Emergy Approach in Determining the Carrying Capacity of Ecosystems Daeseok Kang Ecological Engineering Program Pukyong National University

Purification Habitats Aesthetics Fisheries Flood Control Ecosystem Products and Services  Example : Coastal wetlands

Economic Use of Ecosystems

Real Wealth and Monetary Value  Willingness-to-Pay for market and nonmarket goods and services  Money is only paid to humans

Economic Use of Ecosystems

EMERGY - Energetic Approach in Valuation  Energy Memory, Energy History  Use energy as a common currency to compare vastly different resources  Definition: Available energy of one kind previously required directly and indirectly to make a product or service (Odum, 1996)  Ecological approach in evaluating contributions of natural resources to the real wealth of our economy An effort to include both human efforts and nature’s work put into the production of natural resources

Emergy and Transformity Calculation  Different ability to do work – Conversion factors required

Emergy Valuation and Economic Valuation

Donor Value vs Receiver Value Source : Odum (1996)

Energy Systems Language  Model : A simplified picture of reality A way of representing network properties of complex and dynamic systems  Symbolic modeling language that represents network organization of systems and their properties Top-down systems modeling tool (Holistic approach) Symbols with specific meanings Energetics and kinetics Mathematical relationships between symbols → Equations for computer simulation program

Energy Systems Language  Symbols of the energy systems language

Definition of Carrying Capacity in Emergy Term  Brown and Ulgiati (2001) Environment’s ability to supply the required emergy  Environment’s ability to provide necessary resources for a population and economic endeavor Renewable carrying capacity : lower limit Carrying capacity supported by nonrenewable energies : upper limit

Emergetic Estimations of Carrying Capacity of Ecosystems SystemType Reference Resort developmentSupport areaBrown and Ulgiati(2001) Scuba divingNumber of peopleSerour(2004) Uninhabited islandsNumber of peopleMOMAF(2005) Bay ecosystemFishery productsEum et al. (1996) PopulationNumber of peopleOdum(1996) and others

Case 1 – Deukryang Bay Ecosystem, Korea Area : 37,450 ha

Case 1 – Deukryang Bay Ecosystem, Korea  Eum et al., J. Korean Fish. Soc., 29:  Carrying capacity of the bay ecosystem at the current management level Renewable emergy input / transformity Type Carrying Capacity (ton/yr) Production(1994) (ton/yr) Fishes1, Crustaceans Shellfish1,5531,229 Seaweeds9,0747,619

Case 2 – Seaweed mariculture (preliminary) Area : 4,939 km 2

 Energy systems diagram for seaweed mariculture - Sea tangle, Brown seaweed, Laver Case 2 – Seaweed mariculture (preliminary)

No.Item Raw Units Solar Transfomity (sej/unit) Solar Emergy (sej/yr) Emvalue (Em\) Environmental Input 1Sun2.27E+19J/yr12.27E E+09 2Wind, kinetic energy5.88E+16J/yr E E+10 3Rain, chemical4.34E+16J/yr E E+11 4River, chemical1.64E+15J/yr E E+10 5Tide4.02E+16J/yr E E+11 6Wave1.20E+16J/yr E E+11 Total Env. Emergy Input 4.43E E+11  Emergy evaluation table Case 2 – Seaweed mariculture (preliminary)

 Emergy sustainability index = EYR / ELR (Brown and Ulgiati, 1997) ESI < 1 : Highly developed consumer oriented economy 1 < ESI < 10 : Developing economies ESI > 10 : Endeveloped economies  Emergy yield ratio (EYR) Total emergy of products / purchased emergy from outside higher EYR → more competitive of an economy or process  Environmental loading ratio (ELR) Degree of environmental stress caused by socioeconomic activities (Outside emergy + internal nonrenewable emergy) / internal renew able emergy Low ELR → less impact on the environment Case 2 – Seaweed mariculture (preliminary)

 Carrying capacity of seaweed mariculture grounds at current investment and management levels Renewable emergy input / transformity of each seaweed Emergy sustainability index > 1 Item Mariculture area (ha) Carrying capacity (M/T) Production(2006) (M/T) Sea tangle1, ,60074,626 Brown seaweed1, ,40086,220 Laver10, ,80030,503 Case 2 – Seaweed mariculture (preliminary)

 Emergy concept and methodology as a holistic approach for the combined system of ecology and economy A way of estimating the carrying capacity of the Yellow Sea  More ecosystem parameters such as primary productivity and nutrient inputs, etc  More detailed management costs required for transformity calculations  Emergy indices for specific ecosystems or ecosystem uses Emergy yield ratio Environmental loading ratio Emergy sustainability index Future directions