What can occur as a result of the overuse of pesticides?
Pesticide treadmill where pests develop resistance to the pesticide causing the farmers to have to apply more or use a different pesticide. This cycle is ongoing. Pests become resistant through artificial selection.
Carbon Cycle
The movement of molecules and atoms containing carbon between sources and sinks. Photosynthesis is where plants absorb water and carbon dioxide to sugar and oxygen. Respiration is the opposite when it absorbs the sugar and breaks it down in the presence of oxygen to release carbon dioxide and water as waste products. Long term sinks of carbon are sedimentary rocks, fossils and fossil fuels.
Ogallala Aquifer
It’s an aquifer located underground that contributes to ⅓ of agricultural harvest. There’s been a depletion of the water available because of overuse from farmers. This is because farmers have often put the financial benefits in front of the earth's needs. If the aquifer becomes significantly depleted a drought could occur. The recharge rate of the aquifer is 5-6 ft being retracted a year and only a half of an inch being put back.
What can happen if too much water is pumped out of aquifers?
Saltwater intrusion where freshwater becomes salty due to an imbalance between inland freshwater and ocean water. Ares at low elevation are more likely for saltwater intrusion to occur.
Methods of reducing soil erosion
Windbreaks:Walls of bushes or trees which block wind from moving around the top layer of soil.
Contour plowing: Plowing horizontally across the contours of the land which prevents soil erosion in hilly and contoured areas by capturing water runoff.
Terracing: Reduces a field’s slope length and angle
No-till agriculture: Makes furrows, immediately plants seeds, firms them and covers.
Strip-Cropping: Growing crops in a systematic arrangement of strips in a field.
Persistent organic pollutants-where are they, where do we find them?
They don’t easily break down in the environment because they’re synthetic, carbon-based molecules (i.e., ddt and pcbs). DDt is an insecticide tha was banned in 1972. Countries outside of the US still use ddt to control mosquitoes that spread malaria. Women who are exposed to it are still at risk of developing breast cancer 4 decades later. Pcbs are a group of industrial chemicals that were once used in electrical transformers, plastics and lubricating oils and was banned in the us in the 1970s they still persist in the environment from spills leaks and improper disposal they can remain for many years in soil and the sediment under rivers, lakes and other water bodies.
Strategies for environmental remediation
The removal of pollution or contaminants from water both ground and surface water and soil. These waste products are removed for the protection of human health, as well as restore the environment.
Humans affect biodiversity
Humans affect biodiversity by causing pollution, loss of habitat, destruction of habitat, habitat fragmentation, domestication.
Human sources of nitrogen pollution
Fertilizers that contain synthetic nitrate and burning fossil fuels which convert N2 and nitric oxide.
What happens in each step of wastewater treatment and where in the diagram above does each step/process occur
Primary -> Breaks down big things physically with the use of screens and nets
Secondary -> Breaks down/gets rid of things left behind after primary treatment, biologically w/ bacteria
Tertiary -> Disinfecting done ecologically with bacteria or chemically i.e., bleach
UV -> Paralyzes all bad bacteria making the water safe to drink.
What can cause waste to be unfit to use as fertilizers
Presence of heavy metals.
Methods of IPM (Integrated Pest Management)
Biological -> Uses natural enemies of pests to suppress or prevent an outbreak.
Physical -> Directly remove or kill pests or physically keep pests from teaching their hosts by a barrier or trap.
Intercropping -> Plants different crops in rows next to each other which increases diversity and decreases pest + disease.
Crop rotation ->Replaces a crop that’s susceptible to a serious pest w/ another crop that isn’t susceptible
Chemical -> Use of pesticides
Nitrogen Cycle
The travel of atoms and molecules containing nitrogen between sources and sinks.
Nitrogen Fixation: Bacteria fix nitrogen from the atmosphere in the form of ammonia (NH3) and converts it to nitrate (NO3)
Assimilation: Ammonia and nitrate are absorbed by plants through their roots, humans and animals get their nitrogen supply by eating plants/plant-eating animals.
Ammonification: Nitrogen returning to the cycle when bacteria decomposes the waste or dead bodies (converting organic nitrogen into ammonia)
Denitrification: Other bacteria convert ammonia and nitrate into molecular nitrogen (N2) and nitrous oxide (N2O). Molecular nitrogen is then returned to the atmosphere.
Effects of overgrazing
Overgrazing occurs when too many animals feed on a particular area of land, it can cause loss of vegetation, which leads to soil erosion/desertification.
Persistant Organic pollutants-where are they, where do we find them?
They don’t easily break down in the environment because they’re synthetic, carbon-based molecules (i.e., DDT and PCBs). DDT is an insecticide banned in 1972. Countries out of the US still use DDt to control mosquitoes that spread malaria. Women who are exposed to it are still at risk of developing breast cancer 4 decades later. PCBs are a group of industrial chemicals that were once used in electrical transformers, plastics and lubricating oils and were banned in the US in the 1970s. They still persist in the environment from spills, leaks and improper disposal. They can remain for many years in soil and the sediment under rivers, lakes and other water bodies.
Strategies for environmental remediation
The removal or pollution or contaminants from water (both ground and surface water) and soil. These waste products are removed for the protection of human health, as well as to restore the environment.
How do humans affect biodiversity
Humans affect biodiversity by causing pollution, loss of habitat, destruction of habitat
Human sources of nitrogen pollution
Fertilizers that contain synthetic nitrate, and burning fossil fuels which converts N2 and nitric oxide (NO)
What can increase both the nutrient levels and the bacterial content of bodies in water
Excess fertilizer and sewage runoff
Precent Change Calculation
New Val-Old Val/old val * 100
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