Ecological interactions
Stuff that make the Ecosphere
“work”.
Levels of organization
I. Levels of life organization.
A. Species – Organisms
that are similar, can
reproduce, and produce
viable/ fertile offspring.
- Dogs and wolves
Levels of organization
B. Populations –
Groups of
individuals of one
species, living in the
same area (i.e.
interbreeding)
Levels of organization
C. Communities – A group of organisms of
various species, living in one place, at one
time.
Levels of organization
D. Ecosystem – The
collection of
organisms that live in
one place at one time,
with non-living
systems (considers the
lithosphere,
hydrosphere and
atmosphere).
• Fly mouth
• Moth mouth.
• Rush Skeleton grass
• Goat head
Levels of organization
E. Biome – A group of
ecosystems that
have the same
climate and similar
communities (eg.
Deserts, coral reefs,
rain forests etc…)
Biomes
F. Biosphere –
collection of all of
the biomes on
earth.
*pic is from inside
biosphere 2
Energy Flow
II. Energy flow.
A. Most of the energy sustaining life on earth
originates at the core of the sun (Nuclear
fusion).
-There are a couple of exceptions at the
bottom of the sea. What are they?
Energy Flow
B. The flow of the sun’s
energy through the
biosphere goes in one
direction.
-That means we
constantly need a
fresh supply.
- It begins with the
Producers.
Energy Flow
C. Producers – Organisms
that capture the radiation
energy from the sun and
convert it into chemical
energy (i.e. sugar) by
photosynthesis.
1. Referred to as
autotrophs.
D. Consumers –
Organisms that
harness energy
from the
consumption of
other organisms.
1. Referred to as
heterotrophs.
2. There are
several types.
a. Herbivores
– eat plants
Energy Flow
b. Carnivores – eat
other animals.
c. Omnivores – eat
both plants and
animals
(humans, bears,
etc.)
Energy Flow
Energy Flow
d. Decomposers – break
down organic matter
(bacteria and fungi,
worms etc.).
Energy Flow
2. Levels of
consumers.
a. First-level
consumers are
those that eat
producers
directly
(herbivores).
Energy Flow
b. Second-level
consumers eat
herbivores
(carnivores).
c. Third-level
consumers eat
other carnivores
(carnivores).
E. Trophic pyramid
(energy transfer
beginning at the
sun).
1. Trophic levels
a. First trophic
level are
producers (like
plants).
b. Second
trophic level are
those that eat
the producers.
Energy Flow
c. Third trophic
level are the
carnivores eating
the second
trophic level.
d. Fourth level
are carnivores
feeding off third
level (rare).
Energy Flow
Energy Flow
2. As you move from
one trophic level to
the next only 10%
of the energy is
transferred.
a. Most energy is
lost between
trophic levels as
heat.
Energy Flow
3. The Bio-mass pyramid
is a measure of living
matter at each trophic
level.
-Same 10% rule
applies.
F. Other feeding relationships
1. Food chain is a simple representation of
feeding tendencies. One way chain.
Energy Flow
2. Food web – All
interconnected
feeding
relationships
within an
ecosystem.
III. Nutrient cycles – Conservation
nutrients are
constantly cycled
through the
ecosystem (as
opposed to energy
which is one way.
Example: you are
breathing in some
of the same carbon
a dinosaur
exhaled.
of Matter
Conservation
A. Water Cycle- Water
enters atmosphere
Matter
through evaporation and
transpiration.
1. Through condensation
and precipitation, water
forms streams, rivers
lakes and eventually
returns to the ocean.
………Repeat.
of
B. Carbon cycle – The sugar
in your coffee.
1. Biological processes.
a. Respiration, and
decomposition release
CO2 (gas) into the
atmosphere.
b. Photosynthesis takes
CO2 from atmosphere
and turns it into sugar
(solid).
Conservation of
Matter
Conservation of Matter
2. Geochemical Processes- Volcanoes.
Conservation of Matter
3. Human activities –
a. Burning fossil fuels –releases CO2
b. Burning forests – releases CO2
c. Breathing too much (joke)
d. deforestation
Conservation of Matter
C. Nitrogen Cycle- 70% of our atmosphere is N2
(nitrogen gas) – we cannot use it (makes
proteins).
1. Nitrogen has an atomic number of 7.
Conservation of Matter
2. Bacteria living in Legumes (eg. Peas) changes
N2 into Amonia (N3) which can then be used by
other organisms for protein production.
3. Nitrogen gas (N2) is balanced, non water
soluble and difficult for living things to use.
4. Nitrogen fixation and ammonification convert
Nitrogen gas (N2) into ammonia (NH3).
5. While many bacteria can utilize ammonia, it is
toxic to most organisms. These bacteria
“nitrify” the ammonia into highly biodegradable
and water-soluble Nitrates…. Fertilizer.
Conservation of Matter
D. Phosphorous cycle – P does not enter
Atmosphere. Cycles from soil to organisms.
