Density dependent control of resting egg production promotes coexistence of zooplankton

Resting egg banks are a key factor in plankton coexistence within homogeneous environments, but rapid evolutionary changes may reduce their role in stabilizing species composition. We conducted a series of model simulations to assess the sensitivity of both integrated (total population numbers and biomass) and structural (proportions of different age and sex classes) population characteristics to the life history traits of planktonic cladocerans. We examined the outcomes of direct (within a growing season) and seasonal (across growing seasons) competition between two cladoceran populations, where resting egg production was regulated by density-dependent infochemicals. Results showed that variations in life history traits, such as maximum lifespan and juvenile growth rate, significantly affected competition outcomes. When resting eggs were produced in response to non-specific infochemicals, extinction events were delayed. In contrast, conspecific infochemicals enabled long-term coexistence across a range of trait variations. These findings have broad ecological significance, highlighting how density-dependent mechanisms and life history traits interact to shape species coexistence in dynamic environments. The study underscores the importance of adaptive strategies, like resting egg production, in maintaining biodiversity and population resilience. This knowledge is crucial for understanding species responses to environmental changes. By elucidating the role of infochemicals and trait variability, the research contributes to ecological theory on competition, adaptation, and coexistence.