Patrones espaciales en comunidades de macroinvertebrados acuáticos de la Puna Argentina

Abstract

Spatial patterns in communities of aquatic macroinvertebrates of Argentinean Puna. The macroinvertebrates are a vital component of freshwater ecosystems as they contribute to the process of organic matter while serving as food for other organisms such as fish and amphibians. Unfortunately, the knowledge of the aquatic diversity is poor in the high Andean systems (between 3 200 and 5 200 m.a.s.l. and rainfall below 300 mm per year), especially in the Argentinean peatbogs, a fact which has made difficult the interpretation of spatial patterns on a regional scale. The present study aimed to describe the composition of aquatic macroinvertebrates in seven peatbogs in the Argentinean Puna, and to analyze for the first time their spatial patterns. For this, we studied the relationship of these organisms with the environment, and obtained information about the surrounding vegetation and water physico-chemical characteristics. A total of 3 131 specimens of aquatic macroinvertebrates were collected, representing 25 taxa belonging to 22 families and 24 genera. In addition, 62 species of vascular plants were recorded, belonging to 20 families. The most abundant life form were the tufted grasses, followed by cushions. By using an NMDS (Non-Metrical Multidimensional Scaling) statistical analysis, the sampling sites were ordered in each peatbog as follows. The peatbogs located furthest West and South with higher water temperature were grouped on axis 1, whereas those with higher conductivity, whole water dissolved solids and salt concentration were grouped on axis 2. The water temperature was higher than air temperature at all times, and we found no association between temperature and altitude. The altitude had no correlation with the abundance of macroinvertebrates or with plant richness. Life forms such as scattered graminoids, trailing and prostrate herbs (in many cases they get into the channel) and aquatic plants were more abundant in peatbogs 4, 5 and 7 and they had a correlation with some macroinvertebrates belonging to functional trophic groups such as filter-collectors, collectors and scrapers. Finally, conductivity, whole dissolved solids and salt concentration had their highest value in peatbog 6, where Bivalvia (filter-collector) and Hyalella (collector) were also found. The results obtained attest that these macroinvertebrates displayed diversity and composition spatial patterns, the most important feature being their relationship with the surrounding vegetation, and to a lesser extent, with the physical and chemical traits of water in seven fertile lowlands in the Argentinean Puna. Rev. Biol. Trop. 64 (2): 747-762. Epub 2016 June 01.

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

“…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.) than other taxa.…”

“…The type locality of Hyalellapuna sp. n. is within the Pastos Grandes sub-basin, an area with 90–100 mm total annual rainfall (Nieto et al 2016). This sub-basin belongs to the “Cuenca Cerrada de la Puna” basin (Nieto et al 2016).…”

“…n. is within the Pastos Grandes sub-basin, an area with 90–100 mm total annual rainfall (Nieto et al 2016). This sub-basin belongs to the “Cuenca Cerrada de la Puna” basin (Nieto et al 2016). The benthic fauna of the Puna wetlands in Argentina and Chile consists mostly of undetermined Hyalella species (Scott et al 2015, Rodrigues Capítulo et al 2014, Nieto et al 2016).…”

“…This sub-basin belongs to the “Cuenca Cerrada de la Puna” basin (Nieto et al 2016). The benthic fauna of the Puna wetlands in Argentina and Chile consists mostly of undetermined Hyalella species (Scott et al 2015, Rodrigues Capítulo et al 2014, Nieto et al 2016). In these high Andean wetlands, the macroinvertebrate communities have varying tolerances to different ranges of salinities.…”

Modelling beta diversity of aquatic macroinvertebrates in High Andean wetlands

“…In Argentina, those efforts are of narrow taxonomic scope and refer to certain groups present in mid to low elevation Andean streams such as studies about the spatio-temporal distribution of larvae of Chironomidae performed by Scheibler et al (2008) in Mendoza and Tejerina and Malizia (2012) in Tucumán. Recently, Nieto et al (2016) described the community of seven peatbogs in the Andean region of Salta.…”