1. Phosphorous is highly reactive and rarely
found in pure form. It has an atomic number of
15
• 2. Phosphate is a form of phosphorous that us
highly organically active and soluble in water
(PO4-) ………. Fertilizer
• 2. Phosphate is essential to multiple functions
within living organisms including, DNA and
RNA, ATP, photosynthesis, plant growth etc.
ATP
DNA/RNA
IV. What Shapes an Ecosystem
Factors Shaping Ecosystems
A. Niche- A niche is an organisms Occupation.
1. Defined by how an organism uses physical
(abiotic) and biological (biotic) conditions in
their environment.
a. food it eats
b. What eats it
Factors Shaping Ecosystems
B. Community interactions –
1. Competition – Organisms within a
community compete for resources and space
(including energy and nutrients).
Factors Shaping Ecosystems
2. Predation – An interaction between
organisms in which one feeds on another.
Factors Shaping Ecosystems
3. Symbiosis – A relationship in which two
species live closely to one another. There are 3
basic types
a. mutualism – Both species benefit from the
relationship. Eg. Bees and flowers.
Factors Shaping Ecosystems
b. Commensalism – One of the species benefits
and the other is neither helped nor harmed.
-example – Nemo and sea anemone.
Factors Shaping Ecosystems
c. Parasitism – One organism lives in or on
another and causes it harm.
Factors Shaping Ecosystems
C (capitol C). Ecological Succession (1:21 eco succession
animation)– A predictable series of changes that
take place in an ecosystem over time following
a disturbance. There are 2 major types of
succession.
Factors Shaping Ecosystems
1. Primary Succession- (3:51 Mt. St. Helens)
Occurs on land where No soil exists.
a. For example after a lava flow = no soil.
Factors Shaping Ecosystems
2. Secondary Succession- Occurs after some sort
of disturbance changes a community, but does
not remove soil.
a. For example after a flood or tsunami.
Biomes
V. Land Biomes – A biome is an environment
containing a characteristic group of plants and
animals (ecological community…biotic) and
it’s particular set of abiotic factors (example
climate).
Biomes
- Major biomes include….
A. Tropical rain forest (36 sec. Nasa deforestation)
1. highest species diversity of land biomes
2. high rate of precipitation
3. consistent warm conditions
Biomes
B. Deserts (10 min)
1. very low level of
precipitation (<25cm
per year)
2. High temperature
variation.
3. Organisms evolved
to withstand extreme
conditions.
Biomes
C. Tundra
1. Characterized by permafrost.
2. High latitude and cold conditions.
3. Very little precipitation.
4. Ground hugging plants.
Biomes
D. Boreal forest (Tiaga) (4:41 Happy People)
1. Medium precipitation
2. long cold winter, short summer.
3. Lots of conifer trees and Moose.
Biomes
E. Northwestern Coniferous Forest (Think
McCall).
1. Cold to moderate winters and warm
summers.
2. coniferous trees and some broadleaf trees
3. Ferns, Flowering shrubs and White Tailed
Deer are common.
Biomes
F. Others
include Temperate Forest
(Think New Hampshire),
Temperate grassland (Think
prairie), Temperate Woodland
and Shrubland (Think S.
California foothills)……and more.
VI. Populations
A. How populations grow
Populations
1. Characteristics of Populations.
a. Population density – number of
individuals per unit area.
-number of Saguro cacti plants per
square km is an example.
Populations
b. Geographic Distribution – Area
inhabited by population
Populations
2. Population Growth factors (3 of them) Stuff
that makes them grow or shrink.
a. Birth Rate – number born annually.
Populations
b. Death Rate – number dying annually.
Populations
c. Population Movement
i. Immigration – movement of individuals
into a population.
ii. Emigration – movement of individuals
out of a population.
Populations
d. Death rate increases as space and resources
are used up.
i. As resources get used up, population
growth reaches Carrying Capacity.
ii. Carrying Capacity is a populations limit in
an ecosystem (growth slows and stops)
Populations
3. Limiting factors (LF)are any Biotic or Abiotic
resource causing a population to decrease.
a. Biotic LF– AKA density dependent,
i. Competition
ii. Disease
iii. Predation
Populations
b. Abiotic LF- AKA density-independent.
i. natural disasters are an example.
Populations
4. Growth curvesa. Exponential growth phase – Uncontrolled
growth
i. Constant birth rt. + no LF = Exponential
growth.
Populations
b. Logistic growth curve – Once carrying
capacity is reached populations stop growing.
VII. Human Ecosystem interactions.
A. Renewable sources of fuel are renewable
within a short period of time.
1. Fossils fuels are not renewable.
2. Sustainability means using renewable
energy while ensuring they are not
depleted.
B. Human activities lower Biodiversity (pollution,
deforestation etc.)
1. Biodiversity is number of different species
in the biosphere.
C. Biomagnification means pollutants increase
in concentration as they move up the trophic
levels.
1. DDT and plasticizers are examples.
D. The release of CO2 and other greenhouse
gasses causes global warming
1. A net increase in earth’s surface temp.
2. Burning fossil fuels, and forests release CO2.
The End
• Lingering points for the exam.
• A. What is the term for year after year
precipitation and temp in a particular
location?
• B. What is the greenhouse effect?