Module 3 (Biogeochemical Cycles)

Bottom-up control

A type of control on ecosystem function that states that it is the nutrient supply to the primary producers that ultimately controls how ecosystems function.

Bottom-up control

If the nutrient supply is increased, the resulting increase in production of autotrophs is propagated through the food web and all of the other trophic levels will respond to the increased availability of food. Energy and materials will cycle faster.

Top-down control

A type of control on ecosystem function that states that predation and grazing by higher trophic levels on lower trophic levels ultimately controls ecosystem function.

Top-down control

If you have an increase in predators, that increase will result in fewer grazers, and that decrease in grazers will result in turn in more primary producers because fewer of them are being eaten by the grazers. Thus the control of population numbers and overall productivity "cascades" from the top levels of the food chain down to the bottom trophic levels.

Light energy

Energy is continually inputted into an ecosystem in the form of?

Nutrients

These are recycled within an ecosystem, and their supply normally limits biological activity.

Materials

These can be critical or limiting factors in an ecosystem function.

Biogeochemical Cycling

The movement of elements and compounds that are essential to life. Materials are transported through organisms, the atmosphere, water and land in a series of cycles.

life, participation of organisms

What does “bio” mean in biogeochemical cycling?

abiotic environment as source of nutrients

What does “geo” mean in biogeochemical cycling?

nature of substances being cycled

What does “chemical” mean in biogeochemical cycling?

Hydrological Cycle

Mediates nutrient cycle and a major energy dissipation pathway

1. Evaporation

2. Condensation

3. Sublimation

4. Precipitation

5. Transpiration

6. Runoff

7. Infiltration

What are the phases of the water cycle?

Asphalting

Human impact of the hydrological cycle where in it renders the ground impervious to water blocks infiltration.

Hydrological Cycle

These human impacts are caused by which cycle?

1. More consumption than supply

2. Pumping water from aquifers - not a normal part of the water cycle

3. Garbage and waste pollute the water and clog drainage systems, inducing flooding.

4. Asphalting

Rock Cycle

• Forms and recycles the various layers that make up the Earth.

• The topography of all areas of the world is shaped by its stages.

• Influences and is influenced by other systems and cycles, such as the lithosphere (the Earth's crust and upper mantle), the biosphere (all biological life forms on Earth), and the water cycle (where water evaporates, condenses, and precipitates).

igneous, sedimentary, and metamorphic

What are the three (3) main rock types?

Igneous

This type of rock is formed by the crystallization of MAGMA after it melts.

Metamorphic

This type of rock is formed due to the deformation and metamorphism of a sedimentary rock.

Sedimentary

This type of rock is formed due to the weathering of rocks at the surface, erosion and transport, deposition of sediment, and burial and compaction.

1. Atmosphere

2. Oceans

3. Biomass

4. Litosphere

Where can Carbon be found?

1. Photosynthesis

2. Respiration

3. Decomposition

4. Fossilization

5. Combustion

6. Ocean Uptake

7. Ocean Outgassing

What are the phases of the carbon cycle?

atmosphere, calcium carbonate, fossil fuels

What are the major reservoir in the carbon cycle?

1. Combustion of fossil fuels for vehicles, electricity, and heat

2. Coal

3. Burning of forests, fuelwood, and organic debris

What are the sources of carbon dioxide?

1. Nitrogen Fixation

2. Nitrification

3. Assimilation

4. Ammonification

5. Denitrification

What are the phases of the Nitrogen Cycle?

Nitrogen Cycle

• Even though most of Earth’s air is nitrogen gas (N₂), plants and animals can’t use it directly.

• Bacteria in the soil and in roots change nitrogen gas into forms that living things can use.

• Plants take up nitrogen to grow, animals eat plants to get nitrogen, and when both die or make waste, decomposers return nitrogen to the soil.

• Finally, some bacteria change the nitrogen in the soil back into nitrogen gas, sending it into the air again — completing the cycle.

Nitrogen Cycle

Cycle that is essential for many biological processes, constitutes part of proteins (amino acids), in bases of nucleic acids that make up DNA and RNA.

1. Lightning

2. Bacteria in legumes

3. Free-living bacteria

4. Cyanobacteria

Nitrogen must be fixed by these to be usable to living things.

78%

What is the percentage of nitrogen in the air?

eutrophication

Use of nitrogen fertilizers that causes run off leading to the what of aquatic systems?

Methemoglobinemia

What happens when nitrogen leaches into ground water?

Sulfur Cycle

Cycle were its the sedimentary cycle with atmospheric component.

inorganic sulfur in rocks and fossil fuel

What is the major reservoir of the sulfur cycle?

Sulfur

An important element in protoplasm which is an important component of some amino acids. It is part of proteins, vitamins and hormones.

Acid precipitation

Responsible for the death of trees and other plants, acidification of lakes, damage to metal and stone structures among others.

1. Weathering

2. Absorption

3. Consumption

4. Decomposition

5. Oxidation

6. Atmospheric Return

What are the phases of the sulfur cycle?

purely sedimental

What is the type of the phosphorus cycle?

earth’s crust

What is the major reservoir of the phosphorus cycle?

Phosphorus

This element normally occurs in nature as part of phosphate ion. Most phosphates found as salts in ocean sediments or in rocks. Over time: geological processes can bring sediments from ocean to land, and weathering can bring it from land to ocean.

Phosphorus

This element is also found in bones, in phospholipids which are found in biological membranes. There is also this element’s constituent of nucleic acids in DNA, and energy currency of cell ATP.

Phosphorus

The following human impacts are from what abuse of cycle?

• Humans mine phosphate ores for use in fertilizer production and detergents

• Human actions could lead to eutrophication of aquatic systems which cause algal blooms

• Algal blooms cause fish kills

1. Zinc

2. Selenium

3. Molybdenum

4. Iron

What are the four (4) trace elements?

Zinc

Trace element that is recognized as an essential trace element for plants, animals and humans for more than 70 years.

Selenium

Trace element that is an important part of a molecule in the body that protects blood cells from certain damaging chemicals; together with vitamin E, helps our immune system produce antibodies.

Molybdenum

Trace element that is required for the proper function of several chemicals in the human body; varies significantly and is dependent upon the mineral content of the soil that the plants were grown in.

Iron

Trace element that exists in nature either as ferrous (Fe++) or ferric (Fe+++) ions.

Ferrous iron

This type of trace element oxidized spontaneously to ferric state, forming highly insoluble ferric hydroxide.