Human Influence on The Enviorment Flashcards
Whats nutrient cycling?
When crops are harvested and brought to the barn to feed animals, that is a nutrient flow, as is the return of animal manure to the land. Together these two flows are a cycle because nutrients and carbon return to the fields from which they came.
What are some ways methane is produced?
Decomposition, fermentation by microorganisms in cattle stomachs and fermentation by bacteria in rice fields.
Why do glasshouses work?
The greenhouse effect. Short wavelength infrared radiation entering the glasshouse is absorbed and re-radiated as longer wavelength infrared radiation. This radiation cant escape through the glass, so the glasshouse heats up.
What do glasshouses do?
The transparent walls allow for enough natural light for photosynthesis during the summer, while additional lighting in the winter allows for “longer days”.
What factors do you control to improve yield from crops?
Soil ions, soil structure, soil pH and CO2 levels.
What are the issues that can come up when using pesticides?
They may be slow to decompose,
They build up in the tissues of organisms - bioaccumulation.
They build up and become more concentrated along food chains - biomagnification.
They damage harmless insects too, like bees.
Whats DDT?
Dichlorodiphenyltrichloroethane.
Used as an insecticide until 1972.
Why is DDT contraversial?
DDT is very persistent, it stays in the enviorment for a long time. If used once, around half will be found there 10 years later.
When a herbivore comes in contact with DDT, it isnt broken down or excreted. Instead it becomes concentrated in the fatty tissues of the animals.
This is bioaccumulation.
What is a solution to fish farming?
the fish are kept in densely stocked tanks or enclosures in rivers or in lakes, or in sea cages.
The water quality can be monitored.
The diet is carefully controlled.
The enclosing helps against predators.
What is the disadvantage of fish cages?
The likelihood of disease spreading is far greater because the animals are kept close together.
Antibiotics are used to treat these issues but this may lead to humans consuming these medicines.
Whats carbon monoxide?
A dangerous pollutant, its colorless, odorless and tasteless and can be fatal.
Hemoglobin binds more strongly with CO than O2, if a person breathes in more CO for a period of time, more and more hemoglobin binds with CO and O2 cant.
Whats eutrophication?
Refers to a situation where large amounts of nutrients enter a body of water.
- Pollution by these minerals can have very harmful effects on an aquatic system.
Often caused by the used of artificial fertilizers?
