bisci exam 2 study guide

8/10/2019 Bisci Exam 2 Study Guide

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BISCI 003Exam Study Guide

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Bisci Exam 2 Study Guide

Ch. 6- Human Population

Numbers: World/Global Population

Chinas One Child Policy;

China is the worlds most populous nation

Continued pop. growth could exhaust resources

To decrease birth rates, the govt. implemented an rewards and punishments program to

enforce the one child rule (1979)

Farmers and their families are exempt because their farming success depends on

having many children.

The Policy was a success; Chinas growth rate is down to .5%

Now easier to deal with social, economic, and environmental challenges

Unintended consequence: families prefer sons because they yield a greater

benefit to the parents. Ohhh so sad :/

Most pop. growth occurs in poverty-stricken, developing nations that are too ill-equipped tohandle pop. growth.

Our pop. grows by over 80 million per year

Pop. reached 1 billion just in 1800s

The population sizewill continue to grow

the growth rate peaked during the 1960s (baby boom) by 2.1%, then decreased to 1.2%, the

annual global growth rate (small decrease, large consequences)

Estimating Population Doubling:

70/(countrys percent growth rate)

Global: 70/1.2 = 58.3; will take approx. 58 yrs for pop. to double

China: 70/.5 = 140; will take approx. 140 yrs for pop. to double

Larger growth rate % = less time for pop. to double

Top 5 Nations

Population:

China - 1.34 billion

India - 1.21 billion

US - 312 million

Indonesia - 239 million

Brazil - 195 million

Impact rank (1 = highest total impact and 9 = lowest total impact):

1 China

2 US 3 India

4 Russia

5 Japan

6 Brazil

7 Mexico

8 Ethiopia

9 Belgium


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IPAT model, incl. sensitivity

Population is one of several factors that affects the environment.

IPAT model- represents how our total Impacton the environment results from the interaction

among Population, Affluence, and Technology.

I = P x A x T

Demography - study of statistical change in human population; application of principles from population

ecology.

Demographers - study pop. size, density, distribution, age structure, sex ratio, birth rates, death,

immigration, and emigration of people.

Population Density

The uneven distribution of ppl across the globe

The uneven-ness means that some areas are more environmentally impacted than

others

Density is highest in regions with temperate, subtropical, and tropical climates

Density is lowest in regions with desert, rain forest, and tundra climates (aka extreme-climate

biomes)

Human pop. is dense along seacoasts and rivers; less dense away from water

At local scales, we cluster in cities and towns

Age Structure

definition - the relative numbers of individuals of each age class within a population

Helps predict future human pop.

A pop. with people past reproductive age will decline over time

A pop. with many ppl of reproductive/pre-reproductive age is will increase over

time


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Age Structure Diagram ( aka Population Pyramid)

Show the numbers of different age classes in a population

Canada (0.4% growth rate) has a fairly balanced age structure, while Madagascars

(2.9% growth rate) shows a distribution toward young people.

As Chinas pop. ages, older ppl will outnumber the young (by 2050)

Sex Ratio

definition - ratio of male to female dynamics

this ratio affects the population

Itsbeen observed that for every 100 females, 106 males are born; males are more death prone

any stage in life, making the ratio approx. equal by the time ppl reach reproductive age.

Popn Growth

Population change results from birth, death, immigration, & emigration

Rates of birth, death, immigration, & emigration determine whether a pop. grows,

shrinks, or remains stable.

Total Fertility Rate (TFR)

Total Fertility Rate- Average number of children born per woman during her lifetime; key

statistic demographers use to examine a pop.s growth potential

Factors driving down TFR:


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medical care

urbanization

Govt. (Social Security)

Educational opportunities (for women)

In Europe, these factors have driven TFR from 2.6 to 1.6 in half a century

Natural rate of population change - change due to birth & death rates ONLY, excluding

migration.

Replacement Fertility- the total fertility rate that keeps the size of a population stable.

