Unit 2: Terrestrial Ecology
Notes
Ecology is a study of
connections in nature
◦ How organisms interact with one another and with their nonliving environment
Organisms, the different forms of life on earth,
can be classified into different species based on certain characteristics.
Biological communities differ in the
types and numbers of species they contain and the ecological roles those species play
◦ Species diversity: the number of different species it contains (species richness)
combined with the abundance of individuals within each of those species (species
evenness)
Within a species one may have high genetic
diversity
Species Diversity & Niche
Structure: Different Species
Playing Different Roles
Species that serve as early warnings of
damage to a community or an ecosystem.
◦ Presence or absence of species because they are sensitive to temperature and oxygen
levels
Indicator Species
=
Biological Smoke Alarms
EX: Frogs serve as indicator species
because different parts of their life cycles can be
Species that helps determine the types
and numbers of other species in a
community thereby helping to sustain it
Keystone Species
= Major
Expansion of keystone species category Foundation species can create and
enhance habitats that can benefit other species in a community
◦ Elephants push over, break, or uproot trees, creating forest openings promoting grass growth for other species to utilize
Foundation Species
=
LT: I will be able to differentiate between the
different types of symbiosis and compare and contrast the different types.
A group of individual
organisms of the
same species living
w/in a particular area
Population
Individual
A community of
different species
interacting
together & with
the chemical &
physical factors
making up its
non-living
environment
Ecosyste
m
The population of
all species living
& interacting in
an area
PREDATION
COMPETITION
- Interspecific (Different Species)
- Intraspecific (Same Species)
◦
Competitive exclusion prevents two species
from occupying the same niche.
◦
Some species evolve to reduce or avoid
competition for resources with other
species (known as resource partitioning).
SYMBIOSIS
The closest relationships of all are
symbiosis. These involve a lot of close contact between two species.
◦ When the relationship benefits both organisms, it is called mutualism.
◦ When one organism benefits while the other is unaffected, it is called commensalism.
◦ When one organism benefits at the expense of the other, it is called parasitism.
Parasitism
(+,-)
Commensalism
Mutualism
Amensalism
Symbiosis
EXAMPLES: Sheep creating a trail
which inhibits grass growth
Some allelopathy of
plants
(+,0)
(+,+)
18
Barnacles create homes by attaching themselves to
19 Clownfish have a mucus coating that allows them to live in sea anemones.
20
As bison walk through grass, insects are disturbed and fly
21 Ostriches and gazelles feed next to each other. Ostriches have excellent
22
Mistletoe extracts water and nutrients from the spruce
Abiotic chemicals (carbon dioxide, oxygen, nitrogen, minerals) Heat Heat Heat Heat Heat Solar energy Consumers (herbivores, carnivores) Producers (plants) Decomposers (bacteria, fungi)
Topic: Energy Flow!!
LT: I will be able to draw a complex food web and identify the trophic level of all organisms in them.
Consumers (heterotrophs) get their food by
eating or breaking down all or parts of other organisms or their remains.
◦ Herbivores
Primary consumers that eat producers
◦ Carnivores
Primary consumers eat primary consumers
Third and higher level consumers: carnivores that
eat carnivores.
◦ Omnivores
Feed on both plant and animals.
Consumers:
Eating and Recycling to
Survive
As plant or animal matter dies it will break
down and return the chemicals back to the soil.
◦ Happens very quickly in tropical rainforest which results in low-nutrient soils.
◦ Grasslands have the deepest and most nutrient rich of all soils
Decomposition
Most producers capture sunlight to produce
carbohydrates by photosynthesis:
Producers: Basic Source of All
Food
Topic: Energy Flow!!
LT: I will be able to draw a complex food web and identify the trophic level of all organisms in them.
An organism that digests parts of dead
organisms, cast-off fragments, and wastes of living organisms
EX—bacteria and fungi
Decomposer,
Detritivore/Scavenger
Decomposers : recycle nutrients in ecosystems by secreting enzymes Detritivores: ingest/feed on wastes or dead bodiesHeat
Heat Heat
Heat Heat
Heat Heat Heat
Detritivores
(decomposers and detritus feeders)
First Trophic Level
Second Trophic Level
Third Trophic
Level Fourth Trophic Level
Solar energy
Producers
(plants) consumersPrimary (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores)
Producers - Organisms that produce their
own food
Primary consumers - The herbivores in an
ecosystem; organisms that feed on primary producers
Secondary consumers - The carnivores in an
ecosystem; organisms that feed on primary consumers
Tertiary consumers- The top carnivores in an
ecosystem; organisms that feed on secondary consumers
Shows the decrease in usable energy available
LT: I will be able to explain energy transfer
between trophic levels, and graph and compare an animals zone of tolerance.
