AP BIO Unit 8 Chapter 42 + 43

All the biotic and abiotic factors in a given area

Study of ecosystems focuses on nutrient and energy flow

Energy cannot be created or destroyed

Every exchange of energy increases the entropy of the universe

Matter cannot be created or destroyed

Energy flows through an ecosystem

Nutrients cycle through an ecosystem

The amount of light energy converted to chemical energy during a given time period

Varies by ecosystem

Total primary production in an ecosystem

How much photosynthesis has happened

(Think how much you made at work)

GPP minus the amount of energy used by primary producers for respiration

Only refers to the amount of NEW biomass added

(Think paycheck after taxes)

Total biomass accumulated during a given time

Gross primary production minus ALL respiration

Light

Nutrient limitation (nitrogen, phosphorus)

Temperature

Moisture

Nutrients

Factors that affect production in aquatic ecosystems

Factors that affect production in terrestrial ecosystems

Amount of energy in a consumers food that is

converted to its own biomass

Only about 10% of energy is passed up a tropic

level. Dif animals get dif %

The rest is lost as heat, cellular respiration, feces,

etc

The lowest population is going to be the tertiary consumers, as there’s not enough energy to feed a huge amount of tertiary consumers.

limited by the amount of energy

long food chains are less stable and subject to population fluctuations

Water cycle

Cardon Cycle

Phosphorus Cycle-

A discipline that integrates ecology, physiology, molecular biology, genetics, and evolutionary biology to conserve biological diversity at all level

Both within a population and between populations

The variety of species and ecosystems

Species could provide food, medicine, and even

materials

How natural ecosystems help sustain life

Using plants to detoxify air

Decompose our waste

Habitat loss

Introduced or nonnative species

Overharvesting and overfishing

Global Change

Caused by combustion of fossil fuels

Sulfuric acid and nitric acid are formed in the atmosphere and carried by wind.

Calcium is leeched from the soil and pH of water is lowered

Agriculture constantly removes nutrients from

ecosystems that would ordinarily be cycled back

into the soil

Nitrogen is the main nutrient lost through

agriculture.

The amount of added nutrient that can be absorbed by plants without damaging the ecosystem

When nutrients, usually nitrogen or phosphorus, become extremely high

Leads to rapid algae growth

Algae covering the top leads to plants on the bottom dying - which leads to no oxygen (Anoxia).

Too much could lead to the warming of the atmosphere

Excess nitrogen is added

Algae and phytoplankton grows

Zooplankton eat algae and phytoplankton

Some of the producers die, and zooplankton ‘poops’

Bacterial decomposers thrive off the dead waste and poop

They use lots of oxygen for respiration

Oxygen is all used up

Everything else dies

Humans release toxins - which are not easily broken down

Ex: PCB’s (cause cancer) and DDT (thyroid problems)

That means each level has to eat more of the level

below it

Toxins concentrate at higher trophic levels because at these levels biomass tends to be lower

Ozone protects life from UV radiation

Need it so we don’t get cancer

Due to the increased burning of fossil fuels and

other human activities

• The concentration of atmospheric CO2 has been steadily increasing

The greenhouse effect is caused by atmospheric

CO2

necessary to keep the surface of the Earth at a

habitable temperature