Ecology Test 3

What is ecology?

What is ecology?

The scientific study of the interactions between organisms and their environment (including both biotic and abiotic factors)

What is an example of a BIOTIC environment of an organism?

predators

What are BIOTIC environment examples?

- predators

- mates

- prey/food

- host organisms

- competitors

- symbiotic species

- parasites/pathogens

- HUMANS

What are ABIOTIC environment examples?

- Physical factors: temperature, light, relative humidity

- Chemical factors: pH, oxygen, chemical pollution, nitrogen, phosphorus

What are the structural scales in order from smallest to largest?

1. atom

2. molecule

3. cell

4. tissue

5. organ

6. organ system

7. organism

8. population

9. community

10. ecosystem

Population ecology might study what?

Male:female ratios of coyote population

Community ecology might study what?

Number of bird species present in a forest

Ecosystem ecology might study what?

Effects of precipitation on biodiversity

Organismal ecology might study what?

Effect of temperature on crayfish metabolic rate

To convert population size to population _________ divide the population size by unit area (for terrestrial species) or volume (for aquatic species).

density

What are examples of methods used to count individuals in a population?

surveys (absolute population size), mark recapture (estimate of population size), abundance index (estimate of population size), quadrat sampling (estimate of population size)

What does CPUE stand for and what are the units?

Catch per unit effort

(h^-1...m^-1, ie.)

What are the pros of living in a high-population density environment?

defense from predators, higher genetic diversity, easier to find a mate

What are the cons of living in a high-population density environment?

more susceptible to disease, high competition for mates, more competition for oxygen, reduced survivorship, reduced growth of individuals

Population Pyramid mechanisms?

A: increases most rapidly

B: increases slowly

C: stable

D: decreasing

Population size of (r / k) strategists is limited by reproductive rate, while population size of (r / k) strategists is limited by the carrying capacity of the environment

r; k

What are characteristics you would see in a k-strategist?

- reproduce only to levels that the carrying capacity of the environment can support

- be large; long lived

- produce few offspring

- slow growing populations

- more stable populations

- have parental care

What are characteristics you would see in a r-strategist?

- reproduce at the fastest rate possible

- be small; short lived

- produce many offspring

- fast growing populations

- population size varies over time

- no parental care

Why isn't every species everywhere?

- Resource limitation

- Insufficient time for dispersal

- Barriers to dispersal

- Presence of competitors or predators

What is a generalist?

organisms that can tolerate a wide variety of habitats and resources; tend to have large geographic ranges (succeed to live under many conditions)

What is a specialist?

organisms with a specific habitat and resource requirements; they tend to have small geographic ranges (vulnerable to condition changes)

Which tends to have a larger geographic range: specialists or generalist?

generalist

Which is more vulnerable to extinction when the environment changes: generalists or specialists?

specialist

True or false: the vast majority of species on earth are GENERALISTS

false

What are some examples of barriers to dispersal?

- Mountain ranges

- Large bodies of water

- Canyons

- Dams

- Human development

Random, clumped and uniform distributions?

Random, clumped and uniform

Which would grow faster: a population with more males than females, or females than males?

More females than males

Which environmental factor directly affects male-female ratios in reptiles?

temperature

Which country in the world enacted a "one-child policy" between 1979-2015?

china

Which causes population size to INCREASE: immigration or emigration?

immigration

Populations tend to go (linearly / exponentially), assuming no resource or space limitations?

exponentially

At which point of population growth below is the growth rate the fastest, in the graph below? At A, B, or C?

B

The maximum rate of increase for a population is termed _______?

Fecundity

History Factors effecting fecundity?

- body size

- parental care

- longevity

If parental care is removed from the equation, and females simply make as many offspring as possible, fecundity correlates with ______?

female body size

Carrying capacity has been reached at which point on the curve?

"K" line

What sorts of factors affect the environment's carrying capacity?

- disease

- competition

- oxygen depletion

- ammonia toxicity from waste

What happens when a population overshoots its carrying capacity?

dieback

Quantify species richness in Community 1 and Community 2

These two communities have the same species richness

Which community has greater species evenness?

Community 1

What is an autotroph?

(producers) make their own food through photosynthesis and chemosynthesis

- Ex: plants and some protists

What is a heterotroph?

(consumers) obtain energy by eating

- Ex: giraffe and squirrel

Primary Producer is another name for ______?

autotroph

Examples of autotrophs you would find in the shallow ocean?

phytoplankton and seaweed

Examples of autotrophs you would find in the deep ocean?

chemosynthetic autotrophs around deep sea vents

What is gross primary productivity?

total glucose produced by autotrophs (not counting respiration costs)

What is net primary productivity?

gross primary productivity minus respiration

What are some examples of ecosystems with high net primary productivity?

Tropical rainforest, algal beds and reefs, swamp and marsh

Primary consumers are also known as ______?

herbivores

What percent of energy consumed at one trophic level is available to be passed on to the next? Where does the rest of the energy go?