Topic 10% Rule and Zone of
Tolerance.
Do Now: How many primary, secondary, and tertiary
consumers are there in this food web?
In accordance with the 2nd law of
thermodynamics, there is a decrease in the amount of energy available to each succeeding organism in a food chain or web
Ecological efficiency: percentage of
useable energy transferred as biomass from one trophic level to the next
The energy is “lost” as heat abiding by the
Law of Conservation of Energy (aka the 1st law of thermodynamics)
Energy Flow in an
Ecosystem:
“Losing” Energy in
We assume that 90% of the energy at
each energy level is lost because the
organism uses the energy (heat).
This means it is
more
efficient to eat
lower on the energy pyramid. You get
more out of it!
This is why top predators are few in
number & vulnerable to extinction.
If you want to eat 1 pound of protein…
You could eat enough sardines to equal a pound of protein
(approximately 34.7oz or 2.17lbs of sardines)
Or…
You can eat enough tuna to equal a pound of protein
(approximately 28.6oz of tuna)…to make that pound though, the tuna had to eat approximately (15 pounds of sardine protein
or approximately 520.5oz or 32.5lbs of sardines)
TUNA = approximately $17 per lb
How many people could live on 10 acres of land? If they ate cows, only 2 people can live on this land. If they ate the producers, 60 people could live on this same
A: Represents the biotic potential of the species
B: Shows how the population overshoots the carrying capacity C: Represents the logistic growth
D: Represents linear growth
E: Carrying capacity—the maximum number of individuals that can be supported by a particular ecosystem.
LT: I will be able to describe how
an organism evolves through natural selection over time.
44
Adaptations
The range of tolerance for a species is largely
defined by the presence of physical, behavioral, or physiologic adaptations.
◦ Physical adaptations are structural differences in coloration, body shape, musculature, etc.
◦ Behavioral adaptations include migration, or marking a territory.
◦ Physiologic adaptations, such as skin tanning, occur at the cell or tissue level in an organism.
The gorilla is adapted for living and
feeding on the ground, while chimpanzees gather food from trees.
All of the unique adaptations found in
different organisms are the result of
evolution -- small, advantageous mutations that have accumulated over countless
generations.
◦ Natural Selection describes the process where individuals with better genes survive and
reproduce more successfully, while those with weaker genes do not.
The primary source of this genetic variety is
random mutations. These are small changes of DNA.
◦ Usually these changes produce no effects or bad ones, but occasionally, they can be beneficial.
Evolutionists will cite three
categories of evidence in support of the theory.
Physical Similarities
◦ Most animals have similar bones in their limbs (fins, arms, wings).
◦ These similarities can also be found between living species and fossils.
Comparing DNA
◦ Chimpanzees, bonobos, and
humans share about 99% of the same DNA.
Vestigial Structures
◦ Still exist in the body but are no longer needed
◦ Ex: Appendix, wisdom teeth
An example of natural selection in the
human race can be seen in sickle-cell anemia.
◦ Normal red blood cells have a biconcave –disc shape.
◦ Sickle-shaped red blood cells are the result of a single mutated gene.
Sickle cells can get stuck in small blood
vessels, causing tissues to become oxygen-deprived.
Individuals with sickle-cell anemia or
carriers are also highly resistant to malaria.
◦ The mutation is a disadvantage in climates where malaria is absent due to the long-term health
issues.
◦ The mutation is an advantage in climates where malaria is present due to the resistance it
provides. Sickle cell gene frequency in Africa. Source: University of Oxford study. Distributio n of malaria transmissio n in Africa. Source: American Journal of Tropic Medicine and Hygeine Study.
Evolution is an
very slow process.
Current life on
Earth
represents billions of
years of small mutations and natural
Encouraging Natural
Selection
Four ecological factors will “encourage”
natural selection to favor certain individuals in a population.
◦ Speciation is more likely to occur.
