Ecology

1. Ecology It’s all about interactions!

2. Nature’s Interactions • Ecology • the study of interactions among organisms and their environment. • Abiotic (non-living) & Biotic (living) things are considered. • Materials, such as nitrogen and carbon, are exchanged back and forth from biotic to abiotic. • Ecosystems throughout the world are linked together, and organisms move from one ecosystem to another. Standard I; Objective 3

3. Nature’s Interactions • Quick review of biotic and abiotic factors. Biotic Abiotic Animals Plants Bacteria Fungi Protists Decomposing matter Dead, rotting logs Leaf matter Grass clippings Manure Sunlight Water Oxygen Temperature Soil Inorganic nutrients Rocks Sand Nitrogen Metals

4. Relationships • There are many types of relationships in nature. One example is predator/prey. This is an example of energy flow with predators getting their energy needs from what/whom they eat. Can you think of some predator/prey relationships? Standard I; Objective 3

5. Energy Flow • Energy flows in all ecosystems. All food chains start with photosynthesis, and the energy passes from producers up through the consumers. Carnivores Herbivores Decomposers Producers

6. Project: Mini-Ecosystem • You will now be asked to build/create a mini-ecosystem. • Remember… an ecosystem is the interaction of all of the living and non-living things in an area. Assignment 4-1 • You will earn more points for creating an actual ecosystem.

7. Symbiotic Relationships • Another type of relationship is called symbiosis. • Symbiosis means living together. There are several types of symbiosis. • Mutualism = both organisms benefit • Parasitism = one organism benefits, one is harmed • Commensalism = one organism benefits, the other is neither harmed nor helped. Standard I; Objective 3

8. Examples of Symbiosis Mutualism The Moray eel & shrimp… The eel benefits from the shrimp cleaning bits of food from its teeth. The shrimp gets food, and most likely protection from predators that don’t dare come close to the Moray eel

9. Examples of Symbiosis Parasitism Tick & Dog… The tick benefits by getting nutrition from the dog’s blood. The dog is harmed because of lost blood, and can pick up diseases from the tick.

10. Examples of Symbiosis Commensalism Dugong & Remoras…The Remoras attach themselves to many types of marine animals, and just hang on for the free ride. When the larger animal eats, the Remoras can benefit by picking up scraps. It doesn’t hurt or help the Dugong.

11. Niche vs. Habitat • In a balanced ecosystem, each organism/species occupies it’s own niche (role) in an ecosystem. It also occupies a particular territory (habitat), and gets its nutrients in a certain way. • Competition arises when the niches of two species overlap. Two can share a similar habitat, but must have a unique niche. The greater the overlap, the more requirements the two have in common, and the more intense the competition will be.

12. Relationship Assignment • You have read and learned about different relationships that occur in nature. Symbiosis & Predator/Prey. Please complete the next assignment. Assignment 4-2

13. Food Chains • As you have seen, energy flows from the sun, to producers, to consumers, and back to producers. Carnivores Herbivores Decomposers Producers

14. Food Chains • This flow of energy is called a food chain. Every chain starts with a producer, followed by various levels of consumers. Nutrients are returned to producers. Tertiary Consumer Decomposers Secondary Consumer Primary Consumer Producer

15. Food Chains • Organic material is passed through the food chain. So a 4 level food chain would be… Grass  Mouse  Snake  Hawk. Notice the arrows show the flow of energy. Omnivores –could eat either carnivores or herbivores, or both. 3rd Level Consumer Decomposers Carnivores– meat eaters 2nd Level Consumer Herbivores– plant eaters 1st Level Consumer Producer

16. Food Webs • What’s the difference between a food chain and a food web? A food web is made up of many interconnected food chains. Can you see different food chains in this small food web? Hawk Wolf Snake Notice how energy flows from producer to consumers, and from consumers to other consumers. Rabbit Mouse Grass

17. Food Chains & Food Webs • Can you think of some food chains that occur in nature? Could you put them in to a food web? Assignment 4-3 Standard I; Objective 1

18. Energy Costs vs. Gains • In all food chains, organisms are in a battle to gain more than they spend when eating, fighting, migrating, etc. It’s all about survival. In all food chains for example, as you move from one level to another, 90% of the energy is used to survive. If a plant makes 1000 calories of food, there is only 1 calorie left at the 4th trophic level. .1 % 1 calorie 1 % 10 calories 10 % 100 calories 100 % 1000 calories Standard I; Objective 1

19. Activities that cost energy • Many activities require an investment of energy by the organism. Some of them are… • Growth • Migrations – some animals go thousands of miles yearly • Fighting to breed, protect resources, obtaining prey • Feeding – capturing, metabolism, expenditure of waste • Hibernation – maintaining a constant body temperature • Shelter/home building – bird nest, badger hole, etc. Standard I; Objective 1

20. Nutrient Cycling • There are 4 key nutrients that living things must have. When you think of matter, remember that matter, like energy, cannot be created or destroyed, it can only be converted from one thing to another and back. We will investigate the cycling of these 4 main nutrients. • Water – used in nearly all bodily functions • Carbon – key component in all organic compounds • Nitrogen – important in DNA, RNA & proteins • Phosphorus – part of DNA, RNA & ATP Review the following cycles. Standard I; Objective 2

21. Water Cycle Water cycles from the earth to the atmosphere. It’s one of the nutrients all living things must have.

22. Carbon Cycle Carbon goes from CO2 in the atmosphere to organic compounds on earth. A lot of CO2 comes from fossil fuels burning.

23. Nitrogen Cycle Nitrogen Fixation by Nitrogen fixing bacteria De-nitrification converts solid Nitrogen to N2 gas Nitrogen is fixed/pulled from the air by bacteria in plants, then made available to animals.

24. Phosphorus Cycle Phosphorus helps make phosphate which is needed by many living things. It doesn’t go in to the atmosphere, but goes from mountains to lakes/oceans, to plants, to animals and back to earth.

25. Human Impact • Have you ever stopped to think about what we do to the environment? Do we have a positive or negative impact? Is it all just “Doom and Gloom”? Assignment 4-4

26. Invasive Species • Organisms that are native to an area, are also called indigenous. Occasionally, organisms are introduced accidentally or intentionally in to an ecosystem. These species can be very disruptive, and are known as “Invasive species”. Please watch the short video on Cane Toads, then complete the next assignment. It’s in the “Resources”. Cane Toads were introduced to Australia to control Cane grubs. Assignment 4-5