Environmental Studies - 4 (Introduction to Ecosystem)

This is Presentation 4 in the Environmental Studies series. It provides a comprehensive introduction to ecosystems, including their types and components, structure and functions, food chains and food webs, biogeochemical cycles, and energy flow. This presentation is tailored for Semester 3 MSc.IT (Integrated) students.

Read more on Environmental Studies-
https://www.slideshare.net/slideshow/environmental-studies-1-introduction/270461474
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https://www.slideshare.net/slideshow/environmental-studies-3-introduction-to-environment/270462075
https://www.slideshare.net/slideshow/environmental-studies-4-introduction-to-ecosystem/270462739
https://www.slideshare.net/slideshow/environmental-studiee-5-basics-of-environmental-degradation/270464541

1. Course Code: Course Name: Environmental Studies with focus on Indian Practices Unit No: 1 (PPT 4) Unit Name: Introduction to Environmental Studies SEMESTER: 3 IMSc.IT Prepared by: A/P Jheel Barad Silver Oak College of Computer Applications (SOCCA)

2. ECOSYSTEM Structure, Function & Services

3. Definition : The living community of plants and animals in any area together with the non- living components of the environment- soil, air and water- constitute the ecosystem Ecosystem includes all the living thing (plants, animals and organisms) and nonLiving things in a given area . The interaction of living organisms and nonliving environment (sun, soil and air) produces a stable self sustained system which is called the ecosystem. Ecosystem can be defined as natural self supported system in which there is proper interaction between living organism and their nonliving environment. Ecosystem may be natural ecosystem like forest, lake, desert, grassland, pond, etc., while examples of man made ecosystems are aquarium, crop field, etc.

4. Terrestrial Ecosystem Forests Tropical Rainforests: Located near the equator, high biodiversity, warm and wet year-round. Temperate Forests: Found in temperate regions, distinct seasons, deciduous trees. Grasslands Savannas: Tropical or subtropical regions, scattered trees, seasonal rainfall. Temperate Grasslands (Prairies, Steppes): Found in temperate regions, dominated by grasses, few trees. Deserts Hot Deserts: Extremely dry, high temperatures during the day, cold nights, sparse vegetation. Cold Deserts: Found in high altitudes or latitudes, cold temperatures, limited precipitation. Tundra Arctic Tundra: Located near the poles, cold and dry, permafrost, low biodiversity. Alpine Tundra: Found at high mountain elevations, similar conditions to Arctic tundra, but no permafrost.

5. Aquatic Ecosystem Freshwater Ecosystems Lakes and Ponds: Standing water bodies, varying sizes and depths, support diverse life forms. Rivers and Streams: Flowing water bodies, varying speeds and volumes, crucial for nutrient transport. Wetlands: Areas where water saturates the soil, high biodiversity, important for water purification and flood control. Marine Ecosystems Oceans: Vast saltwater bodies, cover 70% of Earth’s surface, support a wide range of marine life. Coral Reefs: Found in warm, shallow ocean waters, high biodiversity, built by coral polyps. Estuaries: Where freshwater meets saltwater, highly productive, support diverse species.

6. Structural Components of Ecosystem Biotic Abiotic Primary Producers Herbivorous Carnivorous Omnivores Detritivores/ decomposers etc. Sunlight Temperature Precipitation Water Moisture Soil Inorganic & Organic Substances

7. Producers (Autotrophs- self- nourishing) Convert solar energy into chemical energy (food) via photosynthesis. e.g.:Plants, algae, and some bacteria. Consumers (Heterotrophic- nourish on others) 1. Primary Consumers (Herbivores)- Eat producers (plants and algae). - Examples: Rabbits, deer, and caterpillars. 2. Secondary Consumers (Carnivores)- Eat primary consumers. - Examples: Wolves, birds, and frogs. 3. Tertiary Consumers (Top Carnivores)- Eat secondary consumers. - Examples: Eagles, sharks, and lions. Decomposers (Saprotrophs) feed on the dead and decaying organisms)- Break down dead organisms and waste, returning nutrients to the soil. E.g.: Bacteria, fungi, and earthworms.

