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Ecology –
Organisms & Their Environment
Dr. Childs
Science Computer Lab
Spring, 2005
Ecology
Ecology is the interaction of living
organisms and their environment
This lesson will emphasize:
•
Relationships between organisms
•
Food webs
Biotic & Abiotic Factors
Biotic Factors
Living organisms
Abiotic Factors–
Nonliving
Biotic Factors
Plants & Animals
Abiotic Factors
Climate
Air
Rocks
Water
Soil
Sunlight
Relationships
Ecosystem
Terrestrial Ecosystem
Aquatic Ecosystem
Marine Ecosystem
Community
Population
Organism
Organism
- A single living individual
Population
-A group of organisms of the same species
-Live in same area
- Interact & interbreed
Community
- Populations of different species of plants and animals
that live together and interact with each other
Ecosystem
- A community with biotic and abiotic factors.
- terrestrial
- aquatic
- marine
land
fresh water
salt water
Ecosystem
Terrestrial Ecosystem
- Terrestrial ecosystem
- Examples:
- forest
- desert
- field
- jungle
- large dead tree
Aquatic Ecosystem
- Aquatic ecosystem
- Examples:
- lake
- stream
- river
Marine Ecosystem
- Marine ecosystem
- Examples:
- ocean
- estuary
- tidepools
Community Interrelationships
- Symbiosis:
-Mutualism
-Commensalism
-Parasitism
- Predation
Mutualism
- Both organisms benefit
Clownfish & anemone
Insects and flowers
Termite protozoa – digests cellulose
Lichen – algae & fungi
Commensalism
- One organism benefits, other not harmed
Barnacles on mussel
Remora fish on turtle
Cattle egrets with cows
Spanish moss on oak
Parasitism
- One organism benefits, other harmed, but not
killed
Fungus on human
Malaria in human blood
Tapeworm in intestine
Ticks on dog
Predation
- One organism benefits (predator), other is
killed (prey)
Food Chains
Food chains show how animals get their food.
They also show how energy is gained
and lost in an ecosystem.
Autotrophs
Produce own carbon compounds (sugars)
• Energy from sunlight - photosynthesis
• Includes algae and plants
Heterotrophs
Carbon compounds from other organisms
Fungi (include decomposers)
Protozoa and animals
Herbivores
Herbivores are animals that eat only plants
Flat grinding molars
Carnivores
Carnivores are animals that eat other animals
- Meat-eaters
Carnivores
Pointed canines for grasping and
tearing
Omnivores
Omnivores are animals that eat both plants
and animals
Omnivores
Both sharp canines &
grinding molars
And our favorite
Pizza-vores
Food Chains
Sunlight
Secondary consumer
Primary consumer
Scavenger
Decomposer
Producer
Sunlight
Sunlight is the source of energy
in an ecosystem.
Producers
Producers:
- are green plants
- capture energy from the sun
- convert to sugars by photosynthesis
- fix CO2 into sugars
- release oxygen (O2)
- are autotrophs
Producers
Algae
Microscopic
plankton
Primary Consumers / Herbivores
Primary consumers eat producers / plants
- herbivores
- heterotrophs
- among the smallest and largest creatures
Primary Consumers / Herbivores
Secondary Consumers
Secondary consumers eat primary
consumers.
Secondary Consumers
Scavengers
Scavengers:
- Eat dead and rotting meat
Vulture
Hyena
Decomposers
Decomposers:
Digest and break down dead bodies into
simple molecules. Recycle nutrients.
- Includes:
fungi
insects
bacteria
worms
Decomposers
Food Webs
-The interactions among animals for food is
never as simple as food chains. For example,
bears may eat plants or small animal. Eagles may
eat fish or small mammals.
-These interactions are called a “food web”.
Food Webs - Terrestrial
Food Webs - Marine
Trophic Levels
- Levels is a food chain may be defined in terms as
energy as “trophic levels”.
-Energy is lost through each trophic level. This
energy is used to maintain the organism or even lost
as heat.
Trophic Levels
-Organisms are the same trophic level get
their energy from the same sources.
-There are rarely more than 4 or 5 trophic
levels because of the amount of energy lost.
Trophic Levels
Sunlight
3rd trophic Level
4th trophic Level
2nd trophic Level
Note: grasshopper and
rabbit are at the same
trophic level
1st trophic Level
Energy Pyramids
Energy pyramids represent the amount of total
energy in a trophic level. May be represented as
“calories” or “joules”
Producers are at the bottom and each trophic
level in on top.
Energy Pyramids
-The size of each level represents the biomass – the
sum of the mass of all the organisms at that level.
-Be aware that sometimes the producer levels are
smaller than the consumers because the producer may
reproduce much faster.
- There may be only about 10% of energy from one
level to the next.
Energy Pyramid
Energy Pyramid
Energy Pyramid