Ecology Introduction

What is it?  The study of living things and how they interact with nonliving things.  Each organism depends in some way on other living or nonliving things.  Ecology involves collecting information about organisms and their environments and looking for patters and seeking to explain them.

Levels of organization Biosphere: Broadest level of organization including all things found in the thin volume of Earth and it’s atmosphere. Ecosystems: Includes all the organisms and the nonliving environment found in a particular place. Community: Only includes living parts of the ecosystem. (pond)

Levels of organization Population: Includes all the members of a species that live in one place at one time. Organism: Simplest level of organization that consist of only on living thing.

Example: Biosphere Think of it this way: If the earth were an apple the biosphere would be only as thick as the skin on the apple. Living things are not distributed evenly throughout the biosphere.

Example: Ecosystem A pond is an ecosystem that contains a variety of living things: fish, turtles, aquatic plants, algae, insects, and bacteria. Also don’t forget the nonliving: chemical and physical composition (water, sunlight) They all interact in ways that affect their survival.

Example: Community All the living organisms: fish, turtles, pants, algae, and bacteria. Can contain thousands of species

Example: Population All the members of a species that live together at one time. Like a species of frogs living in the same pond and interacting.

Example: Organism One single organism like a duck.

Biotic and Abiotic Factors Biotic: all the living things that affect an organism. Other animals, plants, bacteria, etc. that will affect an organism is a biotic factor Abiotic: all of the non-living things that affect an organism. Things like pH, salinity, temp, amount of sunlight, and precipitation.

Biotic and Abiotic interactions Abiotic and Biotic factors are not independent. Ex: Plants need nitrogen, the availability of nitrogen in the soil affects how fast the plant will grow. Plants also affect nitrogen availability by absorbing nitrogen compounds from the soil.

The Niche A species niche is its way of life, or role the species plays in its environment. A species niche includes a range of things: –Methods of how it obtains food –Number of offspring –Time of reproduction –All other interactions with its environment

Niche Differences A species niche can change in a single generation –Specialist: have narrow niches Ex. Koala who feeds only on a few species of eucalyptus leaves. –Generalist: tolerate a broad range of things Ex. Virginia Opossum lives all over the U.S. and eats almost anything