armadillidiidae, was the first dominant order and 195,161 individuals were collected, representing 88.3% of the total. The mean density of ground arthropods in Sites 1–4, urbanized areas, was much higher than that in paddy field and town forest. The pattern of ground arthropod community in riverbank did not differ from those of urban park, urban forest area, and university campus. Our findings showed that ground arthropods tend to increase biomass in urban areas and some specific groups in areas urbanized and disturbed by human activities.