Terrestrial arthropods as biological indicators of anthropogenic disturbance / Artropodes como indicadores biologicos de pertubação antropica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

In this study, the responses of terrestrial arthropods to different types of anthropogenic disturbance were examined, aiming to select and test ecological indicators. Ten groups of terrestrial arthropods were selected and sampled in an Atlantic Forest reserve with two sites with contrasting histories of disturbance, one with history of selective logging (preserved) and another with history of slash-and-burn (disturbed). The abundance of exotic species was higher in the disturbed area, and this pattern seems to be an adequate indicator of anthropogenic disturbance. Species richness was not significantly correlated between any pair of taxa. In contrast, species composition was significantly correlated among most groups, and clearly discriminates the disturbed from the undisturbed site. The composition of fruit-feeding butterflies and epigaeic Coleoptera were the best indicators in this study, discriminating between the disturbed and the undisturbed sites even in higher taxonomic categories, and acting as surrogates of the remaining arthropod groups. To validate the above findings, two additional Atlantic Forest reserves with different kinds of anthropogenic disturbance were sampled, aiming to find consistent responses to the three sources of disturbance. Fruit-feeding butterflies were used as focal group due to its usefulness as ecological indicators in the first study. Shifts in the species composition, abundance and proportion of three subfamilies (Brassolinae, Charaxinae and Satyrinae) were found to be consistent in our three study areas with different disturbance types and degrees. Results indicate that fruit-feeding butterflies may be promptly employed as disturbance indicators in the Atlantic Forest. On the other hand, disturbance effects on the fauna of the Brazilian Cerrado are still poorly understood. In the third study, the abundance of epigaeic arthropod orders and trophic guilds was assessed in cerrado sites subjected to three burning frequencies: frequent (HighFi), intermediary (MidFi) and infrequent (LowFi). None of the orders or trophic guilds analyzed had higher abundance in the LowFi, being either more abundant in the HighFi or MidFi, or did not differ among the burning frequencies. Results indicate that some arthropod groups may not only be resilient to fire effect, but actually benefit from fire effect in cerrado. Based on the results, springtails (Collembola) and ants (Hymenoptera, Formicidae) seem to be particularly appropriate focal groups for further exploratory studies at species level aiming to verify their indicator properties, since they are abundant in samples and, in the case of ants, relatively well known in the Cerrado. To sum up, the present study supports the potential of using arthropods as ecological indicators in different biomes, showing new directions to future research.

ASSUNTO(S)

butterflie indicadores (biologia) cerrados atlantic forest (brazil) epigaeic arthropod indicators (biology) cerrados artropode epigeico mata atlantica borboleta

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