Modelling the Interactions between Ecological and Social Dynamics

1. Modelling the Interactions between Ecological and Social Dynamics in Integrated Natural Resources Management The usefulness of Multi-Agent Systems (MAS)

2. Several agents using or managing the resources hold by the environment Some entities representing management units A spatial grid some entities holding natural resources with their own dynamics MAS and Natural Resources Management

3. MAS and Natural Resources Management • Behaviours and interactions at different levels of organisation • Investigating collective organisation modes and collective decision making processes (testing contrasted scenarios) • A modelling approach to build common representations of a system shared by the stakeholders (scientists, local people, policy makers, politicians) • Adaptive models (run-time modifications) for adaptive management

4. hypothesisquestions discussion of hypothesisnew questions Experiments’ plan A “Companion” Modelling Approach field model simulations

5. Interacting withDecision Making Processes field Decision Making Processes model simulations

6. Which future for the Causse Méjan grasslands ? A multi-agent approach to solve environment and land management problems Michel ETIENNE, Christophe LE PAGEINRA, CIRAD AVIGNON, MONTPELLIER (France)

7. 1950 2000 population The current land dynamics cereals, hay grasslands Natural increase of Woodland pines afforestation ?

8. Historical context • Plantations or spontaneous encroachment of pine are not manage • The encroachment and the reafforestations of adults are or enter in phase of dispersion • Original grasslands(anthropological origin) are threatened • Breeders, foresters and defenders of the nature express multiple and often conflicting social demands

9. pine encroachment pine afforestation sheep farm croplands native grasslands

10. The questions • How to imagine landscape changes in a man-made natural environment according to contrasting strategies of land management ? • How to account simultaneously for productive and heritage stakes ? • How to support the concertation between agents concerned by the same ecological dynamics ?

11. The ecological process 1 • Encroachment as a pioneer front from • …native woodlands ... • … or afforestations

12. The ecological process 2 • Encroachment from isolated • … > 30 year-old black pines ... • … > 15 year-old Scots pines

13. Dispersal model Scots pine over15 years-old or black pine over 30 years-old Any cell far from the seed-bearers but located inside their seed catchment has a probability to be invaded related to grazing presssure Seed catchment 2 Any grassland cell under the wind is invaded Any cell where mature trees are growing up and located at the eastern edge of a catchment is capable to send seeds to the following catchment ridge 2 ridge 1

14. The agent-based approach • To represent the bare zone of the Causse Méjan on the basis of the current scientific knowledge on the ecological dynamics and the pratices of the local agents (MAS 1) • To make this formalisation accessible to the local agents and share a certain representation of the system with them (Simplified MAS) • To stimulate reactions of stakeholders facing a virtual situation that is close to their reality (pine encroachment) (Role game) • To collectively imagine possible management scenarios and to assess their consequences (MAS 1)

15. tree shrub tree + shrub tree + shrub + grassland shrub + grassland tree + grassland crop grassland the MAS conception • A territory defined by combining vegetation structures that shelter different resources according to the agents 4 ha/cell

16. the MAS conception • Three categories of agents with diverse objectives but which practices modify clearly the pine tree dynamics • Farmers who wish to continue living from sheep husbandry on the Causse • Foresters who wish to make profit from investments realised 30 years ago • Conservationists who are missioned to conserve a very rich but very instable environment

17. Scots pine BlackPine 0 100 à 300 50 à 100 1,5 50 à 100 30 à 50 0 20 à 50 10 à 30 0,5 20 à 50 10 à 30 2,5 0 0 2,5 10 à 20 1 à 5 5 0 0 5 0 0 Productive impacts Sheep farmer (ewes/cell/year) Forester (m3/ha) big trees, high density big trees, low density big + small trees, high density big + small trees, low density small trees, low density a few big trees a few small trees grassland

18. disappearance of Gentiana clusii disappearance of Orchis coriophora no disappearance no disappearance Ecological impact on protected flora big trees, high density disappearance of Saponaria bellidifolia disappearance of Gagea pratensis, Adonis vernalis big trees, low density big + small trees, high density disappearance of all protected species big + small trees, low density small trees, low density disappearance of Gagea villosa a few big trees a few small trees grassland

19. Ecological impact on fauna + than 10 % of pine canopy cover on 1 cell + than 25 % on 6 cells + than 50 % on 6000 cells

20. Modelling farmers • A farm defined by an equilibrium between crops, rangelands and forests • A certain amount of work for controlling pine trees • Sheep rearing practices using more or less rangelands according to their production system • Forestry pratices linked with the availability of incentives • Land tenure fixed until retirement • A plausible future for the farm after retirement

21. Uprooting or mowing Thinning or felling Evaluating range condition Zoning Intervening or not on pine trees Adapting grazing pressure Adjusting Consuming forage Grazing Farmers actions Negociating or not with the partners Balance

22. Shrubland Wood Paddock Grassland with pines Grassland Crop Grassland with young pines Schematic representation of a Farm

23. Paddocks

24. Modelling conservationists • A landscape to conserve defined by a strong dominance of « open land» • Law regulations • An ability to get financial support for the control of pine encroachment • A clear vision of the fauna, flora and landscape stakes • A small owned land • An ability to influence public policy

