1.3 Energy and Equilibria Flashcards
(15 cards)
Positive Feedback Loop
a process in which the end product of an action causes more of that action to occur in a feedback loop, leading to an amplification of the original effect
Examples of Positive Feedback
- stampeding cattle
- eutrophication
- avalanche
- deforestation –> fewer trees
Negative Feedback Loop
a process in which an outcome acts to reduce or dampen the effects of the initial stimulus, leading to stabilization or regulation of the original effect.
Examples of Negative Feedback
- Predator/Prey relationship
- Cloud formation regulates temperature
- Carbon dioxide absorption reduces global warming
Static Equilibrium
a stable state of an ecosystem where species composition and population sizes remain relatively constant over time, with only minor fluctuations due to natural processes.
Compare with “stable equilibrium” and “steady state equilibrium” which are different
Stable Equilibrium
refers to a condition where an ecosystem, after a disturbance, tends to return to its original state due to the inherent resilience and interactions among its components
Associated with negative feedback
Unstable Equilibrium
a state in which a small disturbance or change can lead to a significant shift or departure from the original state, leading to a new equilibrium
Associated with positive feedback
Steady State Equilibrium
a dynamic balance where the input and output of energy and matter in an ecosystem are equal, allowing the system to maintain its structure and functions over time despite ongoing processes and disturbances.
Compare with “stable equilibrium” and “static equilibrium” which are different.
Tipping Point
A threshold where a system shifts to a new equilibrium, often irreversibly.
It is no longer resilient to change and cannot return to a stable equilibrium.
Usually reached through positive feedback (amplifying) processes.
Resilience
The ability of a system to (withstand change and) return to equilibrium after disturbance.
First Law of Thermodynamics
Law of conservation or energy.
Energy cannot be created or destroyed, only transformed from one form to another.
How does the 1st law of thermodynamics relate to a food chain?
When a rabbit eats grass, the chemical energy stored in the grass is transferred to the rabbit and transformed into kinetic energy for movement, and thermal energy for body heat.
The total entropy, or disorder, of an isolated system can never decrease over time, and is only constant if all processes are reversible.
Entropy
Entropy is a measure of the disorder or randomness in a system.
How does the 2nd law of thermodynamics relate to a food web?
energy flows from producers to consumers, with each transfer resulting in increased entropy due to energy being lost as heat (a less-useful and un retrievable form of energy), leading to less energy available for work at each successive trophic level