Physiological stress, inappropriate levels of a
critical environmental factor.
◦ Moisture, Light, pH
Predation, when one organism is hunted and
killed by another.
Competition, the result of other organisms
attempting to use same resources.
Sexual Selection occurs when the female
(usually) responds to specific behaviors or physical traits.
Zone of
intolerance Optimum range Zone of physiological stress Zone of physiological stress Zone of intolerance Temperature Low High No organisms Few organisms
Upper limit of tolerance P o p u la ti o n s iz e
Abundance of organisms Few
organisms No
organisms
Lower limit of tolerance
Speciation
Over a long enough period of time, enough
mutations occur that a new species emerges.
When a population splits and become two
different species, it is called divergent speciation.
Chimpanzees and bonobos are very
closely related primates, with only a few
differences between the species.
◦ They likely diverged during a severe drought millions of years ago.
Convergent speciation
can occur when
natural selection favors unrelated
organisms to evolve to look similar.
Preying Mantis Mantis Fly
Biological
Mimicry
Artificial Selection
The selective breeding of organisms by
10/26
Topic: Biogeochemical
Cycles
LT: I can describe the differences between at least two biogeochemical cycles.
Do Now: How does a zone of tolerance for any factor lead to speciation? (Evolution of
Nitrogen cycle
Biosphere
Heat in the environment
Heat Heat Heat
Phosphorus cycle Carbon cycle Oxygen cycle Water cycle
Biogeochemical Cycles
First, the Water Cycle…
CARBON CYCLE
Largest reservoir
2nd largest reservoir
We alter the carbon
cycle by adding excess CO2 to the atmosphere by:
◦ Burning fossil fuels
◦ Clearing vegetation faster than it is
replaced
Effects of Human Activities
on Carbon Cycle
PHOSPHOROUS
CYCLE
NOT an atmospheric
cycle
◦ Phosphorus is usually found in rock
formations and ocean sediments
We affect the phosphorus cycle by:
◦ Removing large amounts of phosphate from the earth to make fertilizer
◦ Adding excess phosphates to aquatic systems from runoff of animal wastes and fertilizers
This is a big deal because phosphorus is usually
insoluble in water and is not found in most aquatic environments
◦ Reducing phosphorous in tropical soils by clearing forests
Effects of Human Activities
on the Phosphorous Cycle
NITROGEN CYCLE
We alter the nitrogen cycle by:
◦ Adding gases (nitrogen oxides) into the atmosphere that contribute to acid rain
Producing fertilizers
Burning fossil fuels in automobiles and power plants
◦ Contaminating ground water from nitrate ions in inorganic fertilizers
◦ Releasing nitrogen into the troposphere
through deforestation
Effects of Human Activities
on the Nitrogen Cycle
The first step of the nitrogen cycle where
specialized bacteria convert gaseous nitrogen into ammonia
◦ Done by cyanobacteria, or bacteria living in the nodules on the root of various plants
Nitrogen Fixation
Ammonia is converted to nitrite, then to
nitrate
Plant roots absorb ammonium ions and nitrate
ions for use in making molecules such as DNA, amino acids and proteins.
Nitrification
After nitrogen has served its purpose in living
organisms, decomposing bacteria convert the nitrogen-rich compounds, wastes, and dead bodies into simpler compounds such as
ammonia
Convert ammonia nitrite ions and nitrate ions
nitrous oxide gas and nitrogen gas
◦ Occurs when a soil nutrient is reduced and released into the atmosphere as a gas
Ammonification
Denitrification
Legume: the fruit or seed of the bean/pea family
The Nitrogen Cycle Made
Easy
Process
Fix
N
A
A
D
Product
A
N
P
A
N
N
2Fixation
itrification
ssimiliation
mmonification
enitrification
mmonia
(Ammonium)itrites / Nitrates
roteins
(DNA/Amino Acids)mmonia
(Ammonium) We add sulfur dioxide to
the atmosphere by:
◦ Refining sulfur containing petroleum
◦ Burning coal and oil
◦ Converting
sulfur-containing metallic ores into free metals such as copper, lead, and zinc thus, releasing sulfur dioxide into the
