Latitudinal gradient variations in caddisfly assemblages across mountain forest streams

REYNAGA MARÍA CELINA; EDGARDO JAVIER IGNACIO PERO; RUEDA MARTÍN PAOLA ALEJANDRA

Quito

Congreso; AQUATROP: Ecosistemas Acuáticos tropicales en el Antropoceno; 2018

Evidence of latitudinal diversity gradient of benthic macroinvertebratesis variable. This study analyzed how varies the species and genus richness,composition and structure of caddisfly (Insecta: Trichoptera) assemblages inYungas mountain forest of Argentina through a latitudinal gradient from 22º (Tropical)to 28º (Subtropical). Qualitative and quantitative data from 21 sites includingdifferent streams were compared across six latitudinal ranges. The assemblage richness,composition and structure were analyzed by comparing Rank-abundance (RA) curves.Non metric-Multidimensional Scaling (NMDS) and k-medoid clustering PAM methodwere made using Dissimilarity among assemblages. Stream environmental variableswere compared to discard important differences among sites. The species richnessincreased meaningfully through the latitudinal gradient from high to lowlatitude. Although genus richness evidenced the same pattern, it was less noticeablethan species richness. RA curves showed changes in assemblage?s composition andstructure across the latitudinal gradient. The NMDS and PAM analyses revealedthat the overall structure of the Trichoptera assemblages agreed adequatelywith the latitudinal gradient. The sampling sites were segregated in twogroups: the northern sites (22º-25º) and the austral sites (25º-28º). Thisdistribution and richness patterns are similar to others observed in plants andvertebrates from Yungas forest.