25. Locating zones with high heritage value or farmers with good practices Zoning Moving to the most intesresting zone Choosing Uprooting the pine trees Clearing Scanning Visiting other problematic cells Conservationists actions Deciding or not to continue to clear pine trees Negociating or not with the partners Balance / survey

26. Modelling foresters • Management units determined according to the origin of the pine stands (afforestation, natural encroachment) • Regimented woodlands • Woodlands divided into woodlots in order to plan the forest management more easily • An ability to liberate capital and work force to plant and exploit pine trees • A productive vision of pine trees • A patchy and extending land tenure

27. Planting or not Evaluating pine stands condition Inventory Deciding or not to go on producing pine Scheduling an operation calendar Planning Making profit from timber production Thinning and/or Harvesting Foresters actions Negotiating or not with the partners Balance

28. 7 land management strategies • let nature work • let farmers and foresters work • let save the heritage hotspots • let block the ecological process • Let associate naturalists and farmers • Let develop silvopastoralism • Let recreate the steppe

29. Comparing three scenarios according to the “vegetation” point of view Let Nature work Silvopastoralismconcerted with naturalists Let recreate the steppe

30. Different points of view for a same simulation Cutting small pines (farmers - PNC) Timber production (forester) Heritage interest (PNC)

31. The role playing game conception • The land is described by a cellular-automata able to simulate the vegetation dynamics according to the applied management • the players, on the spatial entities they are used to manage and according to the results of the negotiations they decide to conduct as their territory is changing

32. Simplification of the model • The constraints of a ludic application • to reduce the time of playing and the role of the computers • to simulate at least 25 years of vegetation dynamics • to warranty the participation of 4 sheep farmers (1 per type) 2 naturalists and 1 forester (maximum 10, 5 et 2) • The need to simplify the representations • a smaller land • same size and characteristics of the farms • simple indicators adapted to the players uses • The adaptation of the rules • same rules on vegetation dynamics • completely open negotiations

33. The game land • 2000 cells (5 ha/cell) defining... • a serie of pine seed dispersion catchments submitted to a nort-western wind, • and agreggated into 10 sheep farms composed of 50 ha of croplands, 8 paddocks of 50 ha of rangelands, shrublands and woodlands • 3 private forests and 1 hunting ground • grasslands and croplands shelter many endangered species

34. forest shrublands steppe + + + + + crops Natural resources each color corresponds to the overlapping of vegetation layers

35. shrublands woodlands a paddock grasslands invaded by pine trees grasslands croplands grasslands spotted with pine trees The farmer land

36. indffp 3234 ratio 18 j coupes 0 The conservationist markers

37. The game setting 1 After a brief introduction to the game rules meanwhile the PNC analyses the land on the computer each farmer receives a farm ... …and moves to his table with an observer... ...in order to elaborate the grazing calendar 10 minutes later the grazing calendar is put into the computer and the land dynamics is simulated

38. The game setting 2 Each farmer receives a new map of his farm and thinks about the strategy to develop with the pine trees meanwhile the PNC set up a negotiation strategy Then for 10 minutes naturalists, foresters and farmers negotiate Lastly the operations planned during the negotiation are put into the computer

39. A role playing game (RPG)... • To make easier the modelling of the interaction between players • To share collectively a representation of the pine encroachment process • To leave totally open the players creativity to develop original strategies of operation and negotiation

40. The feed-back between MAS and RPG • The MAS permits to test several options of the pine dynamics management and to visualise it according to different view-points • The coupling with a role playing game permits to imagine plausible adaptation strategies of the agents practices to an unusual ecological process • and to elaborate new markers into the MAS in order to better account for the way the agents perceive the pine trees

41. Perspectives • to compare the impact of contrasting land planning policies on the state of Nature and on the dynamics of farm and forestry activities • to stimulate a collective awareness of environmental problems and to identify the main conflictual points between the agents • to support long term planning during collective negotiations on the management of so-called natural resources

42. Reality • the National Park created a fund to support the preventive control of pine encroachment • The Chambre d’Agriculture and the Communauté de Communes set up a collective reflexion on the problem of pine trees • A Local Concerted Management Plan was elaborated and financed to pay collectively planned operations • The Forest Service and the National Park are looking for new procedures to permit anticipated interventions on stratgic ridges

43. 1. Expert knowledge Applied Agent-Based model 2. Social validation Collective and adaptive learning An Approach Combining an Agent-Based Model and a Role-Playing Game 3. Collectively discussed scenarios Role game

44. Combining ABM and RpG • to produce and collect information and knowledge about behaviours, • to present and explain the model to the stakeholders, and to validate it, • to test scenarios and compare them, by the mean of simulation Building a common representation

45. Land allocation between grazing and rice cropping activities in Senegal Negotiations between a shepherd and a forester in a Mediterranean ecosystem Discussions between foresters, shepherds and a national park in an ecosystem facing pine encroachment (South of France), Agricultural land-use in North-Vietnam, Experiments Irrigated schemes in Senegal Environmental mediation about phytogenetics resources management in Madagascar