Temporal dynamics of a subtropical floodplain pool after 2 years of supra-seasonal drought: a mesocosm study

Effects of river regulation on aquatic invertebrate community composition: A comparative analysis in two southern African rivers

“…These wetlands were selected as they represent typical tropical floodplain wetlands that receive water through rainfall and connection with adjacent rivers during flood releases in the wet season, and typically dry out during the dry season when they become disconnected from the rivers (Wantzen et al., 2016 ). These two wetlands comprised shallow water levels, muddy substrates, and abundant floating, emergent and marginal vegetation, as described in previous studies (see de Necker, 2019 ; de Necker, Gerber, et al., 2022 ; Dube et al., 2017 ). These are identical attributes associated with Lake Shokwe.…”

“…These two rivers merge and form a confluence within the NGR. These floodplain habitats are important for the breeding, spawning and foraging of many aquatic biota (Acosta et al., 2020 ; de Necker et al., 2021 ; de Necker, Gerber, et al., 2022 ; van Rooyen et al., 2022 ). As such, both the Phongolo and Usuthu rivers are important to the continued maintenance of biotic diversity and ecological functioning of these floodplain lakes.…”

“…Consequently, the Usuthu River is expected to support a higher biodiversity of aquatic invertebrates. Whether this is indeed the case, and how the biodiversity between the two systems compares to one another is unclear, as prior research in the PRF has focused largely on the Phongolo River (de Necker, Neswiswi, et al., 2020 ; Dube et al., 2015 ; Smit et al., 2016 ), its associated floodplain and the temporary wetlands of the area (de Necker et al., 2021 ; de Necker, Brendonck, et al., 2022 ; de Necker, Gerber, et al., 2022 ; de Necker, Manfrin, et al., 2020 ; Dube et al., 2017 , 2019 , 2020 ). In contrast, information about aquatic biodiversity and community dynamics of the Usuthu River and its associated floodplain lake (Lake Shokwe) is scarce, with no information on how this compares to that of the Phongolo River and its floodplain wetlands, nor the role of these two rivers in the ecological functioning of Lake Nyamithi.…”

“…In contrast, information about aquatic biodiversity and community dynamics of the Usuthu River and its associated floodplain lake (Lake Shokwe) is scarce, with no information on how this compares to that of the Phongolo River and its floodplain wetlands, nor the role of these two rivers in the ecological functioning of Lake Nyamithi. Furthermore, due to drought in South Africa from 2016 to 2018, no flood releases occurred from the Pongolapoort Dam and thus Lake Nyamithi received little to no inflow from the Phongolo River (de Necker et al., 2021 ; de Necker, Brendonck, et al., 2022 ; de Necker, Gerber, et al., 2022 ; de Necker, Manfrin, et al., 2020 ). Therefore, the lake was primarily dependent on freshwater input and inflow of aquatic biota from the unregulated Usuthu River, particularly in 2018.…”

Distribution, abundance, population structures, and potential impacts of the invasive snail, Tarebia granifera in aquatic ecosystems of north‐eastern South Africa

“…Sites were selected within the main channel of the Phongolo River and its floodplain, stretching downstream from the Pongolapoort Dam to before the confluence with the Usuthu River (refer to Figure 1 ). Site selection was based on study sites used as part of previous studies in the region (Dube et al., 2017 ; de Necker, 2019 ; de Necker, Gerber et al., 2022 ). The Phongolo River system is the largest floodplain system in South Africa (Acosta et al., 2020 ) and is often the most southern distribution locality for many lowveld tropical freshwater species, making it an ecologically significant area.…”