| A | B |
|---|
| Population | group of individuals of a single species living in the same general area |
| Ecology | study of interaction between organisms and their environment |
| Population ecology | study of populations in relation to their environment |
| Range | natural or artificial area inhabited by a population |
| Density | number of individuals per unit area/volume |
| Growth rate | how fast a population is growing |
| Distribution | pattern of spacing among individuals within the boundaries of the population |
| Demography | vital statistics of populations and how they change over time |
| Sampling | direct counting within subsets of the area to extrapolate estimated population size of entire area |
| Indicators | count something that demonstrates the presence of the organism without having to observe the actual organism |
| Mark-recapture method | capture a sample of the individuals within the population and visibly mark them and release and recapture at later time |
| Growth rate | changes in population density as individuals are added to or removed from the population |
| Immigration | influx of new individuals from other areas |
| Emigration | movement of individuals out of a population |
| Exponential growth rate | the larger a population gets the faster it grows |
| Carrying capacity | maximum number of individuals of a particular species that a particular environment can support |
| Limiting factors | factors that control growth of a population |
| Logistic growth | a population's growth slows and then stops following a period of exponential growth |
| Density-dependent limiting factors | factors that control population growth but only operate strongly when population density is high |
| Density-independent limiting factors | factors that control population growth and affect all populations equally regardless of population size |
| Competition | too many individuals in a population results in limited resources |
| Predation and herbivory | density-dependent limiting factor where relative population sizes of consumers and their food control one another's population sizes |
| Parasitism and diseases | density-dependent limiting factor where greater host population size allows spread more easily |
| Stress from overcrowding | density-dependent limiting factor where too many individuals packed together results in strain that weakens the immune system or creates parenting issues |
| Clumped distribution | most common distribution pattern where individuals aggregate in patches |
| Uniform distribution | even spacing resulting from direct inhibition among individuals |
| Territoriality | defense of a bounded physical space against encroachment by other individuals |
| Random distribution | independent positioning of individuals due to an absence of strong interactions and/or homogenous resources |
| Age structure | number of males and females of each age a population contains |
| Reproductive rates | how many offspring and reproductive events during a lifetime |
| Survivorship | how long an organism typically survives |
| R-selected species | organisms that create an abundance of offspring and hope that a few will survive |
| K-selected species | organisms that create very few offspring and work to ensure their survival |
| Survivorship curve | graphic method of summarizing survival pattern of a population to help estimate life expectancy for different ages |
| Type II survivorship curve | constant death rates over the organism’s entire life span |
| Type I | low death rates in young which steeply increase in the elderly |
| Type III | high death rates in young but the few that survive youth live a long time |
