Impacto del uso del suelo sobre la condición de ribera en

BOVERI, MARIA; ROSSO, JUAN JOSE; GRANITTO, MARIA; RENNELLA, ARMANDO

Biología Acuática

Asociación Argentina de Limnología

Año: 2016 vol. 31 p. 19 - 27

0326-1638

In the last 30 years agricultural areas have occupied a largerproportion of cultivable zone in the Pampa Plain, generating the movement oflivestock activities to the margins of waterways. These changes in land use cancause hydrological, morphological, physicochemical and biological alterationsin the lotic systems of this region. The aim of this study is to evaluate theimpact of different types of land use on the structure of the fish community instreams of the middle basin of Areco River. To do this, monthly samplings wererealized during the summer of 2014 in four tributaries of the Areco River. Twoof these sections were associated with an unfenced livestock use on the bank stream,while the other two sites had an agricultural use with preserved riparian zone.In each sampling site the structure of the riparian zone was evaluated byapplying a quality index of the banks. On each sampling date physicochemicaland hydrological parameters were surveyed and the fish community was sampled.The quality of the banks in places exposed to livestock was lower than in thosededicated to agricultural use. In the latter, the values of suspended solidswere lower while the total coverage of macrophytes was higher. Moreover, thetotal fish biomass was higher in the sites with higher level of preservation ofthe riparian zone. Significant differences were also observed in the fish speciescomposition among sites with contrasting land use. There were strong positive correlationsbetween the proportion of piscivores and the integrity of the bank. Theseresults show a consistent relationship between the land use and the quality ofthe bank, which ultimately have an impact on the structure of the fishcommunity in the lotic systems of the Pampa Plain.