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ECOLOGY BIO GEOLOGICAL CYCLES
Essential elements and nutrients
Chemistry Basics• Elements a unique type of atom• there are 92 natural elements occurring on
earth• The study of elements needed for life is called
organic chemistry or biochemistry• The essential elements for life are MACRO
– Carbon Hydrogen Oxygen for carbohydrates– Nitrogen Amino Acids and proteins– Phosphorus ATP and ADP– Potassium enzymes– Sulfur amino acids and proteins– Calcium membrane function– Magnesium chlorophyll and enzymes
Bio-geological cycles• Biogeological cycle refers to the elements that
move from geosphere to biosphere and back to geosphere.
• Each cycle may have a corresponding link in the atmosphere and hydrosphere
• Most important 4 are the:– Carbon cycle– Nitrogen cycle– Phosphorus cycle– Water cycle.
The Carbon Cycle
• Carbon is an essential element for all life• Carbon is the 4th most abundant element
in the universe.• It is the element that anchors all life.• All organic compounds contain Carbon• The Carbon cycle begins in the
atmosphere as CO2.
Two Cycles:Long Term and Short term
Long Term Geological• Geological cycle begins with
the birth of earth.• Initial carbon came with the
earth and meteors.• Carbon was present in
atmosphere as C02 through volcanism.
• Carbon combined with elements in earth’s crust to create minerals like calcium carbonate.
• Carbon erodes from this storage into oceans.
Short Term Cycle• Start at C02 in the
atmosphere• Plants photosynthesis to
convert carbon into carbohydrates
• Consumer’s eat • Both plants and animals
use energy through cellular respiration and return carbon to the air
• Decay returns carbon to the ocean and soil.
How industry influences Carbon Cycle
Fossil fuels• Fossil fuels are old plants and
animals that have decayed after millions of years.
• The carbon comes from the organisms that died
• Coal is a type of fossil fuel just from plants
• The carbon is a long term storage.
• Releasing the carbon puts it back in the atmosphere
What We Burn the Most
Where Does C02 Come From
Carbon Yearly and Seasonal
The US and Greenhouse emissions
Greenhouse gases emitted by the United States are from the following :
• Carbon dioxide (CO2) –fossil fuels, respiration
• Methane (CH4)-cows and landfills
• Nitrous oxide (N2O) –fossil fuels, volcanoes
• Water vapor (H2O) natural steam / evaporation.
The Transportation & Industry Sectors emit the greatest amount
Greenhouse Emission per Country
Greenhouse Gas emission
Carbon • When analyzing the carbon cycle
scientists refer to the storage and release as either a sink or source.
• Source: where carbon is coming from
• Sink: where carbon is stored– Short term sink = animals, plants, top
soil– Long term = deep ocean, rainforest,
deep soils and rocks, fossils
Balancing Carbon: Sources vs. Sinks
Sources Ways it gets into atmosphere
• Natural sources– Forest fires– Volcanoes– Respiration
• Anthropogenic Sources– Transportation– Slash and burn – Deforestation– Energy usage– Warming planet
• From ocean• From rocks
Sinks-places to store• Forests• Grasslands• Ocean especially deep
oceans• Deep in forest soils
Major components of the Atmosphere
• Nitrogen• Oxygen• Carbon dioxide• Argon• Methane• Water vapor• Nitrogen oxide• Sulfur oxide• Atmospheric dust
How the Atmosphere influences climate
• The atmosphere acts as a protective bubble surrounding our planet
• Protects against gamma rays and X rays• Protects us from large temperature changes
with the green house gasses.• Also causes our sky to be blue by refracting
sunlight• Causes the water cycle.
