The success of algae with luxury P uptake and mixotrophy in P-limiting periphyton within-reservoir spatial heterogeneity

We evaluated the biomass of the algae with luxury P uptake (LPU) and mixotrophy in the periphyton in a shallow reservoir mesotrophic. We analyzed the relationship between the two adaptive strategies and light and P availability in the environment and periphyton TP content. Water and periphyton on artificial and natural substrates were sampled in different macrophyte stands in dry and rainy periods. Algae with LPU and mixotrophy represented a large part of total biomass and density, respectively. P was a significant predictor of changes in biomass of the algae with LPU and mixotrophy on artificial substrate. For natural substrate, light was a significant predictor for algal biomass in the periphyton. We found a negative relationship between the biomass of algae with LPU and mixotrophy and TP concentration and light. Biomass of algae with both strategies tended to decrease with the increase in TP content in the periphyton. Algae with LPU and mixotrophy had growth success in periods of high shading and low P and both were associated with the P-limiting condition. In conclusion, algae with LPU and mixotrophy can contribute to the storage of the P in the periphyton. Changes in the proportion of autotrophic and mixotrophic algae in the periphyton can affect the potential for removal and retention of P of the community in lakes and shallow reservoirs.