Transcript Ecosystem Unit

Ecosystem Unit
Objectives
•
•
•
•
•
•
•
Describe an ecosystem and its components
Illustrate the E flow through a system
Identify biotic and abiotic things
Distinguish between the different biomes
Create a food chain and web
Understand earth cycles (C, N, etc.)
Explain what a keystone spp is and its job
Words to know
•
•
•
•
•
•
Ecosystem
Biotic
Abiotic
Biome
Food chian
Keystone spp
Ecosystems
• Ecosystem: An area containing an interaction of
living and non-living factors in an area/region
• Example ecosystems:
– Porcupine Mts. in MI
– Forests of WI
– Outer banks coastal water ecosystem
– Sand Lake ecosystem
Ecosystem
Gaia Hypothesis
What is in an Ecosystem?
• Abiotic Factors: The non-living parts of an
ecosystem
– Rocks, soil, temperature, gases in the air, light
• Biotic Factors: The living parts of an ecosystem
– Plants, animals, bacteria, fungus
• Producers: use light to make their own energy
• Consumers: eat other organisms to obtain energy
• Decomposers: break down dead organisms for energy
Biotic
Abiotic
•
•
•
•
•
•
•
•
•
•
•
•
•
Humans
Bacteria
Fungus
Plants
Insects
Amphibians
Reptiles
Mammals
Birds
Water
Soil
Wind or Air
Gases
– oxygen, carbon dioxide,
nitrogen
• Temperature
• Sunlight
• pH
– Acid or base
Abiotic or Biotic?
Biotic
(plant)
Abiotic
(rainwater)
Abiotic or Biotic?
•
•
•
•
•
The air temperature is 45 degrees F = abiotic
The soil is made of rocks and minerals = abiotic
A bird lays eggs = biotic
Bacteria break down dead organisms = biotic
The pH or the water is 2 (acidic) = abiotic
Which of the following is a relationship
between abiotic and biotic factors?
A) The rain on an open field washes away soil
B) A hawk hunts a mouse and swoops down into
the forest for the kill
C) A lake has very acidic water which causes
many fish populations to die
Abiotic
D) A deer grazes in a field of grasses
Biotic
Ecosystems
• Biodiversity
• Change
Members of an Ecosystem
Producer- all autotrophs
(plants), they trap
energy from the sun
• Bottom of the food
chain
• 6CO2 + 6 H2O + solar E
→ C6H12O6 + 6O2
Members of an Ecosystem
Consumer- all heterotrophs: they
ingest food containing the sun’s
energy
• Herbivores
• Carnivores (2° and 3 °)
• Omnivores
• Decomposers
• Detritus feeders
Members of an Ecosystem
Herbivores
– Eat plants
• Primary
consumers
• Prey animals
Members of an Ecosystem
Carnivores
-eat meat
-Predators
– Hunt prey
animals for food
Secondary
consumers
Members of an Ecosystem
Carnivores
- eat meat
• Scavengers
– Feed on carrion,
dead animals
tertiary consumers
Members of an Ecosystem
ConsumerOmnivores -eat
both plants
and animals
Members of an Ecosystem
ConsumerDecomposers
• Breakdown the
complex compounds
of dead and
decaying plants and
animals into simpler
molecules that can
be absorbed
Members of an Ecosystem
• Detritus feeders
Earthworms, some insects, vultures
Little waste
Aerobic respiration
Main Structural Components of an
Ecosystem (E, chem, organisms)
Solar
E
Heat
Chemical
nutrients
(CO2, O, N,
minerals)
Heat
Heat
Decomposers
(bacteria,
fungi)
Heat
Producers
(plants)
Consumers
(plant eaters,
meat eaters)
Heat
Abiotic or Biotic?
Biotic
Abiotic
Biotic
Biotic
Feeding Relationships
•
There are 3 main types of feeding
relationships
1. Producer- Consumer
2. Predator- Prey
3. Parasite- Host
Trophic Levels
• Each link in a food chain is known
as a trophic level.
• Trophic levels represent a feeding
step in the transfer of energy
and matter in an ecosystem.
Trophic Levels
Biomass- the amount of organic matter
comprising a group of organisms in a
habitat.
• As you move up a food chain, both
available energy and biomass
decrease.
• Energy is transferred upwards but is
diminished with each transfer.
