1.3 Energy and Equilibria Flashcards
Law of thermodynamics 1 - Explain
The law of CONSERVATION OF ENERGY, energy can neither be created nor destroyed it can only be transformed
Ex: Food chain
Define entropy
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
Law of thermodynamics 2 - Explain
Entropy of a system INCREASES over time the only way to AVOID entropy is a CONTINUOS ENTRY of additional energy
Negative feedback - definition
Promotes stability in a system as it reverses the change and returns the system to the original state of equilibrium
Positive feedback - definition
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.
Give an exapmle of negative feedback
Predator prey relationship (Ex foxes and rabbits)
Give an example of positive feedback
Climate change:
More CO2 in the atmosphere causes rising temperatures, which causes permafrost to melt, that releases methane and so temperatures continue to rise.
Tipping points - definition
Kick - start self - perpetuatting positive feedback loops that push the systems to a new state of equilibrium
Name some problems that may occur if tipping points are reached
- Environmental support services could colapse
- The lands food production capacity will deteriorate
- The seas food capacity will be compromised
- Climate may spiral into a positive feedback cycle and become unsuitable for human existance
When is a system said to be in equilibrium?
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
Define static equilibrium
Only applicable to non living systems and the components of the system remain constant over a long period of time
Define steady equilibrium
Has many small changes over shorter periods of time and the changes occur within limits
Define stability
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.
Wether the system is resistant of resilient the end product is an ecosystem in…
The SAME STATE after a disturbance
Give examples of natural disturbances
- Floodings
- Volcanic erruptions
- Fires
Give examples of human induced disturbances
- Deforestation
- Introduced species
- Pesticides
List 5 factors that infulence stability in an ecosytem
- Climate and limiting factors
- Biodiversity
- Trophic complexity
- Nutrient stores
- Frequency and intensity od fisturbances
CASE STUDY (Stability Tropical Rainforest Madagascar)
Explain why they deforested and its consequences
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.
- Heavy rainfall washes away the leaf litter, removing yet another store of nutrients.
- Soil is exposed to the torrential tropical rain and is washed away – more nutrients leave the system.
- 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.
- 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.
Tropical Rainforest Madagascar factOUs
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.
