SNC1D Ecology: Food Chains, Webs & Energy Flow through Ecosystems

Why Study Ecology? Sustainability: • ______Ecology:  The study of the ______of ______with each other and with ______factors in their environment.

Abiotic Factors: e.g.

Biotic Factors: e.g.

Ecology can begin at the level of a single organism… But organisms do not live in ______

Ecological Ladder Biosphere* ______Organism* • Ecosystems rarely have sharp ______• Organisms can ______from one ecosystem to another Ecotone: ______• Contains members of the community of both ecosystems Biodiversity: ______• Ecotones have ______biodiversity. • High biodiversity usually indicates a ______ecosystem.

Energy Flow in Ecosystems The Sun: • The source of all energy • ______• ______• ______(for precipitation) • ______• ___% of the total energy is reflected by clouds or Earth’s surface • ___% heats atmosphere, surfaces, • _____% heats and evaporates water • _____ % wind • ______% for photosynthesis

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Biotic Factors Producer Consumer

Alternate Name

• Make (produce) their own food Energy Source • From sunlight and basic nutrients (abiotic factors) Herbivores Example Omnivores Carnivores

Trophic Levels Categorize living things (biotic factors) according to ______First Trophic Level • Contains organisms that are able to ______food from ______factors (e.g.______) • Organisms in the 1st trophic level are called ______or ______• E.g. ______Second Trophic Level • Contains organisms that feed on producers • Rely DIRECTLY on ______for their source of energy. • Organisms in the 2nd trophic level are called ______/ ______/ ______• E.g. ______Third Trophic Level • Contains organisms that rely on ______consumers as their main energy source • But, indirectly, are still dependent on ______• Organisms in the 3rd trophic level are called ______• E.g. ______Decomposers • Organisms that feed on ______Detritus: ______• Return ______(abiotic factors) to the ecosystem • E.g. ______

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Food Chains: • Step-by-step sequence linking organisms that ______on each other • Arrows show the ______(“is eaten by”) • Do not exist in nature (more complex) • Show ______feeding relationships Food Webs: • In reality, each organism has a ______of food sources and is therefore involved in ______food chains • These food chains interlock to form a complex ______

Food Web: Representation ______

Energy Flow Through Ecosystems: • Organisms use about _____ % of the energy they take in to ______and ______, leaving just ______% of the energy they receive to ______to the next trophic level.

Ecological Pyramids • Are used to organize the information of these transfers, and the most common are: Type Pyramid of ______Pyramid of ______Pyramid of ______

Based on…

3 SNC1DE: Ecology SNC1D

Drawing

Homework:  Terms to define: (add to glossary) o organism, species, biome, sustainable Ecosystem, Natural and Artificial Ecosystems, albedo, pest, niche  Complete Food Web assignment sheet

 Answer Questions: 1. Why are producer organisms called autotrophs? 2. How does a heterotroph differ from an autotroph? 3. What type of food would be consumed by a secondary consumer? Explain your answer. 4. In your own words, explain what is meant by the term “top carnivore” Give 3 examples of a top carnivore, including the ecosystem in which you would find each one. 5. Distinguish between a food chain and a food web using examples for each. 6. Explain why an Arctic ecosystem would be more fragile than a southern forest ecosystem. 7. Why are there only a small number of tertiary consumers found in an ecosystem?

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