Impact of water input on plankton temporal dynamics from a managed shallow saline lake

Abstract

La Salada is a shallow saline lake located in the SW of the Pampas subject to significant water management, so the primary objective was to assess whether the water input and physicochemical parameters have an impact on the plankton assemblages over a two year period (2013-dry and 2014-wet). The plankton community structure and physicochemical variables showed substantial changes over the study period. La Salada hosted a plankton community characterized by low diversity and small sized organisms. The nanoplanktonic fraction organisms (2-20 mm) dominate the phytoplankton community. Ochromonas sp. showed the maximum abundance throughout the whole study period. The zooplankton community was dominated by rotifers, with a lack of cladocerans. Halotolerant species, e.g. the rotifer Brachionus plicatilis and the cyclopod Apocyclops sp. were the main species. The seasonal temperature and conductivity dynamics influence the plankton abundance dynamics in La Salada. The increment of nutrients and decrease of conductivity caused by the water input led to an increase in plankton biomass and shaped its composition. These findings emphasize that interactions between plankton, salinity, and nutrients are sensitive to the water input and they improve the understanding of the impact of adequate management decisions.

Trait‐based diatom functional diversity as an appropriate tool for understanding the effects of environmental changes in soda pans

“…The small cell size and this elongated shape further facilitate their movement among the inorganic sediment particles and their ability to hide in the mud. Small size has also been highlighted in planktic communities (Alfonso, Zunino, & Piccolo, ; Somogyi et al, ) as well as the motile feature (Földi et al, ) in other saline lake ecosystems, where species reduce their cell and pore size due to the osmotic stress (Leterme et al, ).…”

“…Disturbed hydrological cycles (e.g., by water abstraction or resupply) can modify limnological variables (e.g., lower conductivity and pH) (Lengyel et al, ), potentially leading to less extreme features characteristic of fresh water, and therefore resulting in higher diversity. This result calls attention to anthropogenic activities (Alfonso et al, ), including even those undertaken for conservation purposes, which have considerable impacts on biodiversity both on the taxonomic (Heino, ; Stenger‐Kovács et al, ) and at the functional levels.…”

“…In these ecosystems, seasons had a less pronounced effect, and the related hydrological cycle, as well as the substrate type, had no significant effect on functional diversity, in contrast to the case of freshwater, where high water periods support the appearance of a number of periphytic algal species with different traits, thus resulting in a high degree of functional diversity (Dunck, Algarte, Cianciaruso, & Rodrigues, ; Dunck, Rodrigues, & Bicudo, ). At the taxonomic level, seasonal effects (Lengyel et al, ) can also be detected in the benthic diatom, as well as in the planktic communities of saline lakes (Alfonso et al, ). However, microhabitat preference (such as substrate type) is negligible at taxonomic levels as a consequence of the extreme environmental conditions (Cejudo‐Figueiras, Álvarez‐Blanco, Bécares, & Blanco, ; Lengyel et al, ).…”

“…At the taxonomic level, seasonal effects can also be detected in the benthic diatom, as well as in the planktic communities of saline lakes (Alfonso et al, 2017). However, microhabitat preference (such as substrate type) is negligible at taxonomic levels as a consequence of the extreme environmental conditions (Cejudo-Figueiras, Álvarez-Blanco, Bécares, & Blanco, 2011;Lengyel et al, 2016).…”

Spatial and temporal dynamics of the mesozooplankton (Crustacea: Cladocera, Copepoda and Decapoda) in a Pampean shallow hyposaline lake during drought conditions

“…Despite the well-known impact of salinity determining community structure, studies have indicated that other physicochemical variables of saline lakes could play a critical role controlling the zooplankton community (Williams, 1998). Other factors, such as habitat permanence, water management, incorporation of freshwater input (enriched by nutrients related to anthropogenic use) and trophic interactions alter the structure of aquatic communities in saline lakes (Alfonso et al, 2017;Echaniz et al, 2009;Larson & Belovsky, 2013;Stenger-Kovács et al, 2014). Zooplankton species richness increases with nutrient enrichment in saline lakes, demonstrating the importance of nutrient supply (Larson & Belovsky, 2013).…”