E
N
E
R
G
Y
Trophic Levels
Tertiary consumerstop carnivores
Secondary consumerssmall carnivores
Primary consumers- Herbivores
Producers- Autotrophs
Why is a vegetarian diet more E
efficient than a meat-based diet?
• E is lost
• Higher up= less E
• Eat a lower trophic level??
Trophic Levels
Food chain- simple model that
shows how matter and energy
move through an ecosystem
Trophic Levels
Food web- shows all possible
feeding relationships in a
community at each trophic level
• Represents a network of
interconnected food chains
FOOD CHAINS AND FOOD WEBS - illustrate the
flow of energy in an ecosystem
*Note the direction of the arrows, they indicate where the energy is going when one
.
organism consumes another
Each step in a
chain or web is
called a TROPHIC
LEVEL
Identify:
Primary Consumers
Secondary Consumers
Tertiary Consumers
Find the Omnivore.
Ecological Pyramids (fig 3-9)
Energy Pyramid
Biomass Pyramid
Pyramid of Numbers
Food chain
(just 1 path of energy)
Food web
(all possible energy paths)
Nutrient Cycles
Cycling maintains homeostasis
(balance) in the environment.
•3 cycles to investigate:
1. Water cycle
2. Carbon cycle
3. Nitrogen cycle
4. Phosphorus
5. Sulfur
Water cycle•Evaporation, transpiration,
condensation, precipitation
Water cycle-
Carbon cycle•Photosynthesis and respiration
cycle carbon and oxygen through
the environment.
Carbon cycle-
Nitrogen cycleAtmospheric nitrogen (N2) makes up nearly
78%-80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into
usable forms.
Nitrogen cycleOnly in certain bacteria and industrial
technologies can fix nitrogen.
Nitrogen fixation-convert atmospheric
nitrogen (N2) into ammonium (NH4+)
which can be used to make organic
compounds like amino acids.
N2
NH4+
Nitrogen cycleNitrogen-fixing
bacteria:
Some live in a
symbiotic
relationship with
plants of the legume
family (e.g.,
soybeans, clover,
peanuts).
Nitrogen cycle•Some nitrogen-fixing bacteria live
free in the soil.
•Nitrogen-fixing cyanobacteria are
essential to maintaining the fertility
of semi-aquatic environments like rice
paddies.
Lightning
Atmospheric
nitrogen
Nitrogen Cycle
Denitrification by
bacteria
Animals
Nitrogen fixing
bacteria
Decomposers
Ammonium
Nitrification by
bacteria
Plants
Nitrites
Nitrates
P Cycle
S cycle
Toxins in food chainsWhile energy decreases as it moves up
the food chain, toxins increase in
potency.
•This is called biological magnification
Ex: DDT & Bald Eagles
Ecosystem - the community plus the physical
factors in an area (rain, light, soil..)
Examples:
Rotting Log
Koi Pond
Lake
Clump of Dirt
A field
An old maple tree
Biomes
• 6 major biomes
– Tropical
– Grassland
– Desert
– Temperate
– Taiga
– Tundra
Tropical
• Tropical rain forest
– Warm temp, adundant rainfall
– Lush vegetaion
– Animals within thick cover, vocal
Grassland
Tropical Grassland
• Warm throughout year
• Dry and rainy season
• Tall grass, scattered trees
• Gazelles, herbivores
Temperate Grassland
• Dry and warm summer,
snow winter
• Short and tall grasses
• Animals below ground (dry,
windy)
Desert
• Dry
• Cacti
• nocturnal
Temperate
Temperate deciduous forest
• Hot summer cold winter
• Precip all year
• Broadleaf forest, deciduous
trees lose leaves
Temperate rain forest
• One long wet season, dry
summer
• Evergreen conifers
• Migration
Taiga
• Long cold winter, short warm humid summer
• Coniferous
• Fur coats
Tundra
•
•
•
•
Subzero
Little precip
Permanently frozen, mosses
low animal diversity
Biome - large area that has a particular climate, and
particular species of plants and animals that live
there (tundra)
Biosphere - the part of the earth that supports life
Ecological methods - how do we study it?
Observing
Experimenting
Modeling
Models are created by
humans to make
predictions.
Sometimes, you must be cautious in how a
model interprets data....
Imagine graphing a
person's height as
they age. One could
predict that by the
time they were age
30, they would be 22
feet tall.
However, the model
would need to
account for the
slowing of growth
after adolescence.