Efectos del gradiente altitudinal sobre las comunidades de macroinvertebrados bentónicos en dos períodos hidrológicos en un río altoandino neotropical

Raúl F García-Ríos,Dieison A Moi,Oscar E Peláez

doi:10.25260/ea.20.30.1.0.995

Raúl F García-Ríos, Dieison A Moi + Show 1 more

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https://doi.org/10.25260/ea.20.30.1.0.995

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Journal: Ecología Austral	Publication Date: Apr 1, 2020
Citations: 3	License type: cc-by

Affiliation: Universidade Estadual de Maringá

Abstract

The altitudinal gradient and the hydrological dynamics affect the establishment and distribution of organisms in Andean rivers. Benthic macroinvertebrates, an essential component of lotic ecosystems, are useful to assess the influence of the altitudinal gradient and changes in environmental characteristics. We analyzed the effects of altitudinal gradient on benthic macroinvertebrates assemblages in the Chillon River (Lima, Peru), and tested two hypotheses: 1) taxa richness decreases with increasing altitude, while dominance increases, and 2) altitude is the primary driver of variation in community composition. We found 47 taxa, being the class Insecta (Arthropoda) the richest and the densest in both hydrological periods. Taxa richness had a negative linear relation with altitude, while dominance had a positive linear relation. The RDA showed that communities varied along the altitudinal gradient. Our results showed that altitude is the main driver of variation in taxa composition; however, more studies must be carried out to understand what factors are essential in organism’s distribution and how they operate in Andean lotic ecosystems.https://doi.org/10.25260/EA.20.30.1.0.995

Highlights

Andean rivers are located at more than 2000 m a. s. l. (Acosta et al 2009), governed by a marked hydrological dynamics constituted by a fast and turbulent water flux (Jacobsen 2008), which makes it difficult for the establishment and migration of organisms (Brown et al 2007)
Our results showed changes in macroinvertebrates community, which were driven by the environmental gradient related to the altitude, confirming our first hypothesis
While richness and Shannon decreased, dominance increases with altitude, validating our second hypothesis. This fact agrees with Jacobsen (2004), who analyzed the Andean rivers of Ecuador and showed a notable decrease in invertebrate orders (e.g., Diptera, Coleoptera, Trichoptera) with increasing altitude

Summary

Introduction

Andean rivers are located at more than 2000 m a. s. l. (Acosta et al 2009), governed by a marked hydrological dynamics constituted by a fast and turbulent water flux (Jacobsen 2008), which makes it difficult for the establishment and migration of organisms (Brown et al 2007). (Acosta et al 2009), governed by a marked hydrological dynamics constituted by a fast and turbulent water flux (Jacobsen 2008), which makes it difficult for the establishment and migration of organisms (Brown et al 2007). Along with strong environmental gradients driven by altitude and topography, spatial isolation makes Andean rivers to exhibit a high number of endemic species (Särkinen et al 2012). For that reason, these ecosystems are considered biodiversity hotspots (Myers et al 2000). One possible explanation for this reduction is the Andean rivers hydrological dynamics, determined by glacial melting and rains, which produces catastrophic effects on aquatic communities (Ríos-Touma et al 2012)

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