Ant Species Identity has a Greater Effect than Fire on the Outcome of an Ant Protection System inBrazilianCerrado

Abstract

Although fire‐ and ant–plant interactions influence the community structure and dynamics of Neotropical savannas, no previous studies have considered their simultaneous effects on target host plants. We monitored the effect of ant exclusion for 3 years on leaf area loss to leaf chewing insects, thrips abundance, and reproductive output of the extrafloral nectary‐bearing shrub, Peixotoa tomentosa (Malpighiaceae). We predicted that the impact of ants on herbivores and plants would depend on the ant species, and that fire would reduce the effect of ants. We deliberately chose control plants that differed in their occupant ant species. Fire occurred in the second year of the study, allowing us to determine its effect on the benefit afforded by ants. Ants reduced leaf area loss and thrips abundance, and increased fruit and seed production in all 3 years. Some ant species were more effective than others, while plants with multiple ant species suffered higher leaf area loss than plants with a single ant species. In the year following the fire, leaf damage was greater than in the other years, regardless of the ant species, and the proportional effect of ants in reducing damage was less. Interactions affecting thrips abundance did not change following fire, nor was the benefit to the plant proportionally reduced. Overall, the identity of the ant species had a greater effect than did the occurrence of fire on the ant–herbivore–plant interaction: the identity of the ant species influenced leaf area loss, thrips numbers, and bud and seed production, while fire only modified the impact of ants on the amount of leaf area consumed by insect herbivores.

Variation in Extrafloral Nectary Productivity Influences the Ant Foraging

“…These species are generalist foragers that set partnerships with honeydew producers [64, 69]. The dominance of these species in Cerrado EFNs-bearing plants was also observed in other studies [2, 13, 70], and it demonstrates their strong adaptation to such environment [25]. …”

“…Although many studies have demonstrated the importance of EFNs-attracted ants to plant defense against herbivores [25–26], the influence of the EFN secretory activity pattern on ants remains yet not fully understood. According to O’Dowd [27], “if a primary function of foliar nectar production is the maintenance on the plant of potential anti-herbivore agents such as ants, then the deciphering of relationships among nectar production, ant visitation and leaf development is particularly important”.…”

Effect of Fire on Ant Assemblages in Brazilian Cerrado in Areas containing Vereda Wetlands

“…torosa. The genus Crematogaster is a cosmopolitan lineage of Myrmicinae, and the majority of species nests on trees (Hölldobler & Wilson, 1990), which reduces insect herbivore attacks (Del-Claro & Marquis, 2015). However, Cr.…”

Interação formiga-planta-polinizador em <i>Palicourea rigida </i>(Rubiaceae) no cerrado: quando a proteção contra a herbivoria impacta negativamente a ação dos polinizadores

“…Porém, o resultado da interação formiga-planta nem sempre é positivo, dependendo das espécies envolvidas, o comportamento da formiga e a estrutura da planta a ser considerada (LANGE; HANNA et al, 2015;DEL-CLARO et al, 2016). Por exemplo, em Peixotoa tomentosa (Malpighiaceae), a produção de frutos variou ao longo de três anos, fato que foi associado às espécies de formigas presentes na planta durante o período de estudo (DEL-CLARO, MARQUIS, 2015). Já em Ouratea spectabilis (Ochnaceae) a presença de formigas da espécie Cephalotes pusillus reduziu a floração da planta por seu hábito de consumir pólen (BYK; DEL-CLARO, 2010).…”