Resumo

FREDES, Natalia A; MARTINEZ, Pablo A; BERNAVA LABORDE, Verónica  e  OSTERRIETH, Margarita L. Microarthropods as indicators of anthropic disturbance in entisols in a recreational area of Miramar, Argentina. Cienc. suelo [online]. 2009, vol.27, n.1, pp.89-101. ISSN 1850-2067.

Human trampling in recreational areas causes alterations in the soil surface horizon, partially or totally disrupting soil structure, reducing porosity and modifying the edaphic microenvironment. Soil mesofauna, is a good indicator of this human impact since it inhabits mainly soil surface horizons. We evaluated the changes in edaphic oribatid mite (Acari) and springtail (Collembola) communities sufferering from the impact of human trampling in the recreational area of Vivero Dunícola "Florentino Ameghino" Miramar, in the Province of Buenos Aires, Argentina. Three impact areas were considered: maximum, medium and minimum. Collembola and oribatid were determined to species level. Species richness, diversity and parity by site and horizon were calculated. A correspondence analysis was carried out and an impact index elaborated taking into account the different horizons and species frequencies. Twenty-nine species of oribatid mites and 19 species of Collembola were found. Diversity (H´) was significantly different between the maximum and minimum impact sites. Factorial Correspondence Analysis defined three groups in terms of degree of alteration of the surfacel horizon and pedological characteristics (organic or mineral horizons). The value of the impact index (II_M) in the maximum trampling area was II_M=9 while in that of minimum impact it was II_M < 1. The results support the usefulness of the microarthropod community as an indicator of human impact and their suitability for bioevaluating the state of the study area.

Palavras-chave : Soils; Bioevaluation; Oribatid mites; Springtails; Impact index.

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