COS 67-3 - Restoration success varies based on time since restoration in a disturbance-dependent wetland ecosystem

Abstract: Habitat restoration often focuses on reaching an idealized steady state, but this is unrealistic for disturbance-dependent ecosystems where temporal variability is inherent and habitat quality is expected to fluctuate. Understanding the ways in which the outcomes of restoration change over time in disturbance-dependent ecosystems can better inform adaptive management plans and increase the likelihood that restoration efforts will be effective. We conducted a decade-long restoration experiment in disturbance-dependent, ephemeral wetlands to test how management efforts to mimic disturbance impact populations of an endangered butterfly and its host plants. We show that changes in plant communities as a response to disturbance vary depending on time since restoration, with target host plants initially increasing and peaking several years post-disturbance but then declining. In the absence of further disturbance, butterfly populations follow a similar pattern as their host plants. In addition, host plant populations show a diminished response to subsequent disturbance events, with lower abundances and earlier declines. Due to this non-linear response, management actions within disturbance-dependent ecosystems need to include long-term monitoring in order to accurately capture changes in habitat response, as well as active, adaptive planning that shifts according to current system stability and addresses variability in ecosystem response to multiple disturbance events. Management efforts within these dynamic habitats are more likely to succeed when temporal variability is explicitly tracked and management actions are responsive to current conditions.