Section 3.1 – what is ecology? The Biosphere Section 3.1 – what is ecology?

Bellwork – what role do enzymes play in living things and what affects their functions?

Ecology

Ecology Definition- Ecology is the scientific study of interactions between organisms and their physical environments Web of interdependence between organisms and their environments Organisms respond to their environment Organisms can change their environment

Write down 3 examples of how humans have changed or affected their environment on either a global or local scale…

Levels of organization Easy way of dividing up a large population Example in school Class Grade level Student body School district State Country World

Levels of organization in ecology

The Biosphere consists of all life on Earth and all parts of the Earth in which life exists, including land, water(11km down in oceans), and the atmosphere(8km upward). It is a dynamic web of interdependence.

Environment Environment : All conditions or factors surrounding an organism Biotic – biological influences on an organism Abiotic factors –Physical components of an ecosystem List 3 common biotic and abiotic factors that affect an ecosystem

Do Biotic and abiotic factors work together? Yes! Physical factors are often affected by living organisms Trees can provide shade Bacteria can live in mud and change it’s properties Roots of trees determine how much soil is there Pine needles can make soils to be acidic

How do we “do” Ecology? 3 key methods Observation Experimentation Modeling

Observation 1st step What species lives there? How many individuals of one species? Behavioral characteristics How does an adult animal protect it’s young? At what age do young animals leave the nest?

Experimentation Test Hypothesis Gather data to solve an environmental problem Artificial experiments in a lab to alter specific conditions Replicate natural ecosystems to see what will happen if conditions are changed

Modeling Some ecological events are difficult to observe and/or they take place over a long period of time Mathematical models often built upon experimental data and observations Further observations can often test models

If you wanted to know if the water in a stream was safe to drink, which ecological method would you use in your investigation? Explain your reasoning