Ecological and human stresses

Question 1

List 3 examples of catastrophic ecological stresses

Answer 1

Drought, flood, volcanic eruption

Question 2

List 3 examples of gradual ecological stresses

Answer 2

Ecological succession, natural climatic changes, adaptation/evolution

Question 3

List 3 catastrophic human stresses

Answer 3

Deforestation, erosion, mining

Question 4

List 3 gradual human stresses

Answer 4

Depletion of groundwater, overhunting, irrigation

Question 5

Define ecological stress

Answer 5

natural factors that can cause disruption to ecosystems

Question 6

Are ecological stresses generally more gradual or catastrophic/fast?

Answer 6

Gradual

Question 7

Example of catastrophic event that was ecological stress

Answer 7

Mt St Helens 1980

Question 8

Define human stress

Answer 8

activities and impacts on ecosystems that are directly caused by human actions

Question 9

T or F_ Ability to instigate large-scale environmental change means people can push state of dynamic equilibrium beyond limits

Answer 9

T

Question 10

What is example of catastrophic event that was human stress

Answer 10

Deepwater Horizon Oil spill 2010 (biggest oil spill in history- off coast of Louisiana- surge of natural gas exploded out of wellhead)

Question 11

What are the 2 broad categories of human stresses

Answer 11

1. Intentional- specifically designed to alter ecosystem (land clearing)
2. Inadvertent- results from careless/ill-informed actions (e.g. shipping killing whales)

Question 12

What are 2 ways to measure effects of ecological and human stresses?

Answer 12

1. Magnitude of change
   (extent to which ecosystem stretched beyond state of dynamic equilibrium- requires benchmark data)
2. Rate of change
   (speed at which change occurring)

Question 13

T or F- more specialised an organism is within set of environmental conditions, the more vulnerable it is to changes

Answer 13

T

Question 14

How does algae affect coral

Answer 14

Algae reduces amount of sunlight for coral growth- coral becomes stressed- contract in size

Question 15

When ecosystem is whole and unaltered by human activity, it is called

Answer 15

Ecosystem integrity

Question 16

Define biocapacity

Answer 16

The regenerative capacity of an ecosystem- the ability of the ecosystem to replace resources used by humans and absorb pollutants emitted by human activities.

Question 17

How does level of biocapacity affect resilience?

Answer 17

The higher the biocapacity, the more resilient it is to stresses caused by humans (stresses often called society’s environmental footprint)