Ecosystem in ecology

Ecosystem ecology is the integrated study of living (biotic) and non-living (abiotic) components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.

1. Mahabubur Rahman ( Farhad ) Lecturer Department of Fisheries and Marine Science Noakhali Science and Technology University EDITED BY: Al Nahian AVRO FIMS 11th batch of NSTU Ecosystem

2. Ecosystem Any ecological unit that includes all the organisms ( i.e ., the communities in a given area) which interact among themselves and with the physical environment, so that a flow of energy leads to clearly defined trophic structure, biotic diversity and material cycle ( i.e ., exchange of materials) within the system is known as ecological system or ecosystem.

3. Kinds of ecosystem Natural Ecosystem Artificial ecosystem

4. Natural Ecosystem Terrestrial ecosystem (forests, grassland, deserts, etc.) Aquatic ecosystem Fresh water ecosystem (Lotic- spring, brook, stream and river and lentic- lake, pond, swamp) Marine ecosystems (ocean)

5. Classification of ecosystem

6. Terrestrial Ecosystem

7. Major components of terrestrial ecosystems.

8. Fresh water ecosystem

9. Marine water ecosystem

10. Artificial ecosystem

11. Natural vs Artificial Ecosystem

12. Structure of Ecosystem The structure of an ecosystem is basically a description of the species of organisms that are present, including information on their life histories, populations and distribution in space. It also includes information on the non-living features of environment, including the amount and distribution of nutrients. Abiotic or non-living components Biotic or living components

13. Abiotic or non-living components Climatic condition and physical factors (air, water, soil, temperature, light, moisture, pH etc.) Inorganic substances (water, carbon, nitrogen, sulphur, phosphorus) Organic substances (proteins, carbohydrates, lipids, humic substances, etc.)

14. 2. Biotic or living components Autotrophic component ( Auto =self, trophic =nourishing) Autotrophic component of ecosystem includes the producers or energy transducers which convert solar energy into chemical energy with the help of simple inorganic substances such as water and carbon dioxide and organic substances such as enzymes. Autotrophs are also called producers. Autotrophs fall into two groups: Photoautotrophs Chemoautotrophs

15. Photosynthesis

16. ii) Heterotrophs ( hetero =other; trophic =nourishing) Heterotrophic organisms are called consumers as they consume the matter built up by the producers. The consumers are of two main type: Macroconsumers ( Primary consumer -herbivore animals like insects, zooplanktons, deer, cattle and elephant; Secondary consumer and tertiary consumer . Microconsumers: these are also called decomposers, reducers, saprotrophs and scavangers. (Bacteria, fungi and actinomycetes)

17. Categories of Consumers primary consumers : (=herbivores) feed directly on producers; secondary consumers : (=carnivores) feed on primary consumers; tertiary consumers : feed only on carnivores; omnivores : consumers that feed on both plants & animals; scavengers : feed on dead organisms; decomposers (saprobes) : consumers that complete the breakdown & recycling of organic materials from the remains & wastes of other organisms; detritivores : feed on detritus (partially decomposed organic matter, such as leaf litter & animal dung).

18. The Importance of Decomposers

19. Pond Ecosystem

20. Abiotic component: heat, light, pH, carbon dioxide gas, oxygen gas, calcium, nitrogen, phosphates, amino acids, humic acid, etc. Biotic component: Producres: Macrophytes: These include mainly the rooted large sized plants which comprising three types of hydrophytes- floating, submerged and emergent aquatic plants ( Trapa, Typha, Nymphaea, Hydrilla, Nelumbo , etc.) Phytoplanktons : These are microscopic, floating or suspended lower plants that are distributed through out the water ( Spirogyra, Ulothrix, Zygnema, Chlorella, Closterium, Cosmarium, Volvox, Diatoms, Anabeana, Oscillatoria, Spirulina , etc.)

21. b) Macroconsumers: Herbivores (primary consumers): 1. Benthos (Fish, insect, beetles, molluscs, crustaceans etc.) 2. Zooplankton ( Brachionus, Asplanchna, Lecane, Euglena, Coleps, Dileptus, Cyclops , etc.) ii) Carnivore order-1 (Secondary consumers): insects, fish, and amphibians. iii) Carnivoe order-2 (Tertiary consumers): these are some large fish that feed on the smaller fish. Decomposers (Microconsumers): Among fungi species Aspergillus, Cladosporium, Pythium, Peniccillium, Circinella, Fusarium, Saprolegnia etc.

