REAL ECOLOGY TEST 3

Lets LOCK IN

What will be the outcome?

Species 2 excludes species 1

What does each alpha value represent?

Alpha = 1 → intraspecific competition = interspecific competition

Alpha > 1 → intraspecific competition < interspecific competition

Alpha < 1 → intraspecific competition > interspecific competition

What will the result be?

Either species 1 or 2 wins - we dont have enough info to predict accuralty

What will the result be?

Competive coexisting conditions, both species below their carrying capacity

What is one hypothesis that explains the success of invasive species?

Enemy release hypothesis:

• Absence of natural enemies in invaded environment allows introduced populations to attain greater abundances

What is one hypothesis that explains the downfall of invasive species?

Biotic resistance hypothesis:

• Species-rich communities are more resistant to invasion

  • Why: More niches filled by other species, higher ability to compete,

For Rhizobium bacteria:

What mutualism is it?

What does each party beenfit?

Trophic:

Bacteria converts N2 for plants

Plants provide carbon through photosynthesis to bacteria

What are the five types of mutualism and their basic definition?

Defensive: species recives food/shelter for providing protectionn

Obligate: They both rely on each other for survival and reproduction

Faculative: Both benefit, bot interactions are not needed

Trophic: Partners specialize in complementary ways to obtain energy and nutrients

Dispersal: One takes food, and disperses seeds/pollen

Example of a cheater!!

Orchid flower:

• resembles female wasp

• Males come to mate with the flower, no reproduction happnes

• But wasp took pollen, so now flower can spread pollen

Is the cost of defense higher for slow-growing plants or fast-growing plants?

Fast growing plants!

Qualitative vs Quantitative defense:

Qualitative:

• Most effective against generalists

• lower concentration → lower effect

• Smaller molecular weight compounds

Quantitative:

• Most effective against specialists

• higher concentration → higher effect

• Reduce digestibility

What organism is typically recruited as a biotic defense for plants?

Insects, commonly such as ants.

What is a nonlethal effect of predator on prey?

Reduced feeding

Example: Mayfly nymphs reduce feeding activity due to predators

What is the pattern between garter snake and newt?

• The more toxic the newts, the more resistant the snakes

• Snakes that are more resistant are slower at moving

• In places where newts did not become as toxic due to the possible lack of predators

Interspecific vs Intraspecific competition:

Inter- between members of diff species

Intra- between members of same species

Fundamental niche vs Realized niche:

Fundamental: Range of conditions/resources to which a species is adapted

Realized: Portion of fundamental niche that it can actually live in. The actual range

Draw the lines:

Okay i did it.

What should you know about basic predator-prey model?

It leads to predator-prey population cycles

Fill in this model

Did it

DI/dt formula

BetaSI - vI - alphaI - dl

dS/dt formula-

b(S+i+r) - betaSI + yR -dS

dR/dt forumal-

vl - yR - dR

What parameter deals with SIR model and vaccination

S (density of susceptible)

What parameter deals with SIR and culling (disease and predation)

alpha (disease-related death rate)

What parameter deals with SIR and mask-wearing and like that

Beta (transmission rate)

What parameter deals with SIR infection and treating infection

v (recovery rate)

What principle relates to giraffe’s eating leaves?

Competitive Exclusion Principle:

• 2 species that use a limiting resource in the same way cannot coexist indefinitely

What does each alpha represent?

• Alpha = 1 ~ Intraspecific comp = interspecific comp

• Alpha < 1 ~ interspecific comp is less intense than intraspecific comp

• Alpha > 1 ~ interspecific comp is more intense than intraspecific comp

Parasite and water relationship:

Waterborne transmission

Give an example of a situation in which a parasite can afford to evolve a high level of virulence

If parasites can survive longer in external environemnts:

Draw coexisting grpah

they be coexisting and zero net grtowth