Chapter 3 1 THE BIOSPHERE Interactions and Interdependence

Chapter 3. 1 THE BIOSPHERE

Interactions and Interdependence: Ecology- scientific study of interactions among organisms and between organisms and their environment

Biosphere- part of Earth in which life exists including land, water and air or atmosphere. Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live.

LEVELS of ORGANIZATION: • • individual species population community ecosystem biome biosphere

Levels of Organization: • Individual- a single organism • Species- group of similar organisms that can breed and produce fertile offspring • Population- group of individuals of the same species that live in the same area • Community-different populations that live together in defined area • Ecosystem- collection of all the organisms that live in a particular place, together with their nonliving environment • Biome – group of ecosystems that have the same climate and similar dominant communities • Biosphere- the highest level of organization

Levels of Organization:

Ecological Methods: Ecologist use different ways to study the environment or living things. There are three basic approaches scientist use: • observing- is the first step in creating questions. Simple questions are formed such as: how many species live in that area? Or how these species interact with each other? • experimenting- scientists can set up artificial environment in a laboratory to imitate the real world and see how animals behave. Or conduct experiments with test tubes when dealing with microorganisms. • modeling- scientist make models to get a better insight into complex interaction such as the effects of global warming on ecosystems. Many models have mathematical formula based on experiments and results and are used on computers.

Look at Figure 3 -1 on page 63: List the organisms that you see in the photograph. Then list the non-living parts of the environment with which the organisms interact. • Living organisms: air, water, rock the snail, ferns, mosses, and other plants • Non-living parts: rocks, water, air, soil and sunlight

3 -1 Session Assessment: 1. List the six different levels of organization that ecologists study, in order from smallest to largest.

2. Describe three basic methods of ecological research.

3. Identify two ways in which you interact with each other of the three parts of the biosphere, land, water, and air- every day.

4. Critical Thinking: Suppose you wanted to know if the water in a certain stream is safe to drink. Which ecological method(s) would you choose and why?