Table 1.

Definitions and examples of key terminology and how used across biological levels.

Term	Definition - resilience in ecology	Definition or use at biological levels	Examples relevant for biological resilience
Disturbance event	abiotic or biotic force, process, or agent with potential to impact a system	equivalent but not often used as a defined term. Somewhat analogous to a selection event	• broad scale e.g. Climate change & local scale e.g. introduction of invasive species • short to long duration, or pulses • multiple disturbances are possible, related directly (e.g. temperature & drought) or indirectly (e.g. eutrophication & invasive species) • can be experimentally approximated in the field and/or lab
Perturbation	response of a system to a disturbance, measured as change in a state variable	alteration of function	• sometimes synonymous with ‘disturbance’ • ‘Perturbation biology’ concerns changes in proteins and cellular features, modelled using networks121 • e.g. gene knock-out studies as perturbation to multiple factors122, conservation translocations of social phenotypes87
Resilience	capacity of a system to manage disturbance	somewhat analogous to homoeostasis, a self-regulating feedback process that maintains physiological stability	• where used, resilience can be a metaphor, property of dynamic models, or a measurable quantity • broad adoption of resilience including socioecological systems, neurobiology, psychology, medicine • disruption of homoeostasis leads to disease, i.e. a state-change123
Resistance	ability to persist despite a disturbance event	preventing infection or invasion by an enemy; includes physical, behavioural or cellular defences	• cellular ‘memory’ from past exposure influences drug resistance of cancer cells124 • behavioural defences against parasites vary according to social structure125
Recovery	ability to return over time towards a pre-disturbance state	somewhat analogous to tolerance, ability to maintain fitness despite e.g. infection, lack of resource	• measured as time to recover, amount of recovery, and rate of recovery11 • physiological drought-tolerance as mechanism for resilience of grasslands to climate change126
Plasticity	not commonly used, but a potentially important mechanism shaping resistance and recovery components of resilience?	variation in the expression of a gene/trait due to differences in environmental conditions	• gene expression plasticity and stress tolerance127 • physiological plasticity and resilience to climate warming46 • behavioural plasticity and resilience of communities128