Socio-ecological systems:

Challenges for modelling and management

Christopher Britton-Foster

• Levin S., Xepapadeas T., Crépin A-S., Norberg J., De Zeeuw A,. Folke C., Huges T., Arrow K., Barret S., Daily G., et al. 2012.

Social-ecological systems as complex adaptive systems: modeling and policy implications. Environment and Development Economics 18: 111-132.

Outline

• Overview• CAS are non-linear• CAS processes have differing time scales• CAS have spatiotemporal heterogeneity• CAS involve strategic interactions• The current state and management strategies

Overview

• Last time: Catastrophic regime shifts brought on by human actions

• This time: How to incorporate key elements of CAS into models that predict catastrophic regime shifts– Management implications

CAS are non-linearHysteresis

Kinzig et al, 2006

CAS are non-linear

• May have Skiba points: branching points where different trajectories could lead to different basins of attraction

• Resulting steady-state depends on history

• Management: - Know the different possible trajectories

- Consider the system’s history

CAS processes have different time scales

• Different processes occur at different rates– Can give the illusion of a constant state for the

slow processes– The lag effect

• Management:– Singular perturbation analysis separates slow

and fast dynamics within the model

CAS have spatiotemporal heterogeneity

• Patchiness of populations– Spatially– Temporally

• Short-range and long-range effects

• Management:– Different quotas or taxes that vary over spatial

zones and over time

CAS can have strategic interactions

• Strategic interactions– Cooperative: agreement on an optimal trajectory– Non-cooperative:• Open-loop: outcome depends on initial state only• Closed-loop: strategies are updated continually

(feedback strategy)

• Management– Widely studied in economics– Important to understand people’s motivations for

decision-making

Current state of management

• Uncertainties:– Inadequate inventories of ecosystem components– Functional dynamics in CAS– Limited modelling capacity

• Options for improved management:– Try to predict regime shifts and use precautionary

principle– Implement adaptive controls

Questions

• Is it feasible to incorporate these complexities into models and management decisions?

• Do you think it is harder to predict the human element, or the ecosystem element of socio-ecological systems?