1. Presented by Ecosystem concepts Dr.B.Victor

2. Concepts of Ecology Definition Ecology is the scientific study of interaction between living systems and their environment Objective Ecology discovers and understands the relationship between living things and their environment

3. More Definitions Hilaire, 1835 -Milieu ambient (French) Haeckel, 1866 – Science associated with life Elton, 1927 – Scientific natural history Shelford, 1929 – Science of communities Andrewartha, 1961 – Study of the distribution and abundance of organisms Odum, 1963 – Study of structure and functions of nature

6. Branches of Ecology Habitat ecology Desert ecology Grassland ecology Freshwater ecology Forest ecology Cropland ecology Marine ecology Population ecology Community ecology Ecosystem ecology Production ecology Conservation ecology Radiation ecology Palaeoecology Gene ecology Systems ecology Microbial ecology

9. Ecological System Concept (Concept of Ecosystem) Ecosystem is the basic structural and functional unit of ecology. “ Ecosystems are the basic units of nature on the face of the earth”. An ecosystem is an ecological unit, or a subdivision of the landscape, or a geographic area that is relatively homogeneous and reasonably distinct from adjacent areas. J.W. Marr, 1961 Tansley, 1935 Definition

11. Components of an Ecosystem Abiotic components- (geographical, climatic, physicochemical characteristics) B iotic components- (Plants, animals, microbes)

12. Ecological Cycle

13. Ecosystem Structure

15. Specific influence of human beings on sensitive Ecosystems Mountain ecosystem – Removal of forest cover Evergreen forests – Over exploitation of forest resources Coral reefs – Human interference, Dynamite fishing River ecosystem – Pollution Land ecosystem – Dumping solid wastes

17. Systems Biology A biology that sees an organism as a living system rather than a machine. Systems theory It looks at the world in terms of the interrelatedness and interdependence of all phenomena. Systems thinking is process thinking System defined A system is an object that is made up of subsystems or components, which interact in such a way that they have collectively a wholeness.

19. Inputs Outputs Simple System Model System

22. Positive feedback Set point Negative feedback Deficiency Excess Negative feedback Death Positive feedback Death Homeostatic Plateau A Cybernetic system of Ecosystem Regulation

23. Systems Concept Nutrients Gases H 2 O Radiant Energy Nutrients Gases H 2 O Bio-systems Producers  consumers Decomposers (Cycling of energy and matter) Outputs Inputs

24. Biotic component 1 Biotic component 2 Biotic component 3 Input Output Ecosystem Output Input Output Input Output Nutrient Flow model

25. System X Y Z Subsystem X Subsystem Y Subsystem Z Inputs Outputs Open system with components

26. Series open system components Plant Cow Man Input Sunlight Output - Input Chemical energy in leaves Output - input Chemical energy in meat of cow Output Heat given off during

27. Features of an open system Open systems process inputs and produce outputs The amount of output produced is directly related to the amount of input received.

30. Biological Systems Hierarchical System Genetic systems Cell systems Organ systems Organismic systems Population systems Ecosystems

31. Dynamics of ecosystems Bio-systems Energy, Gases inorganic matter water organisms Subsystems Plants  animals Microbes Energy Nutrients Gases Inorganic matter Inputs Outputs

32. Gaseous Nutrient cycles Sedimentary nutrient cycles Biogeochemical cycles and population – Evolution spiral Outputs Heat radiated into space Inputs Sunlight (energy) The earth as a single system Earth Ecosystem

34. Functional aspects Inputs Energy, Nutrients, Gases, Inorganic matter Photosynthesis Herbivory Carnivory Decomposition Energy Nutrients Gases, Inorganic matter Outputs Biosystems

35. Energy flow in an Ecosystem Solar energy Photosynthesis Solar energy is converted to chemical energy Respiration Chemical energy is used to do work Ecosystem Degraded Waste Energy

36. Primary Production Phototrophs (Plants) – The rate of photosynthesis per unit of time. Gross Production – Quantity of organic matter produced per unit of time. Net Production – Gross P – metabolic losses (respiration, excretion) Secondary Production All biomass produced per unit of time by organisms called consumers.

38. Production (Stored biomass) Gross Production Producers Photosynthetic Production Secondary Production Respiration Decomposers Consumers and Decomposers Respiration Tissue growth Relationship between plant and animal production Respiration Tissue growth

42. Ecosystem goods and services Direct values Consumptive use value – Non-market value of fruits, fodder, firewood, small timber etc. (People collect them from their surrounds and use them) Productive use value – Commercial value of timber, fish, medicinal plants etc. ( People collect for sale)

44. Ecological Pyramids Pyramid of numbers : No of individuals at each trophic level Graphic representation of tropic structure and function of an ecosystem. Hawks Hyperparasites (microbes) Frogs Parasites (Lice, bugs) Insects Birds Grasses Tree s

45. Pyramid of biomass: Total biomass (dry matter) at each tropic level Fox Rabbit Herbs Pyramid of energy: Amount of energy present at each trophic level. Top Carnivores Carnivores Herbivores Producers

46. Energy relationship

47. Energy cycle

48. Nutrient cycling

49. Cycling of DDT

51. Hydrologic cycling

52. Biogeochemical Cycling

53. Functional Attributes Food chains The sequence of feeding relationships in an ecosystem is called food chain. Trophic structure Each organism in the ecosystem is assigned a feed level or trophic level.

54. Simple food web model Producer : Pond grass Herbivore : Water insects Carnivore : Large fish Herbivore : Small fish Carnivore : Duck Top Carnivore : Man

55. Sunlight Producer Carnivore Herbivore Heat Produced Decomposers Simple Food – Chain Model

58. Kinds of Ecosystems Ecosystem Terrestrial Aquatic Man-engineered e.g. Forest, Desert Grassland, Steppe, Savanna e.g. Agricultural land use, Urban / industrial land use Freshwater Marine Lenti c Lo t ic e.g. Ponds, Lakes e.g. Streams, Rivers Coastal ecosystems Mangrove ecosystems Seagrass ecosystems Coastal lagoon ecosystems Coral reef ecosystems Delta ecosystems Estuarine ecosystems Sandy beach ecosystems Rockyshore ecosystems Coastal upwelling ecosystems

59. Ecosystems

60. Forest Ecosystem 1. Abiotic Component Amount of rainfall and local temperature varies according to latitude, and altitude. 2. Biotic Component Plants – trees, shrubs, climbers and ground cover. Animals – mammals, birds, reptiles amphibians, fish insects and microscopic animals.

65. Desert ecosystem 1. Abiotic components – High temperature, low rainfall dry climate. 2. Biotic components Producers – Shrubs, bushes, grasses, few trees. Consumers – Insects, reptiles, birds, camels. Decomposers – Fungi, bacteria.

66. Aquatic ecosystem 1. Abiotic components – Temperature, light, pH, organic and inorganic matter. 2. Biotic components Producers – Macrophytes, Phytoplankton. Consumers – Zooplankton (insects, fish), Herbivores. Decomposers – Bacteria, Fungi.

69. Outputs City Ecosystems Inputs Typical urban ecosystem model

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