Effects of water-level fluctuations on lakes: an annotated bibliography

Abstract

Water-level fluctuations (WLF) often represent one of the greatest impacts on the development of lake ecosystems. In the year 1931, the Hydroelectric Trentino Company (SIT) requested the hydroelectric use of water bodies in the Upper and Middle Sarca basin. The largest and deepest lakes were dammed to increase lake volume and exploited since mid 1950s. This research uses the sediment record of two small lakes in close proximity to each other (Garzonè and Serodoli) in northern Italy, use for hydroelectric power generation to determine the dependence of diatom-assemblage dynamics on WLF that have taken place over the last 60 years. Historical water-level fluctuations are clearly reflected in the lithological composition and grain-size variations of the sediment cores. During the regression and transgression phases, the boundaries between the Erosion, Transport and Accumulation zones fluctuated, causing redistribution of previously accumulated sediments, and their return into the lake's cycling of biogeochemical matter. The water-level changes not only caused distinct taxonomic shifts in the diatom communities, which were dominated by different species in the core sections of each lake, but also significant shifts in the composition of the diatoms' ecological, morphofunctional and life-form groups. Diatoms with a low-and high-profile attachment type were the dominant morphological forms in the upper core levels, where the most extreme fluctuations in water level had occurred. Increased turbulent mixing caused by WLF favours the presence of large, heavily-silicified centric diatoms, while more stable levels would select for smaller centric diatoms through thermal stratification.

Limnology in the Upper Paraná River floodplain: large-scale spatial and temporal patterns, and the influence of reservoirs

“…Although the effects of water-level fluctuations on physical habitats are relatively well studied, most investigations have been carried out in Europe and North America (Leira and Cantonati, 2008). Because of the strong influence of physical and chemical features on organisms, part of the structure and dynamics of populations and communities in floodplains can be explained by the dynamics of abiotic factors.…”

Adaptation to water level variation: Responses of a floating-leaved macrophyteNymphoides peltatato terrestrial habitats

“…Adaptive plasticity to temporal environmental variations is common and may be important for adaptation to varying environments (Schlichting and Pigliucci, 1995;Bazzaz, 1996;Yamamoto and Tsukada, 2010). In many wetland and floodplain ecosystems, periodic flooding and drought occurrences play an important role in the composition, and productivity of species (Li et al, 2004;Leira and Cantonati, 2008). Wetland plants possess various characteristics in order to survive and function in fluctuating and frequently adverse conditions of wetland ecosystems (e.g., Shangguan et al, 2000;Sultan, 2001;Li et al, 2004;Mommer et al, 2005Mommer et al, , 2006.…”

Fluctuations of Lake Orta water levels: preliminary analyses

“…the third type is the fluctuation that results from the artificial regulation of lake levels by control works at the outflow dam. the seasonal and inter-annual fluctuations of lake level are a normal and essential component of the health of the ecosystem and lake (leira and Cantonati, 2008).…”