Human Impacts on Nitrogen, Phosphorus, and Sulfur Cycles

Human impacts on nitrogen cycle

* Combustion of nitrous oxides
* When they combine w/ water nitric acid is created (HNO3) in the atmosphere
* Fertilizers
* increase nitrogen in aquatic ecosystems and causes eutrophication

Human impacts on phosphorus cycle

* Fertilizers and detergents with phosphorus
* increase eutrophication

Human impacts on sulfur cycle

* Coal combustion and smelting sulfide minerals
* Increase Sulfuric acid in atmospherE This leads to acid precipitation
* Acid mine drainage
* When humans mine, rock with sulfur-bearing minerals are exposed. The runoff created when surface water passes over the exposed rock becomes contaminated

Human impacts on hydrologic cycle

* Excess nutrients, fertilizer and sewage
* cause algal blooms hypoxic conditions, and dead zones
* Removal of large quantities for vegetation
* Natural vegetation decreases, causing increased runoff and less infiltration

Human impacts on carbon cycle

* Fossil fuel combustion
* Releases Carbon from rocks and adds CO2 to atmosphere → increased acidity of oceans
* Animal waste
* Adds CH4 (methane) to atmosphere
* Deforestation
* Lack of trees causes less CO2 to be removed from the atmosphere

Eutrophication

* When excess nutrients (nitrogen and phosphorus) are execreted into a body of water, forming algae blooms.
* The algae blooms prevent sunlight from penetrating, reducing photosynthesis and oxygen.
* When the algae dies, decomposers further deplete the low oxygen levels to break down the algae.
* The water becomes hypoxic.