Principles of Ecology

Section 13.1: Ecologists Study Relationships (Part 1)

Unit Objectives

• To be able to summarize the levels of organization that ecologists study.

• To be able to describe and apply research methods ecologists use to study the environment.

Get Lab Notebooks

• I need you to get a lab notebook for class by next Monday (Sept. 9)

Ecology- The Science of Life’s Interconnectedness

• Ecology – the study of the relationships among living things and their surroundings (including abiotic – non-living - things such as water, climate, minerals, and other non-living parts of an organism’s surroundings).

• Ecology comes from the Greek work Oikos, which means house.

Ernst Haeckel

• A German zoologist and evolutionary biologist who coined the term ecology.

• Wanted to encourage biologists to study the ways organisms interact.

• Saw that nature was complexand its relationships needed to bestudied.

Levels of Life

• Ecology gives order to the world and allows us to better understand it. We break it down into levels:

• Organism – an individual living thing.• Population – a group of the same species living in

one area (a population of tigers, frogs in a pond, or lady slipper orchids on a tallgrass prairie remnant.

Levels of Life

• Community – A group of different species living together in one area.

Ecosystem• Includes all organisms, as well as abiotic elements

(e.g. soil, climate, water, rocks, etc.) in an area.• Can be large or small.– The insides of a hollow tree or an ecosystem on a

much larger scale (e.g. oak/hickory and boreal forests, coral reefs, prairie potholes, etc.)

Biome

• A major regional or global community of organisms. – Typically characterized by climatic conditions and

plant communities (tropical rain forests, tallgrass prairie, and tropical savannah).

More Biomes

Mississippi River Delta Estuary

Montane rainforest, Colombian Andes

Example: Salmon

• What role do Pacific salmon play in their ecosystems?

Salmon and their ecosystem

• Over 140 species utilize the Pacific salmon for food.

• If not eaten, then their bodies decay and return essential nutrients to the rivers where they spawn.

An ecosystem at risk . . .

• Due to profound changes to their environment, 214 species of Pacific salmon (and relatives like steelhead) are threatened with extinction – 106 are already extinct.– Population declines due to:

1. Dams (unable to reach spawning grounds).2. Polluted rivers from mining, logging and other

industries.3. The commercial salmon industry.

Example: Bison

How are bison like Pacific salmon?

Bison, the center of their ecosystem

The bison were (and hopefully will be again) the prairie’s keystone species. They were hunted

nearly to extinction.

Example: Bats

• Bats are essential to ecosystems around the world.

• In the tropics, ecosystems would collapse without bats who pollinate plants and disperse seeds – allowing for forests and 1,000s of plant species to regenerate.

• 300 commercial fruits are pollinated by bats (including bananas and mangos).

Bats in Iowa

• Bats, such as the big brown bat pictured below, eat 600 to 1,000 insects every hour.

• They eat some of the most aggressive agricultural pests and are indispensable to controlling insect populations (including mosquitos).

Bats in Trouble

• Bats need our help.• Due to white-nose disease (a fungus that infects

and can kill a whole colony) and indiscriminate killing, bat numbers are in decline across the United States (4 are endangered).

• We do not want to Face a world without Bats.