University at Buffalo Engineering for Ecosystem Restoration Summer Workshop Series 25 June 2010 David Blersch Dept. of Civil, Structural and Environmental Engineering University at Buffalo

Systems and Ecosystems What is a system? A system is a group of parts which are connected and work together. Systems with living and nonliving parts are called ecosystems (short for ecological system) (Odum, Odum, and Brown, 1997) What is an ecosystem?

Some definitions of “ecosystem” Classic: A dynamic set of living organisms (plants, animals and microorganisms) all interacting among themselves and with the environment in which they live (soil, climate, water, and light). A biotic and functional system or unit which is able to sustain life and includes all biological and non-biological variables in that unit (Jorgensen and Bendoriccio 2001). A community of species interacting to process energy and nutrients through a complex of foodwebs (Adey and Loveland (2007)). A network of biotic (species populations) and abiotic (nutrients, soil, water, etc.) components found at a particular location that function together as a whole through primary production, community respiration, and biogeochemical cycling (Kangas (2004)). An organized system of land, water, mineral cycles, living organisms, and their programmatic behavioral control mechanisms. (Odum 1994).

Properties of Ecosystems An ecosystem… Is the fundamental unit of ecology (?)… Is the “exquisite potential of the universe.” (Adey and Loveland 2007) Is conservative of matter and energy Performs energy capture and transformation Performs mineral retention and cycling Has rate regulation and control Organizes towards production and respiration balance

Thermodynamic Laws First Law of Thermodynamics (Law of Conservation) The total energy of any system and its surroundings is conserved (i.e., Energy is neither created nor destroyed, it changes from one form to another). Second Law of Thermodynamics (Entropy Law) The entropy change of any system and its surroundings, considered together, resulting from any real process, is positive and approaches a limiting value of zero for any process that approaches irreversibility (i.e., for any real process, some energy is lost as waste heat).

Energetic basis for ecosystems Waste Heat Less total energy at each level

Grazers Plants Sun Carnivores Hierarchy: Food Chains and Pyramid Charts Embodied energy at each level

Rudimentary Systems Diagrams Odum 1956

“Electrical” Analog

“Pulmonary” analog

Using a Systems Language Why a systems language? To convert non-quantitative verbal models to… more quantitative, more accurate, more predictive, more consistent, and less confusing network diagrams. Understanding systems… Understanding environment and society as a system means thinking about parts, processes, and connections. To help understand systems, it is helpful to draw pictures of networks that show components and relationships.

Energy Circuit Diagrams From Odum (1994)

Multiplier or Work Gate A B AxB HEAT SINK: A pathway for dissipated energy necessary for any real process.

Autocatalytic unit A stored quantity is used in a feedback loop to interact as a multiplier with the input energy source of that quantity. Maximum Power Principle: Systems prevail that develop designs that maximize the flow of useful energy (Lotka, 1922) “Self-organization selects network connections that feed back transformed energy to increase inflow of resources or use them more efficiently.” (Odum and Odum 2001)

Conventions

Typical Energy Sources Odum (1994)

Hierarchical arrangement of systems

Putting it together Simple Production-Consumption cycle

Systems Model: Aquatic system Odum (1994)

A forest ecosystem…

More complexity

Even more complexity… Nested models…

Your turn… 1 st Annual Ecosystem Model Scavenger Hunt!

Procedures for Circuit Diagramming 1. Draw the frame of attention that selects the boundary 2. Make a list of the important input pathways that cross the boundary 3. Make a list of the components believed to be important 4. Make a list of the processes believed to be important within the defined system. 5. Remember that matter is conserved. 6. Check to see that money flows form a closed loop within the frame and that money inflows across the boundary lead to money outflows. 7. Check all pathways to see that energy flows are appropriate. 8. If a complex diagram has resulted (> 25 symbols), redraw it to make it neat and save it as a useful inventory and summary of the input knowledge. Redraw the diagram with the same boundary definition, aggregating symbols and flows to obtain a model of the desired complexity (perhaps symbols). 9. Conventions:

References Abrams, P., B.A. Menge, G.G. Mittelbach, D. Spiller, and P. Yodzis The role of indirect effects in food webs. Pp In: Food Webs: Integration of Patterns and Dynamics. G.A. Polis and K.O. Winemiller (eds.). Chapman & Hall, New York. Adey, W.H., and K. Loveland Dynamic Aquaria: Building and Restoring Living Ecosystems (3 rd Edition). Academic Press, San Diego, California. Gerardin, L Bionics. McGraw-Hill, New York. Jorgensen, S.E., and G. Bendoricchio Fundamentals of Ecological Modelling (3 rd Edition). Elsevier Science, New York. Kangas, P.C Ecological Engineering: Principles and Practice. Lewis Publishers, Boca Raton, Florida. Odum, H.T Ecological and General Systems: An Introduction to Systems Ecology. University Press of Colorado, Niwot, Colorado. Odum, H.T., and E.C. Odum Modeling for All Scales: An Introduction to System Simulation. Academic Press, San Diego, California.