Populations in Ecosystems- Variation in Population Size Flashcards
What is population size?
The total number of organisms of one species in a habitat
What is carrying capacity?
The maximum stable population size of a species that an ecosystem can support
What happens when abiotic conditions are ideal for a species?
Organisms can grow fast and reproduce successfully
What happens when abiotic conditions aren’t ideal for a species?
Organisms can’t grow as fast or reproduce as successfully
What is interspecific competition?
When organisms of a DIFFERENT species compete with each other for the same resources
What can interspecific competition mean?
Resources that are available to both populations are reduced which will mean that both populations will have less energy for growth and reproduction, so population sizes will be lower for both species
What is intraspecific competition?
When organisms of the SAME species compete with each other for the same resources
When does the population of a species increase?
When resources are plentiful
What happens as the population increases?
More organisms are competing for the same amount of space and food
When does the population begin to decline?
When resources become limited
What does a smaller population mean?
There’s less competition for space and food which is better for growth and reproduction so the population starts to grow again
What is predation?
Where an organism (the predator) kills and eats another organism (the prey)
How are the population sizes of predators and prey interlinked?
As the population of one changes, it causes the population of the other to change
What happens when the prey population increases?
There’s more food for predators, so the predator population grows
What happens when the predator population increases?
More prey is eaten so the prey population will decrease, and then there is less food for predators so predator population will begin to decrease
