Influência da estrutura do ambiente na distribuição da avifauna em um fragmento florestal na mata atlântica do Sul do Brasil

Abstract

The intensification of agriculture has provided intense deforestation and fragmentation in the Atlantic Forest and may lead to changes in the distributions of the species. Birds are largely affected organism by the environmental changes. The objective of this study was recorded bird fauna distribution in the Municipal Park of Sertão and surrounding in the northern part of the state of Rio Grande do Sul, southern Brazil. Nine transects were selected along the three sample areas: Core, Edge, and Buffer area of the Municipal Park of Sertão. Samples were taken from November 2020 to February 2021. We used the counting point sampling and Mackinnon list methods to record species richness and number of individuals in each area. A total of 131 bird species were recorded in the Park and surrounding, distributed through 18 orders and 38 families. Of these, 106 species were recorded in the sample areas and 25 as occasional encounters. The number of the species was higher in Buffer area (N = 74), followed by Edge area (N = 73), and Core area (N = 59). Of the 106 species, 35 (33,01%) were registered in all three areas. The Buffer area showed greater number of exclusive species (N = 18). There was no significant difference in the number of species between the areas. However, there were differences in species composition, diversity and to some ecological traits between the areas. The distribution of species in the Municipal Park of Sertão seems to reflect differences in the forest habitat structure. Our results indicate that despite the effects caused by fragmentation the Municipal Park of Sertão represents an important remnant of native forest in a highly fragmented region and one refuge to regional bird fauna.