Energy flow 4

Question 1

Parasitoid

Answer 1

Any number of insects whose larvae live within and consume their hosts, usually another insect

Question 2

Detritivore

Answer 2

An organism feeds on a freshly dead partially decomposed organic matter

Question 3

Kleptoparasitism

Answer 3

A fundamental decision a foraging animal must make is how to obtain food and where to forage

Foraging in the presence of others- negatively impacting those others

Question 4

General energy flow in boreal ecosystems

Answer 4

Populations and communities can be treated as thermodynamic systems

Question 5

Energetics

Answer 5

Where energy goes when it enters the body and how much is lost

Question 6

Ways energy is wasted

Answer 6

Not used

Urinary waste

Egested

Question 7

Secondary production

Answer 7

Net primary production consumed by herbivores

1.5-2.5 percent in temperate deciduous forest

13 percent in Arctic tundra

60-90 percent in aquatic plankton communities

Question 8

Assimilation efficiency

Answer 8

Percentage of food energy ingested that is assimilated across the gut wall and becomes available for metabolism

Question 9

Nutritional content of plants as food

Answer 9

Body of green plants is quite different from body of animal

Plant cells are bound by cellulose, lignin and or other structural materials (high fiber)

Leads to carbon:nitrogen ratio of 40:1

Question 10

Nutritional content of animals as food

Answer 10

8:1 to 10:1 CN ratio (little structural carbs or fiber components, but are rich in fats and proteins)

Question 11

Why is assimilation efficiency so low

Answer 11

Mammals do not produce cellulolytic enzymes and cannot break down cellulose very efficiently

Many herbivores utilize microfauna that digest the cellulose and release nutrients

Question 12

Basic approaches to assimilation

Answer 12

Foregut fermenters- Low quality, high fiber food, but can extract nutrients easily

Hindgut fermenters-Eats lots of food because they do not extract nutrients easily

Question 13

Coprophagy

Answer 13

Eating faeces

Question 14

Autocprophagy

Answer 14

Eating their own faeces

Question 15

Caecotrophy

Answer 15

Eating soft faeces

Question 16

Willow ptarmigan

Answer 16

Their gut length changes according to the season

Question 17

Production efficiency

Answer 17

Percentage of assimilated energy incorporated into new growth and reproduction

Remaining energy goes into heat and repro

Question 18

Ecological efficiency

Answer 18

Percentage of production available at a lower trophic level that goes into production of energy

Question 19

Top down

Answer 19

Carnivores control number of herbivores

Question 20

Bottom up

Answer 20

Herbivores control number of carnivores

Question 21

In poor environments

Answer 21

Primary productivity will be too low to support herbivores

Bottom up

Question 22

With more primary productivity

Answer 22

The system can support herbivores but is unable to support predators

Question 23

When primary productivity can support herbivores and carnivores

Answer 23

The system should be dominated by the predatory-herbivore interaction

Top-down

Question 24

Reciprocal interactions

Answer 24

Control by predators that are dependent on prey

Question 25

Encountering predators when predator densities are high causes

Answer 25

Chronic stress on mother Lower reproductive success Passes on stress to child Lower repro success in offspring

Question 26

Regime shifts

Answer 26

An abrupt reorganization across trophic levels Ecosystems can shift to new states characterized by different species compositions and dominating interactions

Question 27

What controls primary production of boreal forests

Answer 27

Phosphorous

Question 28

Climate change implications

Answer 28

Potentially makes our understanding of ecosystem structure and trophic interactions to be incorrect Mismatch will have major implications for many species