Effects of fire and edges on plant litterfall in a Neotropical rainforest, Brazil

Abstract

Anthropogenic forest fires are occurring with increasing frequency in tropical forests, with negative consequences for a variety of ecological processes, including litterfall. Litterfall provides several ecosystem services, such as nutrient cycling and carbon storage, thus playing an important role in ecosystem functioning. We assessed the impacts of fire and fire-created edges on litterfall in Atlantic Forest remnants in Bahia, Brazil. Litterfall was assessed at monthly intervals over one year along seven 300 m-long transects placed perpendicular to the edge between the unburnt forest and the burnt forest. We installed litterfall traps at the edge (0 m) and 20, 40, 60, 80, 100 and 150 m into both the burnt and unburnt forest. The total litterfall was smaller in the burnt forest (mean of 2.5 ± 2.2 SD t.ha⁻¹.y⁻¹) than in the unburnt forest (mean of 5.9 ± 3.4 SD t.ha⁻¹.y⁻¹). In addition, leaf litter gradually increased from the edge toward the unburnt forest interior. Our results highlight that there is less litterfall in the burnt forest, and that the relative contribution of different litter types (leaves, twigs, and miscellaneous litter) differ between burnt forest and unburnt forest. The lower amount of litterfall in the burnt forest and forest edge may have negative consequences for the natural regeneration of these areas, as the ecosystem services provided by plant litter that are important for forest regeneration are likely to be impaired.