22. Major components of aquatic ecosystems.

23. Function of an Ecosystem Productivity of Ecosystem ( The productivity of an ecosystem refers to the rate of production, i.e., the amount of organic matter accumulated in any unit time.) Primary productivity Gross primary productivity Net primary productivity 2. Secondary productivity 3. Net productivity

24. Primary Productivity of Ecosytem 1. Gross primary productivity (GPP) is the rate at which an ecosystem's producers convert solar energy into chemical energy as biomass. 2. Net primary productivity (NPP) is the rate at which energy for use by consumers is stored in new biomass. NPP = GPP – R [rate at which producers use biomass]

25. Net Primary Productivity Estimated annual net primary productivity of major biomes & aquatic life zones, expressed as kilocalories per square meter per year. Fig. 4–24

26. Fig . illustration of the flow of matter and energy in ecosystem.

27. The transfer of food energy from the source through a series of organism by regular eating and eaten up In food chain each stage of transfer of food energy is known as trophic level Therefore trophic level refers to successive levels of energy flow that form the link of food chain Food Chain

28. Food Chain Food Chain —series of steps in which organisms transfer energy by eating and being eaten Arrows go in the direction of how energy is transferred Start with producer and end with top consumer or carnivore Ex: grass cricket frog raccoon

29. Type of food chain Grazing food chain: Common in nature. Producer form the first link , herbivores as second and secondary consumer as the third Detritus food chain: The organic waste and dead matter derived from grazing food chain is termed as detritus. Detrivores are the animal that consume detritus and in doing so contribute to decomposition and recycling of nutrient e.g. algea, bacteria, earthworms, millipedes Organism in this food chain are generally smaller, and functional role do not fall in catagories However grazing and detritus food chain are interlinked

30. Food webs It is not possible to depict the real world by means of simple food chain, because the interconnection between different trophic level in real world are extremely complex Various food chain are interlinked with each other and these interlocking pattern formed by several food chain linked together are called food web

31. Food Web — network of food chains within an ecosystem Which of the organisms above is the producer? Which of the organisms above is the top consumer? Hawks Weasels Raccoons Mice Grass

32. Ecological Pyramids An ecological pyramid is a diagram that shows the relationship amounts of energy or matter contained within each trophic level in a food web or food chain.

33. Pyramids Continued Biomass pyramids show the total amount of living tissue available at each trophic level. This shows the amount of tissue available for the next trophic level. Numbers pyramid shows the number of species at each trophic level. Energy Pyramid only 10 of the energy available within one trophic level is transferred to organisms at the next trophic level. Because each trophic level harvests only about one tenth of the energy from the level below, it can support only about one 10 th the amount of living tissue.

34. Pyramid of Numbers Pyramid of numbers displays the number of individuals at each level. 1 owl 25 voles 2000 grass plants

35. PYRAMID OF BIOMASS The total amount of matter present in organisms of an ecosystem at each trophic level is biomass. Biomass is preferred to the use of numbers of organisms because individual organisms can vary in size. It is the total mass not the size that is important. Pyramid of biomass records the total dry organic matter of organisms at each trophic level in a given area of an ecosystem.

36. Biomass Pyramids Displays the biomass at each trophic level.

37. PYRAMID OF ENERGY Shows the amount of energy input to each trophic level in a given area of an ecosystem over an extended period.

38. Energy Pyramid Fig. 4–19 In nature, ecological efficiency varies from 5% to 20% energy available between successive trophic levels (95% to 80% loss). About 10% efficiency is a general rule.

39. Diagram that shows the relative amount of energy or organisms contained within each trophic level of a food chain or web Ecological Pyramids

40. Energy Pyramid Biomass Pyramid 100% 10% 1% .1%

41. Represents amount of energy available at each level as well as amount of living tissue—both decrease with each increasing trophic level Energy and Biomass Pyramid (together)