1.3 Energy and Equilibria

Question 1

Law of thermodynamics 1 - Explain

Answer 1

The law of CONSERVATION OF ENERGY, energy can neither be created nor destroyed it can only be transformed

Ex: Food chain

Question 2

Define entropy

Answer 2

The INCREASE in disorder and randomness in a system. An increase in entropy means a decrease in the amount of energy available to do work

Question 3

Law of thermodynamics 2 - Explain

Answer 3

Entropy of a system INCREASES over time the only way to AVOID entropy is a CONTINUOS ENTRY of additional energy

Question 4

Negative feedback - definition

Answer 4

Promotes stability in a system as it reverses the change and returns the system to the original state of equilibrium

Question 5

Positive feedback - definition

Answer 5

Amplifies the change in the system and keeps it going in the same direction. A small disturbance in the system causes an increase in that disturbance.

Question 6

Give an exapmle of negative feedback

Answer 6

Predator prey relationship (Ex foxes and rabbits)

Question 7

Give an example of positive feedback

Answer 7

Climate change:

More CO2 in the atmosphere causes rising temperatures, which causes permafrost to melt, that releases methane and so temperatures continue to rise.

Question 8

Tipping points - definition

Answer 8

Kick - start self - perpetuatting positive feedback loops that push the systems to a new state of equilibrium

Question 9

Name some problems that may occur if tipping points are reached

Answer 9

1. Environmental support services could colapse
2. The lands food production capacity will deteriorate
3. The seas food capacity will be compromised
4. Climate may spiral into a positive feedback cycle and become unsuitable for human existance

Question 10

When is a system said to be in equilibrium?

Answer 10

If everything in the system is in balance. This does NOT mean there are no changes, but that the impact of the change varies over time and depends on the type of equilibria

Question 11

Define static equilibrium

Answer 11

Only applicable to non living systems and the components of the system remain constant over a long period of time

Question 12

Define steady equilibrium

Answer 12

Has many small changes over shorter periods of time and the changes occur within limits

Question 13

Define stability

Answer 13

The ability of an ecosystem to remain in balance. There are 2 components. RESISTANCE is when the ecosyste, continues to function during a disturbance. RESILIENCE is the ability of the ecosystem to recover after a disturbance.

Question 14

Wether the system is resistant of resilient the end product is an ecosystem in…

Answer 14

The SAME STATE after a disturbance

Question 15

Give examples of natural disturbances

Answer 15

1. Floodings
2. Volcanic erruptions
3. Fires

Question 16

Give examples of human induced disturbances

Answer 16

1. Deforestation
2. Introduced species
3. Pesticides

Question 17

List 5 factors that infulence stability in an ecosytem

Answer 17

1. Climate and limiting factors
2. Biodiversity
3. Trophic complexity
4. Nutrient stores
5. Frequency and intensity od fisturbances

Question 18

CASE STUDY (Stability Tropical Rainforest Madagascar)

Explain why they deforested and its consequences

Answer 18

Tropical rainforests: Madagascar

Why they want to deforest?

The trees are very valuable hardwoods that are good for making furniture and flooring. That tropical rainforest areas contain vast amounts of mineral wealth - gold, silver and diamonds to name a few.

Consequences

1.Nutrients are removed from the system so there are very few left for re-growth.

2. Heavy rainfall washes away the leaf litter, removing yet another store of nutrients.
3. Soil is exposed to the torrential tropical rain and is washed away – more nutrients leave the system.
4. Loss of the trees means that the recycling of water is reduced. Water that is usually taken up by the trees and transpired back into the atmosphere runs into the rivers and leaves the area. That reduces rainfall in other areas, which can cause problems beyond deforestation.
5. Loss of biodiversity of plants and animals. Removal of the vegetation takes away vast numbers of species but it also removes the food source and habitat for others.

Question 19

Tropical Rainforest Madagascar factOUs

Answer 19

Facts:
1. Multiple layers of vegetation, 30-meter-high trees.
2. Does not have a seasonal die-back, the flow of nutrients into the litter store is very limited.
3. High temperatures ensure that decomposition is rapid and the nutrients are released from the litter store very quickly
4. High annual rainfall of over 200 cm/year would wash away the nutrients, lateral root systems of the trees have evolved to catch these nutrients before they are washed away.
5. The biodiversity of the tropical rainforests is one of the highest in the world.