Biotic Factors in an Ecosystem

Dr. K. Rama Rao
Govt. Degree College
TEKKALI; Srikakulam Dt. A. P

1. Biotic factors are the living components of an ecosystem. They are sorted into three groups’ i . e., Producers or autotrophs , Consumers or heterotrophs , and Decomposers or detritivores .

2. 1. Producers Producers – also known as autotrophs , from the Greek words “auto” for “self” and “ troph ” for “food” – are organisms that make their own food using inorganic materials and energy sources.

3. A.  Photoautotrophs : These are the most common type of producers   on Earth today. These producers harness energy from sunlight to power their life functions . Green plants, green algae, and some bacteria are photoautotrophs .

4. Most photoautotrophs use a pigment, such as chlorophyll, to catch photons from the Sun and harvest their energy. Protists :   Protists generally are one-celled microscopic organisms in the ecosystem. Plant-like protists use photosynthesis, so they are producers.

5. Protists

6. Animals such as paramecia and amoebas eat bacteria and smaller protists , so they form part of the food chain. Chemoautotrophs are fairly rare in most ecosystems. They obtain energy from chemicals such as hydrogen, iron, and sulfur, which are not common in most environments.

7. Example: S ulfur-oxidizing bacteria, Nitrogen-fixing bacteria  Iron-oxidizing bacteria and Cyanobacteria

8. B. Plants:   Most ecosystems depend on plants to perform photosynthesis, making food from water and carbon dioxide in the ecosystem . In ponds, lakes and the ocean, many of the plants are grasses, algae or tiny phytoplankton floating on or near the surface.

9. Algae

10. 2. Consumers Consumers, also called “ heterotrophs ,” are organisms that eat other living organisms in order to obtain energy. Herbivores who eat plants, carnivores who eat animals, and omnivores who eat both plants and animals, are all heterotrophs .

11. Animals:  First-order consumers like mice, rabbits and seed-eating birds as well as zooplankton, snails, mussels, sea urchins, ducks and black sharks eat the plants and algae. Predators like Bobcats, bears, Killer whales and Tiger sharks eat first-order consumers. Omnivores like bears and rotifers (nearly microscopic aquatic animals) eat both plants and animals.

12. 3. Decomposers Decomposers or detritovores are organisms that use organic compounds from producers and consumers as their source of energy. They are important to ecosystems because they break down materials from other living things into simpler forms, which can then be used again by other organisms.

13. Decomposers include soil bacteria, fungi, worms, flies, and other organisms that break down dead materials or waste products from other life forms. They are distinct from consumers, because consumers usually consume other organisms while they are still alive.

14. Fungi:  Fungi like mushrooms and slime molds feed off the bodies of living hosts or break down the remains of once-living organisms. Fungi serve an important role in the ecosystem as decomposers.

15. Bacteria:  In deep-sea vents, chemosynthetic bacteria fill the role of producers in the food chain. Bacteria act as decomposers, breaking down dead organisms to release nutrients. Bacteria also serve as food for other organisms.

16. A healthy woodland ecosystem contains producers like grasses and trees, as well as consumers ranging from mice and rabbits to hawks and bears. The biotic components of an ecosystem also encompass decomposers like fungus and bacteria.

17. Woodland ecosystem

18. A healthy aquatic ecosystem includes producers like algae and phytoplankton, consumers like zooplankton and fish, and decomposers like bacteria.

19. Aquatic ecosystem