Ecology The study of the interactions of organisms with one another and within their environment
An Environment Contains… Biotic Factors – “Bio” = Life – Living factors in an environment Abiotic Factors – “A” in front of a word = Non – Non-living factors in an environment
ABIOTIC FACTORS 1.Water- Most living things are mostly water…mostly! Water is a crucial reactant in photosynthesis and respiration.
2.Sunlight- needed for photosynthesis 3.Air/Oxygen- Most living things need this gas. Air breathing organisms get it from the air. Others get it from the water (there’s oxygen dissolved in the water). 4.Soil
How are Environments Organized? Five Levels of Organization – 1. Organism – 2. Population – 3. Community – 4. Ecosystem – 5. Biosphere
Niche - the role an organism plays in an ecosystem An organism’s niche can include: Type of food it eats. How it obtains its food. What organisms eat it. When and how reproduction takes place
3 Types of Interactions: Competition: When two or more individuals try to use the same resource. Predation: One organisms hunts and kills another. Symbiosis: a close relationship between two or more species.
Competition When two or more individuals (or populations) try to use the same resources. Let’s Brainstorm! What are some resources that organisms might compete for?
Resources can be food, water, shelter, space, sunlight, mates, etc.
Competition Competition can happen in one of two ways: 1. Between individuals within a population 2. Between populations in a community.
Competition Individuals within a population: Example: The Elks in Yellowstone National Park Elks are herbivores (what does that mean?) and compete with each other for the same food plants.
Competition Competition between populations: Example: Different species of trees in the forests What do you think they compete for?
When one organism hunts and kills another. Predator: the organism that kills and eats all or part of another organism. Prey: an organism that is killed and eaten by another organism.
What happens if a predator is suddenly removed from a habitat?
News Flash! Not all members of an ecosystem are created equal! All organisms have important roles, but some members are more important to the ecosystem as a whole.
We call these important members the keystone species Example: The sea otter in the Pacific Ocean
Sea otters live in the Kelp Forests of the Pacific Ocean. One of their primary food sources is sea urchins At one point, the otters were hunted to near extinction.
With the otters gone, there was nothing to eat the sea urchins The sea urchins exploded in number and then ate all of the kelp
The kelp was home to dozens of animals, all of which disappeared! Eventually, even the sea urchins disappeared. Otter became protected animals, and grew in number. Over time, the different populations returned!
Organisms develop adaptations (changes) over time in response to their environment in order to survive. – This is called natural selection. Does this apply only to predators? Only to prey? Or to both??
Predator Adaptations A predator must be able to catch their prey! Predators have developed a wide variety of methods and abilities in order to effectively and efficiently hunt their prey.
Examples: speed, sharp teeth, sharp claws/talons, poisonous venom, night vision, “radar”, coloring. The cheetah’s speed gives it an advantage over predators competing for the same prey!
The Goldenrod Spider – Blends in with the goldenrod flower.
Prey Adaptations Prey must be able to avoid being eaten! Prey have developed methods and abilities to keep from being eaten.
Prey Adaptations: Camouflage – Coloration that helps an organism to blend in with its surroundings. Examples: Rabbits – Brown Rabbits, White Rabbits Walking Sticks – Insect that looks just like a twig. – Some even sway to look like they were a stick being blown by a slight breeze!!
Prey Adaptations Warning Coloration – A way to advertise their defensive chemicals – Predators avoid animals that have colors and patterns they associate with pain – Most common warning colors: bright shades of red, yellow, orange, black, and white. Fire Salamander – Bright yellow and black – Sprays a chemical that burns
Pretenders – Don’t have defensive chemicals, but use warning coloration – Example: Scarlet King Snake vs. Coral Snake
Symbiosis Symbiosis is a close, long-term association between two or more species.
Symbiosis 3 types of symbiotic relationships: 1.Mutualism: both species benefit. 2.Commensalism: one species benefits, the other species is unaffected. 3.Parasitism: one species benefits, the other species is harmed.
Mutualism ants and aphids clownfish and sea anemones bees and apple trees
Commensalism: Remoras and Sharks Cattle Egrets and Livestock Orchids Growing on Branches of Trees A titan trigger fish (feeding opportunities for smaller fish by moving large rocks too big for them to shift themselves)
Parasitism The parasite - organism that benefits. The host - organism that is harmed The parasite gets nourishment from its host, while the host is weakened.
Parasitism Tapeworms in human intestines Fleas on dogs Tick
Coevolution Relationships between organisms change over time. Interactions between organisms can also cause a change in the organisms themselves!
Coevolution is when a long- term change takes place in two species because of their close interactions with one another. These changes happen over a very long period of time.
Bumblebees and Flowers Bumblebees and the flowers they pollinate have coevolved so that both have become dependent on each other for survival. Over millions of years, flowers have changed to attract certain pollinators! Flowers attract pollinators with their color, odor, or even nectar.
Hummingbirds and Ornithophilous Flowers Hummingbirds and ornithophilous (bird-pollinated) flowers have evolved a mutualistic relationship. The flowers have nectar suited to the birds' diet, their color suits the birds' vision and their shape fits that of the birds' bills.
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