1. Principles of Ecology
Ecology – study of relationships between living and nonliving parts of the world
Ernst Haeckel (1866) – first to use the word to name the study of how organisms fit into their environment
These slides work alongside the Smartboard Lesson “6.1 Relationships in Ecosystem parts 1-2.”
Corresponding Reading for
Honors – Modern Biology: 18.1 p , 18.2 p , 20.1 p
CP – Holt Biology 2008: 4.1 p.79-84, 5.2 p , 5.3 p
Concepts:
R’ships in an ecosystem
Levels of Biological Organization
Biotic / Abiotic factors
Habitat / Niche
Competition / Predation
Symbiosis – Mutualism / Commensalism / Parasitism

2. Parts of the Environment
Biotic factors – all the living organisms that inhabit the environment
Abiotic factors – non-living parts of an organism’s environment
Air currents, temperature, moisture, light, soil

3. Ecosystem Requirements
#1 - Continuous supply of Energy
#2 – A flow of energy from one population to another

4. Levels of Organization
Organism
Population
Community
Ecosystem
Biome
Biosphere

5. Niche vs. Habitat vs. Ecosystem
Ecosystem – all the organisms in a given area and the abiotic factors that affect them
Habitat – place an organism lives out its life
Niche – role and position a species has in its environment
Includes all biotic and abiotic interactions as an organism meets its needs for survival
If two species are competing for the same niche, one will most likely drive the other out and take control of the niche.
What is your niche?

6. Niche vs. Habitat vs. Ecosystem
An egret lives around Jones Pond which is part of the Smith River Estuary. The egret and its mate eat fish, frogs, salamanders, snakes, crayfish, mice, aquatic insects, crickets, grasshoppers, and a variety of other insects in Jones Pond and build a nest in a tree along side the pond.
What is the egret’s habitat?
What is the egret’s niche?
What is the egret’s ecosystem?
The great egret lives along salt and freshwater marshes, marshy ponds and tidal flats. Some are migratory.
The snowy egret preys on a wide variety of creatures both in and out of the water. The bird's large bill can be used to grasp prey ranging from earthworms and insects to fish, snakes and lizards.
All the organisms with the egret (earthworms and insects to fish, snakes and lizards) in a given area and the abiotic factors (temperature, sunlight, wind, moisture, sand, soil) that affect them

7. Organism Interactions: Predation
The number of predators affects the prey population
More predators, more risk to prey
The number of prey affects the predator population
More prey, more food for predators

8. Organism Interactions: Competition
Competition – a density-dependant factor
Organisms within a population must compete for resources
If population numbers are low, resources are plentiful
When populations grow, resources are in higher demand
If demand is greater than supply……population must decrease
Fight and kill each other
Reproduce less

9. Relationships
All living things form relationships with other living things
Symbiotic Relationship – a relationship between organisms of two different species that live together in direct contact
Ccsdsc_teacher

10. Parasitism One organism benefits, the other is harmed
Some live with in the host
Tapeworms
Heartworms
Bacteria
Some feed on the external surface of the host
Ticks
Fleas
Mistletoe
Most do not kill their host (at least not quickly)

11. Mutualism Both organisms benefit
Acacia tree and ants (Pseudomyrmex sp.) – tree provides food for the ants and the ants protect the tree from animals that would eat the leaves
Lichens: algae and fungus living together Algae provide food (photosynthesis) and the fungus provides protection and attaches the lichen to the rock or wood where it lives.
- Bacteria living in human intestines: break down nutrients and have a safe environment

12. Commensalism One organism benefits while
the other is not affected. Examples include:
Spanish moss on a tree
Burdock seeds on a passing animal
Barnacles on a whale (commensalism or parasitic?)
Moss gets a place to live
The Whale/Barnacle Symbiosis:
‍The whale barnacle is Coronula diadema although barnacles are host specific so there are different barnacle species for different whale species. Cryptolepas rhachiaecti, for example, is the barnacle that attaches only to gray whales. It is unclear whether the symbiosis is commensal or parasitic. According to some researchers, obligate commensalism describes the relationship best because the barnacles need the whales in order to complete their life cycles and the whales do not benefit or lose. However, some researchers argue that since whale barnacles can accumulate to hundreds of pounds on a single whale, this probably bothers whales. Whales may try to rid themselves of the barnacles by rubbing themselves against the ocean floor or rocks. Interestingly, it seems there are more barnacles on slower whale species while faster whale species (similar to dolphins) have fewer barnacles. Similar to whale barnacles, whale lice also share a symbiotic relationship with whales although whale lice seem to definitely negatively affect the whales in a parasitic way since they actually feed off the whale.
FUN FACTS: ---There are normally hundreds of pounds of barnacles on gray whales. Whales can hold up to about 1,000 pounds of barnacles. ---The “glue” like substance that barnacles secrete to attach to whales is so strong that dentists are studying it for its ability to stick so tight. This glue allows the barnacles to remain permanently on the attachment site. Barnacles are so deeply embedded that they usually form prong-like structures that pierce the skin of the whale. Therefore, it is nearly impossible for whales to rid themselves completely of barnacles. ---Slower whales tend to have more barnacles than faster whales --- Barnacles seem to only use one sense: touch. They have very sensitive hair fibers on their limbs that help direct them. They also have a single eye, which probably helps differentiate between light and dark.