Global environmental change

Question 1

What have been the main drivers in global change in the past?

Answer 1

• solar variation
• plate tectonics
• volcanism
  -proliferation and abatement of life
• meteorite impact
• resource depletion
• changes in earth’s orbit

Question 2

What is the main driver for global change in the present

Answer 2

• growing population
• demand for energy, goods, services

Question 3

List some examples of pollution

Answer 3

• chemical substances or energy
• noise
• heat
• light
• classed as point or non-point source

Question 4

What is meant by lethal concentration (LC)50 -

Answer 4

concentration of chemical in the air that will kill 50% of test animals with single exposure

Question 5

What is meant by lethal dose (LD)50?

Answer 5

single dose of a chemical that when fed to a group or applied dermally will kill 50% of the animals

Question 6

What is the difference between additive, antagonistic and synergistic?

Answer 6

• additive - effects of each are simply added together to determine overall effect
• antagonistic - one pollutant my reduce the impact of another
• synergistic - pollutants combine so effects are greater than would be expected additively

Question 7

List the types of sources of pollution

Answer 7

• point source - e.g. sewage outlet
• multi-source - e.g. chimney stacks
• seeping - e.g. fertiliser runoff
• spreading - e.g. volatiles in air-flows

Question 8

What is meant by acute pollution?

Answer 8

• occurs when large amount of waste matter enters environment - usually from a point source
• after event ecosystem begins to recover
• e.g. crude oil

Question 9

What are the biotic effects of crude oil?

Answer 9

• most sunlight is intercepted
• division of algal cells inhibited
• food chains modified

Question 10

What is meant by chronic pollution

Answer 10

• low-level input into the environment
• environment constantly under stress
• ecosystem does not have opportunity to recover
• e.g. pesticides

Question 11

What was the result of use of DDT?

Answer 11

found that breeding numbers of peregrine falcons were falling dramatically

Question 12

What is organocholorine?

Answer 12

• broad-spectrum toxins
• remain in environment for a long time
• DDT, aldrin, dieldrin, heptachlor

Question 13

What is chlorophenoxy?

Answer 13

• chemistry resembles plant auxins
• broken down quickly in soil
• e.g. herbicides such as 2,4-D

Question 14

What is organophosphates?

Answer 14

• highly toxic to human
• readily broken down
• e.g. malathion, parathion, carbamates

Question 15

What is meant by bio-magnification?

Answer 15

occurs when an element or chemical compound moves from one compartment to another - higher concentration in the second

occurs when CF>1

Question 16

Write an equation for concentration factor

Answer 16

concentration of pollutant in consumer / concentration of pollutant in diet

Question 17

What are primary microplastics?

Answer 17

manufactured - direct result of human material and product use

Question 18

What are secondary microplastics?

Answer 18

fragments derived from breakdown of larger plastic debris

Question 19

What is meant by genetic diversity?

Answer 19

total number of genetic characteristics in the genetic makeup of a species

Question 20

What is meant by genetic variability?

Answer 20

tendency of genetic characteristics to vary

Question 21

What is meant by species richness?

Answer 21

count of species

Question 22

What is meant by species evenness?

Answer 22

how equal the abundances of the species are

Question 23

What does simpson’s reciprocal diversity index show?

Answer 23

proportion of species
1/DA > 1/DB —> reflects higher degree of evenness

Question 24

What is the difference between alpha, beta and gamma diversity?

Answer 24

alpha - mean species diversity at a local scale

beta - differentiation among habitats

gamma - total species diversity in a landscape

Question 25

What is meant by endemism?

Answer 25

describes the usually limited geographical distribution of a taxonomic group

Question 26

List some examples of direct use

Answer 26

- food - medicine - biocontrol - industrial materials - ecotourism

Question 27

List the four categories of ecosystem services

Answer 27

- provisioning --> production of food and water - regulating --> control of climate and disease - supporting --> nutrient cycles and crop pollination - cultural --> spiritual and recreational beliefs

Question 28

List the types of trends seen with ecosystem function against species richness

Answer 28

- redundant - increases to a point - rivet - steadily increasing - idiosyncratic - no apparent trend

Question 29

What are the direct effects on plants due to elevated CO2?

Answer 29

- C3 plants generally respond positively - increases ratio of carbon to nitrogen ratio

Question 30

List some effects on agriculture

Answer 30

- increase disparity in cereal production between developed and less developed countries - some crops require cold to initiate germination

Question 31

List some impacts on human health

Answer 31

- heat stress in extreme temps - increase spreading of diseases e.g. malaria - increase refugees