Chapter 3 - Summary Essentials of Environmental Science PDF

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These are the notes on Chapter 3 in Essentials of Environmental Science ...

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Chapter 3 3.1 Learning Objectives ● List the basic components in an ecosystem ○ Biotic components: All the life forms that inhabit it ■ Ex.: Trees, wildflowers, birds, mammals, insects, fungi, & bacteria ○ Abiotic components: The non-organic aspects of the environment that determine what life forms can thrive there. ■ Ex.: Sunlight, temperature, soil, water, pH & nutrients ● Describe how energy forms through ecosystems ○ Plants absorb energy directly from the Sun → Herbivores eat the energy containing plants → Carnivores eat the energy containing herbivores. ● Describe how carbon, nitrogen, and phosphorus cycle within ecosystems (how have humans changed/altered these cycles?) ● Explain the forces that drive global circulation patterns and how those patterns determine weather and climate. ● Describe the major terrestrial and aquatic biomes. Material discussed in lecture and/or from the book ● Define and describe ecosystem [flashcard] ○ A particular location on Earth distinguished by a specific mix of interacting biotic/abiotic components ● Be able to give examples of biotic and abiotic components and how they interact [flashcard] ○ Biotic: Trees, wildflowers. Birds, mammals, insects, fungi, & bacteria ○ Abiotic: Sunlight, temperature, soil, water, pH, & nutrients ● Know the chemical reaction for photosynthesis (backward and forward) i.e. the MAJOR SOURCE of energy on the planet ○ Photosynthesis: Solar Energy + 6H2O + 6CO2 → C6H12O6 + 6O2 ○ Cellular Respiration: C6H12O6 + 6O2 → Energy + 6H2O + 6CO2 3.2 Have a good understanding of trophic levels ● Producers/autotrophs [flashcard] ○ Plants, algae, & other organisms that use the energy of the Sun to produce usable forms of energy. ● Primary, secondary, tertiary consumers ○ Primary: [Herbivores] heterotrophs that consume producers ■ Zebras, grasshoppers, tadpoles ○ Secondary: [Carnivores] heterotrophs that consume primary consumers ■ Lions, hawks, rattlesnakes

Chapter 3 ○ Tertiary: Carnivores that eat secondary consumers ■ Bald eagles [Zooplankton eat algae → Fish eat zooplankton → Eagles

eat fish] Answer: C

Ex. of a food web^

● Scavengers & Decomposers ○ Scavengers: Carnivores that consume dead animals ■ Ex: Vultures ○ Detritivores: Organisms that specialize in breaking down dead tissues and waste product into smaller particles ■ Ex: Dung beetles ○ Decomposers: Organisms that break down and process the small particles broken down by detritivores. They complete the breakdown process by recycling the nutrients from dead tissue and wastes back into the ecosystem. ■ Ex: Fungi and bacteria ○ **Without scavengers, detritivores, and decomposers, there would be no way of recycling organic matter and energy, and the world would fill up with dead plants and animals. ● Relate trophic pyramids to ecological efficiency ○ Ecology efficiency: The proportion of consumed energy that can be passed from one trophic level to another ■ Fairly low; 5-20%, on average 10% ○ Trophic pyramids: A representation of the distribution of biomass among tropic levels ■ Tend to look similar across ecosystems

Chapter 3 3.3 Demonstrate comfort with the units for ecosystem productivity ● GPP vs. NPP. What are they? How do they interact? ○ Gross Primary Productivity: The total amount of solar energy that the producers in an ecosystem capture via photosynthesis over a given amount of time. ○ Net Primary Productivity: The amount captured minus the energy respired by producers ■ NPP = GPP - energy respired by producers ● Where is NPP greatest? Why? ○ Tropical rainforests and salt marshes. ■ They have plenty of sunlight, available water, and warm temperatures. 3.4 Review the biogeochemical cycles discussed in class ● Hydrologic cycle, carbon, phosphorus, nitrogen, sulfur, arsenic...