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A Unified Modelling System for Estimating the Value of Ecosystem Services

Department of Ecosystems and Environmental Informatics

Ecology Centre University of KielGermany

Ernest Fongwa

Albrecht Gnauck

Felix Müller

Contents• Introduction

• Problems of Estimating the Value of Ecosystem Services

• Parameter for Estimating the Value of Ecosystem Services

• Petri Net Modelling Framework

• Simulation and Results

• Discussion and Conclusion

Introduction

Provisioning Service

Category Type of ES ExamplesFood Crops, livestock, fisheries, aquaculture,

wild foods etc.Water Fresh water, rivers, sea and oceans etc.Fibre Timber, cotton, hemp, silk etc.

EnergyBiomass, photosynthesis, solar-rays, oil plants, hydrothermal, geothermal, tidal wave energy, hydro-carbons, fuel wood etc.

Bio-chemicalsBiomedical plants, bio-remediation compounds, herbs, aromatics, chemical substances from plant , animals, insects and bees such as honey from bee wax, snake oil etc.

Regulating ServicesCategory Type of ES Examples

Air quality regulation

- Climate regulation:sequestration like CO2, Evapo-transpiration (precipitation)- Filtering dust particles in air- Regulation of air pollutant like NOx, SOx etc.

Water quality regulation (Surface and ground water)

Water purification, water softening etc.

Pests and diseases regulationRegulation against : parasite, fungi and bacteria invasion of human, plant and animals, air and water born diseases, exposure to poisonous substances etc.

Regulating Services

Category Type of ES Examples

Regulation of soil and erosionRegulate soil depletion through soilbuffering, removal of impurities insoil through soil shrinking, controlof wind and water erosion etc.

Natural hazards regulationStorm and flood control, control of tectonic movement in soil to reduce earthquakes and volcanic explosion etc.

Supporting Services

Category Type of ES Examples

Nutrient cycling and soil formationNutrient balancing by micro- organisms, soil formation by decomposition of dead plants and animals etc.

Crop pollination Pollination by bees, insects and other micro-organisms etc.

Support the earth surface Life on earth, platform for houses, farming, road etc.

Preserving Services

Category Type of ES Examples

Biodiversity Habitat for plant and animal species, noise reduction etc.

Development and maintenance of genetic resource against uncertainty (extinction)

Richness/abundance of genetic species, bio-refugia, hybridisation of species etc.

Cultural services

Category Type of ES Examples

Spiritual and religious valuesSecret places, inspirations, social relations (indigenous culture), sense of place (cultural identity) etc.

Recreational and ecotourismAesthetic values, monuments, sanctuaries, natural parks, natural and cultural tourism, heritage sites etc.

Unified System for Ecosystem Services • Integrating the relationships between ecological, socio-

economic, political and cultural factors in estimating the value of ES after a particular transition event at a place

• They are integrated based on environmental rules for studying the behaviours of multi-agents for policy measures

• Therefore an inventory system is required for estimating the inflow and flow of ES based on the interactions of multi-actors in a unified system

Unified System for Ecosystem Service

• A Petri net modelling framework is used to support the estimation of ES in a unified system

• It has been used to model flow systems such as in transport, business and financial systems, industrial processes, and freshwater ecology etc.

• It is a discret event modelling approach using graphical and mathematical tools

Problem of Estimating the Value of Ecosystem Services• Estimates based on ecological magnitude or transfer

benefits from other services, which can be challenging on particular places due to different catchment areas

• The inflow and outflow values or rates are not clarified making it difficult an understanding of the accounting procedures, which can be also challenging for policies

• Do not show their relationship with athropogenic factors, which influence estimates (dynamic system with many interactions of multi-agents)

Parameter for Estimating the Value of Ecosystem ServicesES- Ecosystem services

TES- Tangible ES

NTES- Non Tangible ES

ES = TES + NTES

VES- Value for ES

Adj. - Adjustment from double counting

SPU- Service production units

SAU- Service antagonising units

SU- Service units

ß- Disturbance from

VES= Σ (ES ± Adj. ± (SPU-SAU) ± ß)

or

VES= Σ (ES ± Adj. ± SU± ß)

Parameter for Estimating the Value of Ecosystem Services

St= Stock of ES

SS= Supply

Δ= Change

DD= Demand

St= Σ (VES ± (SS-DD))

ΣVES ± (SS-DD) = ΣVES ± ΔΣVES

Therefore:

ΔSt = ΔΣVES ± (SPU-SAU) ± ß

Or

ΔST = (SS-DD) ± (SPU-SAU) ± ß

Parameter for Estimating the Value of Ecosystem Services

If :

ΣSt- old stock of ES in a particular region

Then:

ΣSt ± ΔΣSt- Current stock (Phase Transition)

For environmental balancing for preserve ES:

ΔΣSt ≥

0

For environmental improvement for preserving:

ΔΣSt > 0

For environmental deficit for preserving ES:

ΔΣSt < 0

Petri Net Modelling Framework• Models based on their local environment, which are limited to local rule depending whether they are place/time/stochastic nets

Model Building

Verification of Net Properties

Properties Results

Net Class Asymmetric

Liveness Cannot decide

Boundedness Yes

Conservative Yes

Repetativeness Yes

Consistent Yes

Model Building

Verification of Net Properties

Properties Results

Net Class Free choice

Liveness Yes

Boundedness No

Conservative Partially

Repetitiveness Yes

Consistent Yes

Extended Model

Verification of Net Properties

Properties Results

Net Class Asymmetric

Liveness No

Boundedness Yes

Conservative Yes

Repetitiveness Yes

Consistent Yes

Simulation and Reults

Results

Results

Results

Discussion and Conclusion

• Anthropogenic factors are usually not integrated in estimation procedure for the value of ES

• But, they play important roles in determining the state of ES over different place and time that need to be taken into consideration

• The modelling approach show that they can be integrated in estimation methods based on an understanding of their behaviour in the supply and demand of ES

Discussion and Conclusion

• Their behaviours can be use to determine rule-based strategies for resolving concurrencies/conflicts in the demand and supply of ES,which has been envisaged

• Therefore, Petri net modelling framework can offer a good opportunity in modelling the flow of ES for inventory and decision support systems

• Since this is the first attempt in this field, there is a need for further research with Petri nets for determining possible application areas for policy measures on ES

Thanks for your Attention !