Ecosystem is system formed by the interaction of a community of organisms with their physical environment. Ecosystem can be natural or artificial. Ecosystem has both abiotic and biotic components. Ecosystem has primary, secondary and tertiary function. Human social systems and ecosystems are complex adaptive systems Ergonomics is the study of people in their working environment.

1. Introduction to Core Principles of Physiology
“Core Principle 2: Ecosystem”
College of Health Sciences
School of Medicine
Department of Medical Physiology
P.by: Habtemariam Mulugeta
ID No. GSR/2895/14
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2. “Core Principle 2: Ecosystem”
Introduction to Core Principles of Physiology
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Habtemariam M.

3. Outline
 Objectives
 Definition
 Types of Ecosystems
 Components of Ecosystem
 Function of an Ecosystem
 Human-Environmental Interactions
 Ergonomics
 Summary
 Acknowledgement
 References Habtemariam M.
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4. Objectives
When you have completed this session, you should
 Describe briefly about Ecosystem
 Differentiate the different components of Ecosystem
 Understand the functions of ecosystem
 Appreciate Human-Environmental Interactions
 Familiarize with the concept of Ergonomics
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5. Definition
 An ecosystem (or ecological system) system formed by
the interaction of a community of organisms with their
physical environment.
 The term "ecosystem" was first used in 1935 in a
publication by British ecologist Arthur Tansley.
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Chapin, F. Stuart, III (2011), Willis, A.J. (1997).

6. Types of Ecosystems
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1. Natural Ecosystem – operate themselves under natural
condition
I. Terrestrial Ecosystem
II. Aquatic Ecosystem
2. Artificial Ecosystem – operated or maintained by man.
E.g. Croplands, gardens

7. Cont.
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8. Cont.
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9. Cont.
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10. Components of Ecosystem
1. Abiotic Components
2. Biotic Components
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11. Abiotic Components of Ecosystem
 Non-Living Components
 includes basic inorganic elements and compounds, such
as soil, H2O, O2, CO2, phosphates and a variety of
organic compounds.
 It also includes physical factors and ingredients such as
moisture, wind currents and solar radiation
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12. Biotic Components of Ecosystem
 Living Components
 include all living organisms present in the environmental
system.
 can be grouped into two basic nutritive components:
 Autotrophic – All Green Plants
 Heterotrophic - Non-green plants and all animals
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13. Cont.
 Three types of Organisms
 Producers - Plants
 Consumers - Animals
 Decomposers – Microorganisms
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14. Producers
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15. Consumers
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16. Cont.
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17. Decomposers
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18. Cont.
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19. Function of an Ecosystem
1. Primary Function: manufacturer of starch
(Photosynthesis)
2. Secondary Function: distribution of energy in the form
of food to all consumers.
3. Tertiary Function: namely “cycling” – returning raw
materials to the environment
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20. Food Chain
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21. Predator
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22. Prey
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23. Food Web
 a community of organisms where there are several
interrelated food chains
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24. Human-Environmental Interactions
 It is the interactions between the human social system
and the ecosystem.
 Human social systems and ecosystems are complex
adaptive systems.
 Ecosystem Services - People modify the environment for
their purposes and obtain benefits from it.
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25. Cont.
 Ecosystem Services are essential for human well-being
and include for example the provision of resources like
water, land for farming and many more.
 people often reorganize existing ecosystems to achieve
new ones that seem to be more effective in serving their
needs.
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ISTAT, C, 2003)

26. Cont.
 Environment influences human activities.
 Human social systems have to adapt to their specific environment.
 Natural phenomena like storms, earthquakes force people to react
these phenomena which can either be directly or not primarily
caused by human actions and again influence human behavior as
people have to respond to a new situation.
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27. Ergonomics
 Ergonomics can roughly be defined as the study of
people in their working environment.
 The goal is to eliminate discomfort and risk of injury due
to work in the environment.
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international Ergonomics Association Executive Council, August 2000

28. Cont.
 Ergonomics (or human factors) is the scientific
discipline concerned with the understanding of the
interactions among human and other elements of a
system, and the profession that applies theory,
principles, data and methods to design in order to
optimize human well-being and overall system
performance.
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29. Cont.
 To achieve best practice design, Ergonomists use the data and techniques of
several disciplines:
 Anthropometry: body sizes, shapes; populations and variations
 Biomechanics: muscles, levers, forces, strength
 Environmental physics: noise, light, heat, cold, radiation, vibration body
systems: hearing, vision, sensations
 Applied psychology: skill, learning, errors, differences
 Social psychology: groups, communication, learning, behaviors.
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30. Summary
 Ecosystem is system formed by the interaction of a community of
organisms with their physical environment.
 Ecosystem can be natural or artificial.
 Ecosystem has both abiotic and biotic components.
 Ecosystem has primary, secondary and tertiary function.
 Human social systems and ecosystems are complex adaptive systems
 Ergonomics is the study of people in their working environment.
 Click Here
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31. Acknowledgement
 Firstly thanks to the almighty and Our Lord and Savior Jesus Christ
Son of the true Living God Son of Theotokos.
 Next my deepest gratitude goes to my instructor Professor Yosef
Mengesha (MD, PhD) who gave me this chance to prepare and
present on Core Principle of Physiology 2: Ecosystem.
 Finally I thank you my classmates since you listen to me attentively
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32. References
 Chapin, F. Stuart, III (2011). "Glossary". Principles of terrestrial ecosystem ecology. P.
A. Matson, Peter Morrison Vitousek, Melissa C. Chapin (2nd ed.). New York: Springer.
ISBN 978-1-4419-9504-9. OCLC 755081405.
 Willis, A.J. (1997). "The Ecosystem: An Evolving Concept Viewed Historically".
Functional Ecology. 11 (2): 268–271. doi:10.1111/j.1365-2435.1997.00081.x.
 ISTAT, C.Costantino, F. Falcitelli, A. Femia, A.Tuolini, OECD-Workshop, Paris,
May14,16, 2003)
 international Ergonomics Association Executive Council, August 2000
 Worku Legesse, B.Sc.,M.Sc., Ph.D., Teklu Mulugeta, B.Sc., Aragaw Ambelu, B.Sc
Carter Center Introduction to Ecology Habtemariam M.
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33. Thank You
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