
2.d.1 – All biological systems from cells and
organisms to populations, communities, and
ecosystems are affected by complex biotic
and abiotic interaction involving exchange of
matter and free energy (52.2).

The study of the
interactions
between organisms
and their
environment


All living beings (animals, plants, fungi,
etc)
Studied at many different levels
1.
2.
3.
4.
5.
Organismal Ecology
Population Ecology
Community Ecology
Biome Ecology
Biosphere Ecology

Abiotic Factors: nonliving factors
Ex: Temperature, water, wind, humidity

Biotic Factors: living factors
Ex: Competition, Predation (plants, animals, fungi,
etc)
1.
2.
3.
4.
5.
6.
Temperature
Water
Sunlight
Wind
Rocks and Soil
Disturbance


Effects cell contents
Ex:
◦ Cold – cells will rupture if temperatures drop
below a certain point
◦ Hot – many proteins and DNA will denature

Point – life can only exist over a fairly
narrow temperature range


Review the properties of water from Chapter
3.
Cells must maintain a certain water potential
level (keep from exploding or drying out).


Provides energy for Ps, which drives most
food webs.
Plants often compete for light because of
shading or absorption of light by deep
columns of water.


Effects temperature and water conditions for
many organisms.
May carry abrasive particles that limit plant
growth by killing the SAM areas.
◦ SAM??? Shoot apical meristem areas



Physical structure, pH, mineral composition
of rocks and soil limit where plants can grow.
Ex. Se soils.
Plants limit what animals can be found in an
area.



Disturbance is often an important part of
an environment.
Allows organisms to re-colonize an area.
Ex: Fire
Humans
Wind
Yellowstone Fire


Shapes environments and what organisms
can live in a particular area.
Climatic factors:
◦ Solar radiation and latitude
◦ Axis tilt/seasons
◦ Air/Water circulation patterns


Changes the amount of light and energy
delivered per surface area.
Result:
◦ Poles: less light
◦ Equator: more light
◦ Unequal heating causes air and water to circulate



Caused by the Earth's tilt.
Day length changes over time.
Many organisms are restricted in range by
how well they adapt to changing seasons.




Air rises when heated, sinks when cools.
Zones of rising/sinking are created.
Earth's rotation causes zones to "twist”.
Result:
◦ Air circulation patterns
◦ Rain fall patterns
 Rising air: wet areas
 Descending air: dry areas


Broad geographical regions with
characteristic communities of organisms.
Biomes are controlled by:
◦ Temperature
◦ Water amount and proximity
◦ Geography


Areas covered with
dense/lush growth
of trees and vines.
Climate:
◦ Warm temperatures.
◦ Constant day length.
◦ High water.

Vertical layers of
autotrophic growth



Have the greatest diversity of species of
any area on Earth.
Soil is usually very infertile. Most of the
nutrients are in the plant life.
One of the most endangered Biomes.


Grasslands with a few trees.
Climate with three growing seasons:
◦ Cool and dry
◦ Hot and dry
◦ Warm and wet


Rich in herbivores and predator species
Only major biome not found in North America

Characterized by plants adapted
to dry growing conditions.
◦ Cacti, succulents



Climate:
◦ Dry (<30cm/yr).
◦ May be cold or hot.
Often found in areas of descending
air masses.
Low productivity, but still fairly
diverse in species.


Characterized by spiny evergreen shrubs.
Climate:
◦ Mild rainy winters
◦ Hot summers



Ex: Southern California
Maintained by fires
Plants adapted to periodic fires by seeds or
re-growing from the roots



Grasses and other herbs are the dominant
vegetation.
Indiana could be considered a temp.
grassland
Climate:
◦ Intermediate water
◦ Relatively cold winters



Very productive for agriculture. (wheat,
corn)
Need disturbance (fires) to keep trees out.
Come in several types:
◦ Tall grass
◦ Short grass


Deciduous trees dominate (often called
deciduous forest)
Climate:
◦ Relatively high rain
◦ Cold winters



Very little natural area left.
Good diversity of species.
Coniferous forest:
◦ Tall stands of cone-bearing tress


Coniferous trees dominate (also called
coniferous forests)
Climate:
◦ Long cold winters
◦ Short wet summers
◦ Long summer daylength


Relatively low species diversity
Being logged at an alarming rate
(disappearing rapidly!)


Grasses and sedges dominate.
Climate:
◦ Very cold and dry
◦ Low light in winter



Permafrost present
Plants low in height
Poor species diversity



Mirror each other.
Their Biomes are similar because the
environments are similar.
Ex: Alpine = Tundra





Have <1% salt concentration.
Strongly influenced by temperature and light.
Classification – based on water flow patterns.
Flowing: rivers, creeks
Non-flowing: ponds, lakes



Cover 3/4 of the Earth's surface.
Average 3% salt.
Controlled by light and the distance to the
shore.


Photic - Enough light for Ps. Red light lost
rapidly as depth increases.
Aphotic - Lacks enough light for Ps and
depends on food made in photic zone for
energy. Part of the most extensive biome
on the planet.
1.
2.
3.
4.
5.
Estuaries
Intertidal
Coral Reefs
Pelagic
Benthos
Where a
freshwater river
meets the
ocean.
 Salinity variable.
 Very productive
Biome.
 Complex flow
patterns






Characterized by
coral.
Found in shallow
warm waters.
Very productive.
High species
diversity.
Very sensitive to
temperature
changes



Bottom area.
Usually fed by nutrients drifting down from
upper levels.
Fairly rich in life.




Know what is involved with the study of
“Ecology”.
Know the major factors of planet Earth that
shape climate.
Know the major terrestrial biomes and the
factors that control them.
Know the major types of aquatic biomes
and the factors that control them.