Ecosystems

trophic interactions

feeding interationcs

primary producers

species that capture sunlight and build it into chemical bonds through photosynthesis; form organic matter from inorganic matter

primary consumers

eat primary producers

secondary consumers

eat primary consumers

detritivores

species that consume dead organic matter

top carnivore

carnivore at the top of the food chain

secondary production

production of consumer biomass

bottom-up impact

change at a lower trophic level that impacts the levels above

top-down impact

change at at top trophic level in food chain that impacts population size at lower levels

gross primary production

total organic matter formed from inorganic matter by primary producers

net primary production

amount of energy resources left for the consumers in the ecosystem to acquire through herbivory

where is most NPP?

in the world's oceans near algal beds and coral reeds

greatest NPP on land

tropical rain forest

Biosphere

entire ecosystem of the world

what is the energy obtained by each organism used for?

- maintenance of the organisms

- growth and reproduction

- lost as heat or excreted waste from the organism

biomass

combined mass of all the organisms of that species or group in the ecosystem

biomagnification

accumulation of toxin when consumers eat many prey

when can the biomass pyramid invert?

population ecology of the producers includes rapid generation times and little investment in building a physical body

compartments

places where matter is stored (e.g. carbon in rocks, plants, the ocean)

flux

movement of matter between compartments

why does carbon flux?

respiration, photosynthesis, decomposition, burning

does carbon cycle fast in organisms or the environment?

organisms

carbon sink

the carbon in rock is unavailable for use bc it is buried deep in the earth

where is the majority carbon tied up?

tropical forests

what reduces atmospheric CO2?

terrestrial photosynthesis in northern hemisphere during spring and summer

The greatest amount of energy loss in ecosystems occurs through

respiration

Which of the following is true regarding primary production?

Can be fueled by light or chemical reactions

Is the conversion of inorganic to organic matter

Is typically followed by secondary production (heterotroph production)

Creates organic matter from organic matter

Is the basis of most food webs and chains

Can be fueled by light or chemical reactions

Is the conversion of inorganic to organic matter

Is typically followed by secondary production (heterotroph production)

Is the basis of most food webs and chains

Gross primary productivity is higher than net primary productivity. The difference between the two is

the amount of energy that producers burn when they metabolize.

Why are big, fierce animals rare? Most big, fierce animals are tertiary consumers, which implies that

It's hard for an ecosystem to support many of them because so much energy is lost at each level of energy exchange.

Which of the following processes transfers the most energy in a forest ecosystem?

Photosynthesis

Organismal Digestion

Excretion

Respiration

Death

Photosynthesis

About how much energy is transferred from one trophic level to another through feeding interactions?

10%

Which of these organisms can produce organic matter from inorganic materials?

heterotrophs

photoautotrophs

detritivores

chemoautotrophs

chemoheterotrophs

photoautotrophs

chemoautotrophs

Adding autotroph respiration to net community production yields:

Gross primary production

What factors contribute to the difference in shape of biomass pyramids in terrestrial and aquatic ecosystems?

- Terrestrial plants invest a great deal of biomass in structural materials

- In aquatic systems, primary producers can grow much more rapidly than secondary producers

How does the amount of energy available change with increasing trophic level in a food web?

The energy available decreases sharply with trophic level in all ecosystems.

What factor(s) is/are the primary drivers of the annual oscillation in carbon dioxide concentration in the atmosphere?

- CO2 decreases during the Northern hemisphere spring-summer due to terrestrial photosynthesis

- CO2 increases during the Northern Hemisphere winter due to terrestrial respiration.

Biological productivity is commonly limited by nitrogen availability, yet large quantities of N2 are present in the atmosphere and dissolved in the ocean. How can this be?

- N2 can be used by only a few organisms possessing specialized enzymes, so the nitrogen in N2 is unavailable to most organisms.

- Although nitrogen fixation introduces biologically available nitrogen to ecosystems, denitrification converts this biologicaly available nitrogen to N2, making it unavailable to most organisms.

Which of the following fluxes of C is currently the largest?

plant respiration

fossil fuel combustion

respiration by microbes and decomposers

absorption of CO2 by the ocean

deep sea burial of organic carbon

absorption of CO2 by the ocean

Why does a biomass pyramid for a forest show less biomass at the primary consumer level than a grassland does?

Most of the biomass in a forest is tied up in material that is difficult to digest.

We are concerned about carbon dioxide increases in our global atmosphere. Imagine that we planted trees over a large area to grow into a forest perhaps the size of Australia. Would this be a good, permanent way to stop or slow the accumulation of carbon dioxide in the atmosphere?

Perhaps, but when the trees died and decayed, the carbon dioxide would be returned to the atmosphere.

Predator-prey interactions have led to the co-evolution (in the direction indicated) of all of the following except

more cryptic colouration in the predator

more cryptic colouration in the prey

more showy tails as secondary sexual traits in male birds

stronger aposematic colouration in the prey

stronger mimicry of a toxic prey by a non-toxic prey species.

more showy tails as secondary sexual traits in male birds

Which of the following statements about the distribution of barnacles in rocky intertidal systems is/are correct?

the upper limit of a barnacle's distribution is generally set by physical factors.

the lower limit of a barnacle's distribution is generally set by biological factors.

most barnacle species can survive in a broader zone of the intertidal than they actually occupy as adults.

All of the above.

None of the above.

All of the above.

Food webs are made up of:

food chains

producers and consumers

trophic interactions

all of the above

all of the above

Biomass pyramids in the open ocean are inverted in comparison to most terrestrial ecosystems because

the producers reproduce so rapidly that a smaller biomass of producers can support a larger biomass of herbivores.

Which of the following are responsible for the conversion of most organic material into CO2, which can be utilized in primary production?

primary producers

How is it that the open ocean supports the highest total net primary productivity of Earth's ecosystems, yet net primary productivity per square meter is relatively low?

Oceans have the greatest total area.

For the past 150 years there has been a major new input to the carbon cycle. What is it?

Industrialization has resulted in the burning of fossil fuels such as oil and coal, which releases CO2 into the atmosphere.