Ecology Notes
Chapter 1
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Background:
Native Americans lived “conservation” as a way of life. This was the idea of sustainable living.
Example: Cheyanne bison hunt
Strict rules on killing more bison then needed
Used all parts of the animal so none was wasted
Meat eaten for food
Fat used for cooking
Bones used for tools
Hides were used for clothing
Stomachs were used for water pouches.
It was a Native American belief that people must cooperate with nature so that revival and rebirth can continue.
The Mayans believed that cutting down a tree unnecessarily shortened one’s life. Although this was thousands of years ago, there is some truth in this. Trees and plants remove carbon dioxide from the air and reduce global warming.
Quotes from Chief Seattle:
Every part of all this soil is sacred to my people. Every hillside, every valley, every plain and grove has been hollowed by some sad or happy event in days long vanished. The very dust you now stand on responds more willingly to their footsteps than to yours, because it is rich with the blood of our ancestors and our bare feet are conscious of the sympathetic touch.
We know that the white man does not understand our ways. One portion of the land is the same to him as the next, for he is a stranger who comes in the night and takes from the land whatever he needs. The earth is not his brother, but his enemy - and when he has conquered it, he moves on. He leaves his fathers' graves, and his children’s birthright is forgotten.
The Indian prefers the soft sound of the wind darting over the face of the pond, the smell of the wind itself cleansed by a midday rain, or scented with pinon pine. The air is precious to the red man, for all things are the same breath - the animals, the trees, the man. .
The whites, too, shall pass - perhaps sooner than other tribes. Continue to contaminate your own bed, and you might suffocate in your own waste.
When the buffalo are all slaughtered, the wild horses all tamed, the secret corners of the forest heavy with the scent of many men, and the view of the ripe hills blotted by talking wires, where is the thicket? Where is the eagle? Gone.
We are part of the earth and the earth is part of us.
There is no quiet place in the white man’s cities, no place to hear the leaves of spring or the rustle of insects’ wings. Perhaps it is because I am a savage and do not understand, but the clatter only seems to insult the ears.
If the Native Americans lived “conservation,” then what is conservation?
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Testable items:Definition: The practice of modifying human behavior to preserve Earth.
Ecology studies how all species on Earth are connected.
Ugly fact- In 1950 30% of the earth’s land was covered by rainforest, now it is only 7%.
Section 1- The Interactions of Life
Vocab- Biosphere, ecosystem, ecology, populations, community, habitat
Biosphere- The part of the Earth that supports life. 3 parts: the top of earth’s crust, the water, and the atmosphere.
- The biosphere has many different environments such as polar, desert, ocean, etc.
Life on Earth- Very lucky, we are the 3rd planet from the sun
- Any closer too hot, any further too cold
Ecosystems- An ecosystem is all the organisms living in an area and the non-living features of that environment.
-ex: a Prairie’s living parts contain bison, grass, birds, insects, and bacteria. Its non-living parts contain water, temperature, soil, sunlight, and air.
Ecology: The scientific study of the interactions that determine the distribution and abundance of organism.
Ecologists study populations. A population is made up of all the organisms in an ecosystem that belong to the same species.
Ecologists study how populations interact.
-ex: Bison grazing affect prairie grass, birds and insects are in the grass, birds eat the insects.
A community refers to all populations in an ecosystem.
A habitat is the place an organism lives.
Review questions: What’s the biosphere? What’s ecology? What is a community vs. a population, how do they relate?
Section 2- Populations
Competition- Organisms in the same population compete for a variety of things
Food and space
Growth Limits
mates
Population Size- Counting populations can help identify those organisms in danger of disappearing.
The size of a population that occurs within a specific area is the population density.
Measuring- Different models exist for estimating populations. Some include mark-recapture techniques which involves live trapping. The organisms are re-captured and then mathematical equations are used to estimate the population.
Sample counts can be taken if you want to know the number of animals in a particular area. Ex. How many mice are in a 100 acre forest? Count the number of mice in 1 acre and multiply by 100.
Limiting factors- Organism’s need resources. They can’t grow or will stop growing or reproducing if a resource runs out.
-A limiting factor is anything that restricts the number of individuals in a population.
Carrying capacity (K)- The largest number of individuals of 1 species that an ecosystem can support over time. The Earth’s carrying capacity is estimated to be about 10 billion.
Changes in Populations- Birthrates and Death rates
Death>Birth- population gets smaller
Birth>Death- Population gets larger see pg 18 pop. Growth chart
Exponential Growth: The larger a population becomes, the faster it grows.
- Exponential growth occurs till it reaches carrying capacity or K. When this happens it is limited by a resource. For humans it is believed to be fresh water.
See human growth graph pg 19. 6.5 billion now, 10 billion by 2050.
Section 3- Interactions within communities.
Most energy on Earth comes from the sun. Directly or indirectly
Producers- Make their own energy. Plants and photosynthesis
Consumers- Cannot make their own energy. They eat other organisms for their energy.
- Herbivores- Eat plants
- Omnivores- Eat plants and animals
- Carnivores- Eat animals
- Decomposers- Break down dean organisms and waste
Food chains- Model of the feeding relationships in an ecosystem.
Question- What happens when you break a chain?
Symbiotic relationships- close relationships between species
Types: Mutualism (+,+) Both organisms benefit from the relationship
Commensalism (+,o) 1 organism benefits, the other is not helped or affected
Parasitism (+,-) 1 organism benefits, the other is harmed
Niches: An organism’s specific role in its community; its specialized job. Each organism can live in the same area of a community because they use different resources, they have their own role. If two different species need the same niche and have the same job, they will compete till one wins.
Predator/ Prey: The presence of predators increases the number of different species that can live in an ecosystem. They limit populations, therefore, food isn’t as limited.
Cooperation- Some populations work together such as bees, deer, and ants. They have different jobs and tasks. They have a common goal of reproductive success and survival.
