Contrasting stoichiometric dynamics in terrestrial and aquatic grazer-producer systems

The turnover rate of producer biomass in aquatic ecosystems is generally faster than in terrestrial. That is, aquatic producer biomass grows, is consumed, and is replaced considerably faster than terrestrial. The WKL model describes the flow of phosphorus and carbon through a grazer-producer system, hence varying the model parameters allows for analysis of different ecosystems of this type. Here we explore the impacts of the intrinsic growth rate of the producer and the maximal ingestion rate of the grazer on these dynamics because these parameters determine turnover rate. Simulations show that for low intrinsic growth rate and maximal ingestion rate, the grazer goes extinct; for higher values of these parameters, coexistence occurs in oscillations. Sensitivity analysis reveals the relative importance of all parameters on asymptotic dynamics. Lastly, the impacts of changing these two parameters in the LKE model appears to be quantitatively similar to the impacts in the WKL model.

Automated summary

Research shows that the turnover rate of producer biomass in aquatic ecosystems is generally faster than in terrestrial ecosystems. The WKL model describes the flow of phosphorus and carbon through a grazer-producer system, and varying the model parameters can impact the dynamics of different ecosystems of this type. Analysis reveals that the intrinsic growth rate of the producer and the maximal ingestion rate of the grazer play a crucial role in determining the turnover rate and dynamics of the ecosystem.