Chapter 5: How Ecosystems Work

List two examples of each of the following: Herbivore Carnivore Omnivore Decomposer Cow, sheep, deer, grasshopper. Lions, hawks, snakes, spiders. Bears, pigs, humans. Fungi, bacteria

Energy Flow in Ecosystems The cycling of materials such as carbon, nitrogen and phosphorus is essential to keep nutrients balanced in ecosystems.

Trophic Levels Energy transfer from Producers Consumers Producers- -An organism that makes its own food. (AKA autotroph) Consumers- Get energy by eating other organisms. (AKA heterotrophs).

Carnivores/omnivores/ Sun Autotrophs Heterotrophs Carnivores/omnivores/ decomposers Herbivores Exception to the rule: Hydrothermal vents get their energy from bacteria since photosynthesis cannot take place in the total darkness at the bottom of the ocean.

Cellular Respiration The process of breaking down the food you eat to yield energy, which occurs inside the cells of most organisms. Sugar C6H12O6 + + + CO2 H2O Energy oxygen

Excess Energy The excess energy your body obtains is stored as fat or sugar.

Food Chain *A sequence in which energy is transferred from one organism to another.

Food Web Because most animals eat more than one type of food, a food web shows multiple chains linked together.

Trophic Levels: Using the tree, giraffe, lion example, the tree is the lowest trophic level and has the highest amount of energy. Each increasing trophic level has less energy available to it due to loss of heat and other conversions.

Energy pyramid A pyramid is a good way to represent the trophic levels because as the pyramid narrows toward the top, it shows less energy available.

Trophic levels: Ecosystems rarely have more than 3-4 trophic levels because there simply is not enough energy to support higher levels.

Section Review Questions: Page 123 questions 1-5

The Cycling of Materials Lesson 5.2 The Cycling of Materials The Carbon cycle The Nitrogen cycle The Phosphorus cycle Nitrogen and phosphorus for minerals

The Carbon Cycle Carbon is an essential component of proteins, fats, and carbohydrates which make up all organisms. Essential for photosynthesis. Carbohydrate is end product of photosynthesis.

The Carbon Cycle Carbon is cycled between the land, atmosphere, water and organisms. Phosphorus is different

Combustion industry, vehicles, decomposition

Fossil Fuels Essentially stored Carbon left over from bodies of plants and animals that have died millions of years ago. Burning of fossil fuels along with natural burning of wood or forest fires makes up about 6 billion metric tons of CO2 being released to the atmosphere. About half of this remains in the atmosphere, builds up and causes global warming

The Nitrogen Cycle Nitrogen is most abundant gas in atmosphere. Run off from fertilizers, and combustion of fossil fuels

The Nitrogen Cycle All organisms needs nitrogen to build proteins which are used to build new cells. 78% of the gases in the atmosphere. Most organisms cannot use atmospheric Nitrogen.

The Nitrogen Cycle Nitrogen-fixing bacteria turn atmospheric Nitrogen into a useable form for other organisms. The Nitrogen cycle is a process by which Nitrogen is cycled between the atmosphere, bacteria and other organisms. Bacteria makes nitrogen available for plants and it is then released back into the atmosphere.

Bacteria Bacteria play another essential part in the Nitrogen cycle by breaking down the wastes of animals, leaves and other decaying organisms to return the Nitrogen to the soil.

The Phosphorus Cycle Phosphorus is an essential element for bones and teeth in animals. This cycle is slow and does not normally occur in the atmosphere because Phosphorus does not normally occur as a gas. Slowest because it does not have atmospheric state

The Phosphorus Cycle The movement of Phosphorus from the environment to organisms and then back to the environment.

Organisms to land or water Organisms to land or water. lots comes from phosphates in the rocks, fertilizer, runoff, animal waste and decomp.

Fertilizers Fertilizers contain nitrogen and phosphorus to help stimulate rapid growth and bigger plants. Excess can enter terrestrial and aquatic ecosystems leading to rapid growth of algal blooms. Algae can deplete oxygen available to fish and other aquatic life.

Section review questions: Page 128 #1-4.

Lesson 5.3 How Ecosystems Change Ecological succession Primary succession. Secondary succession. Old-field succession.

Ecological Succession Gradual process of change and replacement of the types of species in a community. May takes hundreds or thousands of years.

Primary Succession Occurs on a surface where no ecosystem existed before. Rocks, cliffs, and sand dunes

Secondary Succession Occurs in ecosystems that have been disturbed by humans, animals, or natural processes such as storms, floods, earth, quakes, and volcanos.

Pioneer Species The first organisms to colonize a newly available area and begin the process of ecological succession. Make it more habitable for other species to move in.

Climax Community A final stable community. Still will continue to change in small ways over time.

Old-field Succession Occurs when farm land is abandoned. Grass/weeds (w/in 1 year) Perennial plants/grasses (w/in 2 years) Shrubs (w/in 3-10 years) Pine forest (about year 20) Oak forest (about 150 years)

Succession Primary succession takes much longer than secondary succession. Pioneer species generally tends to be lichen that break down the rocks (can live without soil). Mosses may then grow, etc. starting the succession process.

Section Review Questions Page 133 #1-5.