1. What is Ecology ? Ecology is the scientific study of interactions among organisms and between organisms and their environment, or surroundings.

2. Biosphere The biosphere contains all parts of the planet where life exists. The biosphere contains all parts of the planet where life exists. This includes land, water, and air. This includes land, water, and air. Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live. Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live.

3. Levels of Organization To understand relationships within the biosphere, scientists must study organisms at many levels: –Species- a group of organisms so similar to one another that they can breed and produce fertile offspring. Scientists can study an individual organism.

4. Levels of Organization continued  Populations- these are groups of individuals from the same species that live in the same area.  Communities- groups of different populations that live in the same area

5. Levels of Organization continued Ecosystem- a collection of all the organisms that live in a particular place, including their nonliving environment Ecosystem- a collection of all the organisms that live in a particular place, including their nonliving environment Abiotic- nonliving factors. Examples: water and rocks Abiotic- nonliving factors. Examples: water and rocks Biotic- living factors. Examples: plants and animals Biotic- living factors. Examples: plants and animals

6. Levels of Organization continued Biome- a group of ecosystems that have the same climate and similar dominant communities. Biome- a group of ecosystems that have the same climate and similar dominant communities. Ecologists recognize ten different biomes. Ecologists recognize ten different biomes.

8. Energy Flow Without a constant input of energy, living systems could not function. Without a constant input of energy, living systems could not function. Sunlight is the main source of energy for life on Earth. Sunlight is the main source of energy for life on Earth.

9. Producers Organisms that use the energy from sunlight or chemicals to make their own food are called producers or autotrophs. Organisms that use the energy from sunlight or chemicals to make their own food are called producers or autotrophs. These organisms are very important to the flow of energy through the biosphere. These organisms are very important to the flow of energy through the biosphere. Most producers make their food by photosynthesis and some by chemosynthesis. Most producers make their food by photosynthesis and some by chemosynthesis.

10. Consumers Organisms that rely on other organisms for their energy and food supply are called consumers or heterotrophs. Organisms that rely on other organisms for their energy and food supply are called consumers or heterotrophs. There are different kinds of consumers: There are different kinds of consumers: –Herbivores-eat only plants. Ex: cows –Carnivores-eat animals. Ex: snakes –Omnivores-eat plants and animals. Ex: bears –Detrivores-eat animal remains and other dead matter. Ex: earthworms

11. Food Chains Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs and then to heterotrophs. Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs and then to heterotrophs. A food chain is a series of steps in which organisms transfer energy by eating and being eaten. A food chain is a series of steps in which organisms transfer energy by eating and being eaten.

12. http://www.nationalgeographic.com/ngex plorer/0309/quickflicks http://www.nationalgeographic.com/ngex plorer/0309/quickflicks

13. Food Webs Sometimes feeding relationships are more complex than can be shown with a food chain. Sometimes feeding relationships are more complex than can be shown with a food chain. Ecologists will describe these complex relationships as a food web. Ecologists will describe these complex relationships as a food web. A food web links all of the food chains in an ecosystem together. A food web links all of the food chains in an ecosystem together.

15. Trophic Levels Each step in a food chain is called a trophic level Each step in a food chain is called a trophic level Producers make up the first trophic level Producers make up the first trophic level Consumers make up the second, third, or higher trophic levels. Consumers make up the second, third, or higher trophic levels. Each consumer depends on the trophic level below it for energy. Each consumer depends on the trophic level below it for energy.

16. Ecological Pyramids A diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web is an ecological pyramid. A diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web is an ecological pyramid. There are three kinds: There are three kinds: –Energy pyramid –Biomass pyramid –Pyramid of numbers

17. Energy pyramid Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. This can be shown with an energy pyramid. This can be shown with an energy pyramid.

18. 10% Energy Rule – Only 10% of the energy moves up to the next trophic level. Decomposers

19. Biomass pyramid The total amount of living tissue within a given trophic level is called biomass. It is usually expressed in grams per unit area. The total amount of living tissue within a given trophic level is called biomass. It is usually expressed in grams per unit area. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

20. Pyramid of numbers This pyramid is based on numbers of individual organisms at each trophic level. This pyramid is based on numbers of individual organisms at each trophic level. These pyramids do not always have the same shape as the other ecological pyramids. These pyramids do not always have the same shape as the other ecological pyramids.

21. Cycles of Matter Unlike the oneway flow of energy, matter is recycled within and between ecosystems. Unlike the oneway flow of energy, matter is recycled within and between ecosystems. This matter is passed from one organism or part of the biosphere to another through biogeochemical cycles. This matter is passed from one organism or part of the biosphere to another through biogeochemical cycles. Biogeochemical cycles pass the same molecules around again and again within the biosphere. Biogeochemical cycles pass the same molecules around again and again within the biosphere.

22. Water Cycle Precipitation (rain and snow) fall on plants and ground. Precipitation (rain and snow) fall on plants and ground. Plants respire and evaporate water back into clouds. Plants respire and evaporate water back into clouds. The ground filters the water run-off into the lakes where it evaporates again. The ground filters the water run-off into the lakes where it evaporates again.

23. Carbon Cycle Glucose C 6 H 12 O 6 is produced by plants, eaten by animals. Glucose C 6 H 12 O 6 is produced by plants, eaten by animals.Photosynthesis Animals and plants exhale CO 2 which is taken in by plants to make glucose Animals and plants exhale CO 2 which is taken in by plants to make glucose Cellular Respiration

24. Nitrogen Cycle Lightening and bacteria in the ground “fix” Nitrogen into a form usable by plants. Lightening and bacteria in the ground “fix” Nitrogen into a form usable by plants. It is absorbed by plants, through their roots as nitrates, so they can be used to build amino acids essential for building proteins, enzymes and the nitrogen bases of DNA. It is absorbed by plants, through their roots as nitrates, so they can be used to build amino acids essential for building proteins, enzymes and the nitrogen bases of DNA.

25. Nitrogen Cycle

26. Phosphorus cycle  Phosphorus forms part of important life sustaining molecules such as DNA and RNA  It is not commonly found in the biosphere, but remains mostly on land and in ocean sediments.  As they wear down, phosphorus is released.