Transcript Ecology Notes

ECOLOGY
Ecowhat?
• Ecology
– The study of interactions between organisms
and their environment and between one
another
• Biosphere
– Parts of the planet where life exists
– Includes land, water and air
Ecological Organization
• Species
– Organisms that can
breed and produce
fertile offspring.
• Populations
– Same species that live in
the same area
• Communities
– Different populations that
live in the same area.
Ecosystem
• Ecosystem
– Living and nonliving things that occupy an area
Biotic… Abiotic… Biotic… Abi
• Biotic
– Organisms such as
plants and animals
• Abiotic
– Nonliving factors such
as precipitation,
temperature, soil type
etcetera.
• Habitat
– Address
Energy in an Ecosystem
• Sunlight
– Main energy source of life
• Producers (Autotrophs)
– Make their own food from
the sun
• Consumers (Heterotrophs)
– Rely on other organisms for
food
Types of Consumers
• Herbivores
– Eat plants
• Carnivores
– Eat meat
• Omnivores
– Eat plants and
meat
• Detrivores
– Eat decaying
matter
• Decomposers
– Turn decaying matter
into usable nutrients
Feeding Relationships
• Food Chain
– One way flow of
energy through an
ecosystem (simple)
• Food Web
– Complex feeding
relationships made
up of many food
chains (complex)
Trophic Levels
• Trophic Level
– A step in the food chain or food web
• 1st Trophic Level
– Producers
• 2nd, 3rd, + Trophic Levels
– Consumers
Trophic Level Producer/Consumer Plant/Herbivore/Carnivore
Example
Fifth
Decomposers
Decomposers
Fungi &
Bacteria
Fourth
Tertiary
Consumer
Larger Carnivore
Mountain
Lion
Third
Secondary
Consumer
Carnivore
Weasel
Second
Primary
Consumer
Herbivore
Gopher
First
Producer
Photosynthetic
Green Plant
Wild
Mustard
Ecological Pyramids
•
Ecological Pyramid
– Diagram showing the amounts of
energy in each trophic level.
•
Energy Pyramid
– Shows the amount of energy
available at each trophic level.
– 10% of energy in a level is passed
to the next level.
•
Biomass Pyramid
– Looks at amount of living organic
matter or tissue at each level
•
Pyramid of Numbers
– Shows the number of individual
organisms at each trophic level.
Biogeochemical Cycles
• 4 Biogeochemical Cycles
1.
2.
3.
4.
Carbon cycle
Nitrogen cycle
Phosphorus cycle
Water cycle
Carbon Cycle
Living tissue contain carbon, because they contain proteins, fats and
carbohydrates. The carbon in these (living or dead) tissues is recycled in
various processes.
ADDING CARBON:
- Burning fossil fuels
- Respiration (animals release CO2)
- Decomposers (release carbon from
dead plants/animals)
REMOVING CARBON:
- Photosynthesis (plants absorb
CO2)
- Consumers eat plants taking in
carbon and passing onto rest of
food chain
- Dead animals that are buried
transform into fossil fuels
Nitrogen Cycle
Nitrogen forms about 78% of the air on earth. But plants do not use nitrogen directly
from the air. This is because nitrogen itself is unreactive, and cannot be used by green
plants to make protein.
1 - Nitrogen added to soil by precipitation
2 – Fertilizers also add nitrogen into the
soil
3 – Plants use nitrates absorbed in soil to
build proteins
4 – Animals use nitrogen in plants to create
protein as well
5-6 – Animal poop/pee/carcasses are all
broken down by decomposers and
reintroduce nitrogen into the soil
7 – Nitrates in soil also broken down by
bacteria/released into the air
Phosphorus Cycle
Water Cycle
Ecological Succession
• Ecological Succession
– Predictable changes that occur over
time.
• Primary Succession
– Newly exposed surfaces.
– Example: no soil after a volcano or
glacier
• Secondary Succession
– Soil is present (after primary
succession)
– Example: Fire occurs
• Pioneer Species
– The first species to populate an area in
primary succession.
– Example: Lichen grown on rocks and
breaks them apart creating soil.
Forest Ecosystem
• Tree Population Density
– How many trees are there and what species?
• DBH (Diameter at Breast Height)
– A consistent way to
measure tree size.
Forest Ecosystems & Beetle Kill
Use the http://www.beetles.mt.gov/ website
as well as the resources you were given to
answer these three questions.