8. Structure of Ecosystem

9. Video on Ecosystem

10. Functions of Ecosystem Food Chain Food web Biogeochemical cycles Video on food chain and food web

11. The Energy Flow Energy flow in ecosystem refers to the transfer and consumption of energy that takes place within a food chain. Every ecosystem has several interrelated mechanisms that affect human life. Theses are various cycles, each ecosystem is controlled by these cycles.

12. Biogeochemical Cycle The major biogeochemical cycles are as follows: Water Cycle or Hydrologic Cycle Carbon-Cycle Nitrogen Cycle Oxygen Cycle Phosphorus Cycle Sulphur Cycle The term biogeochemical is derived from ‘bio’ meaning ‘biosphere’, ‘geo’ meaning ‘the geological components’, and ‘chemical,’ meaning the elements move through a cycle. ‘A pathway by which a chemical substance move through biotic and abiotic compartments of Earth.’ The cycles are responsible for maintaining life on Earth. If humans disturb these cycles beyond the limits that nature can sustain, they will eventually breakdown and lead to a degraded earth on which we will not be able to survive

13. Water cycle or Hydrologic cycle Evaporation: Water from oceans, rivers, and lakes turns into vapor. Condensation: Water vapor cools and forms clouds. Precipitation: Water falls back to Earth as rain, snow, sleet, or hail. Infiltration: Water soaks into the soil, replenishing groundwater. Runoff: Water flows over land into bodies of water. Transpiration: Water is absorbed by plants and released into the atmosphere. VIDEO

14. Carbon Cycle Photosynthesis: Plants convert CO2 into organic matter using sunlight. Respiration: Organisms release CO2 back into the atmosphere by breaking down organic matter. Decomposition: Decomposers break down dead organisms, releasing carbon back into the soil and atmosphere. Combustion: Burning fossil fuels and biomass releases CO2. Ocean Uptake: Oceans absorb CO2 from the atmosphere and store it as dissolved carbonates. Too much carbon removed: Atmosphere cools. Too much carbon added: Atmosphere warms. VIDEO

15. Nitrogen Cycle Nitrogen Fixation: Conversion of atmospheric nitrogen (N2) into ammonia (NH3) by bacteria or lightning. Nitrification: Ammonia is converted into nitrites (NO2-) and then into nitrates (NO3-) by bacteria. Assimilation: Plants absorb nitrates and use them to build proteins. Ammonification: Decomposers convert organic nitrogen back into ammonia. Denitrification: Bacteria convert nitrates back into N2, releasing it into the atmosphere. VIDEO

16. NH4- Ammonium NH3- Ammonia NO2- Nitrite NO3- Nitrate

17. Oxygen Cycle Photosynthesis: Plants release oxygen into the atmosphere as a by-product of converting CO2 into organic matter. Respiration: Animals and plants use oxygen to break down organic matter, releasing CO2. Decomposition: Decomposers use oxygen to break down dead matter, releasing CO2. Ozone Formation: Oxygen molecules (O2) are converted to ozone (O3) in the stratosphere, protecting Earth from harmful UV radiation. VIDEO

18. Phosphorus Cycle Weathering: Rocks containing phosphate minerals break down, releasing phosphorus into the soil and water. Absorption by Plants: Plants absorb phosphate from the soil, which is essential for their growth and development. Consumption by Animals: Animals obtain phosphorus by eating plants or other animals. Decomposition: When plants and animals die, decomposers return phosphorus to the soil. Sedimentation: Phosphorus can be washed into water bodies, where it settles into sediments and eventually forms new rocks. VIDEO

19. Sulphur Cycle VIDEO Mineralization: Organic sulfur is converted into inorganic forms like hydrogen sulfide (H2S), elemental sulfur (S), and sulfate (SO4^2-) by bacteria. Oxidation: H2S is converted into sulfate by bacteria, which plants can absorb and use. Absorption by Plants: Plants take up sulfate from the soil and incorporate it into proteins. Consumption by Animals: Animals obtain sulfur by consuming plants or other animals. Decomposition: Decomposers break down dead organisms, releasing sulfur back into the soil as sulfate. Volcanic Activity: Volcanic eruptions release sulfur dioxide (SO2) into the atmosphere, which can form sulfate aerosols. Atmospheric Deposition: Sulfur compounds in the atmosphere can return to the soil and water through precipitation.