The influence of mulch on seasonal fluctuations in Collembola diversity in apple orchards

Collembola, which are among the most abundant soil microarthropods, have been shown to be vital in understanding soil health and the effects of land-use on soil biodiversity. However, Collembola remain understudied in agroecosystems, more particularly in orchards, and information on their taxonomy and ecology are limited in South Africa. This study investigated the differences in Collembola assemblages between apple orchards with and without mulch application on the berm (planting row), over three seasons in the Ceres region, Western Cape, South Africa. Soil samples were taken to a depth of 10 cm from the berm and work row within the orchards, and microarthropods were extracted using Tullgren funnels. Collembola were sorted to morphospecies and identified to genera or species. A total of 33 Collembola species from 11 families and all four orders were identified. Mulched orchards significantly maintained Collembola abundance and species richness from winter to summer compared to unmulched orchards. Additionally, mulched orchards showed a significant difference in community composition between the berm and work row, more pronounced in summer, which was not apparent in the unmulched orchards. Overall, this suggests that mulch not only plays a significant role in buffering Collembola assemblages during seasonal fluctuations but also affects Collembola community composition. This is, to our knowledge, the first detailed study of Collembola diversity in deciduous orchards in Africa, thus providing important baseline knowledge for future work on soil health in commercial orchards and other agroecosystems. • First detailed study on Collembola community composition in South African orchards. • Mulch maintains Collembola abundance and taxonomic diversity from winter to summer. • Collembola community composition differed between berm and row in mulched orchards. • Euedaphic Collembola were more abundant in the presence of mulch. • Effects of mulch on Collembola communities were more pronounced in summer.