Chapter 8/9 Flashcards
population
all the individuals of a species that live in the same geographic area and are able to interact and interbreed.
population dynamics
the changes over time of population size and composition.
minimum viable population
the smallest number of individuals that would still allow a population to be able to persist or grow, ensuring long-term survival.
environmental impact statement
an evaluation of the positive and negative impacts of a proposed environmental action, including alternative actions that could be pursued.
population density
the number of individuals per unit area.
population distribution
the location and spacing of individuals within their range.
clumped distribution
individuals are found in groups or patches within the habitat.
random distribution
individuals are spread out over the environmental irregularly with no discernible pattern.
uniform distribution
individuals are evenly, perhaps due to territorial behavior or mechanisms for suppressing the growth of nearby individuals.
population growth rate
the change in population size over time (births minus deaths over a specific time period)
birth rate
the number of births per 1,000 individuals per year.
death rate
the number of deaths per 1,000 individuals per year.
biotic potential (r)
the maximum rate at which the population can grow due to births if each member of the population survives and reproduces.
exponential growth
population size becomes progressively larger each breeding cycle; produces a J curve when plotted over time.
logistic growth
the kind of growth in which population size increases rapidly at first but then slows down as the population becomes larger; produces an S curve when plotted over time.
carrying capacity (K)
the population size that a particular environment can support indefinitely without long-term damage to the environment.
density dependent
factors, such as predation or disease, whose impact on the population increases as population size goes up.
density independent
factors, such as storm or avalanche, whose impact on the population is not related to population size.
reproductive strategies
how quickly a population can potentially increase, reflecting the biology of the species (life span, fecundity, maturity rate, etc.)
r-related species
species that have high biotic potential and that share other characteristics such as short lifespan, early maturity, and high fecundity.
k-selected species
species that have a low biotic potential and that share characteristics such as long lifespan, late maturity, and low fecundity; generally show logistic population growth.
boom-and-bust cycles
fluctuations in population size that produce a very large population followed by a crash that lowers the population size drastically, followed again by an increase to a large size and subsequent crash.
extrirpation
local extinction of a species.
community ecology
the study of all the populations (plants, animals, and other species) living and interacting in an area.