Population Indicators Flashcards
1
Q
what is the j shaped population curve
A
- graphical representation of the change in population density of an organism as it increases rapidly and then stops suddenly, due to environmental or other factors
2
Q
what is the S shaped Population Curve
A
- graphical representation of change in a population density of an organism when it initially approaches an exponential growth rate, but then decreases and levels off as the environmental carrying capacity is reached
3
Q
what is Equilibrium (set Point)
A
- point at which a system can be maintained e.g population size for a specific environment
4
Q
what is ecological homeostasis
A
- maintenance of a population size commensurate with environmental limiting g factors, mediated by feedback systems
5
Q
what is migration
A
- the movement of individuals of a species from one place to another
6
Q
what is immigration
A
- the movement of individuals of species into a place
7
Q
what is emigration
A
- the movement of individuals of a species out of a place
8
Q
what is direct observation
A
- a method used to measure abundance e.g recording sights, at particular intervals; can be time consuming and dangerous
9
Q
what is Lincoln index
A
- a formula used to estimate animal population sizes through mark and recapture technique
10
Q
what is capture-mark-recapture
A
- an ecological surveying technique used to measure animal populations, in which individual animals are captured marked and released, after a time, the population is resampled and the number of marked animals caught gives an indication of population size.
11
Q
what is random distribution
A
- a measurement of distribution in which organisms are spaced irregularly
12
Q
what is uniform (continuous) distribution
A
- a measurement of distribution in which organisms are evenly spaced
13
Q
what is clumped (grouped distribution)
A
- a measurement of distribution in which individuals are grouped together when biotic and/ or abiotic factors are favourable; can be social (e.g Schools of fish) or clumping of vegetation