chapter 14, 19, 23 EXAM Flashcards
biomagnification
levels of toxins are stronger (magnified) as they pass through food chains and webs. the concentration of a toxic substance will increases in each successive link in the food chain.
-higher trophic level = higher amt. of toxins
bioaccumulation
molecules are absorbed and stored in specific organs or tissues at higher rates than the normal level
DDT
a chlorinated hydrocarbon that has been widely used as an insecticide but is now banned in some countries
- highly resistant
- biologically magnified
GMOs
(genetically modified organisms)
- discourage biodiversity (reason why usage is controversial)
- increases antibiotic resistance
- could cause more pests to be born resistance to pesticides
- pose new allergen risks
- may harm beneficial organisms
positive effects are a higher yield of crops and faster growing crops
how to get rid of insect pests
-pesticides
IPM:
- introducing natural enemies
- cultivation practices
- introducing hormones and pheromones
- traps and barriers
- intercropping, polyculture, crop rotation
circle of poison
when residues or banned or unapproved chemicals exported to other countries can return to the country
integrated pest management (IPM)
-overall goal: reduce crop damage to an economically tolerable level.
steps:
1. monitoring pest damage levels
2. control crop management
3. biological controls and hormone attractors
4. careful usage of chemicals
-biological, chemical and cultivation processes such as natural predators, intercropping,crop rotation, traps and hormone interrupters.
desalination
purification of salt water or brackish (slightly salty) water by removal of dissolved salts
desertification
- when topsoil is lost and changed into desertlike land
causes: overgrazing, deforestation, prolonged drought, soil erosion and climate change
second green revolution
- began in the 1960s
- improved crop production further by developing high yielding crop varieties
- introduction of GMO’s and modified plants
vegetarianism VS eating meat
advantages of being a vegetarian:
- low risk of high cholesterol
- low risk of heart disease
- low risk of high blood pressure
famine
widespread malnutrition and starvation in a particular area because of a shortage of food, usually caused by drought, war, flood, or earthquakes (anything that affects food production and distribution)
no till farming
farmers plant seeds without using a plow to turn the soil
-this prevents the carbon content from the soil to be released from the atmosphere during plowing.
agroforestry
agriculture + forestry
- crops and stock are raised on the same land as a stand of woody perennials.
- high biodiversity levels
- lower soil loss
intercropping
AKA STRIP CROPPING
planting bands of of different crops across a hillside
-prevents erosion by creating an extensive network of roots that hold onto the soil.
interplanting
simultaneously growing several crops on the same plot
-reduces the chance of losing a large yield of crops to pests, bad weather or other misfortunes.
polyculture
many different plants maturing at various rates are planned together
- less need for fertilizer and water because the plants roots systems are at different depths
- protection from soil erosion
- little need for insecticides and herbicides
effects of eating and not eating meat
-missing nutrients that you can only get from meat
-missing high quality protein
-
effects of eating and not eating grains
-
most commonly eaten grains
- wheat
- rice
- corn
by-catch
any species of fish, mammals or birds that are caught that are not the “target organisms
fishery
the industry or occupation devoted to the catching, processing or selling of fish, shellfish or other aquatic animals
aquaculture
the raising of fish and other aquatic species under captivity for harvest
plague
- caused by a bacterium in rodents
- not transmissible from human to human
- antibiotics can be used as treatment
