Ecology M. Saadatian Food chain - PowerPoint Presentation

1. Ecology M. SaadatianFood chain &Ecological pyramids1

2. Food chain &Ecological pyramids

3. Important facts about food chainsIn a food chain each organism obtains energy from the one at the level below.Plants are called producers because they create their own food through photosynthesisAnimals are consumers because they cannot create their own food, they must eat plants or other animals to get the energy that they need.

4. There are two types of food chainsGrazing food chain Detritus food chain Grazing food chain – it starts from green plants (autotrophs or producers) and ends to carnivores by passing through herbivores. Thus, the gross production of plants may need three fates. The grazing food chain is of two types, namely, Predator chain Parasitic chain

5. Predator chain – here one animal captures and devours another animal. The animal, which is being eaten, is called prey and the animal, which eats it, is called predator. The predator chain is formed of plants, herbivores, primary carnivores, secondary carnivores and so on. Parasitic chain – the plants and animals of the grazing food chain are infected by parasites. When the smaller organisms (parasites) consume larger ones without outright killing of the host, the food chain is called parasitic food chain.

6. Detritus food chain – the organic wastes, exudates and dead matter derived from the grazing food chain are usually called detritus. The energy contained in this detritus serves as the source of energy for a group of organisms (detritivores) that are separated from the grazing food chain and generally termed the detritus food chain. The organisms of the detritus food chain are algae, bacteria, actinomycetes, fungi, protozoa, insects, mites, crustacea, nematodes, etc. the detritus organisms gradually break down the complex organic molecules present in the organic waste or dead tissues into much simpler compounds (humic acids).

7. Primary ProducersPrimary producers are “organisms capable of producing their own food”We can also say that they are photosynthetic, use light energy. Examples of primary producers include algae, phytoplankton, and large plants.Primary producers are eaten by primary consumers (herbivores)

8. Ways to Classify ConsumersPrimary Consumers: Herbivores.Secondary Consumers: Carnivores that eat herbivores.Tertiary Consumers: Carnivores that eat other carnivores.

9. Trophic Levels—each step in a food chain or food web 1. Level 1—Producers (autotrophs) 2. Level 2—Primary Consumers (herbivores) 3. Level 3—Secondary Consumers (carnivores or omnivores) 4. Level 4—Tertiary Consumers (carnivore—usually top carnivore)

10. Trophic levelsfeeding relationshipsstart with energy from the sun captured by plants1st level of all food chainsfood chains usually go up only 4 or 5 levelsinefficiency of energy transferall levels connect to decomposers Food chainsFungiLevel 4Level 3Level 2Level 1DecomposersProducerPrimary consumerSecondary consumerTertiary consumertop carnivorecarnivoreherbivoreBacteriaautotrophsheterotrophssun

11. Food Chain—series of steps in which organisms transfer energy by eating and being eatenArrows go in the direction of how energy is transferredStart with producer and end with top consumeror carnivore Ex: grass cricket frog raccoon

12. C. Food Web—network of food chains within an ecosystemHawksWeaselsRaccoonsMiceGrass

13. HawksWeaselsRaccoonsMiceGrassFood Webs

14. ECOLOGICAL PYRAMIDSFood chains and food webs do not give any information about the numbers of organisms involved. This information can be shown through ecological pyramids.

15. Ecological PyramidsAn 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.Energy pyramidsNumber pyramidsBiomass pyramidsEnergy Pyramid only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.

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

17. Energy PyramidFig. 4–19In 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.

18. PYRAMID OF NUMBERSShows the number of organisms at each trophic level per unit area of an ecosystem.

19. Pyramid of NumbersPyramid of numbers displays the number of individuals at each level. 1 owl25 voles2000grass plants

20. PYRAMID OF BIOMASSThe 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.

21. Biomass PyramidsDisplays the biomass at each trophic level.

22. Pyramids ContinuedBiomass 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.Because each trophic level harvests only about one tenth of the energy from the level below, it can support only about one 10th the amount of living tissue.

23. Energy Pyramid shows relative amount of energy available at each trophic level 1. Organisms in a trophic level use the available energy for life processes (such as growth, photosynthesis, cellular respiration, metabolism, etc.)and release some energy as heat Remember: Every chemical process that happens in your body releases heat as a byproduct (ex: burning calories). 2. Rule of 10—only about 10% of the available energy within a trophic level is transferred to the next higher trophic level Biomass Pyramid—represents the amount of living organic matter at each trophic level

24. Energy PyramidBiomass Pyramid100% 10% 1% 0.1%