For every human, replacement fertility equals a TFR of approx. 2.1 (2 Children replace

the mother & father, .1 accounting for the childs chance of death before reproductive

age)

Demographic Transition Model

Demographic Transition - a model of economic and cultural change to explain declining

death/birth rates in western nations as they industrialized

Demographic transition model stages:

Pre-industrial stage (1) - death & birth rates are high; death rate high b/c of

disease widespread, medical care rudimentary, unreliable/difficult to obtain foodsources; birth rate high b/c people compensate for infant mortality(death);

children are valuable as workers in this stage.

Transitional stage (2) - characterized by declining death rates due to increased

food production and improved medical care; birth rate high b/c ppl are not used

to new economic/social conditions and are still compensating for infant mortality

out of habit.

Industrial stage (3)- Industrialization increases opportunity, especially for

women; children become less valuable, in economic terms; access to birth

control exist and the choice to have less children; birth rate falls closing the gap

with death rates and reducing pop. growth.

Post-industrial stage(4) - birth & death rates fall to low stable levels; Pop. sizes

stabilize or decline slightly; no worries economically and no threat of runaway

pop. growth.

The Demographic Transition Modeldisplays a process that has taken some populations from

a pre-industrial stage of high birth rates and high death rates to a post-industrial stage of low

birth rates and low death rates. In this diagram, the wide green area between the two curves

illustrates the gap between birth and death rates that causes rapid population growth during the

middle portion of this process.


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Family Planning define- effort to plan the # and spacing of ones children.

birth control - effort to control # of children had by reducing pregnancy frequency

contraception - deliberate attempt to prevent pregnancy despite intercourse

Empowering Women reduces fertility rates

Women can potentially have very high fertility within their reproductive window but (b)

can reduce the number of births by delaying the birth of their first child to pursue

education and career and by using contraception to space pregnancies or to end their

reproductive window at the time of their choosing.

Poverty & Popn Growth

Pop. policies and family-planning are working around the globe

Reducing poverty lowers fertility

Expanding wealth increases the environmental impact per person


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Chapter 7 - Food

Iowa Farmers practice no-till agriculture.

Food Security

is theguarantee of an adequate, safe, nutritious, and reliable food supply available to all people

at all times, will be one of our greatest challenges in coming decades/the future

Food Production vs Popn Growth

Under-, Over-, & Malnutrition

Undernutrition- receiving fewer calories than the minimum dietary energy requirement

Many are undernourished b/c they are too poor to purchase food

Political obstacles conflicts, and inefficiencies in distribution contribute to hunger as well.

925 people worldwide suffer from malnutrition

Overnutrition- ppl consuming too many calories

Although 1 billion ppl lack access to nutritious food, many ppl consume too many

calories each day from overnutrition Overnutrition leads to unhealthy weight gain > cardiovascular disease, diabetes, and

other health problems.

More than US adults are overweight; more than are obese

Malnutrition - a shortage of nutrients the body needs; occurs when a person fails to obtain a

complement of vitamins & minerals

can lead to disease

Biofuels - fuels derived from organic materials and used in internal combustion engines as

replacements for petroleum

Some biofuels reduce food supplies

In the US, ethanol produced from corn is the primary biofuel.

Traditional vs Industrial Agriculture

Agriculture

define - the practice of raising crops and livestock for human use and consumption

We obtain most of our food and fiber from croplandand rangeland.

Cropland- land used to raise plants for human use

Rangeland- land used for grazing livestock

Agriculture covers 38% of the Earths land surface; 26% of this is rangeland & 12% is

cropland.

Traditional Agriculture define - an approach performed by human and animal muscle power, along with tools

and machinery, to do the work of cultivating, harvesting, storing, and distributing crops.

(practiced today but notmost common)

Traditional farmers typically plant polycultures(many-types) mixing different crops in

small plots on farmland.

Industrial Agriculture


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define - more powerful means of cultivating, harvesting, transporting, and processing

crops; uses large scale mechanization and fossil fuel combustion to agriculture, just as it

did to industry; oxen and horses are replaced with machinery

boosts yields by intensifying irrigation and introducing synthetic fertilizers, while the

advent of chemical pesticides reduced herbivory by crop pests and competition from

weeds

Industrial agriculture is a recent human invention and is practiced on over 25% of the

worlds cropland and dominates areas like Iowa.

