The invertebrate's community in adjacent Alto Iguaçu's anthropic lakes of different environmental factors

Abstract

The invertebrate's community in adjacent Alto Iguaçu's anthropic lakes of different environmental factors. Biota Neotrop. 13(1): http://www.biotaneotropica.org.br/v12n4/en/abstract?article+bn00813012013Abstract: Environmental differences occur between lentic and lotic communities' establishment, especially because of water time residence. Here we used a combination of field measurements and statistical analysis to evaluate the influent factors on the aquatic macroinvertebrates' composition and structure in 15 anthropogenic lakes from Alto Iguaçu's region. Macroinvertebrates were sampled from the marginal vegetation (with or without macrophytes) and sediment. Chemical parameters ranged among the anthropogenic lakes, mainly those which are connected to the Iguaçu River, beyond the presence or absence of macrophytes, interfering on the community's structure. Lake's morphometric data were measured in each lake and its relation to community was tested. The community structure was not related to the margin development index (Ds), macrophytes and altitude. Higher equitability was associated to the macrophytes presence in more than 30% of water surface and also where the riparian vegetation was more complex. Chironomids and oligochaetes densities were associated to lakes with the water surface completely covered by macrophytes and complex riparian vegetation. We observed a close association between productivity (phosphorous and nitrogen) and the community equitability (R = 0.3; p < 0.05) and Oligochaeta dominance (R = 0.32; p < 0.05), and not to Ostracoda's (R = 0.33; p > 0.05) and Chironomidae's (R = 0.34; p > 0.05) dominances, although we had not weighty difference among analyzed biological indexes. Resumo: Diferenças ambientais ocorrem entre o estabelecimento de comunidades de ambientes lênticos e lóticos, especialmente por causa do tempo de residência da água. Foi usada uma combinação de métricas de campo e análise estatística para avaliar os fatores influentes sobre a composição e estrutura de macroinvertebrados aquáticos em 15 lagos antropogênicos da região do Alto Iguaçu. Os macroinvertebrados foram amostrados da vegetação marginal (com ou sem macrófitas) e sedimento. Parâmetros químicos variaram entre os lagos antrópicos, principalmente aqueles conectados ao Rio Iguaçu, além da presença ou ausência das macrófitas, interferindo na estrutura da comunidade. Dados de morfometria de lagos foram mensurados e sua relação com a comunidade foi testada. A estrutura da comunidade não foi relacionada ao índice de desenvolvimento da margem (Ds), macrófitas e altitude. Maior equitabilidade foi associada à presença de macrófitas em mais de 30% da superfície da água e também onde a vegetação ripária foi mais complexa. Densidades de quironomídeos e oligoquetas foram associadas a lagos com a superfície completamente coberta por macrófitas e complexa vegetação ripária. Foi observada associação entre a produtividade (fósforo e nitrogênio) e a equitabilidade da comunidade (R = 0.3; p < 0.05) e dominância de Oligochaeta (R = 0.32; p ...

Residence‐time‐based classification of surface water systems

“…Because a larger system volume of interest (e.g., longer arbitrary reach length) will automatically produce a larger iT R value, all else being equal, the interpretation of the iT R metric must carefully account for the chosen total system volume. Many residence time studies define the study volume of interest via natural geographic or anthropogenic constraints, such as a lake or a dammed‐reservoir [ Benenati et al ., ; Krawczyk et al ., ; Rennella and Quirós , ], or a specified river reach [ Hein et al ., ; Baranyi et al ., ; Adebisi , ]. If an analysis does not properly account for the dependence of iT R on the bulk system volume, the analysis might provide unrealistic characterizations.…”

“…In creating the histograms, the iT R results were binned into time periods that reflected thresholds used in the literature and separated by logically spaced intervals. The bins were defined as follows: less than 1 h, 1–6 h, 6–12 h, 12 h to 1 day [ Basu and Pick , ; Rennella and Quirós , ], 1 day to 1 week (7 days) [ Baranyi et al ., ; Hein et al ., ; Rennella and Quirós , ; Bledzki and Ellison , ], 1 week to 1 month (30 days) [ Baranyi et al ., ; Hein et al ., ], 1–3 months, 3–6 months [ Mooney and McClelland , ], 6 months–1 year (365.25 days) [ Rennella and Quirós , ], 1–2 years, 2–5 years, 5–10 years [ Krawczyk et al ., ], and greater than 10 years.…”

“…Unfortunately, such simple residence time thresholds appear to be either system-specific or species-specific, as Blędzki and Ellison [2001] found that a 6 day residence time was appropriate for discriminating between lentic and lotic zooplankton biomass behaviors for the Wloclawek Dam Reservoir (Poland) and the Upper Lake (South Hadley, Massachusetts, USA) systems. At the extreme end of the lentic/lotic continuum, residence time in years for lakes has been noted as a key lentic feature [Krawczyk et al, 2013, by Rasmussen et al, 1989.…”

“…In creating the histograms, the iT R results were binned into time periods that reflected thresholds used in the literature and separated by logically spaced intervals. The bins were defined as follows: less than 1 h, 1-6 h, 6-12 h, 12 h to 1 day [Basu and Pick, 1996 [Krawczyk et al, 2013], and greater than 10 years.…”

Oligochaeta (Annelida: Clitellata) associated to aquatic macrophytes in Brazil

“…Moreover, macrophytes serve as cover for excessive luminosity (WELCH, 1952), shelter against predators, and they can be used as nest for egg deposition (GLOWACKA et al, 1976). Invertebrate density and biomass may change according to the habitat complexity degree, which is optimized by macrophytes (MORMUL et al, 2010;KRAWCZYK et al, 2013).…”