Chapter 6 Ecosystems and Their Interactions Ecosystems and Their Interactions

“You could cover the whole world with asphalt, but sooner or later green grass would break through.” Ilya Ehrenburg – Russian writer

Energy Flow in Ecosystems

The ultimate source of energy for all living things is the sun.

Plants, algae and some bacteria can capture solar energy and store its food. What is this process called? Photosynthesis Photosynthesis

Photosynthesis is a chemical reaction that requires H20 and CO2.

Producers are organisms that produce their own energy. They are also known as autotrophs.

Consumers are organisms that get their energy by eating other organisms. They are also known as heterotrophs.

Important: All living things get energy from the sun, some directly and others indirectly. List examples:

One exception to the rule: Deep ocean communities that have a bacteria that make energy from Hydrogen Sulfide released through fissures in the ocean floor.

What eats what list …define together Producer Producer – Produces its own food (energy) through photosynthesis Consumer Consumer – Eats other things to convert to energy

There are four types of consumers Can you guess what they are? HerbivoreCarnivoreOmnivoreDecomposer

The process of breaking down food to yield energy is called cellular respiration. Not to be confused w/ respiration

Does anybody know the chemical equation???? C6H12O6 + 6O2 --->6CO2+6H2O +Energy

Name three reasons for making energy? Immediate energy- Immediate energy- Fix Things Fix Things Store for later Store for later

How is energy transferred through (in) ecosystems? Food Chains and Food Webs

Food Chains show the sequence in which energy is transferred from one organism to the next as one eats the other.

Food Webs show the many feeding relationships in an ecosystem.

Each step in the transfer of energy through an ecosystem is known as a Trophic Level. Producers (photosynthesis) Primary Consumers Secondary Consumers Tertiary Consumer

Producers (Plants) Primary Consumers Secondary Consumers Tertiary Consumer There is a 90% energy loss between Trophic Levels 100% 10% 1%.1%

What role does sunlight play in an ecosystem? It provides the light that is transferred into energy.. It provides the light that is transferred into energy.. Could there be life on earth w/out producers? Could there be life on earth w/out producers? Would 20 acres of land support more people if they ate only plants or plants and animals both ? Would 20 acres of land support more people if they ate only plants or plants and animals both ?

The Cycling of Materials

The Water Cycle: The water cycle is the cycling of water between the earth’s atmosphere and its surface.

The process by which water returns to the surface is called Precipitation. Precipitation falls in three states. Rain (liquid) Rain (liquid) Sleet (mix) Sleet (mix) Snow or Hail (solid) Snow or Hail (solid)

Transpiration- water released from plants (remember photosynthesis) H2O + CO2 + Light ----  C6H12O6 + O2

Groundwater may flow below the surface and above ground at different times (How could pollution present a problem and where is it most sensitive?)

The sun is the driving force behind the cycle Describe why!!!!

The Carbon Cycle Problem exists because we are burning large quantities of fossil fuels and over concentrations of CO2 exist. Problem exists because we are burning large quantities of fossil fuels and over concentrations of CO2 exist. Plants also give off a certain amount of carbon as cellular respiration is carried out. Plants also give off a certain amount of carbon as cellular respiration is carried out. C6H O > CO2 + H2O + Energy C6H O > CO2 + H2O + Energy Fossil fuels are Hydrocarbons (bonds of H & C) Fossil fuels are Hydrocarbons (bonds of H & C) When burned C is released into the atmosphere. When burned C is released into the atmosphere.

The Nitrogen Cycle:

78 % of the atmospheric gases are nitrogen. There are few species that can use N2 directly from the atmosphere. There are few species that can use N2 directly from the atmosphere. These are bacteria and are known as nitrogen-fixing bacteria. These are bacteria and are known as nitrogen-fixing bacteria. Fixing means transforming to usable forms. Fixing means transforming to usable forms. These bacteria provide N2 a way into plants and animals eat plants as a source of nitrogen. These bacteria provide N2 a way into plants and animals eat plants as a source of nitrogen. These plant are called Legumes. These plant are called Legumes. Decomposers also provide a closure to the N2 cycle by returning the fixed nitrogen back to the ecosystem. Decomposers also provide a closure to the N2 cycle by returning the fixed nitrogen back to the ecosystem.

What is Nitrogen used for in our bodies? Nitrogen is a component in the production of protein. Nitrogen is a component in the production of protein. Proteins are our bodies building blocks. Proteins are our bodies building blocks. They help build and fix things!!! They help build and fix things!!!

Succession Succession is a regular pattern of change in a community. Succession is a regular pattern of change in a community. This may take place over hundreds or thousands of years. This may take place over hundreds or thousands of years. It occurs because of proper conditions and seed dispersal. It occurs because of proper conditions and seed dispersal.

What causes succession? Proper conditions and seed dispersal Proper conditions and seed dispersal Must be left undisturbed Must be left undisturbed Each new community makes it difficult for the previous to survive. Each new community makes it difficult for the previous to survive. ie/ The shrubs around your house make it difficult for the grass to grow underneath. ie/ The shrubs around your house make it difficult for the grass to grow underneath. A pine forest with larger pines shadow the smaller ones A pine forest with larger pines shadow the smaller ones But oaks can grow taller and need less light so they succeed and cause problems for the smaller pines. But oaks can grow taller and need less light so they succeed and cause problems for the smaller pines.

Primary Succession The first group of plants to begin growing in in an ecosystem. The first group of plants to begin growing in in an ecosystem. Usually small Usually small Referred to as Pioneer Communities Referred to as Pioneer Communities Pioneers are those plants which first colonize any newly available land. Pioneers are those plants which first colonize any newly available land.

Secondary Succsession The volcanic eruption around Mt. St. Helens leveled about 45,000 acres. The volcanic eruption around Mt. St. Helens leveled about 45,000 acres. It has since started to grow back... It has since started to grow back... This is not primary succession. This is not primary succession. It is secondary. (a community already existed there. ) It is secondary. (a community already existed there. ) Secondary Communities are the second group of plants to take over and area. Secondary Communities are the second group of plants to take over and area.

Questions How does the water cycle help succession? How does the water cycle help succession? Explain why it could be damaging in the long run to put out forest fires... Explain why it could be damaging in the long run to put out forest fires... What are lichens? What are lichens? What is the role of lichens in primary succession? What is the role of lichens in primary succession? If a lake becomes a forest is this primary or secondary? Explain... If a lake becomes a forest is this primary or secondary? Explain...