Nucleo de Pesquisas em Limnologia
Nucleo de Pesquisas em Limnologia
Rocha M.P.,University of Oulu |
Rocha M.P.,Finnish Environment Institute |
Heino J.,Finnish Environment Institute |
Machado-Velho L.F.,Nucleo de Pesquisas em Limnologia |
And 6 more authors.
Freshwater Biology | Year: 2017
Metacommunity structure may be strongly influenced by spatial dynamics and environmental factors, as well as biogeographic effects. Here, we examined variation in lake cladoceran communities associated with floating macrophytes in the four major Brazilian floodplain systems (Amazônia, Araguaia, Pantanal and Paraná) in relation to local environmental factors, spatial components, climate variables and basin identity. Moran's eigenvector maps were used as a proxy to examine spatial structures within each drainage basin. The final sets of local environmental, climate and spatial variables were selected for constrained ordination models, using a forward selection method. We used variation partitioning to decompose variation in cladoceran community composition in relation to the four sets of predictor variables. Beta-diversity indices were calculated to quantify the contributions of turnover and nestedness components to total beta diversity of cladocerans within each basin and across the basins. Variation partitioning showed that the pure fractions were relatively small, ranging from around zero for spatial and basin identity variables to 2% for climate variables and 4% for local environmental variables. The shared effect of local environmental, climate and basin identity was considerable, accounting for 17% of the total variance. Furthermore, the shared effect of climate and basin identity was also considerable (6%). In total, 32% of variation in cladoceran community structure could be explained by our predictor variables. Cladoceran metacommunities showed high levels of beta diversity attributed to the turnover component, within each floodplain and across all four floodplains. Our finding showed that species sorting was likely to be the main agent structuring cladoceran communities. Spatial processes were not important at very large spatial scales, contrary to what has been found in previous studies. This finding was most likely due to the inclusion of climatic variables in our analysis, combined with the high dispersal ability of cladocerans. © 2017 John Wiley & Sons Ltd
Rodrigues L.C.,Nucleo de Pesquisas em Limnologia |
Pivato B.M.,Nucleo de Pesquisas em Limnologia |
Vieira L.C.G.,University of Brasilia |
Bovo-Scomparin V.M.,Nucleo de Pesquisas em Limnologia |
And 3 more authors.
Hydrobiologia | Year: 2017
We analyzed the temporal (dry and rainy periods) and spatial (zones) phytoplankton biomass variation (FGs—functional groups) in a tropical reservoir, and determined the main drivers. We hypothesized that water flow negatively affects the FG–environment relationship because high flow promotes dispersal stochasticity. Our results indicated that the FG–environment relationship was affected mainly by the rainfall regime. Periods with intermediate precipitation showed greater predictability than periods with extreme precipitation. This suggests that the effect of stochastic processes on the phytoplankton community is more important in both the highest and lowest water flow, and deterministic processes are more important at intermediate flow. The longitudinal gradient of nutrients, light, and water-column mixing influenced the distribution of the FG biomass. The riverine zone showed high nutrient concentrations, low light availability, and a high biomass of organisms related to highly enriched systems (FG J—chlorophyceans) and shade-adapted taxa (FG S1—cyanobacteria). The lacustrine zone showed high light availability and a high biomass of heterocytous cyanobacteria (FGs SN and H1) and meroplanktonic diatoms (FG MP). The functional approach can be applied to understand the processes responsible for species coexistence and for the organization of aquatic ecosystems. © 2017 Springer International Publishing AG
Brito J.E.C.,State University of Maringá |
Gazarini J.,State University Londrina |
Zawadzki C.H.,Nucleo de Pesquisas em Limnologia
Acta Scientiarum - Biological Sciences | Year: 2010
This study aims to evaluate the abundance and frugivory of bats from the Recanto Marista, a small riparian forest remnant in the margins of the Ivaí river. The Recanto Marista has 57.6 ha, of which 40.8 ha are covered by semideciduous seasonal forest and is located in the Doutor Camargo municipality. Collections were conducted from May 2007 to January 2008 using mist nets (7 × 2.5 m) totaling 13,475 m2 h and comprising about 72 hours. Ten species were found pertaining to two families, Phyllostomidae (Artibeus lituratus, Sturnira lilium, Carollia perspicillata, Artibeus cf. fimbriatus, Artibeus planirotris, Desmodus rotundus and Pygoderma bilabiatum) and Vespertilionidae (Myotis nigricans, Eptesicus sp. and Lasiurus blossevillii) totaling 193 specimens. One Molossus rufus individual was found dead on the ground. Fruits pertaining to the families Moraceae (Ficus guaranitica, Ficus insipida, Ficus sp. and Maclura tinctoria), Solanaceae (Solanum aspero-lanatum and Solanum sp.), Piperaceae (Piper aduncum, Piper amalago and Piper sp.) and Urticaceae (Cecropia pachystachya and Cecropia sp.) made part of the diet of the captured bat species.
Garcia D.A.,Nucleo de Pesquisas em Limnologia |
Benedito E.,Nucleo de Pesquisas em Limnologia |
Takeda A.M.,Nucleo de Pesquisas em Limnologia
Brazilian Archives of Biology and Technology | Year: 2010
This study analyzed the muscle energy content (caloric density) of L. platymetopon captured at different sites of the Upper Paraná River floodplain, and potential relationships between the content and various environmental variables (water temperature, oxygen dissolved in water, food availability, relative numeric abundance) and biological variables (body size and reproductive cycle). Quarterly samplings from September 2006 to June 2007 in the lakes and rivers resulted in a sample of 739 specimens, whose muscle caloric density was determined using a calorimeter. Differences between the caloric averages of the males and females and among the different stages of gonadal development were not significant. Caloric density varied over time and space, with two seasonal variation trends. The intensity of the correlation between the caloric density and each environmental variable, as well as the type of correlation, varied according to the sampled site. Body size and reproductive cycle were not correlated with caloric density.
Dunck B.,Programa de Pos Graduacao em Ecologia de Ambientes Aquaticos Continentais PEA |
Bortolini J.C.,Programa de Pos Graduacao em Ecologia de Ambientes Aquaticos Continentais PEA |
Rodrigues L.,Nucleo de Pesquisas em Limnologia |
Rodrigues L.C.,Nucleo de Pesquisas em Limnologia |
And 2 more authors.
Revista Brasileira de Botanica | Year: 2013
Functional diversity and adaptative strategies of planktonic and periphytic algae in isolated tropical floodplain lake. This study aimed to test the hypothesis that after a great magnitude and high duration of flood pulse in floodplain, functional diversity of phytoplankton and phycoperiphyton communities will be higher during high water. The strategies' dynamics evaluated during high and low water periods consisted of size classes, life forms, and functional groups. For the phytoplankton, the adaptations to floating, and for phycoperiphyton, the intensity and structure for attachment to substrate were also analyzed. Functional diversity was calculated from functional dendrograms of species. Functional diversity, richness, and density of both communities presented the greatest values during the high waters. In the high waters, Cryptomonas marsonii Skuja was dominant in plankton and Pseudoanabaena skujae Claus in periphyton, while in the low water, Merismopedia tenuissima Lemm. was dominant in plankton and Fragilaria capucina Desm. was dominant in periphyton. Thus, the flood pulse promoted the dominance of free-floating species in plankton, during the high water, and of metaphytic species in periphyton. In the low water, we observed the dominance of species with higher surface/volume ratio in plankton, and strongly attached in periphyton. We concluded that, in isolated floodplain lake, possibly the flood pulse directs the functional diversity of phytoplankton and phycoperiphyton. © 2013 Botanical Society of Sao Paulo.