1. Why is there beetle kill and how
widespread of a problem is it?
2. Why is it a bigger problem now than in the
past?
3. What can be done?
Beetle Kill Q’s
Read the article then go to:
http://ngm.nationalgeographic.com/2015/04/pine-beetles/rosner-text
Click on the link on the left side – Death by a Thousand Bites
1. Make a timeline of how a beetle affects trees
Click on the next link – Chronology of an Epidemic/watch the
animation
2. What is the trend in beetle kill in North America over the last 23 years?
Use the article
3. Even though the pine beetle is native to North America, it has created an
epidemic that is unprecedented. Write a paragraph to explain in your own
words why this is occurring.
4. How can the spread of pine beetles be controlled?
5. What occurs in an ecosystem after trees are killed by pine beetles?
Why is there beetle kill and
how widespread is it?
IMPORTANCE OF
BARK BEETLES
• Insects account for 90% of tree mortality in U.S.
• 60% of insect losses attributed to scolytids
• MPB losses in U.S. since 1865 est. to be 1.5 billion
bd-ft/yr. (typical ponderosa pine is 150 bd-ft = 10
million trees)
HISTORICAL ROLE OF BARK
BEETLES IN FOREST SYSTEMS
• Along with fire, mistletoe, and root disease, a
common way for old forests to die and start over
(i.e., a catalyst to succession)
• Provide dead trees upon which many other
organisms depend
• Interval between epidemics is quite cyclic and
variable (every 20-50 years for MPB, maybe
100-300 years for SB). In general about as
predictable as the weather.
BARK BEETLES AND
FUNGI
ambrosia beetle
tunnels with stain
bluestain introduced by
“regular” bark beetle
•
•
•
•
Basically all bark beetles have fungal associates
Staining fungi often called “bluestain”
In some cases this is “obligate”, in others inadvertant
Our understanding of these associations is evolving
RESISTANCE TO ATTACK
• A FUNCTION OF:
– TREE VIGOR
– STAND AND SITE
CONDITIONS
– # OF ATTACKING
BEETLES
Why is it a bigger problem
now than in the past?
• Warmer temperatures – you need three
consecutively cold winters to keep the pine
beetle population in check.
• Trees are stressed – warmer temperatures
= less water = trees that can’t protect
themselves (they normally “sap-out”
predators)
What can be done?
• Biofuel
– Pros – Less Carbon from burning slash piles
– Cons – Cost, environmental impacts of logging wood to use as
biofuel
• Leave it
– Pros – No cost, natural, no logging impact
– Cons – Fire and recreational hazard
• Burn it
– Pro’s – eliminating fire and recreational hazards
– Pollution and cost
• Log it for lumber
– Can make money turning it into something useful
– Cost and pollution
Niche
• Niche
– An organisms occupation (job)
• Includes
– What it does in the food web.
– What temperature it thrives in.
– How does it get its food?
– How does it reproduce?
Competition Exclusion Principle
• Competition Exclusion Principle
– 2 species can not occupy the same niche at
the same time in the same place.
Predator-Prey Relationships
Lots of Prey = an increase in predators = reduction in prey
Symbiotic Relationships
•
Symbiosis
–
•
Organisms living together
Types of Symbiosis
1. Mutualism
–
Both species benefit from
the relationship
2. Commensalisms
–
One member benefits and
the other doesn’t benefit or
suffer from the relationship.
3. Parasitism
–
One organism suffers from
the relationship.
Biomes
•
Biome
–
–
A geographical region that has a certain group
of plants and animals.
Determined by 2 things:
1.
2.
Temperature
Precipitation
Population Density
• Number of organisms in a species in a
given area
• Example: Number of wolves/mile in
Yellowstone
Limiting Nutrients
• Limiting Nutrient
– A nutrient in short
supply will limit an
organism's growth.
– Example:
• If one batch of cookies
requires 2 cups of flour
and you have plenty of
other ingredients but
only 2 cups of flour
then you can only
make one batch of
cookies and your flour
is your limiting nutrient.
Types of Limiting Factors
• Density Dependent Limiting Factors
– Factors that affect population and are changed
based on the population density (biotic)
– Examples: Availability of food, disease
• Density Independent Limiting Factors
– Factors that affect population but are changed
by abiotic factors
– Examples: Natural disasters such as flooding
Invasive Species
• A species that is not native to an
environment.
http://www.defenders.org/sites/default/files/publications/montana.pdf