Sorting Out Life

Sorting Out Life

Middle School

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Learning Objectives

• Define and compare a community, ecosystem, and biome.

• Identify the key biotic and abiotic factors that define different biomes.

• Describe how different organisms interact within an ecological community.

• Explain the four types of ecosystem services with an example for each.

Key Vocabulary

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Community

All the different populations of organisms that live together and interact in a specific area.

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Ecosystem

All the living organisms in an area and the nonliving, abiotic factors of their environment.

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Biome

A large group of ecosystems that share similar climates and types of organisms.

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Abiotic Factors

The nonliving parts of an ecosystem, such as water, soil, sunlight, and temperature.

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Ecosystem Services

The many varied benefits that humans gain from the natural environment and properly-functioning ecosystems.

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Provisioning Services

The products obtained from ecosystems, such as food, fresh water, wood, and fiber.

Key Vocabulary

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Regulating Services

Benefits from the regulation of ecosystem processes, such as air and water purification.

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Cultural Services

Non-material benefits people get from ecosystems through recreation and aesthetic or spiritual experiences.

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Supporting Services

Services like nutrient cycling and soil formation that are necessary for producing all other services.

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What is a Community?

• An ecological community consists of all the living organisms in one area.

• It includes populations of plants, animals, fungi, and other living things.

• Organisms interact, like a robin eating a worm or nesting in a tree.

• Decomposers recycle nutrients from dead organisms, connecting all life in the community.

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Multiple Choice

Which of these best defines an ecological community?

• All the living organisms in one area.

• Only the plants and animals in one area.

• A single population of one type of organism.

• The living organisms and the non-living environment.

Multiple Choice

What is the primary way decomposers connect all living things in a community?

• By providing food for animals like robins.

• By building nests in trees for birds.

• By recycling nutrients from dead organisms.

• By converting sunlight into energy for plants.

Multiple Choice

Based on the interactions described, what would be the most likely consequence if all decomposers were removed from a community?

• Robins would no longer be able to eat worms.

• Nutrients from dead organisms would not be recycled back into the community.

• Plants and fungi would have no organisms to interact with.

• The community would have more trees for birds to nest in.

Ecosystems and Their Services

• An ecosystem includes all living and nonliving things in an area.

• Ecosystem services are the many benefits that humans receive from nature.

• These include providing food and water, and regulating the climate.

Multiple Choice

What is an ecosystem?

• All the living and nonliving things in a particular area

• Only the animals and plants in a particular area

• The benefits that humans get from the environment

• Only the nonliving things like rocks and water

Multiple Choice

What is the relationship between ecosystems and ecosystem services?

• They are benefits that humans receive from ecosystems.

• They are the nonliving components within an ecosystem.

• They are services that animals provide to each other.

• They are the processes that create new ecosystems.

Multiple Choice

If a large forest ecosystem is destroyed, what is the most likely impact on the ecosystem services it provides?

• The loss of benefits like climate regulation and clean water.

• An increase in the number of living things in the area.

• An increase in the benefits that humans receive.

• No significant change to the nonliving parts of the environment.

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What are Biomes and Climate?

• A biome is a group of ecosystems with similar environments and organisms.

• Climate is the long-term pattern of weather, like temperature and precipitation.

• Earth has three main climate zones: polar, temperate, and tropical.

• Abiotic factors like temperature and water salinity help define biomes.

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Multiple Choice

What is a biome?

• A group of ecosystems with similar environments and organisms.

• The long-term pattern of weather in an area.

• A single type of animal or plant species.

• The daily changes in temperature and wind.

Multiple Choice

What is the relationship between climate and a biome?

• The climate of a region is a major factor that determines its biome.

• The organisms within a biome determine the region's climate.

• Climate and biomes are unrelated to one another.

• A biome is defined by a single climate zone, like polar or tropical.

Multiple Choice

If a temperate region experienced a significant, long-term increase in temperature and decrease in precipitation, what would be the most likely effect on the biome?

• The biome would change to one suited for warmer, drier conditions.

• The biome would remain unchanged because it is a stable system.

• The region would shift from a temperate to a polar climate zone.

• The number of organisms in the biome would increase immediately.

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A Tour of Terrestrial Biomes

• Deciduous forests have four seasons and trees like maple that lose their leaves.

• The taiga has long, cold winters and is dominated by evergreen trees like pine.

• Tropical rainforests have consistent rain and the most biological diversity of all biomes.

• Temperate grasslands have rich soil and are dominated by grasses and grazing mammals.

• The arctic tundra is a treeless landscape with permanently frozen soil, or permafrost.

• Deserts have very little precipitation and are home to drought-resistant plants like cacti.

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Multiple Choice

Which biome is described as having long, cold winters and being dominated by evergreen trees like pine?

• The taiga

• The arctic tundra

• A deciduous forest

• A tropical rainforest

Multiple Choice

What is the most significant difference between a tropical rainforest and a desert?

• The presence of four distinct seasons

• The amount of annual rainfall

• The existence of permanently frozen soil

• The presence of grazing mammals

Multiple Choice

A farmer wants to grow crops that have deep roots. Which biome's soil conditions would make this impossible?

• The temperate grassland, because it is dominated by grasses.

• The deciduous forest, because its trees lose their leaves.

• The arctic tundra, because of its permanently frozen soil.

• The taiga, because of its long, cold winters.

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A Tour of Aquatic Biomes

Coral Reef

• ​Coral reefs are created by tiny animals called coral polyps in warm, shallow ocean waters.

• ​​These coral polyps have a symbiotic relationship with photosynthetic algae that provides them with food.

• ​The complex structure of the reef supports an extremely diverse population of marine organisms.

Kelp Forest

• ​Kelp forests are found in cold, shallow ocean waters and are dominated by large brown algae.

• ​​Kelp can grow very quickly, forming a dense, forest-like environment for many marine animals.

• ​This underwater forest provides both crucial food and shelter for a variety of marine species.

Multiple Choice

What is a primary environmental difference between a coral reef biome and a kelp forest biome?

• Water temperature

• The number of fish species

• The depth of the ocean floor

• The presence of large rocks

Multiple Choice

How are the roles of coral polyps and kelp similar within their respective ecosystems?

• Both form the foundation of the structure that provides shelter for many other marine organisms.

• Both are tiny animals that have a symbiotic relationship with algae for food.

• Both are large brown algae that grow very quickly in shallow ocean waters.

• Both can only survive in warm, shallow ocean environments.

Multiple Choice

If the photosynthetic algae that live in a symbiotic relationship with coral polyps were to disappear, what would be the most likely consequence for the coral reef biome?

• The coral polyps would lose their main food source, leading to a decline of the entire reef structure.

• The reef's structure would remain, but the population of other marine organisms would increase.

• The coral polyps would quickly find a different type of algae to provide them with food.

• The kelp would begin to grow in the warm water and take over the reef.

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Common Misconceptions

Misconception	Correction
A community includes nonliving things like rocks and water.	A community has only living things. An ecosystem includes nonliving things.
Humans do not depend on the environment for resources.	All our resources, like food and water, come from the environment.
Ecosystems within the same biome are exactly alike.	Same-biome ecosystems have unique communities due to local geography and soil.

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Summary

• A community is all the interacting living populations in one area.

• An ecosystem includes the community and its nonliving environment.

• A biome is a large group of ecosystems with a similar climate.

• Climate is the main factor that determines the characteristics of a biome.

• Humans rely on the many benefits provided by healthy ecosystems.

• Earth has many diverse biomes, from frozen tundras to hot deserts.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

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• 3

• 4