Experimental plot design
Data were collected within the MOSAIK (Monitoring Savanna Biodiversity in Kruger National Park) project, which explores the patterns and interactions among plant, insect, bird, and mammal communities (see Hejda et al. 2022). Data were collected along a gradient of water availability and on two types of bedrock. Water supply was accounted for by locating the plots in three habitats: (i) near a perennial river or another permanent water source, such as artificial water points or dams, (ii) near a seasonal river with a lack of water during dry periods, and (iii) on dry crests, at least 5 km from any source of water (Fig. 1). These habitats types affect groundwater availability for animals as well as soil moisture for deep-rooting perennial species. The plots were grouped into triplets by habitats, with plots within the triplet being closer to each other (~ 7–13 km apart) than to other plots outside the triplet. The plots were located on two contrasting bedrocks, basalt and granite, which weather into soils that differ in nutrients, water retention capacity, and texture (Venter et al. 2003, Mucina and Rutherford 2006). We established 60 permanent plots 50 × 50 meters that were equally distributed among the three habitats (20 in each) and two bedrocks (30 in each) (Fig. 2). As we focused on the shrubby savanna, we placed our plots outside the riparian gallery forests, and the presence of trees in the plots was generally very low if any.