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Flashcards in Exam 3 Deck (18)
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1
Q

Gamma Diversity

A

Number of species in a regional pool

  1. Can limit the number per species, but give an area great population density
2
Q

Net Ecosystem Production

A

The difference between the amount o organic carbon fixed in an ecosystem by photosynthesis and total ecosystem respiration

  1. Determine if the ecosystem is autrophic or heterotrophic
3
Q

Assimilation Efficiency

A

. Proportion of ingested food that is assimilated- how efficiently an organism extracts energy from what it eats

  1. The absorption and digestion of food or nutrient by the body
4
Q

Gross production efficiency

A

Rate at which photosynthesis occurs by plants in a given are

  1. total amount of carbon being fixed by autotrophs
5
Q

Obligate Mutualism

A

When two species provide fitness benefits to each other and require each other to persist

  1. Keystone species, helps keep two species alive
6
Q

What did Robert McArthur find when studying warbler distributions in trees in Maine conifer forests? How did his study contribute to our knowledge on what determines local species diversity?

A

a. As the height of the tree foliage density increase, the number of warblers increased
b. The number of niches controls the number of species that can reside in an area
c. Higher the tree means more the different niches

7
Q

Explain the intermediate disturbance hypothesis in relation to species richness. and label the axis.

A

Low disturbance: leads to competition exclusion

High disturbance: filters out all but most opportunistic species= adapted species

Medium disturbance: good competitors can establish, but not take over

X- axis: Disturbance frequency
Y- axis: Number of species

8
Q

Define one type of mutualism and give an example from the book or lecture.

A

Obligated mutualism: two species provide fitness benefits to each other and require each other to persist

i. Soap weed and Yucca moth: yucca moth is the sole pollinator and larvae dependent on soapweed

9
Q

Pick an organism that is a keystone species. Using the definition of what a keystone is, justify why this species is a keystone species.

A

Keystone species: One species that falls the rest and will fall in a cascade

i. Pisaster: When it is present the mussel population decreases allowing there to be an increase in population diversity
ii. When the pisaster is not present the mussel population increases causing population density to decrease

10
Q

You are studying cougar hunting behavior in the Laramie Range and find that they eat 50 mule deer per year and 20 white tailed deer. The population sizes of the deer in the same are 1000 mule deer and 60 whitetails. Of these 2 links in the food web, which link likely has a higher interaction strength? Why?

A

a. Proportionally more whitetail deer are consumed
i. 20/60=0.33> 50/1000= 0.05
b. Interaction strength for whitetail deer is higher
i. (20-60)/60= -0.667
ii. (50-1000)/1000= -0.95

11
Q

What is the difference between primary and secondary succession? Give an example of each for terrestrial plants.

A

a. Primary= where no plants have been before, a blank slate
i. Ex. Glaciers
b. Secondary= where a plant community has something to build on
i. Ex. Fires; previously existing vegetation

12
Q

What element limits the rate of primary production in the Southern Ocean (the ocean around Antarctica)? How did oceanographers find that out?

A

The amount of ice determines whether primary production can produce so the element that determines amount of ice is temperature. they used remote sensing.

13
Q

Island biogeography. Draw a graph of how colonization rate vs. the number of species changes for two islands near and far from the mainland. Don’t worry about extinction rate here-just colonization. Label the axes.

A

Size of the island influences extinction rate where distance from island influence colonization rates. So islands closer to mainland have more species colonization there.

This graph X= number of species Y= # spp/year

Regular graph
x= number of species
Y= colonization
Z= extinction

14
Q

How did Simberloff and Wilson test this prediction of Island biogeography (i.e. distance from mainland) in mangrove islands in Florida? What did they find? Label axes on any graphs.

A

a. Fumigated island and watched species recolonize
b. Islands closer to the mainland prospered while farther islands did not do as well

x= time
y= number of species
15
Q

Name and give the mechanism behind 2 controls of terrestrial net primary production.

A

a. Grazers: control NPP, usually decreases but sometimes it can increase
i. Ex. Wildabeasts eating grass
b. Water and temperature: increase NPP if temperature and precipitation increase

16
Q

You measure secondary production of the herbivore assemblage on the Serengeti (wildebeest, antelope, etc) and find that it is 100 times lower than the net primary production of their primary food, the grasses. Where did all of the rest of the carbon go?

A

The carbon was either respired or used for decomposition

17
Q

In your summer internship, your supervisors send you down to the Laramie River for the afternoon to observe feeding habits and then asks you to construct a food web based on those observations. What is a food web? Is it possible that your depiction of the food web will be complete? Why or why not?

A

a. Food web: is the related links between consumers and prey
b. Depending on how long you stay and observe it is possible your food web will be completed, but not very likely. There is so much of who eats what it is very unlikely that you will see every interaction.

18
Q

Kit foxes in Southern California sneak around neighborhoods at night. It is believed that these rare foxes actually do well around humans because they receive a tasty garbage subsidy from trashcans in alleys. Given that much human food scraps found are based on plants with C4 photosynthesis (corn, cane sugar), how could you tell how much garbage foxes eat relative to native prey (which all eat plants with C3 photosynthesis)? Please describe, in some detail (draw a graph of the data) the method you would use to measure the foxes diets given that they are easily trapped, but are too sneaky and rare for behavioral studies.

A

Isotopes where used to determine where the plants consumed are C3 or C4. Istotope carbon C13 is higher means the plant is C4