Data from: Tropical biome switching: Ant communities transition from savanna to rainforest following cessation of burning

Savannas and rainforests co-occur as mosaics across large areas of the tropics. These mosaics are dynamic, with savanna and rainforest switching in relatively short-time scales, largely through the effects of fire. Most research to date focuses on assessing how this biome switching affects vegetation, with little attention given to faunal responses to transitions between savannas and rainforests.

Aim: To assess faunal responses to biome switching from savanna to rainforest following 50 years of fire cessation.

Location: Iron Range (Kutini-Payamu) on Australia's Cape York Peninsula.

Taxon: Subterranean, leaf litter, epigaeic, and arboreal ant assemblages.

Methods: We sampled ant assemblages using pitfall, subterranean and arboreal traps, and leaf litter extractions across different vegetation types: savanna, secondary forest, primary dry forest and primary wet forest.

Results: We find a clear switch from savanna to rainforest ant communities and that the ant communities in secondary forest are very similar to that in primary forest. This is despite low similarity in floristic composition due to a poor representation of primary rainforest trees. However, the secondary forest is still missing a range of specialist forest taxa, especially cryptobiotic species from the soil and leaf litter, and possibly also specialist canopy species.

Main conclusions: The current 50 yr-old secondary forest has much of the ant biodiversity value of primary rainforest, including for regionally endemic species that are rainforest specialists. This indicates that ant communities respond more strongly to vegetation structure than to plant species composition. However, some specialist taxa are not in secondary forests, and it is unclear under which circumstances they may reappear.