Transcript The Body in Motion

Ecology
Biomes & Populations
Biome
–A large, relatively distinct
terrestrial region with
characteristic
Climate
Soil
Plants
Animals
Interacting landscapes
Using
precipitation
and
temperature
to identify
biomes
Significance of precipitation in temperate
biomes
The world’s major biomes
 Human
effect on biomes
–Tundra
Oil exploration and military
exercises result in long-lasting
damage
–Taiga/Boreal forest
Clearcut logging destructive
–Temperate and deciduous forests and
tropical rain forests
Removed by logging and
development
 Aquatic
ecosystems
–Important environmental
factors
Salinity
Amount of dissolved oxygen
Availability of light for
photosynthesis
 Aquatic
life divided into
–Plankton
Free-floating organisms
–Nekton
Strongly swimming
organisms
–Benthos
Bottom-dwelling organisms
Zonation in a large lake
Thermal stratification in a temperate lake
 Marine
environments
–Intertidal zone
Shoreline between low and high
tides
–Benthic environment
The ocean floor
–Neritic province
Open ocean from shoreline to
depth of 200 m
–Oceanic province
Ocean deeper than 200 m
Zonation in the
ocean
Human effect on water biomes
 Eutrophication
– water is enriched
w/nutrients, usually fertilizers from
runoff
– Causes increase in organism growth
that leads to depleted oxygen
Types of lakes
 Which
has greater primary
productivity?
 Population
density
–Number of individuals of a
species per unit at a given
time
 Population dispersion (spacing)
–Clumped dispersion
–Uniform dispersion
–Random dispersion
Dispersion of
individuals with a
population
 Four
factors that produce
changes in population size
–Natality
–Mortality
–Immigration
–Emigration
 Intrinsic
rate of increase (rmax)
–Maximum rate at which species or
population can increase under
ideal conditions
–Carrying capacity (K) is the largest
population that can be maintained
Exponential population growth
(J-shaped curve)
Logistic population curve (Sshaped curve)
Exponential population growth
Carrying capacity and logistic population
growth

Density-dependent factors
– Regulate population growth by affecting
a large proportion of the population as
population rises
– Examples include predation, disease,
and competition
 Density-independent
factors
–Limit population growth but are
not influenced by changes in
population density
–Examples include hurricanes and
blizzards
 Survivorship
curves
–Type I
Mortality is greatest in old age
(large mammals)
–Type II
Mortality is spread evenly across all
ages ( birds, small mammals)
–Type III
Mortality is greatest among the
young (insects)
Survivorship curves
Age structure diagrams
Developing
countries tend to
have people overpopulation
that degrades the
environment
Developed countries have
consumption overpopulation
that degrades the
environment