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Modelling the Interactions between

Ecological and Social Dynamics

in Integrated Natural Resources Management

The usefulness of

Multi-Agent Systems (MAS)

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MAS and Natural Resources Management

A spatial grid

some entities holding natural resources with their own dynamics

Some entities representing management units

Several agents using or managing the resources hold by the environment

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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

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A “Companion” Modelling Approach

model

field

simulations

hypothesisquestions

Experiments’ plan

discussion of hypothesisnew questions

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Interacting withDecision Making Processes

model

field

simulations

Decision Making Processes

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Which future for the Causse Méjan grasslands ?

Michel ETIENNE, Christophe LE PAGEINRA, CIRADAVIGNON, MONTPELLIER (France)

A multi-agent approach to solve environment and land management problems

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1950

2000

The current land dynamics

cereals, hay

grasslands

Natural increase ofWoodland pines

afforestation

population

?

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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

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pineencroachment sheep

farmpine

afforestation

native grasslands

croplands

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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 … or afforestations

Encroachment as a pioneer front from

…native woodlands ...

The ecological process 1

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… > 15 year-old Scots pines

Encroachment from isolated … > 30 year-old black pines ...

The ecological process 2

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Seed catchment 2

Dispersal model

ridge 1

ridge 2

Any grassland cell under the wind is invaded

Any cell far from the seed-bearersbut located inside their seed catchmenthas a probability to be invaded related

to grazing presssure

Any cell where mature trees are growing upand located at the eastern edge of a catchment

is capable to send seeds to the following catchment

Scots pine over15 years-oldor black pine over 30 years-old

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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)

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the MAS conception

A territory defined by combining vegetation structures that shelter different resources according to the agents

tree + shrub + grassland

shrub + grassland

tree + shrub

grassland

tree + grassland

crop

tree

shrub

4 ha/cell

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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

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Sheep farmer (ewes/cell/year)

Productive impacts

5

0,5

1,5

2,5

0

2,5

0

5

Forester (m3/ha)

0

20 à 50

50 à 100

0

20 à 50

10 à 20

100 à 300

0

BlackPine

0

10 à 30

30 à 50

0

10 à 30

1 à 5

50 à 100

0

Scots pine

big + small trees, low density

small trees, low density

big + small trees, high density

grassland

a few big trees

a few small trees

big trees, high density

big trees, low density

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Ecological impact on protected flora

disappearance of Gagea pratensis, Adonis vernalis

disappearance of Gentiana clusii

disappearance of Orchis coriophora

disappearance of all protected species

disappearance of Gagea villosa

disappearance of Saponaria bellidifolia

no disappearance

no disappearance

small trees, low density

big + small trees, high density

grassland

a few big trees

a few small trees

big trees, high density

big trees, low density

big + small trees, low density

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Ecological impact on fauna

+ than 25 % on 6 cells

+ than 50 % on 6000 cells

+ than 10 % of pine canopy cover on 1 cell

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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

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Farmers actions

Balance

Zoning

Evaluating range condition

Grazing

Consuming forage

AdjustingAdapting grazing pressure

Intervening or not

on pine trees

Uprooting or mowingThinning or felling

Negociating or not with the partners

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Grassland

Paddock

Shrubland

Grassland with young pines

Crop

Grassland with pines

Wood

Schematic representation of a Farm

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Paddocks

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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

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Conservationists actions

Zoning

Locating zones with high heritage valueor farmers with good practices

Choosing

Moving to the most intesresting zone

Visiting other problematic cells

Scanning

Clearing

Uprooting the pine trees

Balance / survey

Deciding or not to continue to

clear pine trees

Negociating or not with the partners

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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

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Foresters actions

Balance

Inventory

Evaluating pine stands condition

Thinning and/or Harvesting

Making profit from timber production

PlanningScheduling an operation calendar

Deciding or not to go on

producing pine

Planting or not

Negotiating or not withthe partners

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7 land management strategies

let nature work let farmers and foresters worklet save the heritage hotspotslet block the ecological processLet associate naturalists and farmersLet develop silvopastoralismLet recreate the steppe

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Comparing three scenariosaccording to the “vegetation” point of view

Let Nature work

Silvopastoralismconcerted with naturalists

Let recreate the steppe

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Different points of view for a same simulation

Timber production(forester)

Cutting small pines(farmers - PNC)

Heritage interest(PNC)

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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

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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

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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 groundgrasslands and croplands shelter many

endangered species

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forest

shrublands

steppe

crops

+ +

+

+

+

Natural resources

each color corresponds to the overlapping of vegetation layers

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The farmer land

grasslands

a paddock

shrublands

grasslands spottedwith pine trees

croplands

grasslands invadedby pine trees

woodlands

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The conservationist markers

3234180

indffpratio

j coupes

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After a brief introductionto the game rules

meanwhile the PNC analysesthe land on the computer

The game setting 1

each farmer receivesa farm ...

…and moves to his tablewith an observer...

...in order to elaboratethe grazing calendar

10 minutes laterthe grazing calendar

is put into the computer

and the land dynamicsis simulated

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The game setting 2

Each farmer receivesa new map of

his farm

and thinks aboutthe strategy to develop

with the pine trees

meanwhile the PNCset up a negotiation strategy

Then for 10 minutesnaturalists, foresters

and farmers negotiate

Lastly the operationsplanned during the negotiation

are put into the computer

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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

A role playing game (RPG)...

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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

The feed-back between MAS and RPG

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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

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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

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An Approach Combining an Agent-Based Modeland a Role-Playing Game

Applied Agent-Based

model

1.Expert knowledge

Role game

2.Social validationCollective and adaptive learning

3.Collectivelydiscussed scenarios

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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

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Experiments Irrigated schemes in Senegal

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,

Environmental mediation about phytogenetics resources management in Madagascar