Question

Human Impact on Biogeochemical Cycles Worksheet Using the textbooks, the University Library or other resources, answer each of the following questions in 150- to 300-words. Be sure to provide references for the sources you use. Question Response

Your neighbor faithfully applies fertilizer to his lawn to ensure beautiful, healthy green grass. Explain how your neighbor’s fertilizing habit affects at least one nutrient cycle.

Your friend commutes to work every day by driving a standard gasoline-powered car. Explain how your friend’s commute affects one or more nutrient cycles.

Urban areas typically have lots of pavement and compacted soils. Explain how these impermeable surfaces affect at least one aspect of the hydrologic cycle

Answer 1

1) There is a natural cycling of the nutrients such as nitrogen that takes place with the help of bacteria which convert the atmospheric nitrogen in to usable form and are then sent back in to the atmosphere by a different set of denitrifying bacteria and this cycle continues in the environment but fertilizers disturb this cycle.With increase usage of nitrogen fertilizers the concentration of nitrogen increases in the soil and are not acted upon by microorganisms and gradually the excess nitrogen in the soil does not get converted in to atmospheric nitrogen which causes the leaching of nitrogen and finally makes its way to groundwater or gets washed away by rain and reaches water bodies where it causes eutrophication of the water body.

2) Gasoline-powered cars as we know is not a clean fuel and contributes to air pollution when it burns.It releases high levels of  NOx_, CO₂ and some unburnt hydrocarbons.If we consider the example of carbon cycle we know that there is a continuous cycling of this elements through the different spheres of earth but my friends daily commute will add to the concentration of carbon which was earlier stored deep in the lithopshere in the form of fossils and this carbon was not actively a part of the carbon cycle because of which now the source of carbon has increased thereby disrupting the natural cycling of element.

3) The construction of concrete roads in urban settings takes away the ability of water to percolate in to the deeper layers of the soil where it gets stored as groundwater causing all the water to flow down to open water bodies and less accumulation of water in the aquifers hence affecting the major inflow of hydrological cycle.This problem affects the groundwater recharge.