Lesson 1.01 Introduction to Ecology: Ecosystems and Biomes

Biotic Factors

When you go outside to take a walk, play a sport, or go to school, you have entered your local environment. You are coming into contact with many different factors. You are affecting and being affected by each one. These factors can be either biotic or abiotic. Some factors may be very noticeable while others may be microscopic and you cannot tell they are there.

Living parts of the environment are called biotic factors. Biotic factors include

• animals,
• plants,
• fungi,
• bacteria, and
• protists.

Most often when you think of living things you probably think of plants and animals that are macroscopic visible to the naked eye; you do not need a microscope . However, there are also living organisms that cannot be seen with the naked eye. These organisms have an important and specific role in the environment.

Visit the following link to see examples of these different types of living organisms, where they live, and what role they play in the environment: The Six Kingdoms.

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Abiotic Factors

The nonliving parts of the environment are called abiotic factors. Although not living, abiotic factors have an impact on the environment and the organisms in it. Many of the abiotic factors that you can readily see in the environment are

• rocks,
• light,
• soil/dirt/sand,
• water, etc.

The abiotic factors that you might not readily be aware of are

• air,
• air quality,
• water quality,
• all types of pollution,
• topography,
• altitude,
• climate,
• precipitation,
• humidity/moisture, and
• temperature to name a few.

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Biomes

Life on earth is organized from organisms to populations to communities to ecosystems to biomes. These levels of organization build upon one another with the organism being the smallest level and the biome being the largest. Each of these different levels contributes to making up the biosphere.

Ecosystems are made up of the interacting abiotic and biotic factors in an area. Groups of ecosystems in the same area that have the same types of abiotic and biotic factors are biomes. There are 6 major types of terrestrial biomes on earth:

1. Rainforest,
2. Tundra,
3. Taiga (coniferous forest),
4. Grasslands,
5. Temperate Deciduous Forest, and
6. Desert.

Each biome can be identified and classified based on the types of abiotic and biotic factors that are present. Climate is the greatest factor in determining the type of biome. Climate is influenced by

• latitude,
• altitude, and
• geographical structures, such as mountain ranges and large bodies of water.

Climate is the main determining factor in soil type and plant life that is present in an area. Plant life is a major factor in the type of animal life that is present. Therefore terrestrial biomes are often named after the type of plant life that is present.

Although there are 6 specific terrestrial biomes, there are not clear lines that separate one biome from the other. There is most often a transition area between biomes known as an ecotone. In these transition areas, you will see plant and animal species that are representative of two or more different biomes.

Visit World Biomes to explore the six different terrestrial biomes. Download and complete 1.01 Notes Guide while you review the sites. This notes guide will help you complete the tasks in this lesson as well as serve as a study guide.

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