Ecosystems: Changing Populations Flashcards
Biodiversity
A range of different species in an ecosystem
Population dynamics
The study of the changes in population numbers
Strategies to estimate population
Quadrant, line transcect and capture-recapture
Pros and cons: quadrant
It isn’t good for extremely mobile animals but is simple
Pros and cons: line transect
Can see the distribution of a species but may miss creatures as it is so long
Pros and cons: capture-recapture
Animals may be affected by the traps, tagging may affect the animal but is efficient for mobile animals
Formula for capture-recapture estimation
(N 1* N 2)/M 2
Word equation for capture-recapture estimation
(Total captured in 1 * Total captured in 2)/Number marked in 2
Carrying Capacity
The maximum population of a species that an ecosystem can sustain
‘Marine snow’
Inorganic dust on/in the ocean
Biological Control
The planned introduction of a species to control pests
Food web
A system of interdependent food chains.
Food chain
A chain of organisms each dependent on the next as a source of food.
Natural factors that affect population growth
Limiting resources, seasonal changes, presence or absence of other species, disease and extreme natural changes
Human factors that affect population growth
Pollution, enhanced greenhouse effect and introduced species
