ARC Processes
In Phase I of the RESIST project, we have published and tested a novel theoretical framework to disentangle mechanisms causing stressor interactions during phases of ecosystem degradation and recovery: the Asymmetric Response Concept (ARC) (Vos et al., 2023).
The ARC concept holds that three key mechanisms influence population, community and ecosystem trajectories:
- Tolerance
- Dispersal
- Biotic interactions
As the central tenet of the ARC, the significance of tolerances, dispersal and biotic interactions differs fundamentally between phases of degradation and recovery. The shifting importance of these mechanisms creates asymmetries between the ecological trajectories that follow increasing and decreasing stressor intensities. This recognition helps to understand multiple stressors’ impacts and to predict which measures will restore communities that are resistant to restoration.
Results from Phase I
Though yet limited to benthic invertebrates, the results of Phase I supported the Asymmetric Response Concept: in initial recovery phases, dispersal plays a key role while biotic interactions gain relevance later (support for Main Hypothesis MH1). For microorganisms, however, biotic interactions (monopolisation effects) inhibited biotic recovery, strong support for Main Hypothesis MH2 on differences in the processes guiding recovery between macro- and microorganisms. We validate the ARC by investigating its individual components and their effects on ecosystem degradation and recovery.