Influencia de la ganadería en los macroinvertebrados acuáticos en microcuencas de los Andes centrales de Colombia. Cattle raising influence over the aquatic macroinvertebrates in microbasins of central Andes, Colombia.

Abstract

. In Colombia, livestock activity is of great importance for the rural economy and the country’s food
supply. In order to measure the impact of cattle raising and riparian corridors on the composition and diversity
of benthic macroinvertebrates in Andean microbasins, nine headwater streams were selected in the municipality
of Villamaría (Caldas, Colombia), five of them with riparian corridors and four without protection. During July
2013, macroinvertebrate samples were collected using D-net and Surber nets, and each streams was characterized according to water quality, channel metrics and habitat quality score. In total 98 934 individuals were
collected, distributed in nine classes, 17 orders, 56 families and 92 genera. Veneroidea was the most abundant
order followed by Trichoptera, Diptera, Tubificida and Ephemeroptera. Coleoptera was the richest order with 28
genera, followed by Diptera with 18, Trichoptera with 11, Ephemeroptera with 10 and Odonata with 8. Streams
with riparian corridors were deeper, had higher proportion of coarse substrates and Habitat Quality Score and
presented higher genus diversity than those unprotected (P < 0.05). The genera Ferrisia, Eurygerris, Heleobia
and Pisidium; total nitrogen, ammonia nitrogen and silt proportion on the streambed were correlated with unprotected streams, whilst the genus Rhagovelia, the subfamily Chironominae, the Habitat Quality Score and the
proportion of coarse substrates were correlated with streams with riparian corridors. This information confirms
that riparian corridors help reducing the negative impact generated by cattle ranching practices and improve the
provision of environmental services, and therefore it is recommended to maintain or restore the strip of riparian
vegetation to protect the streams in cattle ranching landscapes.