Effective biodiversity monitoring and rehabilitation relies on a good understanding of the factors that influence species distributions and assemblage composition. Here we investigated the influence of plant community characteristics on arthropod diversity, abundance and community composition at the radioactive waste-disposal facility of the South African Nuclear Energy Corporation (NECSA), Northern Cape Province. Plant alpha-diversity and cover was similar between all five plant communities surveyed. Similarly, total arthropod alpha-diversity did not differ between these plant communities. In contrast, arthropod abundance differed between the different plant communities and was negatively correlated with plant alpha-diversity and positively correlated to vegetation cover. Also, more beta-diverse plant communities did not necessarily support greater beta-diversity of arthropods. However, different plant communities generally had different arthropod communities. This highlights the importance of maintaining a mosaic of different plant communities for the effective conservation of arthropod biodiversity in this semi-arid region.