Potential of social-ecological modelling to understand dynamics of pastoral land use

under processes of change

Birgit Müller, Gunnar Dressler, Felix John

ADRAS-Workshop ILRI, June 2015

Content

1. Junior Research Group POLISES

2. Methods: Social-ecological modelling

3. Study 1: Stylized modelling study: Side effects of rain-index insurance on sustainable land use

Study 2: Polarisation between pastoralists

Study 3: Multi-agent model on pastoral land use of Borana

4. Further ideas for collaboration (Social networks, Board game on nomadic land use)

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Junior Research Group POLISES: „Global food security policies and their social-ecological side effects in regions prone to global change”

Team: Head + 2 PhDs Postdocs, foreign fellowsDuration: Aug 2014 – July 2018 (+ 1 year)Funding: By German Ministry of Research (1.3 Mio €)

Objectives• explore the impacts of global food security policies on local land use

strategies• investigate the resulting social-ecological resilience of land users (in

particular pastoralists) in Africa• focus on combined effects of different processes of global change• advance the design of such policies to be appropriate for the most

vulnerable groups

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Global food security policies

Locally installed instruments to enhance food security

Environmental instruments

Land policies instruments

Instruments to cope with risk

Combined effects of global change (e.g. climate change, demographic change, environmental change)

Other land user

Pastora-list

Pastora-list

Natural resources

Loca

l Sys

tem

1

Mor

occo

, 2 E

thio

pia/

Keny

a

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5/18

Methodological approach

• Social-ecological modellingAgent-based modelling

• Modelling human decisions

• Social network analysis

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Methodological approach:Social-ecological modelling

1. Exploration of behaviour of social-ecological system in time and space

2. Including the feedbacks between the social and ecological components and understand mechanistic functioning

3. Virtual lab: Systematic analysis of combined effects of global change processes (turn processes on/off)

Stylized model / “Toy model”

4. Behaviour of land users can be modelled more realistically: adaptation, interaction, learning

Rule-based simulation models

Agent-based model

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Our modelling strategy: Start with simple model and add complexity step by step

Decision criteria /

strategy choice

Social-ecological system

ClimatePrecipitation

Institutions Insurances /

Access regimes / …

Technologies Trucks /

Fodder supplements /…

Livestock Sheep

Agents Pastoralist households

VegetationEcological Model

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Ecological submodelClimate

Vegetation

precipitationlognormal distribution

Livestock Sheep

green

biomass

reserve

biomass

growth

rain / grazing history

feeding reproductionforage

grazing

curr

ent

rain

fall

Ecological-economic study:Role of resting in rainy years• Natural insurance• Investment in the future

Müller et al. 2007 Agricultural Systems

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Fair insurance i - Payment of insuranceb - Insurance primep* - Strike level of insurance

z.B. wenn Regen unter 75% des langjährigen Mittels fällt

Without insuranceWith insurance

Opti

mal

frac

tion

of re

sting

α in

%

strike-level of the insurance in % of MAP

Results:1. The higher the strike level … the less resting … the lower the sustainability in the long-term

Müller et al. 2011, Ecological Economics2. If strike level low enough: Unintended side-effects avoided

ifif

Study 1: (Side) effects of index-insurances

One agent, homogeneous pastureDecision rules: Expected utility

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Study 2 - Polarisation: Multi-agent model

• Inspired by Moroccan case study

• Temporal structure: Discrete, yearly time steps, time horizon = 100 years

• Spatial structure: patch network on a hexagonal grid

• Dynamic feedback between ecological and economic component

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Study 2 – Polarisation: Approach

Diploma Thesis: Falk Hoffmann

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Stepwise add types of heterogeneity

0. Homogeneous rainfall1. Spatial heterogeneous rainfall

Agent heterogeneity:2. High / low mobility agents

(low costs / high costs)3. Plus different initial herd size4. Plus different initial cash savings

D. Kreuer

Study 2 - Polarisation: Results & Next steps

Case 1: If vegetation resilient Initial conditions of agents differ + different mobility costs

No polarisation

PolarisationCase 2: If vegetation less resilient Combined effect of heterogeneous mobility costs+ Heterogeneous initial herd sizes

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Currently carried out: Systematic sensitivity analysisNext step: Investigate measures against polarisation

Study 3: Multi-agent model on pastoral land use of Borana – Pastoralists

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Central village patch

Permanent remote patch

Dry season Rainy season

Herd movement

Once per season(4 seasons per year)

Dry season, if rain sufficient

Temporary remote patch

In cooperation with Russell Toth

Study 3: Multi-agent model on pastoral land use of Borana – Pastoralists

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Model reproduces boom and bust cycles of herd sizes

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First version of index-insurance implemented

Study 3: Research questions for Borana model

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1. Under what conditions is mobile pastoralism sustainable, in the absence of insurance?

2. How does the uptake of insurance influence livestock numbers and vegetation conditions over the long term?

3. How does the design of the insurance influence uptake, and therewith the livestock numbers and vegetation conditions ?

4. What is the impact of change of weather conditions ( climate change) on these outcomes?

5. What is the impact of other institutional changes – e.g., land use restrictions?

R. Toth

Further research topics for collaboration

1. Crowding out of social networks by microinsurances

Abstract model: Use of social network analysis coupled with multi-agent model of pastoral

system

2. Educational games: Board game NomadSed

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NomadSed: A board game on sustainable land use of mobile pastoralists under global change

1. Educational purposes • Insights in coupling

environment & livelihood• Challenges of nomadic life

2. Science-society interface

Use of the game:

In cooperation with Vétérinaires sans Frontières Germany

Project days in schools„Long night of sciences“Exhibition at museum University education (national & international)

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Key messages

Use of stylized models not for predictionas tool for thinking, interdisciplinary communication and hypothesis testing:

• Rise awareness of unintended side effects• Inspire discussions with policy makers, insurers, scientists and other

stakeholders• Advice: If new policy instruments are designed – monitor impact on land use

strategies

Use of agent-based models:

• Include human-decision making in more realistic way than standard economic approaches incorporation of social learning, diffusion of innovations

• Explicit incorporation of feedbacks between socio-economic and ecological system components

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Thanks for your attention

And to cooperation partners:

Russell Toth (University of Sydney)Brigitte Kaufmann (German Institute for Tropical and Subtropical Agriculture)Mohamed Mahdi (École Nationale d‘ Agriculture Meknès, Morocco)

More information: www.polises.de