Week 3 Part 2

Question 1

What is secondary production

Answer 1

Heterotrophs get their energy by consuming organic compounds that were produced by other organisms which is secondary production

Question 2

What is the equation of Net secondary production

Answer 2

Igenstion- respiration-egestion

Question 3

What is lower net secondary or primary production

Answer 3

Secondary because so much is lost

Question 4

What are trophic interactions

Answer 4

What they eat and what eats them determines the influence of an organism on the movement of energy and nutrients through an ecossytem so it describes the feeding positions of groups of organisms in ecosystem

Question 5

What are the different levels of trophic interacations

Answer 5

Autotrophs - herbivores - primary carinvores - secondary carinvores

Question 6

What are detritus and detrtivores apart of

Answer 6

Detritus is the first trophic level detritivores are part of the second level

Question 7

What is allochthonous

Answer 7

External energy inputs for example the stuff that grows on the outside of rivers dies and goes into the water

Question 8

What is autochthonous

Answer 8

Energy produced by autotrophs this becomes more important as water flows downstream (energy that comes from itself)

Question 9

What bodies of water reley on what

Answer 9

Moves downstream wider rivers and slower current autochthonous because more important

Question 10

What do trophic pyramids portray

Answer 10

Realtive amounts of energy or biomasses at each trophic level

Question 11

What do terrestrial ecosystems pyramids look like

Answer 11

Heavier on the base for both energy and biomass

Question 12

What do aquatic ecosystems trophic pyramids look like

Answer 12

Energy is the same most exist at the lowest trophic level but inverted biomass there are not alot of primary producers

Question 13

Where are inverted biomass pyramids most common

Answer 13

When productivity is lowest such as nutrient- poor regions of the open ocean because there is very few nutries avialble anything that does usally get eaten

Question 14

What are the three hypotheses of why don’t terrestrial herbivores consume more of the available biomass

Answer 14

1. Herbivores are constrained by predators and never reach carrying capacity (experiments support this hypothesis in some ecosystem)
2. Autotrophs have defences against herbivory such as secondary compounds
3. Phytoplankton are more nutritious and easier to digest for herbivores than terrestrial plants (there is a lot of terrestrial herbivores where not every part is nutrious

Question 15

What plants have stronger defences

Answer 15

plants from resource-poor environments

Question 16

What is trophic efficiency and how much gets transfered

Answer 16

Amount of energy at one trophic level divided by the amount of energy at the trophic level immediately below it about 10% gets transfered

Question 17

What is consumption efficiency

Answer 17

Proportion of available energy that is consumed ( how good is the trophic level of consuming)

Question 18

What is assimilation efficiency

Answer 18

Proportion of ingested food that is assimilated lost during respiration and injestion

Question 19

What is production effciency

Answer 19

Proportion of assimilated food that goes into biomass

Question 20

Where is consumption higher

Answer 20

In aquatic ecosystems that in terrestrial ecosystems also tend to be higher for carnivores than for heribvorese because they arent intrested in eating woody parts of the plants there more food for carnivores

Question 21

Why is foodquality of plants and fetritus low

Answer 21

Complex compounds such as cellulose and lignin that are not easily digested 2. Low concentrations of nutrients such as nitrogen and phosphorus

Question 22

What is production of efficiency related to

Answer 22

Thermal physiology and the size of the consumer endotherms allocate more energy to heat production and have less for growth and reproduction and have less for growth and reproduction than ecotherms

Question 23

What effects heat loss

Answer 23

Body size as body size increase the surface area to volume ration decreases

Question 24

What has the lowest production efficiency

Answer 24

Birds because they are so active

Question 25

What determines the # of trophic levels in an ecosystem

Answer 25

1. The amount of energy entering via primary production: More production should allow more trophic levels the larger the base the more levels
2. Frequency of disturbances Higher trophic levels depend on lower levels, and take time to re-establish after disturbance for higher to even exist if disturbance is frequent higher levels may never establish
3. Ecosystem size larger ecosystems support larger populations, have more habitat heterogenity and higher species diversity

Question 26

What did a study in the Bahamas show

Answer 26

Found that island size was correlated with number of trophic levels. Disturbance frequency didnt really impact it hto

Question 27

What are food webs

Answer 27

Conceptual models of the trophic interactions of the organisms in an ecosystem

Question 28

What is a problem with food webs

Answer 28

Many organisms change their feeding over their lifetime

Question 29

Why did Inuit women have higher PCB concentration in their breast milk higher than women in southern quebec

Answer 29

The higher up the trophic level they feed the highest levels of POP. Concentrations of these animals at higher trophic levels become higher eating prey withhigher concentrations this is biomagnificaition

Question 30

What are PCB

Answer 30

Industrial chemical compounds they remain in the envionroment for a long time have no direct exposure to PCBS

Question 31

How do PCB get to the Artic

Answer 31

Produced at low latitudes are in gaseous form and enter the atmospher circulation patterns carry them to the artic where they condens to liquid and fall to earth

Question 32

What is the relation to POP and diet

Answer 32

Communities that eat mammals tend to have the highest levels of POP eating

Question 33

What is bioaccumulation

Answer 33

Chemicals are not metabolized or excreted and become progressively more concetrated in tissues over an organisms lifetime