Climate, Niches, & Community
Interactions
Weather vs. Climate
Weather is the day to day conditions of the earth’s atmosphere.
Climate is the year to year patters of temperature and precipitation.
 A microclimate can form when environmental conditions
vary over small distances.
Factors that effect climate:
• Trapped solar energy
• Latitude
• Heat transport by winds and currents
Solar Radiation and The Greenhouse Effect
The balance between heat that stays in the biosphere and
that lost to space determines earth’s average temperature.
The Greenhouse Effect allows solar radiation to enter our biosphere
but slows the loss of reradiated heat to space.
If the greenhouse gasses rise, more heat is trapped and earth is
warmed. If greenhouse gasses drop, so does the temperatures.
Greenhouse Effect
Global Warming
GW is the enhanced greenhouse effect brought on by human activities
such as the burning fossil fuels.
Latitude and Solar Energy
Near the equator, solar energy is the
most intense because is almost
directly overhead at noon all year.
The poles have less direct sunlight,
and therefore heat, from the sun
This unequal distribution of heat
creates three distinct climate zones:
Tropical
Temperate
Polar
The 3 ways communities interact are:
Competition
Predation
Symbiosis
Niche
A Niche is the range of physical and biological conditions in which a
species lives and the way the species obtains what it needs to survive
Every species has its own range of tolerance, or the ability to survive
and reproduce under a certain set of environmental conditions.
Competitive Exclusion Principal
States: No two species can occupy exactly the same niche in
exactly the same habitat at the same time.
If two species attempt to occupy the same niche, one species will be
better and competing for these limited resources and eventually
exclude the other species.
By causing species to
divide resources,
competition helps
determine the number
and kind of species in a
community and the
niche each species
occupies.
Competition
Intraspecific – between the same species
Interspecific – between different species
Predation
Predator-Prey relationship: When one animal (predator) captures and feeds
on another animal (prey). Predators can affect the size of prey populations in a
community and determine the places prey can live and feed
Herbivore-Plant relationships : Herbivory is when an organism feeds on
producers. Herbivores affect both the size and distribution of plant populations
in a community and determine the places that certain plants can grow.
Keystone species: A species in the environment that is not usually abundant in
the community but exerts a strong control over the structure of the community.
Example: Sea Otters.
A century ago otters nearly disappeared and so did the kelp forests. Why?
Yellowstone Wolves Video Clip
Symbiosis
Any relationship which two species live closely
together (and at least 1 benefits)
The three types are:
Mutualism
Commensalism
Parasitism
Mutualism
an interaction
between species in
which BOTH
benefit
(+,+)
Commensalism
an interaction
between species in
which one benefits,
and the other is not
helped or harmed
(+,0)
Parasitism
an interaction
between species in
which one benefits
and one is harmed
(+,-)