Effects of industrial agriculture have been mixed

Monoculture - (one-type) a highly organized approach to farming, leading to vast areas being

planted with single crops in orderly, straight rows

Makes farming more efficient, but provides fewer habitats in farm fields, reducing

biodiversity.

Genetically similar plants in one field

All plants become equally susceptible to viral diseases, fungal pathogens, or insect

pests that can spread quickly from plant to plant.

Seed Banks - institutions that preserve and conserve seed types

Green Revolution- (came in mid-late 20th century) agricultural revolution that introduces new

technology, crop varieties, and farming practices to the developing world and increased food

production in these nations drastically.

boosted production and exported industrial agriculture.

Sustainable agriculture is agriculture that maintains healthy soil, clean water, and genetic

diversity essential to long-term crop and livestock production; reduces environmental impacts

Low-input agriculture uses lesser amounts of pesticides, fertilizers, growth hormones,

antibiotics, water, and fossil fuel energy used in industrial agriculture

Soil Formation

Soil - complex system consisting of disintegrated rock, organic, matter, water, gases, nutrients,

and microorganisms

Soil consists of approx. 50% mineral matter and approx. 5% in organic matter

Soil forms slowly

Parent material - the base geological material in a particular location

broken down by weathering, which converts large rock into smaller rocks

bedrock - continuous mass of solid rock that makes up Earths crust


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A soil profile consists of layers known as horizons

Mature soil consists of layers, or horizons, that have different compositions and characteristics.

Uppermost is the O horizon, or litter layer (O = organic), consisting mostly of organic matter

deposited by organisms. Below it lies the A horizon, or topsoil, consisting of some organic

material mixed with mineral components. Minerals and organic matter tend to leach out of the E

horizon (E = eluviation, or leaching) into the B horizon, or subsoil, where they accumulate. The

C horizon consists largely of weathered parent material and overlies an R horizon (R = rock) of

pure parent material.

Leaching - the process where solid particles suspended or dissolved in liquid are transported toanother to another location.

In some soils, minerals may be leached so rapidly that plants are deprived of nutrients

Regional differences in soil traits affect agriculture

Warm temperatures speed up decomposition of leaf litter and uptake of nutrients by plants

Soil Degradation - a process where soil deteriorates in quality and declines in productivity

Causesof soil degradation include:

Soil Erosion

Nutrient Depletion

Water Scarcity

Salinization - buildup of salts in surface soil layers

Waterlogging - over-irrigation causing water table to rise and water drowns plants,

depriving them of access to gases, suffocating them.

Chemical Pollution

Changes in soil structure and pH

Loss of organic matter from the soil


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Erosion

define- the removal of material from one place and its transport to another from wind or water.

Erosion can degrade ecosystems

Soil erosion is a global problem (dust bowl/Great Plains: TX, KS, NM, CO, OK)

Deposition - when eroded materials arrive at a new location and is deposited.

Erosion & deposition arenatural processes that can help soil in the long run.

Causesof erosion include:

Over cultivating fields w/ poor planning or excessive tilling

Over grazing rangeland with more livestock than the land can support

clearing forests on steep slopes or with large clear-cuts

Soil Mgmt. Techniques

Techniques help reduce impacts of conventional cultivation on soils and combat soil

degradation.

The worlds farmers have adopted various strategies to conserve soil.

Rotating cropssuch as soybeans and corn (a) helps restore/return soil nutrients and

reduce impacts of crop pests; consists of alternating the crops grown in a field from one

season to the next. Contour farming(b) reduces erosion on hillsides; consists of plowing furrows sideways

across a hillside, perpendicular to its slope and following natural contours of the land.

Terracing(c) minimizes erosion in steep mountainous areas; the transformation of

slopes into stairs allowing farmers to cultivate hilly land w/o losing huge amounts of soil

to water erosion.

Intercropping(d) can reduce soil loss while maintaining soil fertility; consists of planting

different types of crops in alternating bands or spatial arrangements.

