## 27 terms

### carrying capacity

the number of individuals in a population that the resources of a habitat can support

### cohort life table

a life table follows the fates of a group of individuals born into a population at the same time from their birth to the death of the last individual

### continuous time approach

an approach to pop. modeling assuming that time flows continuously and that change can occur at every instant.

### density dependent

having an influence on a population that varies with the size of the population

### density independent

having an influence on a population that does not vary with the size of the population

### discrete time approach

an approach to pop. modeling that uses discrete time intervals between reproductive periods

### exponential growth

continuous increase or decrease in a population at a rate that is proportional to the number of individuals at a given time

### generation time

the average period between the birth of an individual and the birth of its offspring

### geometric growth

increase or decrease in pop. as measured over discrete intervals in which the increment is proportional to the # of individuals at the beginning of the interval

### inflection point

the point at which a logistic or other sigmoid growth curve changes from its accelerating to its decelerating phase (N = K/2)

### logistic equation

the mathematical expression of an exponential rate of population increase that decreases in linear fashion as population size increases

### negative density dependence

a population response to increasing density that depresses survival and birth rates

### net reproductive rate

the number of female offspring produced by an average female during her lifetime

### positive density dependence

a population respons to increasing density that increases survival and birth rates (inverse)

### self-thinning curve

a characteristic relationship between average plant weight and pop. density found in plant pop that are limited by space or other resources

### stable age distribution

the proportions of individuals in various age classes in a population that is growing at a constant rate

### stable life table

a life table that follows individuals of various age classes within a pop. over a given time interval (time specific )

### -3/2 power law

a generalization proposing that the relationship between the logarithms of the biomass and the density of a plant population has a slope of -3/2