Temporal changes in bird communities in areas with different histories of fire disturbance in highland grasslands of Brazil.

Abstract

Despite the importance and ubiquity of grasslands, the degradation and the loss of these habitats have negatively affected bird populations throughout the world. The use of fire to manage grassland areas in some regions of southern Brazil can help to maintain these areas but can also influence the bird community in different ways. We assessed temporal changes in richness, abundance, and composition of bird communities in areas with different histories of fire disturbance in highland grasslands of southern Brazil, the most extensive remnant of grassland of the Atlantic Forest domain. We censused birds during four breeding seasons (2015-2018), through point counts in areas burned only once in the last ten years (OF, n = 3), areas burned annually (AF, n = 2), and areas without fire in the last ten years (WF, n = 2). In OF the richness, abundance, and species composition changed in the year of the fire, compared to the previous year, and returned to the initial values two years later. In AF and WF we found some differences among the years, but not with an equally clear pattern. Three of the six grassland associated species assessed individually for density responded significantly to temporal habitat modification since the fire. Our results show that two years without fire were enough time for the bird community to recover after a fire, but some responses are species-specific. Therefore, fire can be used as a management tool for grasslands and may help in the conservation of birds of southern Brazil, as long as with a minimum interval between fires in an area is guaranteed.