biosphere cycles

• roles of water

  -it is a universal solvent

  -it is polar

  -has a relatively high boiling and melting point

  -has a special adhesive and cohesive properties

  -high heat capacity
• water is considered polar which means it has a positive and negative end in the molecule which created hydrogen bonds


  causes water to stick to itself and therefore it takes a lot of energy to break water molecules apart which results in the high melting and boiling point
• hydrogen bonds also cause cohesion (water attracted to other water particles) and adhesion (water attracted to other substances which causes water to move up the xylem in a plant)
• evaporation


  as water is heated from the sun, its surface molecules become energized enough to change the liquid to water vapour
• transpiration

  water vapour emitted from leaves of plants
• condensation


  as water vapour rises, it cools and changes to a liquid on tiny particles of dust. this liquid may also freeze and for ice, hail or snow to form clouds
• precipitation


  water falling to earth in the form of rain, snow, or hail
• runoff


  excessive rain or snowmelt can produce overland flow to creeks and ditches which is a visible flow of water
• percolation


  water that moves down or infiltrates through cracks and pores in soil and rock until it reaches the water table
• groundwater


  subterranean water that is held in cracks and pore spaces and can also flow to support steams and can be used as well water
• water table

  the level to which water will rise in an open well
• biogeochemical cycles

  water cycles causes nitrogen, phosphorus, carbon, and oxygen to also be used and recycled
• rapid cycling


  occurs when the nutrient goes from organism into the air and then is taken back immediately
• slow cycling


  occurs when the nutrient can be trapped for thousands of millions of years in nutrient reservoirs like mountains
• combustion


  the process of burning that releases carbon dioxide into the air
• photosynthesis


  the process of incorporating carbon dioxide into complex carbohydrates
• weather


  the breakdown of rock material through erosion
• uplifting


  the formation of mountains or hilly areas through plate tectonic movements
• decomposition 


  release of carbon dioxide through the breakdown of organic matter this process can also result in the formation of coal and fossil fuels if there is sediment on top of the decomposing matter
• cellular respiration


  the breakdown of carbohydrates in animals ro create energy produces carbon dioxide
• carbon sources/sinks

  the atmosphere, the ocean and earth's crust hold largest amounts of carbon
• shelled creatures


  carbon is incorporated into carbonate compounds of the shell and can fall to the ocean floor and only reappear after uplifting
• sulphur cycle


  -important part of protein and vitamins

  -plants and algae use sulphur in the form of sulphate when the plants die the decomposers quickly return the sulphur to the soil or atmosphere

  -most airborne sulphur returns to earth in acid precipitation

  -many types of bacteria help with the cycling of sulphur including sulphate reducers and sulphate oxidizers
• nitrogen fixation

  when bacteria convert nitrogen gas into ammonium compounds that often live in root nodules of leguminous plants in a mutualistic relationship which is also partially completed by lightning changing atmospheric nitrogen and oxygen to nitrates
• ammonification

  when decomposers break down organic matter like dead organisms or fecal matter into ammonia and then ammonium
• nitrification

  when ammonium is changed to nitrite and then possible into nitrate which can be used by plants which occurs aerobically
• denitrification


  denitrifying bacteria complete the cycle by converting nitrite or nitrate back into nitrogen gas which occurs in anaerobic environment
• assimilation/biosynthesis


  when organisms change nitrates into useful proteins required for life (done in plants and animals)
• leaching


  when minerals of any sort move out of the soil through ground rock and move out of rapid cycling pathways
• phosphorus cycle

  -the slow cycling includes movement of phosphate through oceans and lakes and settling into detritus at the bottom

  -the phosphate enters rock and can only be recovered after billions of years of uplifting and erosion or weathering

  -rapid cycling occurs with the phosphate being taken up by plants, moving into animals and then decomposers returning the phosphate to soil where it can quickly be taken up by plants again

  -phosphate located in animal bones and teeth and in plant proteins it is used in cell membranes and in energy storage molecules like atp
• acid rain


  -both sulphur and nitrogen compounds are now regularly put into the atmosphere through human activities

  -sulphur dioxides and nitrogen dioxides become sulphuric and nitric acid as they mix with water vapor and come down to earth in the form of acid rain or snow or they fall as acid deposition in dry form

  -soil pH can change killing trees

  -waterways have a flush of acid in the spring time killing tadpoles and young frogs

  -plants can have leaf damage resulting in less photosynthesis
• Greenhouse effect

  -carbon dioxide levels have increases due to a much larger use of fossil fuels and the cutting down of the world's forests

  -has resulted in an overall warming of the earth's atmosphere which in turn is affecting plant growth

  -kyoto accord has been put into place but we have yet to see a reduction in carbon dioxide worldwide
• fertilizers and ecosystems

  -both nitrogen and phosphorus have been found to increase plant growth and have been used intensively in agricultural areas

  -an issue with runoff of these fertilizers when used in excess has resulted in huge algal blooms in many rivers and streams causing death to the normal flora and fauna