environment
Effects of Human Activities
on the Sulfur Cycle
1. What is the product of nitrification?
• Nitrites and nitrates
2. Name the steps of the nitrogen cycle.
• Fix: Nitrogen Fixation
• N: Nitrification
• A: Assimilation
• A: Ammonification
• D: Denitrification
3. Is the phosphorus cycle is a slow or a fast process?
• A slow process
4. Eutrophication is caused by excess _______ & ________.
• Nitrogen (mainly from fertilizers) & phosphorus (mainly from plant debris)
5. Which biogeochemical is primarily associated with acid rain?
• Sulfur
PAUSE FOR REVIEW
1. Name and explain the types of symbiosis.
• Amensalism, Commensalism, Mutualism, & Parasitism
2. Predation is necessary because _______.
• Circle of life
• Kills off the weak and improves the gene pool
3. Humans effect the carbon cycle by ______.
• Burning fossil fuels and destroying trees due to
urbanization, desire for commericial wood products, etc…
4. What is resource partitioning?
• Similar species use limited resources in different ways
5. Name a keystone species and explain why the species would be considered a keystone species.
• EX: Sea otter protects the kelp from sea urchins
PAUSE FOR REVIEW
Biomes – large terrestrial regions
characterized by similar climate, soil, plants, and animals
The most important factors in a biome are
temperature and precipitation
Also determined by soil type
Biomes tend to converge
around latitude lines on the globe
Elevation also plays a large
key in biome type as well
Ecoton e
Ecoton e
Ecoton e
Different climates
lead to different communities of
organisms, especially vegetation
Each biome contains
many ecosystems whose communities have adapted to
differences in
climate, soil, and
other environmental factors
BIOMES: CLIMATE & LIFE ON
LAND
BIOMES: CLIMATE & LIFE ON
LAND
The evaporation can be greater than the
precipitation (usually less than 25 cm)
Covers 30% of the earth
Found in tropical, temperate, and cold regions
Variations in annual
temperature (red) and
precipitation (blue) in
tropical, temperate & polar deserts
DESERT BIOMES
Rainfall is erratic & fires are common
Has shrubs that are good for grazing
animals
Variations in annual
temperature (red) and precipitation
(blue) in tropical, temperate,
and
polar grasslands
GRASSLANDS
BIOMES
Tropical &
subtropical
grassland
Warm all
year long
with
alternating
wet & dry
seasons
GRASSLAND BIOMES
Savanna
Temperate
shrubland
◦
Overall mild
climate
Coastal
areas
Winters are
mild & wet
Summers
are long,
hot, & dry
GRASSLAND BIOMES
Chaparral
Cold winters Hot dry
summers
Deep and
fertile soil
Ideal for
growing crops and grazing cattle
GRASSLAND BIOMES
Temperate Grassland
Polar grassland
Covers 10% of earth’s land
Most of the year, these treeless plains are bitterly
cold with ice & snow
Have a 6-8 week summer w/ sunlight nearly 24
hours a day
GRASSLAND BIOMES
Tundra
Have enough precipitation to support
stands of trees
Found in tropical, temperate, and polar
regions
Variations in annual temperature (red)
and precipitation (blue) in
tropical, temperate &
polar forests
FOREST BIOMES
High-elevation
islands of biodiversity
Often have
snow-covered peaks that reflect solar
radiation and
gradually release water to
lower-elevation streams and ecosystems
FOREST BIOMES
Near the equator Has year-around
uniformity warm
temperatures, high humidity & heavy rainfall
Very rich with
species that fill specific niches
FOREST BIOMES
Tropical Rain Forest
Coastal areas support huge
cone-bearing evergreen trees
such as
redwoods and Douglas fir in a
cool moist environment
FOREST BIOMES
Temperate Rain Forest
Moderate temperatures Long, warm summers
Cold winters & lots of rain
FOREST BIOMES
Temperate
Deciduous
Forest
Trees
include oaks,
hickory, maple, and
Deciduous means Lose
Leaves
Most of the trees survive
winter by dropping their
leaves, which decay and
produce a
nutrient-rich soil
FOREST BIOMES
Temperate Deciduous Forest
Just south of the
tundra (northern part of N. America)
Covers 11% of earth’s
land
Winters are
long, dry & cold
Some places have
sunlight 6-8 hours/day
Summers are short
and mild, with sunlight 19 hours a day
FOREST BIOMES
Taiga, Boreal/Evergreen Coniferous
Forest
cone-bearing evergreen trees that keep their needles year-around
In addition to changing altitude, the
presence of mountains has a major
influence on the distribution of precipitation.
