Exam 2

multiple interacting species that live in the same area
number of individuals within a population per unit area
population density
stabilizes a population at its carrying capacity
environmental resistance
species occurring in only one area
a population is a
group of individuals of a single species that live in one area
high population density can
increase the incidence of disease transmission
the carrying capacity is the
maximum population size that a given environment can sustain
density dependent factors
include the effects of disease and predators on a single species within a community
a population that is limited by a resource is expected to have an exponential growth curve
An example of a density independent factor would be
cold weather causing the lake to freeze
A cumber of coyotes move into an area and begin to ear a population of small harvest mice. After several years, the harvest mice are much speedier runners than before the coyotes came. This is an example of
directional selection
Lifestyle changes brought about by ___ and ____ have decreased the economic need for children?
Industrialization and urbanization
the human population is approximately
6.7 billion
Declining death rates due to increased food production and improved medical care while birth rates remain high is characteristic of the _______ stage?
Which of the following factors drives TFR down?
social and economic security
According to the IPAT model, technology that enhances our acquisition of minerals, fossil fuels, timber, and ocean fish
Increases environmental impact
The Cornucopian view held by many economists suggests that resource depletion due to greater number of people
Is not a problem if new resources can be found to replace depleted ones
The sensitivity factor in the model used to represent human environmental impact denotes
the sensitivity of an environmental to human pressures
if growth rate of a given area is steady, population size will soon stabilize
poorer societies have lower birth rates than more affluent societies
Presently over 80% of the world's population lives in developing nations
the number of people per household is rising rapidly in the US and Great Britain
as of 2008, TFR is highest in Europe and lowest in Africa
Humus is
composed of organic compounds and is necessary for fertile soils and for holding soil moisture
removes nutrients from soil
the loss of more than 10% productivity in arid areas due to erosion, soil compaction, forest removal, and an array of other factors is called
The US agency charged with slowing soil degradation is the
Natural Resources Conservation Service
Shelterbelts are to _____ as terraces are to ______
wind erosion; water erosion
The buildup of salts in soils as a result of overirrigation is
The consequences of overfertilization can include
eutrophication in nearby waters
what is the basis for soil textural determinations?
particular size