Composition and diversity of the Chironomidae in subtropical streams: effects of environmental predictors and temporal analysis

Abstract

AIMS: The aims of this study were (i) to evaluate the spatial and temporal distribution of chironomids in subtropical streams and (ii) to investigate the importance of environmental predictors in the distribution of this group. METHODS: Samples were collected in four annual seasons between 2010 and 2011, in 10 streams located in an agricultural matrix in southern Brazil, using a Surber sampler. Organisms were identified to the genus level. Some environmental variables were analysed in the sampling sites of the Chironomidae. The variations in abundance and diversity were compared by Analysis of Variance, whereas the community composition was analysed using Multivariate Analysis of Variance. A Redundance Analysis was used to evaluate the effect of environmental variables on the chironomid community. RESULTS: 7,349 individuals were identified, belonging to three subfamilies (Chironominae, Tanypodinae and Orthocladiinae) and 57 genera. The abundance and richness of the Chironomidae were similar between sites and seasons. However, the composition varied spatially and temporally (p < 0.001). Water temperature, total organic carbon, total nitrogen and carbon:nitrogen ratio were variables that influenced the chironomid community. The genera Thienemanniela, Pentaneura, Paratanytarsus, Parapentaneura, Parametriocnemus, Hudsonimyia, Labrundinea and Larsia were present in summer, whereas Parakiefferiella, Paramerina, Metriocnemus were indicators for winter. CONCLUSIONS: The spatial distribution of chironomids was directly related to the environmental conditions of the sampling sites. The temporal variation in the community followed a pattern in relation to water temperature. The variables physical and chemical operate as environmental filters and thereby alter the chironomid community.

Effectiveness of protected areas for the conservation of aquatic invertebrates: a study-case in southern Brazil

“…In recent decades, aquatic ecosystems have been significantly affected by multiple environmental impacts caused by the expansion of human activities (Budke et al, 2012;Chen et al, 2014;Mendoza et al, 2017). This has caused a disruption of the physical and chemical environment, has altered the natural dynamics of biological communities, led to environmental changes (Callisto et al, 2012;Tejerina & Malizia, 2012), and has significantly reduced the quality of the water and decreased aquatic biodiversity (Restello et al, 2014). Thus, aquatic ecosystems are among the most threatened ecosystems in the world (Harrison et al, 2016).…”

Nestedness of stream insects in Subtropical region: importance of inter-annual temporal scale

“…The region has its area occupied by human activities, in particular by intensive agricultural practice (~ 80% of the total area; Rovani et al, 2019). We selected 10 small-order streams (<3 rd order) with an approximate width of 2 m, depth of about 0.3 m and substrate composed mainly of stones and leaves (Restello et al, 2014). Environmental variables.…”

“…Variations in precipitation can generate variations in the assemblages of aquatic ecosystems (Bispo et al, 2006). These variations result in a decrease in the abundance of organisms and, consequently, in the species richness due to the drift caused by the flow increase in rivers and streams (Restello et al, 2014;Peralta & Martin, 2015).…”

“…The precipitation intensity isone of the mainly factors that control the temporal distribution of stream insect assemblages (Flecker & Feifarek, 1994;Restello et al, 2014;Nava et al, 2015). The increase on the pluviosity levels intensifies the water flow, resulting on aquatic insects drift by physical perturbations.…”

“…Chironomidae (Diptera) is a very diverse and common insect family that are frequent in all the different aquatic ecosystems (Ferrington, 2008). The Chironomidae has different levels of tolerance to organic pollutants (Sensolo et al, 2012;Restello et al, 2014), and environmental plasticity, which indicates their use as model organisms in studies about ecological patterns and process on streams (Rosin & Takeda, 2007). In addition, studies on the diversity and composition of Chironomidae do not present details on the structure patterns of these assemblages especially on beta diversity patterns.…”