Shelterbelts (aka wind breaks) (e) protect against wind erosion; rows of trees & tall

plants along the edge of fields slows wind down.

In (f), corn grows up from among the remains of a cover crop used in no-till

(conservation tillage) agriculture.


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Govt. Subsidies and Programs

Conservation Reserve Program- pays farmers to stop cultivating highly erodible cropland and

instead place it in conservation reserves panted w/ grasses & trees.

FAO - Food & Agriculture Organization

Agricultural subsidiesaffect soil degradation

*Food Production:

Water

Fertilizers - substances that contain essential nutrients

Pest Control

Pesticides - used to suppress pests and weeds

Insecticides, herbicides, fungicides

Pests evolve resistance to pesticides. Biological control pits one organism against another.

the enemy of my enemy is my friend

Integrated Pest Management (IPM) combines varied approaches to to pest control.

Through the process of natural selection (pp. 4649), crop pests may evolve resistance

to the poisons we apply to kill them. When a pesticide is applied to an outbreak of insect

pests, it may kill all individuals except those few with an innate immunity, or resistance,

to the poison (resistant individuals are colored red in the diagram). Those surviving


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individuals may establish a population with genes for resistance to the poison. Future

applications of the pesticide may then be ineffective, forcing us to develop a more potent

poison or an alternative means of pest control.

GMOs

Of the worlds genetically modified crops (a), soybeans constitute the majority so far. Of

the worlds nations (b), the United States devotes the most land area to GM crops.


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Animals

Different animal food products require different amounts of input of animal feed.

Chickens must be fed 2.8 kg of feed for each 1 kg of resulting chicken meat, for

instance, whereas 20 kg of feed must be provided to cattle to produce 1 kg of beef.

Producing different types of animal products requires different amounts of land and

water. Raising cattle for beef requires by far the most land and water of all animal

products.

Most meat eaten in the United States comes from animals raised in feedlots, or factory

farms. These locations house thousands of chickens (a) or cattle (b) at high densities.

The animals are dosed liberally with antibiotics to control disease.


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Organic & Local Food

Sales of organic food in the United States (a) have increased rapidly in the past decade, both in

total dollar amounts (bars) and as a percentage of the overall food market (line). Since the mid-

1990s in the United States (b), acreage devoted to organic crops and livestock has each

quadrupled, and the number of certified operations has more than tripled.

The average grocery store item travels 1,400 miles from its origin to your shopping cart.

This long distance transport consumes oil and contributes to pollution and climate

change.

Locally grown produce and locally made products cut down on the carbon footprint of

our food.

Make a difference

ask schools food director to buy locally grown produce

shop at farmers markets

partner w/ farmers in community supported agriculture programs

Corn-uses

Uses of corn include ketchup, peanut butter, Twinkies, cheese, cheez-its,salad dressing, jelly,

Coke, Sweet n' Low, syrup, juice, Kool-aid, batteries,charcoal, motrin, meats, feeding animalslike fish and cows, and fast foods.

The product containing corn that surprised me most was diapers!

Chapter 12 - Water

Freshwater locations

Only 2.5% of Earths water is fresh water. Of that 2.5%, most is tied up in glaciers and

ice caps. Of the 1% that is surface water, most is in lakes and soil moisture.

Water Cycle

Groundwater- water beneath the surface held within pores in soil or rock

groundwater is contained within aquifers, or porous sponge-like formations of rock, sand, or

gravel that hold water


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Surfacewater

Rivers

Lakes

Wetlands

Watershed

Benthic

Ocean

Surface & Vertical Currents

Thermohaline Circulation

El Nino

Coastal Ecosystems

Estuaries

Salt Marshes

Mangroves

Rocky Intertidal

Kelp

Coral Reefs

Human Water Usage Levees and Dams

Depletion/Overuse and Conservation

Water Pollutants

Great Pacific Garbage Patch

Drinking Water Treatment

Bottled Water

Wastewater Treatment

Artificial Wetlands

Commercial Fisheries

Aquaculture

bisci exam 2 study guide

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