Transcript Cycles of Matter

I. Recycling in the Biosphere
* Biogeochemical cycles- a process in which
elements, chemical compounds, and other
forms of matter are passed from one organism
to another and from one part of the biosphere
to another.
Classification of Biogeochemical
processes
a. Biological- activities performed by organisms
including: eating , breathing, burning food,
waste elimination
b. Geological- activities performed by the earth:
volcanic eruptions, rock formation and
degradation
c. Chemical/Physical- formation of clouds and
rain, flow of running water and the action of
lightning
Biogeochemical processes (cont.)
d. Human Activitymining, farming,
fertilizer use, and
burning of fossil
fuels affects the
cycles of matter.
Cycles
Biogeochemical cycle- exchange of matter through the
biosphere.
*Matter cannot be created or destroyed!!!*
Cycling of nutrients in the biosphere involves:
Matter in living organisms
Physical processes found in the environment
Transforming energy into usable forms
Water Cycle
• Water is constantly evaporating into atmosphere (water vapor)
• Vapor rises, cools, forms clouds (condensation):
– 90% of water vapor evaporates from ocean, 10% from surface of
plants (transpiration).
• Water falls from clouds in form of precipitation
Water cycle
• https://www.youtube.com/watch?v=2D7hZpIYlCA
Nitrogen Cycle
 *Nitrogen enters the food web when plants absorb nitrogen
compounds from soil*
 Consumers get nitrogen by eating plants or animals that contain
nitrogen.
• Nitrogen – needed to make proteins
• Conversion of nitrogen into a form that is useable by plants is called nitrogen
fixation.
THE GOAL!
Atmospheric nitrogen (N2)
Nitrates (NO3)
Nitrogen Cycle (cont.)
 Nitrogen is returned to the soil in several ways:
1. Animals urinate
2. Organisms die (decomposers!)
3. Lightning
 Organisms convert ammonia into usable nitrogen
compounds. (Nitrification)
 Fixed nitrogen converted back to gas and reenters
atmosphere (Denitrification)
In the soil
• https://www.youtube.com/watch?v=leHy
-Y_8nRs
The Carbon Cycle
• Carbon
• Major part of organic molecules
• Carbohydrates, proteins, fats, and nucleic acids.
• Contained within…
•
•
•
•
•
animal skeletons
rocks
the atmosphere (CO2)
dissolved in oceans
fossil fuels (coal, natural gas, oil)
Carbon Cycle
http://blogs.dickinson.edu/copenhagen/files/2009/09/carbon-cycle.gif
Human Impact
• Fossil fuels release carbon stores very slowly
• Burning anything releases more carbon into
atmosphere — especially fossil fuels
• Increased carbon dioxide in atmosphere
increases global warming
• Fewer plants mean less CO2 removed from
atmosphere
• https://www.youtube.com/
watch?v=2D7hZpIYlCA
Phosphorous Cycle
• Phosphorous
• essential to organisms as it is part of molecules
such as DNA and RNA.
• Remains mostly on land and in the ocean as
inorganic phosphate- usually in rocks or soils.
• Rocks and sediments release phosphate as
they wear down
* Plants bind phosphate into organic
compounds when they absorb it from the soil
or water.
* Organic phosphates make their way through
the food web to the rest of the ecosystem
Phosphorus Cycle
• https://www.youtube.com/wa
tch?v=leHy-Y_8nRs
IV. Nutrient Limitation
• Primary productivity is the rate at which
primary producers (plants) create organic
material.
• If one essential nutrient in an ecosystem runs
short, then primary productivity will be
limited
A. Nutrient limitation in soils
* In farming, growth of crop plants is limited by
a lack of one or more nutrients in the soil,
which is why fertilizers are used
* Fertilizers usually contain: nitrogen,
phosphorous, and potassium
* Micronutrients are nutrients that are needed
in smaller amounts: calcium, magnesium,
sulfur, iron, and manganese
Iron deficiency in leaves of melon
plant
Soybean plant showing
manganese deficiency
* All nutrient cycles work together like
interlocking gears. If one gear slows down
(one nutrient runs short), the whole system
slows down or even stops.
B. Nutrient limitation in aquatic ecosystems
* The open oceans are relatively nutrient poor
when compared to many land areas
* In saltwater environments, nitrogen is
typically the limiting nutrient
* In freshwater environments, phosphorous is
typically the limiting nutrient
* Heavy rains can bring fertilizer runoff from
agricultural fields into aquatic environments
and causes dramatic effects such as, algal
blooms.