Data from: Fire frequency drives habitat selection by a diverse herbivore guild impacting top–down control of plant communities in an African savanna

In areas with diverse herbivore communities such as African savannas, the
frequency of disturbance by fire may alter the top–down role of different
herbivore species on plant community dynamics. In a seven year experiment
in the Kruger National Park, South Africa, we examined the habitat use of
nine common herbivore species across annually burned, triennially burned
and unburned areas. We also used two types of exclosures (plus open access
controls) to examine the impacts of different herbivores on plant
community dynamics across fire disturbance regimes. Full exclosures
excluded all herbivores > 0.5 kg (e.g. elephant, zebra, impala)
while partial exclosures allowed access only to animals with shoulder
heights ≤ 0.85 m (e.g. impala, steenbok). Annual burns attracted a diverse
suite of herbivores, and exclusion of larger herbivores (e.g. elephant,
zebra, wildebeest) increased plant abundance. When smaller species, mainly
impala, were also excluded there were declines in plant diversity, likely
mediated by a decline in open space available for colonization of uncommon
plant species. Unburned areas attracted the least diverse suite of
herbivores, dominated by impala. Here, herbivore exclusion, especially of
impala, led to strong declines in plant richness and diversity. With no
fire disturbance, herbivore exclusion led to competitive exclusion via
increases in plant dominance and light limitation. In contrast, on
triennial burns, herbivore exclusion had no effect on plant richness or
diversity, potentially due to relatively little open space for
colonization across exclosure treatments but also little competitive
exclusion due to the intermediate fire disturbance. Further, the diverse
suite of grazers and browsers on triennial burns may have had a
compensating effect of on the diversity of grasses and forbs. Ultimately,
our work shows that differential disturbance regimes can result in
differential consumer pressure across a landscape and result in
heterogeneous patterns in top–down control of community dynamics.