Landscape composition as a determinant of diversity and functional feeding groups of aquatic macroinvertebrates in southern rivers of the Araucania, Chile

Abstract

ABSTRACT. Changes in land use which directly or indirectly affect freshwater fauna constitute one of the principal anthropic factors which have caused world biological diversity to disappear rapidly during recent decades. This fauna includes aquatic benthic macroinvertebrates, organisms presenting temporal and spatial variation due to a variety of factors, one of which is the diverse food resources available in the rivers. To assess the effect of anthropic activities on this fauna, the distribution, abundance and characterisation of the functional feeding groups of aquatic macroinvertebrates were analysed, together with the physical and chemical variables in the environments of four coastal river basins of southern south-central Chile. A total of 104 taxa of macroinvertebrates were recorded, the principal component of the community being the Diptera (26 taxa). The abundance and richness of taxa were greater in summer and lower in winter. The most abundant species belong to the order Ephemeroptera and Plecoptera. Macroinvertebrates were affected by different land use: stations with less anthropic activity and greater altitude had higher macroinvertebrates abundance, while the lowest abundance was found at the lowest stations. The functional feeding groups which were most abundant spatially and temporally were the collector-gatherers and the shredders. The physical and chemical water quality variables proved to be of exceptional quality in all the stations. These results suggest that policies governing changes in land use in central and southern Chile should take into account the dramatic alterations that these changes impose on the macroinvertebrates community. Policies for biodiversity conservation should therefore focus on these small but important organisms in the north Patagonian region of South America, which is a hotspot of world diversity. Keywords: diversity, macroinvertebrates, functional feeding groups, land use, Chile.Composición del paisaje como determinante de la diversidad y de grupos funcionales alimentarios de macroinvertebrados acuáticos en ríos de la Araucanía, Chile RESUMEN. Los cambios en el uso de suelo que afectan directa o indirectamente la fauna dulceacuícola, son uno de los principales factores antropogénicos por los cuales la diversidad biológica mundial está desapareciendo a elevadas tasas durante las últimas décadas. Dentro de esta fauna se encuentran los macroinvertebrados bentónicos acuáticos, organismos que varían temporal y espacialmente debido a diversos factores, uno de los cuales son los diversos recursos alimentarios disponibles en los ríos. Para esto, se analizó la distribución, abundancia, y caracterización de los grupos funcionales alimentarios de macroinvertebrados, y las variables físicas y químicas de cuatro cuencas costeras del centro-sur de Chile. Un total de 104 taxa de macroinvertebrados fueron registrados, siendo los dípteros (26 taxa) el componente principal de la comunidad. La abundancia y riqueza de taxa fue más conspicua en verano y menor en invierno. Las especie...

First report of inventory and role of macroinvertebrates and fish in Cautín river (38° S, Araucania region Chile)

“…Smith), freshwater crabs of the genus Aegla (Leach, 1820), and the southern Chilean river prawn, Samastacus spinifrons (Phillippi, 1882) (De los Ríos-Escalante et al, 2012;Jara, 2013;Rudolph, 2013), and Diptera, Trichoptera and Ephemeroptera larval stages (Figueroa, 2000;Figueroa et al, 2003Figueroa et al, , 2007, many of these groups are currently endangered due to human-induced alterations in their habitats and the introduction of alien salmonids species since 1914 (Golusda, 1907(Golusda, , 1927Barros, 1931;Jara et al, 2006;Encina et al, 2017;Vega et al, 2017). The (introduced) salmonids, specifically, constitute non-selective, active predators (Soto et al, 2006(Soto et al, , 2007Fierro et al, 2012Fierro et al, , 2015Fierro et al, , 2016Piedra et al, 2012;Valdovinos et al, 2012;Vargas et al, 2010Vargas et al, , 2015. Also, some rivers of this kind have undergone alterations in their surrounding drainage basins, viz., through anthropogenic enterprises as agriculture, deforestation, forestatation, growing cities, industry, among others, these new conditions affect the water quality (Kristensen et al, 2009), and, by consequence, also the benthic species that are sensitive to water pollution are affected in their abundance (Figueroa et al, 2003(Figueroa et al, , 2007Tello et al, 2010;Vega et al, 2013Vega et al, , 2017Gorski et al, 2015;Nimptsch et al, 2015).…”

Macrobenthos of the coastal Budi Lagoon, southern Chile: Changes associated with seasonal environmental variation

“…Most animal populations show considerable spatial and temporal fluctuations in distribution and abundance (UNDERWOOD; CHAPMAN, 1996;BENEDETTI-CECCHI et al, 2001;BERTRÁN et al, 2001;FIERRO et al, 2014;FIERRO et al, 2015). In the case of benthic macrofauna, distribution and abundance are mainly related to certain variables of the sedimentwater interface, where multiple effects of contamination and organic enrichment are exerted (GLÉMAREC, 1986).…”

“…In the case of benthic macrofauna, distribution and abundance are mainly related to certain variables of the sedimentwater interface, where multiple effects of contamination and organic enrichment are exerted (GLÉMAREC, 1986). The principal physicochemical variables that determine macrobenthic distribution are temperature, salinity, suspended solids, nitrates (HOLLAND et al, 1987;BEUKEMA, 1990;FIERRO et al, 2015), and sediment characteristics, such as texture and organic material content (RITCHER, 1985;NICHOLS et al, 1986). Macrobenthic organisms inhabit different types of sediments (HYNES, 1970) over the course of the year (BERTRÁN, 1989;BERTRÁN et al, 2001;FIERRO et al, 2012), generating varied distribution and abundance patterns (JARAMILLO et al, 2001).…”

Evaluation of land use impact on river water quality using macroinvertebrates as bioindicator in Lahumoko Watershed, Buton Island, Indonesia

“…The relatively high variation of water quality parameters related to various types of land use are characteristics that can be used to inform or predict aspects of water quality in rivers that lack data. In this study, physicochemical parameters were significantly different among the stations as the measure in observing water quality that was related to the presence of macroinvertebrates (Mophin-Kani K and Murugesan 2014; Fierro et al 2015;Shokri et al 2014). Water temperature in the upstream of the watershed was low due to the closure of the water body by the forest compared to the middle and downstream part which was already opened, especially at the edge of the river (Rezende et al 2016).…”