Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter Five: How Ecosystems Work
Document related concepts
Safety data sheet wikipedia , lookup
Photosynthesis wikipedia , lookup
Theoretical ecology wikipedia , lookup
Natural environment wikipedia , lookup
Microbial metabolism wikipedia , lookup
Renewable resource wikipedia , lookup
Low-carbon economy wikipedia , lookup
Transcript
CHAPTER FIVE: HOW ECOSYSTEMS WORK Section One: Energy Flow in Ecosystems Life Depends on the Sun Energy enters the ecosystem through photosynthesis Photosynthesis: plants use sunlight to make sugar molecules Solar energy helps change carbon dioxide and water into sugar and oxygen Section One: Energy Flow in Ecosystems Producers and Consumers Producer: an organism that makes its own food Also called a autotroph Consumer: organisms that get their energy by eating other organisms Also called a heterotroph Section One: Energy Flow in Ecosystems What eats what? Herbivores: Consumers that eat only producers Carnivores: Consumers that eat only herbivores Omnivores: Consumers that eat producers, herbivores, and carnivores Section One: Energy Flow in Ecosystems Decomposers Consumers that get their food by breaking down dead organisms Examples and fungi are bacteria Section One: Energy Flow in Ecosystems Cellular Respiration The process of breaking down food to yield energy Sugar and oxygen combine to yield carbon dioxide and water Section One: Energy Flow in Ecosystems Energy Transfer Occurs each time one organism eats another Food Chains and Food Webs Food Chain: a sequence in which energy is transferred from one organism to the next Food Web: shows many feeding relationships that are possible in an ecosystem Section One: Energy Flow in Ecosystems Section One: Energy Flow in Ecosystems Trophic Levels: each step through which energy is transferred Each time energy is transferred from one organism to another, some of the energy is lost as heat and less energy is available to organisms at the next trophic level Section One: Energy Flow in Ecosystems How energy loss affects an ecosystem? There are fewer organisms at the higher trophic levels The loss of energy between trophic levels limits the number of trophic levels Section Two: The Cycling of Materials The Carbon Cycle A process by which carbon is cycled between the atmosphere, land, water, and organisms Section Two: The Cycling of Materials Section Two: The Cycling of Materials How humans affect the carbon cycle Burning fossil fuels by cars, power plants, and factories Increased carbon dioxide could lead to global warming Section Two: The Cycling of Materials The Nitrogen Cycle A process in which nitrogen is cycled between the atmosphere, bacteria, and other organisms All organism need nitrogen to build proteins Nitrogen-fixing bacteria: bacteria that fix atmospheric nitrogen into chemical compounds Decomposers and the Nitrogen Cycle Break down decaying and dead materials and return nitrogen to the soil Section Two: The Cycling of Materials Section Two: The Cycling of Materials The Phosphorus Cycle The movement of phosphorus from the environment to organisms and then back to the environment Part of the cells of many organisms Section Two: The Cycling of Materials Fertilizers and the Nitrogen and Phosphorus Cycles Excessive fertilizers can enter the water as runoff Causes algae growth which causes an algal bloom Algal blooms can deplete the water of nutrients Section Three: How Ecosystems Change Ecological Succession: the gradual process of change and replacement of some or all of the species of a community May take hundreds or thousands of years Primary Succession: the type of succession that occurs on a surface where no ecosystem existed before Secondary Succession: occurs on a surface where an ecosystem has previously existed More common type Section Three: How Ecosystems Change Primary Succession Section Three: How Ecosystems Change Secondary Succession Occurs in ecosystems that have been disturbed or disrupted by humans or animal or by natural processes such as storms, floods, earthquakes, or volcanoes Pioneer species: the first organism to colonize any newly available area and begin the process of ecological succession Climax community: a final and stable community Section Three: How Ecosystems Change Section Three: How Ecosystems Change Old-field Succession A type of secondary succession Occurs when farm land is abandoned
