4.1 Ecosystems Part 1 Unit Goals: 1. Summarize how energy derived from the sun is used by plants to produce sugars (photosynthesis) and is transferred within a food chain or food web (terrestrial and aquatic) from producers to consumers to decomposers. 2. Explain how plants respond to external stimuli (including dormancy and forms of tropism) to enhance survival in an environment. 3. Summarize how the abiotic factors (such as temperature, water, sunlight and soil quality) of biomes (freshwater, marine, forest, grasslands, desert, and tundra) affect the ability of organisms to grow, survive, and/or create their own food through photosynthesis.

Ecosystems Support Life Ecology: The scientific study of how organisms interact with their environment and the organisms that live in the environment. Ecosystem: Describes a particular environment and all of the living things supported by it. - Can be as small as a pond or as big as the desert. - Most important part of an ecosystem is how the living and non living parts relate to each other. - Consist of biotic(living) and abiotic(nonliving) members.

Biotic Factors Biotic Factors: Living parts of the ecosystem. (fish, plants, microorganisms) How Plants Help: - Important source of food for animals. - Plants determine type of animals that live in the area. - Affect temperature by blocking sunlight. - Roots hold soil in place (river banks) - Alter the atmosphere by turning CO2 into O2 Impact of Animals - Alter the flow of rivers (beaver dams) - Cause soil erosion by overgrazing grasslands. - Major source of food and population control depending on their position on the food pyramid.

Abiotic Factors Abiotic Factors: Include physical and chemical parts. - Physical Factors: Things you can see or feel. (temperature) - Chemical Factors: Minerals and compounds in soil. (fresh or salt water) Temperature: - Effects type of plant life that will thrive. - Type of plants available for food and shelter determine the type of animals. Light: - Sunlight's provides warmth and energy plants and animals need to survive. - Strength and amount of light influences which type of plants and animals will live in that area.

Abiotic factors (cont) Soil: - Soil is a mixture of small rock and mineral particles. - Organisms within the soil break down remains of dead plants and animals, providing important raw materials to living plants and animals. - Soil characteristics effect which plants are present.(ability to hold water, air and minerals) Water: - The amount of water available to directly proportional to the amount of life present. - Water is a vital part of all living things survival. - The more water present the more diverse and ecosystem will be.

Matter in the Ecosystem Chapter goals: 1. To be able to explain how matter is exchanged between organisms and their environment. 2. Understand the water, carbon and nitrogen cycle.

Needs of an Ecosystem Cycle: A series of events that happens over and over again. - Matter in a eco system changes form but never leaves the system. - Living things depend on the matter (materials) in an eco system to survive. When they die all matter that was absorbed returns to the ecosystem.

Ecosystem cycles: water cycle -The movement of water through the environment. - Water changes between gas, liquid and solid as it moves through the cycle. Step 1: Evaporation Step 2: Condensation Step 3: Precipitation Step 4: Run off

Carbon Cycle Carbon Cycle: The way Carbon moves through an ecosystem. - Carbon enters the living part of an eco system through carbon dioxide gas. Photosynthesis: is a process used by plants and other organisms to convert light energy, normally from the Sun, into chemical energy that can be later released to fuel the organisms' activities. - Respiration: when plants and animals break down carbon compound in order to create energy. - Carbon is also released by animal waste, dead animals, decaying plant and animal life.

Nitrogen Cycle Nitrogen makes up 4/5th's of air you breathe. - Oxygen cannot supply the Nitrogen your body needs to survive. - Nitrogen is instead supplied by plants. - Plants absorb the nitrogen through their roots, along with water and other nutrients. How does Nitrogen go from the atmosphere to the soil? - Lighting strikes: strikes break apart pure nitrogen, changing it into a form that plants can use. This form then falls to the ground when it rains. - Nitrogen-fixing bacteria: live in oceans and soil, responsible for breaking down dead plants and animals. A small amount is released back into the atmosphere by bacteria capable of turning nitrogen into gas.