The assemblages of aquatic Coleoptera from shallow lakes in the northern Iberian Meseta: Influence of environmental variables

Abstract

Abstract. Aquatic Coleoptera in shallow lakes associated with the Canal de Castilla (Palencia Province, Spain) in the northern Ibe rian Meseta were sampled over the course of a year (spring 1998-winter 1999). These waterbodies are typical plateau wetlands with dense vegetation and vary in permanence and area (from 3.3 ha to 29.35 ha). Oxygen concentration, conductivity and pH were recorded at the time of sampling. Lake area, depth, water permanence and type of vegetation were also taken into account. Ninety two species were collected. Species richness was high in comparison with other wetlands in Spain. The assemblage structure was assessed in terms of three community parameters: richness, abundance and diversity (Shannon index). Their relationships with envi ronmental variables were explored using correlation coefficients. The assemblage composition was analysed by multivariate tech niques. First, the sites were classified by means of TWINSPAN. The presence of each species in the different TWINSPAN groups was used to assess their habitat preferences. Second, the sites and species were ordinated by Detrended Correspondence Analysis (DCA) using the CANOCO statistical package. Richness was significantly correlated with water permanence, conductivity and aquatic macrophyte cover. The first DCA axis was significantly correlated with water permanence and conductivity, but not with any of the other parameters. Conductivity was significantly inter-correlated with permanence. Therefore, water permanence and aquatic vegetation cover seem to be the main factors influencing richness, but only water permanence appears to determine species composition.

Aquatic Coleoptera assemblages in protected wetlands of North-western Spain

“…This is explained by the combination of these factors, which formed a gradient from the interior (temporal wetlands at high altitude with low values of conductivity) to the coast (permanent wetlands at low altitude with high values of conductivity) in our study area. This result is in agreement with other studies that found a relationship between these factors and changes in the composition of aquatic beetle assemblages (Valladares et al, 1990(Valladares et al, , 2002Eyre et al, 1992;Garrido et al, 1994;Fairchild et al, 2003). However, in the study of Picazo et al (2012) altitude, conductivity and anthropogenic impact were the most important factors, but hydroperiod did not seem to be a key factor in assemblage composition.…”

“…Conductivity is a good indicator of different types of pollution, like waste waters, mining or fertilizers (de Paz, 1993;García-Criado, 1999;Trigal, 2006), but in the case of the group 3 it can be considered a natural stressor due to the influence of saline water in coastal lagoons. The species that most contributed in this group was Ochthebius viridis fallaciosus, exclusively collected in coastal lagoons and typical of habitats with high values of conductivity or salinity (Valladares et al, 2002;Garrido and Munilla, 2008). Other species typical of coastal lagoons that contributed to the group characterization was Limnebius furcatus, which was only captured in this type of habitat, confirming the results of other studies for this species in Galicia (Díaz- Pazos and Otero, 1993;Garrido and Sáinz-Cantero, 2004;Garrido and Munilla, 2008).…”

“…Helophorus jocoteroi (Angus and Díaz-Pazos, 1991;Valladares and Ribera, 1999;Pérez-Bilbao et al, 2011) and Ilybius dettneri (Fresneda et al, 1990;Fery and Nilsson, 1993;Fery and Fresneda, 2007;Pérez-Bilbao et al, 2010) have only been collected in Galicia, north of Portugal and the latter also in Barcelona, while Helophorus bameuli is scarcely cited in the Iberian Peninsula (Valladares and Ribera, 1999;Foster, 2002;Pérez-Bilbao et al, 2011). Another interesting species was Agabus labiatus, which has only been cited in the north of the Iberian Peninsula (González, 1992;González and Novoa, 1995;Valladares and Garrido, 2001;Valladares et al, 2002;Pérez-Bilbao et al, 2010). These species present a narrow geographical and ecological range and are rarely sampled in the Iberian Peninsula.…”

“…According to Boix et al (2001), hydroperiod is one of the main factors affecting the composition and structure of aquatic assemblages. Organisms that live in temporary waters have to adapt to temporary drought conditions to survive, sometimes being exclusive to these ecosystems (Williams, 2006;Boix et al, 2001;Valladares et al, 2002). Species like Agabus labiatus, Hydroporus nigrita or Helophorus jocoteroi were only collected in temporary habitats, while other species like Hydraena rugosa were very abundant.…”

Coleoptera associated with macrophytes of the genus Salvinia in four oxbow lakes in two river basins in southeast Brazil

“…Such perennial plants, when they also cover a broad area (owing to an extended root system), exhibit high richness, abundance and diversity of Coleoptera (Scheffer, 1998;Thomaz and Cunha, 2010). In the lakes under study, Salvinia formed a dense vegetation cover, which favored the high taxon richness observed among the Coleoptera, also observed by Valladares et al (2002) in shallow lakes located at one end of the Castille Canal, north of the Meseta Ibérica. Fontanarrosa et al (2013) also reported a dominance of those coleopterans associated with macrophytes, in two lakes in the province of Buenos Aires, Argentina.…”