Ch. 56 Population Ecology Flashcards
number of organisms of a given species in a given unit area or volume
Population Density
a square framed sampling device used to obtain a density estimate per square meter
Quadrat
long piece of string is stretched our and any tree along its length is counted
Line Transect
capture animals and then tag and release them
Mark-recapture technique
clustered together or spread out to varying degrees
Dispersion
most common form of disperson
Clumped
single reproductive event; organisms reproduce once and die
Semelparity
groups of same-aged young that grow at similar rates
Cohorts
reproduce in successive years or breeding seasons
Iteroparity
study of birth rates, death rates, age distributions and the sizes of populations
Demography
a table that provides data on the number of living individuals in various age classes in a population and their relative fertilities
Life Table
graphical plot of the number of surviving individuals for each age class in a population
Survivorship Curve
rate loss of juveniles is low, increasing age leads to increasing losses
Type I
uniform death rate
Type II
increased amount of loss in juveniles, survivorship curve flattens out after juvenile phase
Type III
examine rates of change with time; makes it easier to plot a wide range of population sizes
Log Scale
when r = 0, population at equilibrium
Zero Population Growth
if conditions are optimal for population growth, r is at its maximum
Intrinsic Rate of Increase
upper boundary for the population size in a given environment
Carrying Capacity
mortality factor whose influence increases with the density of the population
Density-Dependent Factor
a mortality factor whose influence is not affected by changes in population size or density
Density-Independent Factor
a mortality factor whose influence decreases with increasing population size
Inverse Density-Dependent Factor
examines the spatial arrangement of suitable habitats for various populations, which, in turn, can influence overall population densities
Landscape Ecology
a series of small, separate populations in individual habitat patches that mutually affect one another
Metapopulation
species that have a high rate of per capita population growth (r) but poor competitive ability
R-Selected Species
species whose populations are relatively stable and often exist at or near the carrying capacity (K) of the environment
K-Selected Species
proposes that organisms select food in terms of the nitrogen content of the tissue
Nitrogen-Limitation Hypothesis
quantity and quality of plants may be limiting for the population sizes of all other species that rely on them
Bottom-Up
predators control populations of their prey and their prey (herbivores) control plant populations
Top-Down
part of the generational mortality that would not occur should the mortality factor in question be removed from the life system, after allowance is made for the action of subsequent mortality factors
Indispensable Mortality
instead of adding additional mortality to the population (i.e., additive mortality), increases in predation result in compensatory declines in other causes of mortality
Compensatory Mortality
adds additional mortality on top of existing mortality
Additive Mortality
relative number of individuals of each defined age group
Age Structure
average number of live births a woman has during her lifetime
Total Fertility Rate
the amount of productive land needed to support a person
Ecological Foot Print
