Limited plankton community shifts over winter inundation events in Austral temporary wetlands.

Abstract

Plankton are key components of wetland ecosystems, comprising different food web levels. In the present study, we assessed temporal plankton diversity patterns in three temporary wetland systems over winter inundation periods. We examined taxon relationships with environmental variability associated with wetland inundation phase changes, over six consecutive sampling events (i.e. T1–T6; or until the ponds dried). Fifty-nine phytoplankton species belonging to 36 genera were identified across the three wetlands, with 21, 22 and 19 taxa being identified for Wetlands 1, 2 and 3, respectively. Twenty-five zooplankton taxa were also identified across the three wetlands. Significant differences in environmental variables were found across sampling events. Ammonium, conductivity, dissolved oxygen, water temperature, turbidity, nitrates (NO3–N) and zooplankton abundances were identified as important variables structuring phytoplankton communities, whereas, NO3–N, phosphates and chlorophyll-a concentration were identified as important environmental variables for zooplankton. No significant differences were, however, observed in plankton community structure over time or among wetlands. Accordingly, hydroperiod phases did not have any significant influence on the plankton taxa richness in this study, in contrast to other seasons in the region and other parts of the world. The present study highlights that where temporary wetlands are characterised by both summer and winter inundation events, community succession dynamics may be seasonally distinct and require sampling in both periods to fully understand propagule and emergent community dynamics.