Food Chains, Food Webs, and the Transfer of Energy

Transcription

1 Food Chains, Food Webs, and the Transfer of Energy

2 What is Ecology? Ecology is the scientific study of interactions between different organisms and between organisms and their environment or surroundings

3 Every organism has a habitat and a niche. A habitat is all the aspects of the area in which an organism lives biotic (living) factors such as trees, animals abiotic (non-living) factors such as water, soil, sun, wind Where are you from? A niche includes all of the physical, chemical, and biological factors that a species needs to survive, stay healthy, and reproduce. What do you do? (behavior) What do you eat / how do you eat? Are you the top predator? You can think of a habitat as where a species lives and a niche as how it lives within its habitat. Niche Video

4 All can live in the area because they occupy a different ecological niche

5 How are organisms classified in an ecosystem? What they eat or how they get their food (producers, consumers, and decomposers).

6 The Producers (Autotrophs) A group of organisms that can use the energy in sunlight to convert water and carbon dioxide into Glucose (food) through photosynthesis. They make /produce their own food. Sunlight is the main energy source for life on earth The chemical formula for photosynthesis is:

7 The Producers (Autotrophs) Autotrophs are also called Producers because they produce all of the food that heterotrophs use Without autotrophs, there would be no life on this planet Ex. Plants and Algae

8 The Consumers (Heterotrophs) Organisms that do not make their own food can be referred to as consumers, they consume other organisms for their energy and food supply. Ex. Rabbits, Deer, Mushrooms

9 Consumers (Heterotrophs) Scavengers/Detritivores feed on the tissue of dead organisms (both plants and animals) Ex. Vultures, Crows, and Shrimp

10 The Consumers (Heterotrophs) Herbivores eat ONLY plants Ex. Cows, Elephants, Giraffes

11 The Consumers (Heterotrophs) Carnivores eat ONLY meat Ex. Lions, Tigers, Sharks

12 Heterotrophs the Consumers Omnivores eat BOTH plants and animals Ex. Bears and Humans

13 Decomposers Decomposers absorb any dead material and break it down into simple nutrients or fertilizers Ex. Bacteria and Mushrooms

14 Feeding Interactions between organism Energy Flow and the Food Chain Energy flows through an ecosystem in one direction from the sun or inorganic compounds to autotrophs (producers) and then to heterotrophs (consumers)

15 FOOD CHAINS Food Chain series of steps in which organisms transfer energy by eating and being eaten. Start with producer and end with top consumer or carnivore **The sun is the initial source of energy for food chains. eagle snake Keep in mind that the arrow tip always points towards the eater. The direction of how energy is transferred.. frog eater grasshopper grass food

16 Food Chains Question: Which direction does the arrow points? Answer: It points to the direction of the energy transfer, NOT what ate what Question: What is the primary source of energy for life on earth? Answer: The Sun

17 FOOD CHAINS Broken down into producers and consumers. Since they cannot make their own food, they must eat or consume other organisms. They form the basis of almost all food chains. They use the energy in sunlight to make their own food through a process called. photosynthesis eagle snake frog grasshopper grass

18 FOOD CHAINS There are different levels of consumers.. Top carnivore: any organism that is not hunted by any other. It s at the top of its food chain. eagle quaternary consumer The 4th consumer in a food chain. It eats tertiary. consumers snake tertiary consumer The 3rd consumer in a food chain. It eats secondary. consumers frog secondary consumer The 2nd consumer in a food chain. It eats primary. consumers grassprimary consumer hopper The 1st consumer in a food chain. It eats. producers grass

19 FOOD CHAINS All organisms eventually die and decompose. eagle snake Detritus: is the waste matter and rotting remains of dead organisms. frog grasshopper detritus Decomposers: are organisms that eat detritus and break it down into. nutrients The cycle restarts. grass decomposers Nutrients: are substances needed for an organism s nutrients growth and. repair

20 Let s THINK What would happen if there were no decomposers?

21 HUMANS AND FOOD CHAINS Have you ever eaten one of these? What is it made of? What food chains did you participate in when you ate this? wheat tomato beef cheese onion lettuce

22 No ecosystem is only made up of only one food chain. Most organisms eat more than JUST one organism. Members of When you connect all. the food chains of different organisms from one ecosystem together, you form. FOOD WEBS

23 Create a Food Web Form groups of 3, create a basic food web for each of the following habitats. Freshwater wetland Forest

24 What are Trophic Levels? The Energy movement from one organisms to another when it is eaten Each step in this transfer of energy is known as a trophic level

25 TROPHIC LEVELS It is the position an organism occupies in a food chain. Each link in the chain represents one tropic level. The first trophic level starts with the producers. eagle 5 th trophic level shark snake 4 th trophic level larger fish frog grasshopper 3 rd trophic level 2 nd trophic level small fish zooplankton grass 1 st trophic level phytoplankton

26 TROPHIC LEVELS eagle snake frog grasshopper grass 0.1 kcal 1 kcal kcal 10 kcal 100 kcal - 9 kcal - 90 kcal kcal 1000 kcal As organisms eat one another, energy is transferred up the food chain. only about 10% of the available energy within a trophic level is transferred to the next higher trophic level This 10 % is used to build biomass as well as to provide energy for bodily functions This means that 90 % of the energy is mostly lost, in the form of detritus and as heat used in metabolic processes.

27 With your group, pick one food chain for your habitat and create a trophic level.