Unit 8: Energy Flow and Ecosystem Dynamics

What is the 10% rule in energy transfer within ecosystems?

• Only about 10% of energy is passed to the next trophic level.

• The rest is lost as heat.

What are the four trophic levels in an ecosystem?

• Producers

• Primary Consumers

• Secondary Consumers

• Tertiary Consumers.

What are producers in an ecosystem?

• Autotrophs

• Convert sunlight into chemical energy via photosynthesis.

Who are primary consumers in ecological terms?

• Herbivores

• Eat producers, such as rabbits and deer.

What defines secondary consumers?

• Carnivores or omnivores

• Eat primary consumers, like snakes and foxes.

Who are considered tertiary consumers?

• Apex predators

• Eat secondary consumers, such as hawks and wolves.

What does an energy pyramid illustrate?

• Shows the relative amount of energy at each trophic level.

What is measured in kcal or joules within an energy pyramid?

• The energy flow at each trophic level.

What does a biomass pyramid represent?

• Shows the mass of organisms at each trophic level.

What information does a numbers pyramid convey?

• Shows the number of individuals at each trophic level.

What defines an invasive species?

• Non-native species

• Disrupt ecosystems by outcompeting native species.

What effect does the kudzu vine have on ecosystems in the USA?

• Overgrows

• Smothers native plants.

What impact do zebra mussels have on aquatic environments?

• Outcompete native aquatic species.

What are some consequences of invasive species?

• Biodiversity loss

• Habitat destruction

• Economic damage.

What is ecological succession?

• The gradual change in ecosystems over time.

What is primary succession?

• Succession starting from barren land

• No soil, such as volcanic islands.

What characterizes secondary succession?

• Occurs after a disturbance

• Soil remains intact.

What are pioneer species?

• First organisms to colonize barren areas

• Includes lichens and mosses.

What are limiting factors in ecosystems?

• Factors that restrict population growth.

What are density-dependent factors?

• Factors affected by population size

• Examples include competition, disease, and predation.

What are density-independent factors?

• Factors affecting populations regardless of size

• Include natural disasters and climate change.

How do trophic levels relate to photosynthesis?

• Producers rely on sunlight for energy

• Forms the base of all trophic levels.

How can invasive species disrupt biodiversity?

• Alter population dynamics

• Outcompete native species.

In what way is ecological succession influenced by environmental cycles?

• Influenced by cycles such as carbon and nitrogen cycles.

What are two examples of secondary succession disturbances?

• Fire

• Flood.

What type of consumers are foxes categorized as?

• Secondary consumers.

What kind of organisms are lichens considered in the context of ecological succession?

• Pioneer species.

What role do producers play in an ecosystem?

• Convert solar energy into chemical energy

• Form the base for all other levels.

What can cause habitat destruction in ecosystems?

• Invasive species outcompeting native species.

How does climate change classify as a limiting factor?

• It affects populations independent of their size.

Can you name a common example of a primary consumer?

• Rabbits or deer.

What happens to energy flow as it moves up trophic levels?

• Energy decreases due to the 10% rule

• Most is lost as heat.

What is the main outcome of ecological succession?

• A gradual change in and development of ecosystems over time.