Influência da mata ripária na colonização e sucessão ecológica de invertebrados bentônicos, em afluentes do Rio Ampére, Sudoeste do Paraná

Abstract

Objectives: To evaluate the influence of the state of conservation of riparian forest on the composition and richness of benthic invertebrates, associated with leaf litter in the Ampére river tributaries, Sudoeste do Paraná. Methods: The experiment was carried out in March and April of 2018, in eight streams of first order, with different degrees of conservation (natural, altered and degraded) of APP (permanent preservation area). The method used in the evaluation of the benthic community was the "litter bag" trap containing leaves of Ocotea sp. as a natural substrate. The experiment was installed in streams for 35 days with withdrawals at 3, 7, 14, 21, 28 and 35 days. OD, pH, temperature, electrical conductivity, total alkalinity and BOD were also evaluated in the installation and in each withdrawal. Results: 2,223 individuals of benthic invertebrates distributed in 29 taxa were registered. In the natural springs 585 individuals were obtained the lowest abundance, with the lowest number of 18 taxa. For the altered springs, 857 individuals from 20 taxa were registered, in the degraded ones were sampled 781 individuals belonging to 19 taxa. There was no statistically significant difference between the three types of springs in relation to abundance and richness as well as in the physical and chemical variables. There was also no pattern of colonization and ecological succession, and colonization occurred randomly. Discussion: The natural springs with conserved ciliary vegetation showed a pattern of diversity similar to the altered ones. Therefore, even with characteristics of preserved ciliary vegetation, it was verified that these bodies of water are suffering with the adjacent areas and the hypothesis for this pattern is that even the springs with better conservation have been suffering with the diffuse pollution with entrance of water of the conduit rainfall, pasture, annual crops, among others.