Environmental controls on the distribution and diversity of lentic Chironomidae (Insecta: Diptera) across an altitudinal gradient in tropical South America

Abstract

To predict the response of aquatic ecosystems to future global climate change, data on the ecology and distribution of keystone groups in freshwater ecosystems are needed. In contrast to mid‐ and high‐latitude zones, such data are scarce across tropical South America (Neotropics). We present the distribution and diversity of chironomid species using surface sediments of 59 lakes from the Andes to the Amazon (0.1–17°S and 64–78°W) within the Neotropics. We assess the spatial variation in community assemblages and identify the key variables influencing the distributional patterns. The relationships between environmental variables (pH, conductivity, depth, and sediment organic content), climatic data, and chironomid assemblages were assessed using multivariate statistics (detrended correspondence analysis and canonical correspondence analysis). Climatic parameters (temperature and precipitation) were most significant in describing the variance in chironomid assemblages. Temperature and precipitation are both predicted to change under future climate change scenarios in the tropical Andes. Our findings suggest taxa of Orthocladiinae, which show a preference to cold high‐elevation oligotrophic lakes, will likely see range contraction under future anthropogenic‐induced climate change. Taxa abundant in areas of high precipitation, such as Micropsectra and Phaenopsectra, will likely become restricted to the inner tropical Andes, as the outer tropical Andes become drier. The sensitivity of chironomids to climate parameters makes them important bio‐indicators of regional climate change in the Neotropics. Furthermore, the distribution of chironomid taxa presented here is a vital first step toward providing urgently needed autecological data for interpreting fossil chironomid records of past ecological and climate change from the tropical Andes.

Geo‐climatic factors drive diatom community distribution in tropical South American freshwaters

“…Our results seem to be consistent with the idea that the strong physical structuring of the study regions, with the distinct climatic and topographic conditions, override local environmental effects (partially supporting H1). Previous studies have also demonstrated the importance of macroscale descriptors over water chemistry in shaping aquatic community composition (diatoms and macroinvertebrates) in Arctic (Mykrä, Heino, & Muotka, ; Pajunen, Luoto, & Soininen, ; Vilmi, Karjalainen, & Heino, ), temperate (de Mendoza & Catalan, ) and tropical freshwaters (Matthews‐Bird et al., ; Steinitz‐Kannan et al., ).…”

Climate variability and human impact in South America during the last 2000 years: synthesis and perspectives from pollen records

“…However, where there is no direct evidence of human land use, such as cultigen pollen, distinguishing natural from anthropogenically induced burning and vegetation change can be difficult. In some cases anthropogenic deforestation and decreased moisture may result in similar signals in the pollen record, and therefore complementary proxies of past environmental change can be used to support interpretations, such as chironomids (Matthews-Bird et al, 2015;Williams et al, 2012) and geochemical records from speleothems.…”

“…. A.Flantua et al: Climate variability and human impact in South America during the last 2000 years cludes considering chironomids(Matthews-Bird et al, 2015;Williams et al, 2012), while indications of humans can come from non-pollen palynomorphs, such as the dung fungus Sporormiella(Williams et al, 2011).…”

Madicolous Chironomidae from the Brazilian Atlantic Forest: a checklist with notes on altitudinal distributions (Diptera, Insecta)

“…Compositional changing in chironomid assemblages along altitudinal gradients have been verified by many researchers worldwide (McKie et al 2005, Tejerina and Malizia 2012, Henriques-Oliveira and Nessimian 2010, Scheibler et al 2014, Robinson et al 2016, Matthews-Bird et al 2016). In mountain ecosystems the occurrence of chironomid species can be influenced by environmental changes related to altitude variation, such as temperature and oxygen availability (Oliver 1971, Pinder 1986, Eggermont and Heiri 2012), dispersal capacity (Ashe et al 1987), historical events (McKie et al 2005, Allegrucci et al 2006, Krosch et al 2011) or other regional particularities (Körner 2007).…”