Ch. 55: Ecosystems

Question 1

ecosystem

Answer 1

sum of biotic and abiotic interactions in an area

Question 2

flow of energy

Answer 2

energy (usually sunlight) transformed to chemical energy by autotrophs, all eventually lost as heat

Question 3

cycling of nutrients

Answer 3

elements continually recycled; move between ecosystems

Question 4

primary producers

Answer 4

autotrophs; plants and protists

Question 5

primary consumers

Answer 5

herbivores that consume producers

Question 6

secondary consumers

Answer 6

carnivores that eat herbivores

Question 7

tertiary consumers

Answer 7

carnivores that eat carnivores

Question 8

detritivores/decomposers

Answer 8

get energy from detritus (non-living organic material

Question 9

primary production

Answer 9

amount of light converted to chemical energy in a given span of time

Question 10

gross primary production

Answer 10

total primary production for an ecosystem

Question 11

net primary production

Answer 11

part of production stored as organic matter; gross primary production minus respiration

Question 12

measure of light absorption

Answer 12

use light reflected back to satellites to measure how much is being absorbed by chlorophyll; highest in warm, humid, tropical, terrestrial areas, not that productive in oceans

Question 13

secondary production

Answer 13

new biomass added to consumers; amount of primary production converted to consumer

Question 14

assimilated

Answer 14

energy that is used or stored

Question 15

respiration

Answer 15

used energy

Question 16

% production efficiency

Answer 16

(net primary production)/(assimilated primary production)*100%
-endotherms have low efficiency 1-3%
-ectotherms have 10-40%

Question 17

trophic efficiency

Answer 17

% production transferred up to the next level; can express pyramid of net production (J)

Question 18

limiting nutrient

Answer 18

if adding a nutrient increases productivity then it is limiting

Question 19

eutrophication

Answer 19

increased algal production due to pollution, results in drop in oxygen

Question 20

biogeochemical cycles

Answer 20

nutrient cycles through ecosystems; both biotic and abiotic

Question 21

4 most important nutrient cycles

Answer 21

H20, C, N, P

Question 22

reservoirs

Answer 22

storage of nutrients; nutrients transferred between

Question 23

decomposition

Answer 23

critical for cycling; the rotting/decay of organic waste

Question 24

scavengers

Answer 24

start the process by consumer large portions of dead organisms

Question 25

detritivores

Answer 25

consume decaying/dead organisms

Question 26

decomposers/saprotrophs

Answer 26

break down organic molecules to inorganic so they can be used by primary producers

Question 27

fertilizer

Answer 27

the addition of nitrogen into soil; excess N exceeds critical load and runs off into rivers, leading to dead zones

Question 28

acid rain

Answer 28

burning fossil fuels releases S and N, combines with water to make sulfuric and nitric acids, leads to acid rain (pH <5.2)

Question 29

biological magnification

Answer 29

synthetic chemicals in ecosystems become more concentrated in higher trophic levels

Question 30

chlorofluorocarbons (CFCs)

Answer 30

used in refrigeration, air conditioners, escape to atmosphere and breaks down ozone

Question 31

Greenhouse Effect

Answer 31

CO2, CH4, and H2O retain solar heat, leading to increased global temperature

Question 32

climate change

Answer 32

the global warming trend on Earth has had greatest effect at high latitudes; under positive feedback; leads to change in precipitation patterns, increase in sea level, extinctions

Question 33

polar amplification

Answer 33

poles have a more pronounced change in temperature