Land use effect on invertebrate assemblages in Pampasicstreams (Buenos Aires, Argentina)

SOLIS, M; MUGNI, H.; HUNT, L.; MARROCHI, N.; FANELLI, S; BONETTO, C.

ENVIRONMENTAL MONITORING AND ASSESSMENT

SPRINGER

Lugar: Berlin; Año: 2016

0167-6369

Agriculture and livestock may contribute to water quality degradation in adjacent waterbodies andproduce changes in the resident invertebrate composition. The objective of the present study was to assessland use effects on the stream invertebrate assemblages in rural areas of the Argentine Pampa. The four sampling events were performed at six sites in four streams of the Pampa plain; two streams were sampled inside a biosphere reserve, and another one was surrounded by extensive livestock fields. The fourth stream was sampled at three sites; the upstream site was adjacent to agricultural plots, the following site was adjacent to an intensive livestock plot and the downstream site was adjacent to extensive breeding cattle plots. Higher pesticide concentrations were found at the site adjacent to agricultural plots and higher nutrient concentrations at the sites adjacent to agricultural and intensive breeding cattle plots. The invertebrate fauna were also different at these sites. Multivariate analysis showed a relationship between nutrient concentrations and taxonomic  composition. Amphipoda (Hyalella curvispina)  wasthe dominant group in the reserve and extensive breedingcattle sites, but was not present in the agriculturalsite. Also, Chironomidae were absent from the agriculturalsite while present at other sites. Gasteropoda(Biomphalaria peregrina), Zygoptera, and Hirudineawere dominant at the most impacted agricultural and intensive breeding cattle sites.