Chapter 42: Ecosystems and Energy

How do detritivores and decomposers fit into the food chain/web?

they fit into the end of the web cycling energy back into the earth and preparing for the restart of the process

What is the difference between energy flow and cycling?

energy flows through the system once then leaves but chemicals are what is cycled through the ecosystem over and over again

Primary productivity

the rate at which plants and other producers make energy (food) from sunlight or chemicals in an ecosystem

Eutrophication

when too many nutrients build up in water, causing lots of algae to grow and when algae dies, oxygen in water drops and kills organisms

Limiting nutrient

the nutrient that is in shortest supply and controls how much organisms can grow in an ecosystem

Key biotic and abiotic factors impacting the primary production in aquatic ecosystems:

B: amount of algae, plants, phytoplankton, herbivores that eat producers, decomposers, and bacteria that recycle nutrients

A: light, nutrients, temperature, carbon dioxide, oxygen levels, water movement

Key biotic and abiotic factors impacting the primary production in terrestrial ecosystems:

B: types of plants, herbivores that eat plants, decomposers that recycle nutrients,

A: sunlight, water availability, nutrients, temperature, carbon dioxide

Production efficiency

how well an organism turns its food into growth and new biomass

Tropic efficiency

how much energy actually gets passed from one tropic level to the next

Difference in biomass pyramids between terrestrial and aquatic ecosystems

Terrestrial: plants (producers) have the most biomass and it decreases as you move up to herbivores and so on

Aquatic: phytoplankton (producers) have very little biomass at any moment but reproduce super fast supporting more biomass of herbivores at higher levels

Why are the top level carnivores more likely to go extinct and why?

• less energy available

• small populations

• large space/food needs

• slow reproduction

• human impacts

Biogeochemical cycling

how essential elements get cycled and reused between organisms, the atmosphere, soil, and oceans

Water cycle

1. Evaporation

2. transpiration

3. condensation

4. precipitation

5. run off

6. infiltration

Carbon cycle

1. photosynthesis

2. respiration

3. composition

4. combustion

5. ocean exchange

Human impact on water cycle

pollution alters precipitation and reduces infiltration ( which reduces more run off)

Human impact on carbon cycle

deforestation and more fossil fuels creates more co2

Human impact on nitrogen cycle

nitrogen run off and water creates utrafication (process where water bodies become overloaded with dissolved nutrients which is bad)

Human impact on phosphorus cycle

Mining phosphate rocks removes phosphorus from soil and affects the cycle