Chapter 3 The Biosphere Section 3-3; pages 74-80 Cycles of Matter Chapter 3 The Biosphere Section 3-3; pages 74-80 Energy Flow & Cycles Element Cycles (Revised August 4, 2003)

Matter within ecosystems is recycled within and between ecosystems BIOGEOCHEMICAL CYCLES-connecting the biological, geological, and chemical aspects of the biosphere Matter Statement: Matter within ecosystems is recycled within and between ecosystems BIOGEOCHEMICAL CYCLES Matter within an ecosystem is recycled. (diagram of consumer--->decomposer--->soil--->producer--->consumer)

BIOGEOCHEMICAL CYCLES Cycle - water, carbon, oxygen, nitrogen & other elements cycle from the abiotic (“geo” nonliving environment) to biotic (“bio” living organisms) & then back to the environment. Simply put, biogeochemical cycles pass the same molecules around again and again within the biosphere. biotic abiotic BIOGEOCHEMICAL CYCLES Water, carbon, oxygen, nitrogen & other elements cycle from the abiotic (“geo” nonliving environment) to biotic (“bio” living organisms) & then back to the environment.

BIOGEOCHEMICAL CYCLES atmosphere “bank” Most element cycles have an atmospheric “bank” where the element is found in large amounts. BIOGEOCHEMICAL CYCLES (This slide series points out the repeated events in most cycles.) Most element cycles have an atmospheric “bank” where the element is found in large amounts. The soil and the ocean are additional major banks for some elements.

BIOGEOCHEMICAL CYCLES RIP atmosphere “bank” Elements move from the “bank” into organisms. Organisms release elements in daily activities or after death. BIOGEOCHEMICAL CYCLES Decomposers (or combustion or erosion) break down organic matter. What is a result of their actions? The element is released back into the atmosphere bank. Decomposers (or combustion or erosion) break down organic matter. What is the result of their actions?

BIOGEOCHEMICAL CYCLES Three example cycles: Water Carbon (carbon-oxygen) Nitrogen H2O C N O BIOGEOCHEMICAL CYCLES Three example cycles: Water Carbon (carbon-oxygen) Nitrogen

WATER CYCLE evaporation – heating of water from liquid to atmospheric gas. condensation – cooling of water from vapor to tiny droplets that form clouds. precipitation – droplets too large to be contained in clouds and water returns to earth as rain, snow, or hail. transpiration – evaporation of water from leaves of plants. runoff – excess water from precipitation that comes from streams and rivers and carried to oceans and lakes. accumulation – collection of water on earth. (Have the students make a heading for Water Cycle and copy the words with space for) definition. WATER CYCLE Use the next diagram to help you define the following: evaporation condensation precipitation transpiration runoff accumulation

Refer to Figure 3-11, page 75 Accumulation http://ga.water.usgs.gov/edu/watercyclesummary.html

CARBON CYCLE The exchange of gases during photosynthesis and respiration is a major example of the living-nonliving cycle of carbon-oxygen. respiration photosynthesis O2 CO2 CARBON CYCLE The exchange of gases during photosynthesis and respiration is a major example of the living-nonliving cycle of carbon-oxygen.

CARBON CYCLE How does carbon enter the living part of the cycle? CO2 CO2 CO2 CO2 CO2 CARBON CYCLE How does carbon enter the living part of the cycle? CO2 + H2O ----> C6H12O6 + O2 Carbon enters living portion of the carbon cycle through photosynthesis. CO2 CO2 CO2 CO2 + H2O ----> C6H12O6 + O2

CARBON CYCLE Carbon is returned to the atmosphere environment by: cellular respiration erosion combustion decomposition CARBON CYCLE Carbon returned to environment by: cellular respiration erosion combustion decomposition

