Efeitos do fogo sobre aves de sub-bosque na área de proteção ambiental do Inhamum, Caxias, Maranhão

Abstract

The decrease in vegetation coverage and the alteration of the forest structure, caused by several types of impacts, can change the composition and abundance of bird communities. The disturbance caused by the action of fire in forest environments is harmful and deleterious for some species, opening the opportunity for new populations to establish themselves or to increase already established populations. However, it is not known significantly how the Bird communities react to the action of fire in different environments.. This study aimed to measure the impacts of fire on the understory bird community in a forest remnant in eastern of Maranhão. The study was carried out in the Environmental Protection Area (EPA) of Inhamum (3,500ha), situated about 2km from the urban perimeter of the municipality of Caxias, Maranhão. The birds were sampled monthly (September-2017 to August-2019) by the method of counting points in two forest stretches of the APA, one hit by fire in 2016 (CF) and a control section (SF), with no recent record of the occurrence of fire. 140 bird species were recorded in the two areas, of which 128 were observed in the CF and 91 in the SF (G = 6.281, p <0.05). It was found that 63 species were benefited by the passage of fire, that is, they presented significantly greater relative abundance in FC, among them Cyclarhis gujanensis and Formicivora grisea, for example Contrary, 17 bird species showed significantly greater relative abundance in SF, that is, they were affected by fire, including Eucometis penicillata and Penelope superciliaris. For the other species, fire did not act as a determining factor. Of the 14 species of climbing birds recorded, five were benefited (Campephilus melanoleucos, Campephilus rubricollis, Colaptes melanochloros, Picumnus pygmaeus, and Veniliornis passerinus), the other species were not harmed. Although the species showed a greater relative abundance in the burned area, it should be noted that most of them are species of wide occurrence and that show some tolerance in the face of environmental changes. Among the five environmental variables measured, the crown height did not show a significant variation between studied areas. Canopy height and coverage decreased in CF. The density of the understory and the number of dead trees were higher in the CF area. It is concluded that the passage of the fire affected the bird species of the Inhamum APA in a different way. Fire acted as a determining factor for species richness and abundance, with the burned area having a greater number of species. Burning should be seen as an opportunity to expand what is known about its effects on biota, aiming at planning conservationist strategies such as the creation of fire prevention and management interventions to reduce the occurrence and extent of fires in dry periods.