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nutrient cycles powerpoint presentation

  1. NUTRIENT CYCLE- power point presentation
  2. The Nutrient Cycle  Nearly 30-40 elements are required for proper growth and development of living organism.  Most important of these are C, h, O, P, K, N, S, Ca, Fe, Mg, B, Zn, Cl, Mo, Co, I, and F.  These elements flow from abiotic to biotic components and back to the non living component again in a more or less cyclic manner. This is known as Nutrient Cycles.
  3. Types  There are 3types of nutrient or biogeochemical cycles: -hydrologic cycle or water cycle -gaseous cycle -sedimentary cycle  The nutrient cycle focuses primarily on two nutrients, carbon and nitrogen (of the gaseous cycle).
  4. Gaseous cycle  Biogeochemical cycles in which reservoir is the air or oceans(via evaporation).  Include those of nitrogen, oxygen, carbon, and water.  Tend to move more rapidly than do sedimentary ones and to adjust more readily to changes in the biosphere because of the large atmospheric reservoir.
  5. Nitrogen cycle  Biogeochemical cycle by which nitrogen is converted into various chemical forms as it circulates among the atmosphere, terrestrial and marine ecosystems.  Conversion of nitrogen can be carried out through both biological and physical processes.  Majority of earth’s atmosphere is nitrogen(78%). However, atmospheric N2 has limited availibility for biological use, and this form is relatively non-reactive and unusable by plants.
  6. Steps of nitrogen cycle
  7. Elaboration  Nitrogen fixation- atmospheric nitogen must be fixed in a usable form to be taken up by plants, mostly fixation is done by free living (eg. Azotobacter & Closteridium) or symbiotic (Rhizobium).  Nitrification- conversion of ammonia to nitrate is performed primarily by soil living bacteria and other nitrifying bacteria. (eg. Nitrosomonas sp.- ammonia to nitrites & Nitrobacter sp.- nitrite to nitrate.)  Assimilation – plants take nitrogen from soil by absorption through their roots as amino acids, nitrate ions, nitrite ions or ammonium ions.
  8.  Ammonification- when a plant or animal dies or an animal expel waste , the initial forms of nitrogen is organic. Bacteria or fungi convert the organic nitrogen within the remains back into ammonium , a process called ammonification or mineralization.  Denitrification- reduction of nitrates back into the largely inert nitrogen gas, completing the nitrogen cycle.( bacterial species involved are Pseudomonas & Clostridium)
  9. Carbon cycle  Combined process, including photosynthesis, decomposition, and respiration, by which carbon is a component of various compound cycles between its major reservoirs- the atmosphere, oceans and living organisms.  Carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and the atmosphere of the Earth.
  10. Elaboration  Carbon moves from the atmosphere to plants. In the atmosphere, carbon is attached to oxygen forming carbondioxide through the process of photosynthesis carbon dioxide is pulled from the air to make plant food from carbon.  Carbon moves from plants to animals. Through food chains, the carbon that is in plants moves to the animals that eat them. Animals that eat other animals get the carbon from their food too.  Carbon moves from plants and animals to the ground. When plants and animals die, their bodies, wood and leaves decay bringing the carbon into the ground. Some becomes buried and become fossil fuels.
  11.  Carbon moves from living things to the atmosphere. Each time you exhale, you are releasing carbon dioxide gas into the atmosphere.  Carbon moves from fossil fuels to the atmosphere when fuels are burned.  Carbon moves from the atmosphere to the oceans. The oceans and other bodies of water, soak up some carbon from the atmosphere.
  12. Significance  The nitrogen cycle is important due to its role as a basis for the production of nitrogen that is essential to all forms of life.  Nitrogen is required for the synthesis of amino acids, nucleic acids (DNA & RNA) in chlorophyll molecules. It is an essential component of the proteins that build cell materials, and plant tissue.  Carbon is the fundamental building block of life and an important component of many chemical processes.  Increased levels of carbon dioxide insulate the earth, causing temperatures to rise. Understanding how carbon dioxide is absorbed and released helps us to understand the climate and predict global warming.  Carbon is not in balance, so it’s important to learn where it is being stored and released. The rate at which carbon is deposited is not the same as the rate it is returned to the Earth.
  13. Reference  Steven B. Carroll ; Steven D. Salt (2004). ECOLOGY FOR GARDENERS. Timber press. P. 93. ISBN 978-0-88192-611-8.  Galloway, J.N.; et al.. (2004). “Nitrogen cycles: past, present, and future generations”.  Steffen, w. (2000) ; Linder, ‘’THE GLOBAL CARBON CYCLE: A TEST OF OUR KNOWLEDGE OF EARTH AS A SYSTEM”  Prentice, I.C. (2001).” THE CARBON CYCLE AND ATMOSPHERIC CARBON DIOXIDE ” climate change 2001.  “AN INTRODUCTION TO THE GLOBAL CARBON CYCLE” University of New Hampshire. 2009. Retrieved 6 February 2016.
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