EFEITOS DO FOGO NAS COMUNIDADES DE AVES EM FLORESTAS SAZONALMENTE ALAGADAS AO LONGO DE RIOS DE ÁGUA PRETA AMAZÔNICOS NA BACIA DORIO NEGRO

Abstract

Aim Fire has been one of the events that most disrupt the coverage of tropical forests in the Amazon. Forests seasonally flooded by blackwater rivers (e.g., igapó) show an even greater vulnerability to fires, and because they harbor species of organisms specialized and adapted to the seasonal dynamics of water, the threat to this forest also jeopardizes these organisms. Birds can provide interesting insights into the effect of fire on the environment, as they provide essential ecosystem services. Here, we investigate how fire events at different time intervals affect the richness and species composition of birds in igapó forests. Location Negro River basin, Northwest Amazon. Methods We used autonomous recorders to survey bird species at 57 sampling points divided among control igapós (without a history of fire), igapós burned longer ago, and recently burned igapós. We compared the richness and species composition among the three igapó treatments and investigated how the vegetation structure affected by fire influenced the avifauna. Results Recently burned igapós showed the highest species richness, while those burned longer ago had richness similar to control igapós. Species composition differed across all igapó categories, with turnover being the beta diversity component that most influenced compositional differences. Canopy closure was the vegetation structure that most influenced species richness. Main conclusions For at least 38 years after the fire, the igapó bird community appears not to recover, even though richness reaches values similar to control igapós. Species richness is negatively influenced by canopy closure. Birds from igapó forests seem highly vulnerable to fires, not returning to burned igapós even after 38 years. Urgent actions for fire monitoring and preservation of igapó remnants are essential. Key-words: Autonomous recorders; composition; igapó; rainforest threats; species richness dynamics; turnover; vegetation structure.