Chapter 2 Principles of Ecology You will learn: ▪1.What an ecologist does. ▪2. Some important aspects of an organism’s environment. ▪3.Trace the flow of energy and nutrients in the living and nonliving worlds

Why it’s important: To understand life. Know how organisms meet their needs. Reduce the impact of the human population. Understand how living things depend on their environment.

2.1 ORGANISMS AND THEIR ENVIRONMENT A. What is Ecology? The Scientific study of interactions among organisms and their environment. ▪1. Ecological study reveals relationships among living and nonliving parts of the world –Techniques include the fields of mathematics, chemistry, physics, geology and many more. ▪2. Scientific research includes both descriptive and quantitative methods. ▸ ** Descriptive - fur, carnivorous, long canine teeth, warm blooded, feed young milk. ▸ ** Quantitative - how many eyes, how long the teeth are (International System of measuring; commonly known as SI)

What are some of the things we can learn from scientific research? Think about what it would be like without water treatment plants, vaccinations, microwaves etc.. Technology has caused problems as well. For example; over irrigation, toxic waste etc..

II. Aspects of Ecological Study ▪ A. Living things can be found in the air, on land and both fresh and salt water. ▪B. The Biosphere is the portion of Earth that supports life. ▪C. Nonliving Environment.

The Living Environment 1. Biotic factors - All the living organisms that inhabit an environment. ▸ (Name some) 2. How do living plants affect you? ▸ How do dogs affect you?

Interactions among living things and abiotic factors from ecosystems ▸ Ecosystems - The interaction among the populations in a community and the community’s abiotic factors. –Three kinds of Ecosystems –A. Terrestrial — land –B. Aquatic - lakes and rivers –C. Marine -oceans and seas `

IV. Organisms in Ecosystems Niche - the role and position a species has in its environment. Each species is unique in how it satisfies all of its needs. Living relationships - Some species enhance their chances of survival by forming relationships with other species

○1. Symbiosis - living together ○2. Predator/prey - one species gets food the other is eaten. ○3. Commensalism - one species benefits. The other is neither harmed nor benefitted. ○4. Mutualism - two species living together both are benefitted. ○5. Parasitism - One species is benefitted the other is harmed but is not usually killed. Types of Living Relationships

2.2 Nutrition and Energy Flow ▪ I. How Organisms obtain energy ▸ Energy drives all events – walking, flowering and reproducing. The ultimate source of energy on Earth is the Sun.

▪A. The producers: Autotrophs. ▸ Organisms that use energy from the sun or energy stored in chemical compounds to make their own nutrients. –Plants, some unicellular organisms are the most common.

▪B. the Consumers: Heterotrophs ▸ Organisms that obtain nutrients by eating other organisms. –1. Herbivores - eat plants –2. Carnivores - eat animals –A. Scavengers - feed on carrion and refuse – Why are scavengers important? –3. Omnivores - eat both plant and animal material. –4. Decomposers - fungi; breakdown dead and decaying material

II. Matter and Energy flow in Ecosystems ▪A. Food Chains: Pathways for matter and energy ▸ Nutrients and energy proceed from Autotrophs to Heterotrophs and then to decomposers. – Chains consist of 3 steps - but most have no more than five. Why? ▪B. Trophic Levels – represent links in the chain. Each step in a chain represents a Trophic level. ▪C. Food Webs - all the possible feeding relationships at each Trophic level in a community. ▪D. Energy and Trophic levels: Ecological pyramids. ▸ 1. Shows how energy flows through a ecosystem. ▸ 2. Each Pyramid summarizes interactions of matter and energy at each Trophic level. ▸ 3. The total energy transfer from one Trophic level to the next is only about 10%. ▸ 4. The energy lost enters the environment as heat. ▸ 5. A pyramid of numbers is based on population size.

Energy and Trophic levels: Ecological Pyramids ▸ 1. Shows how energy flows through an ecosystem ▸ 2. Each Pyramid summarizes interactions of matter and energy at each Trophic Level. ▸ 3. The total energy transfer from one Trophic Level to the next is only about 10% ▸ 4. The energy lost enters the environment as heat. ▸ 5. A pyramid of numbers is based on population size.

Food Web

Pyramid of Numbers

Pyramid of Energy