Bio 120 exam 2

What is a/an introduced/exotic/alien/non-native species?

A species living outside of its native distribution

What are ecoregions? How are they different from political boundaries?

Areas where ecosystems are generally similar

– Geology, landforms, soils, vegetation, climate, land use, wildlife, and hydrology

What makes a species an invasive species vs. just a non-native species? What is the 10% rule?

Invasive species

– Alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health

10% rule

– 10% of non-native introduced species will survive in the new environment

– 10% of those will become invasive

How could a non-native species be introduced? (We talked about several ways this could happen.)

• On purpose

• Pet release / escape

• Shipping

What is ballast? How can ballast be a source of non-native species?

• Non-cargo weight used to provide stability

• Organisms can travel in ballast

• Global shipping is a huge source of invasive species

What types of organisms can become invasive species?

•Plant

• Animal

• Fungus

•Protist

• Microbe

• Viruses

What are the characteristics of invasive species, or why do species become “invasive?”

•Fast growth

• Rapid reproduction (not same as growth)

• High dispersal ability

• Tolerance of a wide-range of environmental conditions (ecological competence)

• Ability to live off of a wide range of food types (generalist)

• Association with humans

• Disturbance at invasion site

• Islands

What are some examples of the impacts that invasive species can have where they invade?

Zebra Mussels - Has a huge impact on ecosystems where they invade

Brown-headed cowbirds - Negative effect on songbirds

How can we manage invasive species? What are the differences between prevention, control, and eradication?

Prevention

– Early detection and rapid response

• Control

• Eradication

– Often very difficult

What is ecology?

scientific study of how organisms interact with one another and the environment and abundance and distribution of organisms

What is community ecology?

•Community = all species that interact with one another within a particular area.

•Studies interactions between species

What is coevolution?

•Pairs of species influence each others’ evolution

What is a habitat?

physical place where members of a population typically live

What is a niche?

total of all the resources a species needs

When does competition occur between 2 species?

Competition occurs when 2 or more species have overlapping niches

What are the differences between the species interactions competition, mutualism and commensalism?

Competition -/-

Mutualism +/+ both partners benefit

Commensalism +/0 one species benefits, other not significantly affected

What is a symbiosis? Which community interactions are considered a type of symbiosis?

•Close physical interaction between species

• Mutualism

• Commensalism

• Parasitism

What is the difference between predators and parasites?

predatos usually kill their prey and parasites usually do not kill their host at least right away

How can prey defend themselves from predators?

- Camouflage

– Warning colors

– Weapons and structural defenses

What is a keystone species

makes up a small proportion of the community by weight, yet has a large influence on community diversity

What is ecological succession?

Ecological Succession – gradual change in a community’s species composition

What is the difference between primary and secondary succession?

Primary succession – occurs in an area where no community previously existed

Secondary succession - occurs where a community is disturbed but not destroyed, with some soil and life remaining

What are the characteristics of pioneer species?

Pioneer species are the first to colonize

What is a climax community?

not much change at this point

What is an ecosystem?

all biotic (organisms) + abiotic (nonliving), components within a defined area

What does ecosystem ecology study?

–Nutrient cycling

–Energy flow

–between organisms and the atmosphere, soil, or water

What is a food chain? Trophic level?

Food chain – series of organisms that successively eat each other

Trophic level – position in the food chain

• What are autotrophs, producers, heterotrophs, consumers and decomposers/detritivores?

Primary producer/autotroph

– Directly or indirectly provide energy for all other organisms

• Consumer/heterotroph

– Obtain energy from producers or other consumers

• Decomposers

– break down detritus

• What is the difference between a primary and secondary consumer?

•Herbivores – primary consumer

• Carnivores – secondary or tertiary consumers

• What is a food web? Is it more realistic than a food chain?

Food web – network of interconnected food chains

A food web is more realistic than a food chain

• What is GPP? NPP? Why would anyone care about NPP?

•GPP = Gross Primary Productivity

–Total amount of photosynthesis

•NPP = Net Primary Productivity

–GPP minus energy lost to make ATP or lost as heat

–Energy invested in new plant tissue

• Does energy flow with 100% efficiency from one level in the food web to the next? If not, what is the efficiency rate?

2-30% energy transfer from one trophic level to the next

– “10% rule” convenient estimate

What is an energy pyramid?

Each trophic level is a block whose size is directly proportional to the energy stored in new tissues per unit time

Why does it take less acreage of corn to support human vegetarians compared to human meat-eaters?

The lower humans eat on the food chain, the more people we can feed

What is biological magnification (or biomagnification)?

When a substance becomes more and more concentrated in the tissues of organisms at higher trophic levels

What can happen to DDT in food webs?

Birds that are carnivores accumulate DDT in their tissues, produce brittle egg shells

• What is a biogeochemical cycle?

Organisms / environment interactions continuously recycle elements

• Water

• Nitrogen

• Phosphorus

• Carbon

Know that “hydrologic cycle” and “water cycle” mean the same thing.

YES

What is happening during the fluxes of the hydrologic cycle? 

1. Precipitation

2. Evaporation

• Temperature and humidity affect these

3. Interception

4. Transpiration

• 3 & 4 are connected to vegetation

5. Infiltration/Percolation

6. Overland Flow / Runoff

7. Storage

• 5, 6, & 7 happen in or below soil

How can human impact affect each of those fluxes?

1. Precipitation

• Increase in Earth’s air temperature can alter atmospheric circulation patterns

2. Evaporation

• Increase in Earth’s air temperature can increase evaporation

3. Interception

• Decreased with loss of forests and vegetation

• Can increase soil erosion

• Can increase runoff

• Can decrease evaporation

4. Transpiration

• It depends!

• Decreased w/ fewer plants than normal, especially trees

• Increased if more plants than normal

• Changes amount of water moving to atmosphere

5. Infiltration / percolation

• Increases with decrease in plants

• Decreases with increase in impervious surfaces

6. Overland Flow / Runoff

• Increases with decrease in plants

• Increases with impervious surfaces

How can human impact affect overland flow / runoff?

• Increases with decrease in plants

• Increases with impervious surfaces

• How can human impact affect storage?

It can happen in or below soil