- 10% of energy consumed gets passed on to the next trophic level when the organism gets eaten

- Some is respired and some is pooped out

A forest with 1,000 kg of plants could support approximately_______ kg of primary consumers, and _______ kg of secondary consumers.

100; 10

What are some examples of ecosystems with very low NPP?

tundra and desert

What is a keystone species?

A species may be low in abundance, but still plays an extremely important role in balancing community structure

In the otter/abalone/kelp/fishermen story, which species was the keystone species?

otter

Why is there an overabundance of deer on the east coast (and elk in the west)?

- There is low predation when there is an overabundance of deer

- Wolves eat elk but not deer

Removing top carnivores results in a (top-down / bottom-up) trophic cascade?

top-down

: Converting forest to farmland would result in a (top-down / bottom-up) trophic cascade?

bottom-up

What is a fundamental niche?

the range of environmental conditions an organism could survive and thrive in, if not restricted by predation, competition, etc.

What is a realized niche?

the range of environmental conditions in which you actually find an organism in lieu of other species

- Ex: predation and competition

Which is larger: a species' fundamental or realized niche?

fundamental

Which scenario below illustrates Chthamalus (brown barnacle) in its realized niche?

Top: realized

Bottom: fundamental

According to the competitive exclusion principle, if two species' niches overlap, what are two possible outcomes?

1. The weaker competitor will be regulated to another part of its niche with less competition

2. The weaker competitor will go locally extinct

You should find the greater number of species in:

- complex habitats

- habitats with many refuges or hiding spots

- habitats with many different food options

The process illustrated:

character displacement

Examples of disturbances that would precede primary succession?

- lava flow

- land slide

- glacial retreat

What would you see in a disturbed site about to undergo primary succession?

bare rock

What organisms can grow on bare rock?

lichens (pioneer species)

Examples of disturbances that would precede secondary succession?

- fire

- flood

- mowing

What is the correct order of plant groups in which they would move in following a disturbance?

1. annual herb

2. perennial herbs

3. pine trees

4. hardwood trees

Why do pine trees move into a cleared field before hardwood trees (like oak, pine, and hickory)?

they thrive in a dry, sunny environment

The transition stage of a forest involves the transition from?

pine to hardwoods

What economically valuable resource do old growth forests contain?

carbon

True or False:

Some species require fire to reach maturity

True

The greatest number of species tend to occur in habitats with ________ disturbance?

intermediate

Which life history strategy dominates during EARLY succession?

r

Which life history strategy dominates during LATE succession?

k

What are the stages of lake succession in order?

1. oligotrophic

2. mesotrophic

3. eutrophic

Which stage of lake succession is characterized by deep layers of organic sediment?

eutrophic

Humans can accelerate the speed at which lakes undergo succession through addition of ______?

fertilizer

What is eutrophication?

when nutrient tun-off leads to large blooms of phytoplankton

How do "Dead zones" result?

eutrophication leads to dead zones

What are dead zones?

areas of low oxygen levels that are detrimental to marine life

What is mutualism?

both organisms benefit (+/+)

What is commensalism?

one benefits and the other is unaffected (+/o)

What is parasitism?

one organism benefits at the expense of the host (+/-)

What are examples of mutualism?

1. gut bacteria that help organisms digest plant matter

2. remora and sharks

3. oxpecker birds and mammals

4. mycorrhizae and plants

5. acacia trees and ants

6. fungi and algae in lichen

What are examples of commensalism?

1. barnacles and whales

2. lichen and the tree it grows on

What are examples of parasitism?

1. aphids and plants

2. brown-headed cowbirds and other tree-nesting song birds

3. parasitoid wasps

What is a endoparasite?

parasite that lives inside the host

What is a ectoparasite?

parasite that lives on the surface of the host

True or false:

Desert climates are defined by low precipitation year-round

True

Most of the world's deserts occur at ______ latitudes and on the _______ side of mountain ranges.

30* North and South; leeward

What are some examples of adaptations of plants to the desert?

- small leaves

- spines

- photosynthesis moved to stem

- water storage

- spacing

- CAM photosynthesis

How is CAM photosynthesis similar and different to C4 photosynthesis?

They are similar because both involve storing CO2 as 4-carbon molecules, allowing stomata to close and water to be conserved. They differ in that CAM plants open stomata and store CO2 AT NIGHT while C4 plants do it during the day, and store CO2 in special enlarged "bundle sheath" cells

What are some examples of adaptations of animals to the desert?

- derive water from metabolism

- often nocturnal to stay cool and retain water

Which biome is known for frequent fires during summer?

Chaparral biome because it has hot and dry summers

Chaparral climates are defined by (dry / wet) summers and (dry / wet) winters.

dry summers and wet winters

What are some examples of places you could go to see chaparral?

- Southern California

- Athens Greece

- Tuscany Italy

What is the coldest biome?

Tundra: average temperature is -5C

What is the difference between alpine and arctic tundra?

- Alpine tundra: begins at the treeline due to it is the altitude where it is too cold for trees to grow

- Arctic tundra: below treeline