El uso de gremios tróficos en macroinvertebrados acuáticos como herramienta de monitoreo en los Altos Andes del Sur de Ecuador

ABSTRACT Aquatic macroinvertebrates are widely used as indicators of water quality. However, in the Andean region of Ecuador, little is known about how the macroinvertebrate community assemblage responds to changes in the habitat where they occur. One of the main drawbacks is taxonomy, where classifying organisms on a full taxonomic scale becomes complicated. To resolve this point, in a in a NMDS (non-metric multidimensional scaling) ordination analysis, the abundance of macroinvertebrates obtained in 12 monitoring stations in the Cajas Massif, southern Ecuador, was used. The rankings were contrasted using the trophic guilds approach versus the family taxonomic approach (the maximum taxonomic classification available). The ordering analyzes showed a more differentiated spatial organization with the trophic guilds approach than with the family-level approach. When explaining the organization of the communities, the ABI (Andean Biotic Index) and the elevation, significantly explains the organization of the community from the trophic guilds approach; although, only the elevation explains the ordering from the family scale approach. The results suggest that, from the trophic guilds approach, a better approximation of the general ecological role of the macroinvertebrate community associated with environmental services such as water quality is represented. Guilds such as shredders, scrapers, and detritivores adjust to increasing ABI (i.e. water quality). Consequently, monitoring with a focus on the trophic guilds can be used in studies of water quality and its relationship with the community.