Ecosystems

• What is an ecosystem?• Energy Flow in Ecosystems• Cycling of matter

Why it matters…..

• Humans are apart of a community of organisms

• Humans are dependent on healthy ecosystems

• Humans can disrupt ecosystems harming the organisms and themselves

What is an ecosystem?

• An ecosystem includes a community of organisms and their physical environment.

• Web of relationships– Predator/prey– Symbiotic – Competition

• Biotic and Abiotic factors

• Habitat– Food, shelter, water, space

• Biodiversity– Variety of organisms in a given area– Abiotic factors– When biodiversity decreases in an ecosystem,

health of the ecosystem decreases.

Energy Flow in Ecosystems

• Trophic levels– Each step in the transfer of energy in an

ecosystem– Primary source, Sun– Producer– Consumer– Decomposer

Food Chain VS Food Web

• Food Chain– Producer to herbivore to carnivore – Omnivore

• Food Web– Interconnected food chains– Complicated– Loss of energy/10% Rule

Energy Pyramid• Demonstrates the amount of energy

transferred to each level• 10% Rule

Succession

• Replacement of one kind of community by another at a single place over a period of time– Change in an ecosystem– Volcano, fire, mudslides– Pioneer species

• Equilibrium– Ecosystems respond to change so that equilibrium

is restored

• Rock succession

Major Biological Communities

• Climate– Helps determine the types of organisms found in a

particular place– Average weather conditions in an area over a long

period of time (temp and precipitation)

• Biome– Large region characterized by specific climate,

plants, and animals

Terrestrial Biomes

• Tropical Biomes• Temperate Biomes• High – Latitude Biomes

Aquatic Ecosystems

• Freshwater• Wetlands• Estuaries• Marine ecosystems

Cycling of Matter

• Organisms are made up of– Carbon, Oxygen, Hydrogen, Nitrogen, and

Phosphorus

• Matter needs to cycle through ecosystem – Water Cycle– Carbon and Oxygen Cycles– Nitrogen Cycle– Phosphorus Cycle

Water Cycle

Continuous movement of water between the atmosphere, the land, and the oceans•Condensation•Precipitation•Percolates•Evaporation•Transpiration

Carbon Cycle

Carbon Cycle• Continuous movement of carbon from

nonliving environment into living things and back

• Photosynthesis; carbon dioxide, organic molecules, water, oxygen

• Animals; oxygen, breakdown organic molecules, carbon dioxide

• Respiration is the exchange of O2 and CO2

• Combustion, burning of a substance

Nitrogen Cycle

• Process in which nitrogen cycles among the air, soil, water, and organisms in an ecosystem

• Organisms use nitrogen to make proteins• Atmosphere is about 78% Nitrogen gas• Nitrogen fixation is the process of combining

nitrogen with hydrogen to form ammonia– bacteria, lightning, combustion

Phosphorus Cycle

• Movement of phosphorus in different chemical forms from the surroundings to the organisms then back to the surroundings

• Found in soil, rocks which break down and plants absorb through roots

• Animals eat plants, when animals die phosphorus is released back into the soil