Functional diversity can facilitate the collapse of an undesirable
ecosystem state
Abstract
Biodiversity may increase ecosystem resilience. However, we have limited
understanding if this holds true for ecosystems that respond to gradual
environmental change with abrupt shifts to an alternative state. We used
a mathematical model of anoxic-oxic regime shifts and explored how trait
diversity in three groups of bacteria influences resilience. We found
that trait diversity did not always increase resilience: greater
diversity in two of the groups increased but in one group decreased
resilience of their preferred ecosystem state. We also found that
simultaneous trait diversity in multiple groups often led to reduced or
erased diversity effects. Overall, our results suggest that higher
diversity can increase resilience but can also promote collapse when
diversity occurs in a functional group that negatively influences the
state it occurs in. We propose this mechanism as a potential management
approach to facilitate the recovery of a desired ecosystem state.