Borboletas Frugívoras e a Integridade de Florestas Ripárias na Amazônia Oriental

Abstract

Butterflies represent a diverse group of insects in riparian forests, which are favored in more heterogeneous environmental conditions, with microclimatic variations, and microhabitats and abundant food resources, provided by these riparian ecosystems. Considering the importance of riparian forests as one of the only forest fragments in anthropized landscapes, butterflies find shelter, refuge and food in these green areas. Despite being recognized for their sensitivity to environmental changes, little is known about the effects of anthropic disturbances on the community of frugivorous butterflies, mainly in riparian forests in the Maranhão Amazon. The objective of this research was to evaluate how the frugivorous butterfly community responds to anthropic disturbances and loss of integrity of riparian forests in urban and peri-urban areas. The research was carried out in 20 riparian areas of Upaon-Açu Island (Maranhão – Brazil). In each area, two 150-meter transects were established for the collection of butterflies in 12 traps, in the period of five consecutive days at the end of the rainy season (2019 and 2021). Vegetation structure parameters were measured in two plots of 60x10m, four of 4x4m and 1x1m. Physical and chemical parameters of soil and stream water (quality) were estimated in each riparian area (six samples of each). A total of 2,392 fruit-eating butterflies (Nymphalidae) were recorded, distributed in 54 species and morphospecies. The most representative subfamily was Satyrinae (26 species), the most abundant species were Taygetis laches (486 individuals), Colobura dirce (235 individuals), Cissia penelope (194 individuals), Opsiphanis invirae and Hypna clytmnestra (149 individuals each). The rarest species were Morpho menelaus, Callicore pygas, Temenis laothoe, Eunica cuvierii, with only one recorded individual. Canopy opening promoted an increase in the richness, abundance and diversity of frugivorous butterflies, as well as the greater basal area of trees had a significant negative effect on diversity. Biomass showed an inverted quadratic effect on diversity, which reduced to a minimum followed by an increase with greater biomass. Thus confirming that the butterfly community in these areas is favored by disturbances in the vegetation structure, dominated by generalist and opportunistic species, adapted to a greater range of environmental conditions and preference for more open areas. Changes in the composition of the butterfly community were found during the period studied, in which an ecological group of species was associated with more degraded areas, while another group was associated with areas with greater riparian habitat integrity. Therefore, the results of this research work make relevant contributions to the ecological knowledge of frugivorous butterflies in the Eastern Amazon, providing importante informations for the systematization of conservation and restoration strategies for remaining riparian forests in urban and peri-urban areas