Chapter 14 - Ecology of Human Populations Flashcards
What are the pros/cons of 2/3 of the global pop living in urban areas by 2050?
pros: could ease GHG emissions per capita (less car driving)
cons: cities require land and so they must take away from natural areas to get this land
What is the root of most environmental problems?
The large, growing global population because more people means an increased requirement for energy and resources
What is a demographic transition?
It is the switch form high birth and death rates to low birth and death rates.
ex. after baby boomers
Why has a demographic transition from high to low occurred?
B/c medical advances reduce death rates while personal choices reduce birth rate (voluntary). Important with the assumption of a global carrying capacity
What are emerging infectious diseases?
They are diseases appearing in the human population for the first time or expanding rapidly in incidence or geographic range (must faster than environmental change).
ex. HIV, ebola, SARS, lyme disease
What are most emerging infectious diseases classified as?
Most are zoonoses, meaning they are infections that circulate naturally in non-human vertebrate hosts, but they can be transmitted to humans
What is a pest species?
It is a species that humans consider undesirable, usually because it harms us directly or damages/competes with crops. Essentially, it is any species causing economic damage
What is economic injury level (EIL)?
It is the point in pest control in which further reduction would cost more than would be gained in improved yield. Therefore, total eradication is never profitable
What is monoculture?
It is when a single species is farmed in dense pops, which often increases the pest problem
What is the main approach to pest control?
Mainly different kinds of pesticides
What is a pesticide? What are the types?
It is a chemical used to control pests and was developed with increased use in synthetic N fertilizers
- herbicides - targets weeds
- insecticides - targets insects
- fungicides - targets fungi
What is bioaccumulation?
It is an environmental issue often caused by pesticides because it occurs when a pesticide is present in an organism that becomes the prey of another and the predator fails to excrete/metabolize the pesticide, causing it to accumulate in the predators body.
ex. tuna is at the top of the food chain because it is a longer living species, meaning it has longer to accumulate more mercury
What is biomagnification?
It is an environmental issue often caused by pesticides because when a pesticide is present in prey, there will be more present in predators and is magnified the most at the top of the food chain, which can be lethal.
ex. tuna is at the top of the food chain (K-selected species) so it will have the most mercury
What is target pest resurgence?
It occurs when treatment kills a large number of pests and its natural enemy, which causes surviving pests to find themselves with fewer enemies and plentiful food, so the pop could explode
What is resistance?
It is when pests become resistant to a pesticide, causing the pesticide to lose all value