Environment Science - Exam 3

World Population

Total number of humans currently living in the world

Population growth

Dynamic and ever changing. Because pop- grows by births/immigration, and decreases by deaths/emigration

Immigration

Movement into an area

Emigration

Movement out of an area

Density

The number per unit area

Thomas Malthus

Predicted our quick, population growth would lead to famine and war

Karl Max

Proposed poverty caused pop- growth, argued low wages and job insecurity led to a more imporvished population

Rapid Growth

(0-15) Pre-productive is a rapid pop- growth making it a wide base, due to age level moving upward every year

Stable Growth

Equal to each other, each age group reproducing enough to replace lower levels

Declining Growth

Narrow base, not reproducing to replace lower levels

Total Fertility Rate

Average number of children a woman gives birth to in her lifetime, can be affected by many social and biological factors

Demographic Transition: Stage 1

High birth and death, high infant mortality and fertility

Demographic Transition: Stage 2

Stable leading to fewer deaths, births remain the same

Demographic Transition: Stage 3

Deaths decrease, and births slow

Demographic Transition: Stage 4

Decrease of births and deaths, wealthy nation

Undernourishment

Getting less than 2,000 calories per day

Malnourishment

Nutritional imbalance caused by lack of specific dietary components or inability to absorb essential nourishment

Food Security

Having food on a day-to-day basis

Famine

When food runs short, caused by disasters, wards, corruption making people and environment suffer

Veggies as a food source

Much of food is agricultural farming but it also changes environment/landscape

Meat as a food source

Good in proteins and iron but industrial livestock is bad for the environmen

Seafood as a food source

Wild-caught protein source 90%, but fisheries are overharvested

Fisheries

A fishing ground or area where fish are caught

Tragedy of the commons

When a natural resource is unowned or open to everyone

Primary Production in biomes determined by

Temperature and precipitation

Primary Production

Total organic matter produced by producers

Thermodynamics

Amount of energy available in food chains, precipitation, and temperature

Soil

Complex ecosystems, hold water, air , nutrients, ect. Created by erosion of rock and bedrock, decaying organism and erosion particles

Sand

(Largest) Granular material composed of finely divided rock and mineral particles

Silt

(Middle) Granular materials of a size between sand and clay

Clay

(Smallest) Finely grained natural rock or soil material smaller than silt

Soil Horizons

Develop as result of climate characteristics and action of soil organisms

Leaching

Water moves through to fast and can take nutrients with it

O Horizon

Surface layer with organic matter and active decomposition

A Horizon

Mix of inorganic and organic materials that is rich in nutrients called top soil

E Horizon

Formed from leaching of clay minerals to lower horizons

B Horizon

Depositional layer that receives leached materials from higher horizons

C Horizon

Deepest soil layer of weathered parent material

R Horizon

Lightly weathered, consolidated rock

Green revolution

Made food more widely available in countries facing famine leading to the spread of monocultures and industrial agriculture

Pesticides

Chemical compound used by farmers to kill pests

Genetically Modified Crops

A response to reduce pesticide use, making crops have a increased vitamin production

Traditional Farming

Small family farms using manual labor to serve a family or community

Industrial Farming

Most widespread called intensive farming

Monoculture Farming

Producing/growing single crops at a time, requiring large amounts of pesticides/fertilizer increasing efficiency but at the cost of equipment and practices

Polyculture

More than one species grown at the same time, most prevalent agriculture, and a great ability to control pests

Tillage

Preparation of soil by mechanical agitation by removing weeds and enhancing plant growth

No-Tillage

No soil disruption, decreasing soil erosion and increasing water infiltration

Overgrazing

Plants exposed to intensive grazing over a long period of time increasing soil erosion and invasive plant species

Desertification

Land degradation in drylands where productivity is lost due to human activity

Deforestation

Removal of trees increasing soil erosion

Slash and Burn

Used in areas with poor soil returning nutrients back but increases air pollution

Irrigation

Accounts for 70% of water withdraws

Stages of Demographic Transition

1. Pre-Industrial

2. Transitional

3. Industrial

4. Post-Industrial