CARBON CYCLE respiration – process where organisms obtain energy from breakdown of glucose. photosynthesis – plants use light energy (sun) to make glucose. decomposition – breakdown of dead organic matter. combustion – burning of fossil fuels (gas, petroleum, coal) which release CO2 into atmosphere. erosion – runoff of soil into body of water CARBON CYCLE Use the next diagram to help you define relationship of the following terms to the carbon cycle. respiration - CO2 is released back into the atmosphere when food (glucose) is broken down during respiration photosynthesis - CO2 is taken from the air and trapped into food (glucose) during photosynthesis decomposition - CO2 is released back into the atmosphere as organic matter is broken down during decomposition combustion - CO2 is released back into the atmosphere when organic material is burned (undergoes oxidation, similar to respiration ) erosion – CO2 is released back into the atmosphere when erosion breaks down rock such as limestone containing CaCO3 (calcium carbonate)

Carbon Cycle Refer to Figure 3-13, page 77 http://www.windows.ucar.edu/earth/climate/images/carboncycle.jpg

N2 free nitrogen NITROGEN CYCLE 79% of the atmosphere is nitrogen gas but it is in a form most living things cannot use. N2 free nitrogen NITROGEN CYCLE 79% of the atmosphere is nitrogen gas but it is in a form most living things cannot use.

NITROGEN CYCLE If we can’t take in free nitrogen, how do we acquire it so we can use it in our bodies? Why do we need nitrogen in our bodies? NITROGEN CYCLE If we can’t take in free nitrogen, how do we acquire it so we can use it in our bodies? Why do we need nitrogen in our bodies? (Don’t answer these now – they lead to next item.)

NITROGEN CYCLE How do we acquire usable nitrogen? Nitrogen-fixing bacteria convert nitrogen into nitrates. Plants absorb nitrates. Animals eat plants. NITROGEN CYCLE How do we acquire usable nitrogen? Nitrogen-fixing bacteria convert nitrogen into nitrates. Plants absorb nitrates. Animals eat plants. N2 in air nitrogen-fixing bacteria NITRATES

NITROGEN CYCLE How does the nitrogen return to the atmosphere? Denitrifying bacteria convert the nitrates back into nitrogen. denitrifying bacteria NITROGEN CYCLE How does the nitrogen return to the atmosphere? Denitrifying bacteria convert the nitrates back into nitrogen. N2 in air nitrogen-fixing bacteria NITRATES

? NITROGEN CYCLE Why do we need nitrogen? protein Nitrogen Nitrogen is an essential element for all proteins (amino acids) and nucleic acids. ? Nitrogen

NITROGEN CYCLE Simplified Free N2 in Atmosphere denitrifying bacteria nitrogen-fixing bacteria NITROGEN CYCLE SIMPLIFIED diagram of nitrogen cycle Discuss the diagram and have student label on their handout. RIP Organic material NITRATES

NITROGEN CYCLE Simplified free N2 bank – atmosphere nitrogen fixation – conversion of atmospheric nitrogen to ammonia nitrates – converted form of nitrogen from atmosphere. organisms – living things organic material – components of living things made of C, H, O, N denitrification – ammonia and nitrates converted to nitrogen and released back into atmosphere NITROGEN CYCLE Simplified Use the next diagram to help you define relationship of the following terms to the nitrogen cycle free N2 “bank”: Free means pure nitrogen not in any other compound. The “bank” is the atmosphere which is made up of 79% nitrogen. nitrogen-fixation: nitrogen-fixing bacteria convert free nitrogen into nitrate compounds nitrates: the form of nitrogen that can can be used by organisms organisms: Plants take in nitrates and use them in their tissues; animals eat the plants and get the nitrates from their tissues organic material: Dead organisms, animal waste and organic litter are decomposed by bacteria and other decomposers denitrification: Denitrifying bacteria convert nitrates from decomposition back into free nitrogen.

Refer to Figure 3-14, page 78 N2 in Atmosphere NO3- & NO2- NH3

All Cycles Are Related All cycles are related. Diagram showing interaction of water, carbon, nitrogen, sulfur, phosphorus cycles. Just view that many things are being recycled. (Do not teach the cycles from this slide at this time. Repeated at end of slide show for review.)