The influence of resource heterogeneity on pastoral agistment strategies – A game theory approach

1. The influence of resource heterogeneity on pastoral agistment strategies –A game theory approach Art Langston on behalf of Ryan Mcallister

2. A history of Australian landscape utilisation Consolidation: Spatial connectivity restoredby property consolidationand agistment arrangements Regional Fragmentation: More uniform resource accessallows splitting of largerproperties Nomadism: Opportunistic movementaround entire region rangingout from key resources Resource Excision: ‘Ownership’ of a key resourceproviding partial accessto surrounding area Stokes, Ash, McAllister 2004 Fragmentation of Australian Rangelands Australian Rangeland Society Conference, Alice Springs 5-8 July.

3. Intensification Approximate percentage of land available to grazing 1860 Artificial water,-1960 New breeding,1970- Abbott, McAllister 2004, Using GIS & Satellite Imagery to Estimate the Historical Expansion of Grazing Country in the Dalrymple Shire , Australian Rangeland Society Conference, Alice Springs 5-8 July.

5. Systems of pastoral opportunism • “African” systems • Well studied • Generally long established • Generally based on common property rights • Generally informal institutions • Current Australian system of agistment • Not well studied • New, perhaps only 30yrs old • Based on private property rights • Embedded within a formally institutionised system

6. Studying in a simulated environment Real Landscape Simulated Landscape Design principles: • Define the landscape and the agents (pastoralists) who occupy it; • Develop small scale behavioural rules (the GAME), including interactions between society, economy and environment; • Observe large system behaviour under different “treatments”. Agistment opportunities Grazing distribution

7. The rules of the Game – Iterated prisoner’s dilemma • Pairs of agents play iterated one-shot prisoner’s dilemma game. • Opponents are paired based on biophysical conditions. • Agents use evolving ‘symbols’ to estimate trust. • Players may withdraw, cooperate or defect, based on expected trustworthiness of other. Demander Agent R – Reward, S – Sucker, P – Punishment, T - Temptation

8. Real costs of defection to Stock owner (demander) • Missing stock • Theft • Poor fencing • Mortality • Loss of condition • Inadequate water supply • Overstocking of paddock • Inadequate supplements Land owner (supplier) • Infrastructure damage • Stocked with “wild” beasts • Weed/Pest Introduction • Payment disputes Opportunity cost of not agisting stock!!

9. Results • The effectiveness of agistment networks depend on the characteristics of resource variation. • Best outcomes are in systems where spatial variation is high, spatial co-variation is low. system McAllister, Gordon, Janssen, Abel. (in review) Pastoralists' responses to variation of rangeland resources in time and space, Ecological Applications

10. Results It pays to be trusted when spatial variation is high! McAllister, Gordon, Janssen, Abel. (in review) Pastoralists' responses to variation of rangeland resources in time and space, Ecological Applications

11. Results When spatial variation is high you need to trust others more but you can trust others too much! system McAllister, Gordon, Janssen, (in review) Trust and cooperation in natural resource management: The case of agistment in rangelands, MODSIM2005

12. G-Bay concept • Making good agistment decisions depends on the system rewarding cooperation and punishing non-cooperation. • Making the network smaller may allow more information to be processed per individual in the network, large networks are needed to link resource variation. • G-Bay: using modern technology to complement the existing pastoral networks (CSE internal funding).

13. Thanks ryan.mcallister@csiro.au