4.1 Population Dynamics Flashcards
(20 cards)
Define Distribution
The geographical area where individuals of a population are found
Define Intraspecific
Interactions within species
Define Interspecific
Interactions between species
Define Predation
Where one organism feeds/preys on another (predator-prey relationship)
Define Competition
Two species compete for the same resources
Define Symbiosis
A close relationship between two organisms, where at least one benefits
What are the four types of symbiosis?
Mutualism, Parasitism, Allelopathy and Commensalism
Define Mutualism
Symbiosis beneficial to both organisms involved
Define Parasitism
A symbiotic relationship where one organism, the parasite, benefits by living on or in another organism, the host, and causes it harm
Define Allelopathy
One organism, typically a plant, releases chemicals that can either inhibit or promote the growth, survival, or reproduction of other organisms
Define Commensalism
Symbiosis between two organisms in which one benefits and the other derives neither benefit nor harm.
What is a Limiting Factor?
The bare minimum of resources needed by a population E.g. food, water
What is Carrying Capacity?
When a species population reaches equilibrium and becomes relatively constant, reaching the maximum population size the ecosystem can sustain
Define Disease
Any process that adversely affects the normal functioning of tissues in an organism
Example - Outline the negative effects of removing wolves from Yellowstone then effects of their re-introduction
Negative:
- Elk (prey) population doubled causing overgrazing and their hooves eroded the bank
- Small mammal populations lowered as they had no place to hide
- Beavers could not build dams leading to suffering of aquatic life due to murky water
Re-introduction Effects:
- Elk numbers brought back down
- Cleaner drinking water and flora on bank
- Carcasses left for other predators
Random Quadrats
Method: Randomly place quadrats
Investigates: Abundance of non-mobile organisms
Belt Transect
Method: Place quadrats side by side along transect
Investigates: Distribution/abundance of non-mobile organisms across changing environment
Interrupted Transect
Method: Place quadrats at regular intervals along the transect
Investigates: Distribution/abundance of non-mobile organisms across changing environment
Line Transect
Method: Lay tape measure along and count number of organisms touching line
Investigates: Distribution of non-mobile species across changing environment
Mark-Release-Recapture
Method: Capture a sample of organisms, mark, release then recapture
Investigates: Abundance of mobile organisms
