Biogeography Final Exam

What are major limiting factors on human population?

Food - Thomas Malthus 1798

Disease - plague 1300s

What are minor limiting factors on human population?

Predation

Wars/homicide

What developments removed the main constraints on human population?

modern medicine and agriculture (1850-1950)

What is the current human population?

8 billion

What is the percent growth of the human population?

0.9%

What is the doubling time of the human population? How is this calculated?

~75 years

70 / % growth

What is the global fertility rate, and what is the range by country?

Global fertility rate: 2.3

Range: 1.5-5, stable 2.1

What is the population projection for 2100?

10.5 billion

T/F: The human population has nearly doubled from 1975 to 2025.

True

When considering the carrying capacity of Earth for humans, what are some questions that should be asked?

Do we want:

1. only humans and food supply, or other things?

2. “first” world resource use, or low-resource use?

3. quality vs quantity, and a sustainable population

Define “just in time delivery”

materials brought just in time for use

Humans need food, water, and space, and so does all other life. How is this typically managed?

parks and reserves

What are the three major drivers of habitat destruction?

housing, agriculture, commercial

What system existed prior to formal agriculture? How much disturbance did it cause?

hunter/gatherer - minimal disturbance

What are some methods associated with plant farming?

Slash and burn

Animal and plow

Mechanical

What parts of plant farming does machinery take part in? Describe some issues associated with mechanical farming.

ground preparation, planting, and harvest

irrigation, fertilizers, pesticides, structures

What are some issues associated with industrial animal ranching?

density, antibiotics, cages, feed lots, crowding

What are some examples of modern aquatic ranching?

Salmon - ponds, partial free range

Catfish, shrimp - ponds

Commercial land use has a large foot print. List examples.

factories, mining, logging, shopping/sports, roads, dams

What are factories responsible for?

production of various goods and services

Describe strip mines, as well as underground mines.

strip mines: remove surface layer

underground mines: dig/bore shafts/tunnels

Why has there been a major push for rare Earth metals? What do these require?

used in electronics

require large mining operations

What are issues associated with mining?

waste mine debris, contaminated water

What are 3 common logging practices?

selective cut, shelter cut, clear cut

Describe selective cut logging.

individual trees are picked

least damage

Describe shelter cut logging.

small continuous patches cut

trees left intact between cut patches

Describe clear cut logging.

Very large areas cut to the ground

most damage to forest and greater ecosystem

What are some issues associated with logging?

water runoff and logging roads