Modelling beta diversity of aquatic macroinvertebrates in High Andean wetlands

Abstract

Central Andean Highlands represent a singular environment characterized by various extreme conditions. Among them, peatbogs are exceptional marshy habitats scattered throughout this arid and harsh area. In an effort to understand the patterns of beta diversity, we sampled the benthic macroinvertebrates of thirteen peatbogs and related the biological distance with ecological distance using the GDM (Generalized Dissimilarity Modelling) approach. Variables analyzed were altitude, geographical distance, physical and chemical parameters of the water. A coefficient based on the ordering properties of count data, from the perspective of both sites and taxa, was used to measure the compositional similarity between samples. The most frequent taxa were: Hyallela, Simuliidae, Andesiops, Austrelmis, Podonominae, Protallagma, Trichocorixa, Orthocladiinae and Glossiphonidae. The highest altitudinal record ever for leeches is reported here. Altitude and conductivity contributed greatly to the single ecological predictor of beta diversity. Sampling points can be classified first by altitude (cutoff sets at 4200 m), which can be considered a surrogate of a regional factor (distinction between Puna and High Andean ecoregions) and then by conductivity (cutoff sets at 135 µS cm -1 ), which can be considered a proxy of a local factor (distinction between hyperfresh and more mineralized habitats). These results suggest a system of ecological filters acting on them.

Macroinvertebrados bentónicos de ríos de zonas áridas del noroeste argentino

“…Los macroinvertebrados bentónicos en estos sitios han recibido diferente atención, y los más estudiados son los ambientes de Patagonia y Cuyo (e.g., Miserendino 2001;Miserendino and Brand 2007;Pessaq and Miserendino 2008 para Patagonia;Medina et al 1997;Medina and Paggi 2004;Scheibler and Debandi 2008;Scheibler et al 2008 para Cuyo). En las zonas áridas del NOA hay estudios para las regiones Monte, Chaco y Puna (e.g., Tejerina and Molineri 2007;Colla et al 2012;Zelarayán and Salas 2012;Nieto et al 2017), aunque existe un gran vacío de información de base en regiones amenazadas.…”

The presence of rainbow trout reduces drift of aquatic insects in Yungas streams (Tucumán, Argentina)

“…Regarding the diversity indices, we believe that the absence of significant differences reflects the high beta diversity of the area (von Ellenrieder, 2007;Nieto et al, 2017), since when comparing the sections with and without trout of the same river (lower and upper sections in Azucenas and Chasquivil) changes in the values of richness, dominance and diversity were observed. Some works pointed to a nocturnal shift in the drift of larger insects in the presence of trout (Douglas et al, 1994;McIntosh et al, 2002).…”

A new species of Hyalella (Crustacea, Amphipoda, Hyalellidae) from the Puna biogeographic province in Argentina

“…In these high Andean wetlands, the macroinvertebrate communities have varying tolerances to different ranges of salinities. Electric conductivity was the second main characteristic associated to compositional changes of the benthic macroinvertebrate communities (Nieto et al 2017); thus, decreases in the abundance, taxonomic richness, and diversity of various zoobenthic taxa have been attributed to an increase of salinity and conductivity (Rodrigues Capítulo et al 2014). However, the data reported for physicochemical parameters here (Pozuelos basin, FML-CRUST 01200) and in previous studies of Puna wetlands from northwestern Argentina (Scott et al 2015; Rodrigues Capítulo et al 2014; Nieto et al 2016) have shown that Hyalella species are generally more tolerant to greater salinity and conductivity levels (191.15 to 2,203 μS/cm approx.)…”

“…Hyalella is the most conspicuous taxon in the benthic macroinvertebrate communities of the Puna Mountains in Salta province, Argentina (Nieto et al 2017). As part of the results of a project for the study of freshwater macroinvertebrates (Fundación Miguel Lillo), a new Hyalella species is described herein.…”