Sirine Boucenna, Vasilis Dakos, Gael Raoul

While it is known that shallow lakes ecosystems may experience abrupt shifts (ie tipping
points) from one state to a contrasting degraded alternative state as a result of gradual envi-
ronmental changes, the role of evolutionary processes and the impact of trait variation in this
context remain largely unexplored. It is crucial to elucidate how eco-evolutionary feedbacks
affect abrupt ecological transitions in shallow lakes. These feedbacks can significantly alter
the dynamics of aquatic plants competition, community structure, and species diversity, po-
tentially affecting the existence of alternative states or either delay or expedite the thresholds
at which these ecological shifts occur. In this paper, we explore the eco-evolutionary dyna-
mics of submerged and floating macrophytes in a shallow lake ecosystem under asymmetric
competition for nutrients and light. We use adaptive dynamics and a structured population
model to analyze the evolution of the growth depth of the submerged and floating macro-
phytes population, which influences their competitive ability for the two resources. We show
how rapid trait evolution can result in complex dynamics including evolutionary oscillations,
extensive diversification and evolutionary suicide. Furthermore, we find that the co-evolution
of the two competitive species can play a stabilizing role, while not significantly affecting
the overall evolutionary dynamics. Overall, this study shows that evolution can have strong
effects in the ecological dynamics of bistable ecosystems.