Green House Effect
Nitrogen cycle
The Nitrogen Cycle
• Nitrogen exists as an unusable Gas N2.• It represents 79% of our atmosphere• Nitrogen is essential for protein, DNA and
many other parts of life.• Nitrogen needs to be converted by special
bacteria for organisms to utilize.• The nitrogen cycle is dependent on these
nitrogen fixing bacteria
Vocabulary• Nitrogen fixation- process by which unusable nitrogen is converted to NH3 (ammonia)
• Nitrification- process where ammonia is put into nitrite and nitrates which are usable by plants. Ammonia can be toxic to most plants.
• Denitrification- process by which nitrogen in the soil is returned to the atmosphere
• Nitrogen fixing bacteria- bacteria that turn nitrogen and ammonia into to nitrate
How Nitrogen gets fixed (changed) Lightning- approximately 5-8% is converted this way.
Nitrogen gas is split by lightning and comes down in rain as nitric acid.
Bacteria – approximately 40-50 % is currently fixed this way.Bacteria convert Nitrogen gas to nitrates or ammonium
and plants take it up.
Industrial – 50% of nitrogen is fixed this way It is changed from nitrogen gas in the atmosphere to
ammonia, which plants take up.This includes inorganic fertilizers and combustion
Nitrogen fixing BacteriaLive in nodules of legumes like beans, chick peas, lentils, lima beans and soy.Use to organically improve nitrogen of soil in a garden.
Nitrogen fixed by Industry
• Increasingly more and more nitrogen is being added to our environment through production of fertilizers, explosives and combustion.
• Excess nitrogen causes acid rain and pollution.
Percentage of Nitrogen Introduced by Anthropogenic Sources
How is Nitrogen converted through bacteria
• Nitrogen is converted using special bacteria• N2 is converted to NH3 in the soil = ammonia and
ammonium.• It is then converted into nitrites and nitrates.• Both ammonium, nitrites and nitrates are used
by organisms.• Nitrogen returns to the soil as decay happens.• Returns to atmosphere as gasses are released by
bacteria and decomposers Denitrification
How Nitrogen Cycles Back to the Atmosphere
• Once nitrogen is in the plants, animals eat the plants.– Organisms excrete nitrogen in the form of Urea or
Uric acid this ends up in the soil– Organisms die and decay the nitrogen ends up in
the soil and organisms that acted as decomposers⁻ From there the Nitrogen is changed back to gas by
the process of denitrification.
Nitrogen in the Atmosphere
Lightning Bacteria Industrial
Nitrates Nitrates Ammonium
Food Chain
denitrification
Simple CycleThe nitrogen cycle begins in the atmosphereThis is converted to ammonia by bacteria or lightningIf By lightning goes from N2 to NO3 directly.By bacteria it goes through several steps : N2 to NH3 to NO2 to NO3N03 is taken up by plants to yield protein.Nitrogen is returned to soil in decay and manure.NO3 goes to atmosphere by denitrifying bacteria
When Nitrogen Becomes a Problem
• Excess nitrogen leeches into water bodies• Nitrogen is a limiting resource/factor A limiting
factor is something that limits the growth, reproduction or distribution of organisms (ex: water, food, shelter)
• It stimulates massive algae growth.• The algae suffocates the ecosystem by blocking sunlight
and taking up large amount of oxygen when it dies.• This causes Hypoxia-condition in which oxygen levels
are too low to support life also called Dead zones
Eutrophication- process by which growth of a nuisance plant (algae) is stimulated due to the addition of a limiting resource (usually nitrogen or phosphorus) and leads to pollution of the water body.
Problems with Nitrogen
• Currently largest problem is due to increases amounts of inorganic fertilizer and excess waste from Feed lots.
• Second largest problem is due to combustion of fossil fuels
Dead Zones• The largest
hypoxic zone currently affecting the United States, and the second largest hypoxic zone worldwide, is the northern Gulf of Mexico adjacent to the Mississippi River.
Phosphorus Cycle
Sources of Phosphorus
Very similar to the sources of nitrogen.
Sources of Phosphorus
Problems with Excess Phosphorus
• Similar to excess nitrogen, phosphorus causes an overgrowth of algae in water and eventually leads to hypoxia.
