INALI   02622
INSTITUTO NACIONAL DE LIMNOLOGIA
Unidad Ejecutora - UE
capítulos de libros
Título:
Benthic Invertebrates
Autor/es:
INÉS EZCURRA DE DRAGO; MERCEDES MARCHESE; LUCIANA MONTALTO
Libro:
The Middle Paraná River. Limnology of a Subtropical Wetland
Editorial:
Springer Verlag
Referencias:
Lugar: Heidelberg, Alemania; Año: 2006; p. 251 - 275
Resumen:
In this chapter, we summarize studies carried out on benthic organisms (≥100 μm) since 1969 in floodplain water bodies, since 1980 in the main channel and secondary channels of the Middle Paraná River, and since 2001 in marginal wetlands. Results on adult stages of indigenous Bivalvia (Hyriidae and Mutelidae) are not included.≥100 μm) since 1969 in floodplain water bodies, since 1980 in the main channel and secondary channels of the Middle Paraná River, and since 2001 in marginal wetlands. Results on adult stages of indigenous Bivalvia (Hyriidae and Mutelidae) are not included. The Middle Paraná River system is arrayed as a mosaic of habitats undergoing succession. Key factors controlling benthic structure and composition are hydrosedimentological flood pulses, hydraulic conditions, hydrological connectivity degree, aquatic plants cover and water quality. Thus, benthic communities from aquatic habitats of the Paraná River system show the following patterns: – The central strip is the most descriptive and diagnostic area of the rivers due to a higher stability of the benthic structure, with lower riparian and land-use influence. – Benthic structure and composition in the main and secondary channels of higher discharge and permanent flow are similar along the longitudinal dimension, with a slight decrease in density and biomass downstream and very little seasonal variations. – Benthic structure and composition in secondary channels of low discharge and intermittent flow show marked spatiotemporal variations between the straight reaches (SR) and the confluence scour holes (CSH). During the low water phase, the composition is similar between both sectors, but in the high water phase it changes abruptly. – Benthic structure and composition in floodplain lakes vary according to origin, morphometry, floodplain location, degree of connectivity with the channels and successional stages. The greatest variations are given between the irregular lakes connected with several embayments, and the isolated round-oval lakes with a decreasing gradient in density, biomass, species richness and diversity. – The increase in the water level phase produces a reset in the successional stages, mainly in the directly or indirectly connected lakes, while in secondary channel with intermittent flow and in the isolated lakes, far away from the main channel, such reset is partially verified in the El Niño events. – The spatiotemporal variations in the temporary marginal wetlands are very pronounced in relation to the flood pulse and the river overflow, with a gradual change in the composition of aquatic and terrestrial invertebrates. However, many aquatic invertebrates remain at these sites even in the drought period because of the adaptive strategies (cysts, eggs, refuge in hyporheos, etc.) that allow them to recolonize the habitats when conditions are favorable again. – A gradient from the main channel to permanent flow secondary channels, to isolated lakes and temporary marginal wetlands is observed, with a decrease in density and an increase in biomass, richness, and diversity of species. In the same direction, an increase in the complexity of functional groups and trophic webs, and in the connectance, is produced. – The shredders functional group, although scarce, is more represented in the floodplain environments where CPOM is very high. However, a great amount of necromass accumulates in the bottom of floodplain habitats, mainly in those of advanced successional stages. – The typical benthic species assemblage of the main channel central strip and higher secondary channels is characterized by endemic species of the Neotropical region, as Narapa bonettoi, Myoretronectes paranaensis, Itaspiella parana, Haplotaxis aedeochaeta, while Potamocaris spp., Tobrilus sp. and Parachironomus spp are occasionally registered. – The typical benthic species assemblage of the main channel banks and higher secondary channels is similar to that of the secondary channels that show intermittent flow, with dominance of Paranadrilus descolei, Botrhioneurum americanum, Campsurus cf. notatus and Pisidium sterkianum. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – The typical benthic species assemblage of the main channel banks and higher secondary channels is similar to that of the secondary channels that show intermittent flow, with dominance of Paranadrilus descolei, Botrhioneurum americanum, Campsurus cf. notatus and Pisidium sterkianum. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – The typical benthic species assemblage of the main channel banks and higher secondary channels is similar to that of the secondary channels that show intermittent flow, with dominance of Paranadrilus descolei, Botrhioneurum americanum, Campsurus cf. notatus and Pisidium sterkianum. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – The increase in the water level phase produces a reset in the successional stages, mainly in the directly or indirectly connected lakes, while in secondary channel with intermittent flow and in the isolated lakes, far away from the main channel, such reset is partially verified in the El Niño events. – The spatiotemporal variations in the temporary marginal wetlands are very pronounced in relation to the flood pulse and the river overflow, with a gradual change in the composition of aquatic and terrestrial invertebrates. However, many aquatic invertebrates remain at these sites even in the drought period because of the adaptive strategies (cysts, eggs, refuge in hyporheos, etc.) that allow them to recolonize the habitats when conditions are favorable again. – A gradient from the main channel to permanent flow secondary channels, to isolated lakes and temporary marginal wetlands is observed, with a decrease in density and an increase in biomass, richness, and diversity of species. In the same direction, an increase in the complexity of functional groups and trophic webs, and in the connectance, is produced. – The shredders functional group, although scarce, is more represented in the floodplain environments where CPOM is very high. However, a great amount of necromass accumulates in the bottom of floodplain habitats, mainly in those of advanced successional stages. – The typical benthic species assemblage of the main channel central strip and higher secondary channels is characterized by endemic species of the Neotropical region, as Narapa bonettoi, Myoretronectes paranaensis, Itaspiella parana, Haplotaxis aedeochaeta, while Potamocaris spp., Tobrilus sp. and Parachironomus spp are occasionally registered. – The typical benthic species assemblage of the main channel banks and higher secondary channels is similar to that of the secondary channels that show intermittent flow, with dominance of Paranadrilus descolei, Botrhioneurum americanum, Campsurus cf. notatus and Pisidium sterkianum. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In lakes connected to the river, the typical benthic species assemblages is similar to that of secondary channels banks with permanent flow and that of the center of intermittent flow, except for P. descolei, which is only registered in rivers. In isolated lakes or in embayments of irregular lakes with more advanced successional stages and a higher content of organic matter in bottom sediments, the typical assemblage is given by the dominance of Branchiura sowerbyi, Chaoborus sp. and Chironomus gr. decorus. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – In temporary wetlands, in addition to many oligochaete species common to other floodplain environments, there is a higher representativeness of Insecta (mainly Coleoptera Berosus spp., Chironomidae Polypedilum spp., Ceratopogonidae spp., Dolychopodidae spp., Tipulidae spp., Odonata Aphylla sp.) and Ostracoda. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial heterogeneity, habitat structure, temporal instability and high productivity determine the higher importance of the lateral dimension than the longitudinal dimension in large floodplain rivers. – Spatial h