QUEIMALIÑOS claudia Patricia
congresos y reuniones científicas
Plankton restoration from the seedbank of Patagonian wetlands: impact of water level and nutrients.
SOTO CÁRDENAS, C; GEREA, M; DIÉGUEZ, MC; REISSIG, M; QUEIMALIÑOS, C
Grand Rapids, Michigan
Simposio; Joint Aquatic Sciences Meeting 2022; 2022
Temporary wetlands are stressed by droughts and interannual water level variations that affect the development and phenology of aquatic communities and disrupt trophic interactions. Waterbirds are vital components of wetlands with strong effects on aquatic communities through fertilization by feces and consumption. In this study we addressed the effects of water level and nutrients on plankton hatching from sediments through mesocosm experiments, applying a factorial design consisting of two water levels (0.4 and 0.7 m) and nutrients with and without feces of the waterbird Chloephaga picta. Feces contributed large amounts of P and N, enhancing phytoplankton biomass and Chla, regardless the water level. Phytoplankton composition was similar in all treatments; however, nutrients and water level drove its succession. Threeperiods were detected in the succession: the first was characterized by nutrient release from sediments and feces, and the emergence of colonizing phytoplankters of the Functional Group (FG) X 3 (Chromulina, Ochromonas); the second, showed decreasing nutrients, an increase of phytoplankton biomass and FG diversity (X 1, X2, Y, Lo, including Chlorella, Monoraphidium, Plagioselmis, Chlamydomonas, Peridinium), and the increase of zooplankton abundance; and the third displayed nutrient depletion, adecrease of phytoplankton biomass with predominance of groups X2 and C (Aulacoseira), and the emergence of large zooplankton. Phytoplankton diversity, richness and evenness were higher in the nutrient-enriched treatments. Our results showed that changes in water level and nutrient inputs by waterbirds impact the hatching, diversity and production of planktonic communities, underscoring the potential effect of climate-driven changes on wetlands´ communities.