L34 Ecology of Populations Flashcards
Define Population ecology
The study of factors affecting the size of a population and how it changes over time
What affects the size of a population
adding and removing individuals
(immigration/births and emigration/deaths)
3 ways a population can change over time
reach a stable size
fluctuate irregularly
rise and fall in regular cycles
Define population
Group of individuals of a single species living in the same general area
How are populations described
by their boundaries and size
What types of population boundary is there
Natural (lake/ island)
Arbitrarily defined by an investigator (country)
How do individuals in populations interact
To reproduce or compete for resources
What is intra-specific competition
Competition for resources between members of same population/species
What is inter-specific competition
Competition for resources between members of different populations/species
three main population concepts
Populations have structure
Populations are regulated
Populations are dynamic over time
Mortality type 1 (4 features)
Mortality highest in older age classes
Found in long lived species
Living in a stable environment
Iteroparous (reproduction spread throughout lifetime)
Mortality type 2 (4 features)
Mortality constant throughout life
Found in short-medium lived species
Living in a relatively stable environment
Iteroparous (reproduction spread throughout lifetime)
Mortality type 3 (4 features)
High mortality in juveniles
Short lived species
Often semelparous (reproduction in a single breeding event)
Unpredictable and temporary environment
3 types of population dispersal
random, uniform, clumped
Random Dispersal
Position of each individual is independent of other individuals
Occurs in the abscence of strong competition or constant distrobution of key physical or chemical factors
