Chapter 3 “Biosphere”

3-1 What is Ecology?  Ecology - study of how the living and nonliving world interacts.  Organisms and their environment  Biosphere – portions of the planet where all life exists  (land, water, and air)

Biological Organization  Individual – a single organism of a species  Population – group of individuals of the same species living together in a specific area

Biological Organization  Community – different populations living together in a specific area  Ecosystem - collection of all nonliving and living organisms living in a specific place

Biological Organization  Biome – group of ecosystems that have similar climates and communities  Biosphere - portions of the planet where all life exists  (land, water, and air)

Methods of study  Observation – using the 5 senses and recording our findings  Experimentation testing the hypothesis; done in natural or unnatural (labs) environments  Modeling – done when the event or object being studies is too large or too far from us.

Section 3-1 Assessment  1. List the six different levels of organization ecologists use to study the environment.  2. Describe the three basic methods of ecological research

3-2 Energy Flow  The main energy source for life on Earth is the sun.  How do you and I use the sun’s energy?  Those organisms that directly use the sun’s light to produce their own food are called Autotrophs.  Producers – another name for autotrophs on Earth

Energy Flow  Not all autotrophs use the sun’s energy. Some rely on other inorganic chemical compounds.  Those organisms that do get their energy from the sun carry out a common process to use light energy to carry out chemical rxns.  These are called “chemoautotrophs”

Photosynthesis  Chemical rxn that converts carbon dioxide and water into oxygen and sugars  6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 carbon water light sugar oxygen dioxideenergy

Chemosynthesis  Process used by some autotrophs, they use chemical energy to produce carbohydrates  Similar to photosynthesis

Consumers  Cannot harness energy directly from the environment as autotrophs do, instead they acquire energy from other organisms.  Heterotrophs – organisms that rely on other organisms for their energy and food supply

Types of Consumers  Herbivores – obtain energy by eating only plants (cattle)  Omnivores – obtain energy by eating both plant and animals (humans)  Carnivores – obtain energy by eating other animals / meat (wolves)

Types of Consumers  Detritivores – feed on plant and animal remains and other dead matter (earthworms)  Decomposers – break down organic matter (bacteria)

Levels of Consumers  Trophic Level : A step in a food chain or food web  Tertiary : These individuals feed on secondary consumers; carnivores  Primary Consumer : These individuals feed on producers; herbivores  Secondary Consumer : These individuals feed on primary consumers; carnivores

Feeding Relationships  Energy flows through an ecosystem in one direction, it is not a cycle. It begins with the sun, then producers, and on to the consumers.  A diagram showing a single pathway of how energy travels through the ecosystem is called a food chain. A diagram showing multiple pathways of how energy travels through the ecosystem is called a food web.

Ecological Pyramids  Shows the relative amounts of matter in each trophic level in the food chain / web  Energy Pyramid – only 10% of the energy stored in one trophic level is passed on to the next level; the remaining 90% is used or lost as heat.

Ecological Pyramids  Biomass Pyramid – shows the total amount of living tissue within a given trophic level; represents the amount of potential food available for each trophic level.  Numbers Pyramid – based on the number of individual organisms at each trophic level; shape is not always a pyramid

3-2 Section Review  1. What is the main form of energy that powers living things?  2. Briefly describe the flow of energy among organisms in an ecosystem.  3. What proportion of energy is transferred from one trophic level to the next?

3-3 Cycles  Unlike energy, matter is recycled within the ecosystem  Biogeochemical cycles – show how elements, chemicals, and other forms of matter are passed from from one organism to another in the ecosystem.  Connects biological, geological, and chemical aspects of the biosphere

Water cycle  Evaporation – process by which water changes from liquid to gas form  Transpiration – process by water evaporates from the leaves of plants  Condensation – process by which water changes from gas to liquid form

Water cycle  When it rains, snows, etc. ( precipitation ) the water will…  Runoff to ponds/lakes  Soak in and become  Groundwater  Taken up by roots and transpire  Evaporate

Nutrient cycles  Carbon  Nitrogen

Nutrient Limitation  Primary productivity  Limiting agent