Science 10 - Human Impacts

Science 10

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1.Ecosystem and Sustainability

2.Scienfic Methodology

3.Feeding Levels

4.Describing Trophic Compounds

5.A Matter of Life and Death

6.The Carbon Cycle

7.The Nitrogen Cycle

8.Human Impacts

9.Change and Succesion

Human Impacts
EIn the early 20th century, scientists figured out artifisial way to fix nitrogen.
EThey used this to make artifical fertilizers.
EAt the end of the twentieth century, the amount being fixed in nuture!!!
EDon't forget, the burning of fossil fuels releases nitrogen compounds which form acids that will fall back to Earth (acid rain!!.Eeeewww!!!)
EModem farming the combustion of fossil fuels and other human activities now move about 140 million tons of extra nitrogen through the environment each year!
ETHe plants can only use a certain amount! they ecosystem is said to be in "nitroden staturation"
EThe excess nitrogen washes into streamsor other water source.
EExtra nitrogen can stunt tree growth, damage tree roots, caurse coniferous tree needes to turn yellow and fall.
ETHese changes are as a result of the nitrogen increasing acidic levels in the soil!

Effect on Ecosystem
ENitrates from the fertilizers and phosphates from detergents cause an increase in the growth of algac and weeds
ESewage has the same effect.
EThe build up of plant life on the surface will choke out the deeper specise these things die, the decomposition requires oxygen thus decreasing oxgen levels, the fish can't breathe and have nothing to eat.
EThe build up of nutrients in an aquatic ecosystem is called eutrophication.
ENitrates in our drinking water are converted into nitrites by bacteria in our stomachs which reduce the blood's ability to carry oxygen!!

Biodiversity
EBiodiversity is a measure of the rariely of spesies on Earth - or more specifically, an ecosystem.
EAs a rule, biedirersity is reduced in extreme conditions.(think of arstic climates relative to trophical!)
EAn excess of nutrients an have the same as similar effect on biodiversity on an ecosystem as excessive cold, hot, acidic, wet conditions.