◦ As warm, moist air travels up a mountain range, the air cools (due to altitude) and the moisture condenses.
As a result, the windward side of the
mountain facing the incoming air currents receives disproportionately more
precipitation than the opposite, leeward side.
◦ This is called the rain shadow effect.
What do you think the pH of _______ is?
Human Skin
Blood
Urine
Saliva
Rainwater
5.4
5.4
7.35 - 7.45
7.35 - 7.45
4.5 - 8.0
4.5 - 8.0
6.0 - 7.4
6.0 - 7.4
5.6
1. What is the difference between climate and weather
• Weather is the physical conditions over a short time period.
• Climate is the average weather conditions over an extended period of time.
2. A biome is determined primarily by _______ & ________.
• Temperature and precipitation (as well as soil type)
3. Why did we discuss elk?
PAUSE FOR REVIEW
1. Name the different biomes. • Deserts • Tropical • Temperate • Polar • Grassland
• Tropical (savanna)
• Temperate (chaparral, temperate grassland)
• Polar (tundra)
• Forests
• Tropical (tropical rain forest)
• Temperate (temperate rain forest, temperate deciduous)
• Polar (taiga, boreal, coniferous)
PAUSE FOR REVIEW
The process where plants & animals of
a particular area are replaced by other
more complex species over time
Primary begins with a lifeless area where there
is no soil (ex. bare rock)
◦ Soil formation begins with lichens or moss
Secondary begins in an area where the natural
community has been disturbed, removed, or destroyed, but soil or bottom sediments
remain
Primary vs. Secondary
Succession
LICHENS AND MOSS
Pioneer
Communities
DOMINATED BY A
FEW, LONG-LIVED
PLANT SPECIES
Climax
rock
lichen
small shrubs
large shrubs
small trees
large
trees
Stages of Succession:
LAND
bare bottom
few/small underwater
vegetation
temporary pond and
prairie
forest and swamp
Stages of Succession:
WATER
Ecosystems are constantly changing
in response to changing environmental conditions
Succession’s Relation to
Biomes and Biodiversity
Damaged or disturbed more than half of the
world’s terrestrial ecosystems
Had a number of specific harmful effects on
the world’s deserts, grasslands, forests, and mountains
Human Impacts on Terrestial
Ecosystems
Natural Capital Degradation Desert
Large desert cities
Soil destruction by off-road vehicles
Soil salinization from irrigation
Depletion of groundwater
Land disturbance and pollution from mineral extraction
Oil production and off-road vehicles in arctic tundra
Overgrazing by livestock Release of CO2 to
atmosphere from grassland burning
Conversion to cropland Grasslands
Natural Capital Degradation
Approximately 70% of Brazil’s tropical savanna (once the size of the
Amazon) has been cleared and converted to the world’s biggest grain
Clearing for agriculture, livestock
grazing, timber, and urban
development
Conversion of diverse forests to tree
plantations
Damage from off-road vehicles
Natural Capital Degradation Forests
Pollution of forest streams
Natural Capital Degradation Mountains
Agriculture
Timber extraction Mineral extraction
Hydroelectric dams and reservoirs
Increasing tourism Urban air pollution Increased UV radiation from ozone depletion Soil damage from off-road vehicles
Native, nonnative, indicator, keystone, and
foundation species play different ecological roles in communities.
◦ Native: those that normally live and thrive in a particular community
◦ Nonnative species: those that migrate,
deliberately or accidentally introduced into a community
EX—The Chinese chestnut had a fungus that
spread & virtually eliminated the American chestnut
TYPES OF SPECIES
What are the effects of
introducing a nonnative
Displace native species Lower biodiversity
Adapt very quickly to local habitats
Can contribute to habitat fragmentation Reproduce very quickly
Introduced Invasive
Species
Other biodiver
sity
“decreasers”?
Over-hunting/hunting of top predators for big game CFC’s, CO2, oil spillsHunting
Trying to rebuild what was ruined
Habitat Restoration
Returning vegetation to an area that has
been mined or disturbed by human use
This can be done by re-planting, cleaning up
pollution, regulations (laws) or any other activity designed to “fix” a destroyed area
