type of biome

Deforestation in Costa Rica

Most direct use - Wood

without involving destruction:

Latex extraction 

Outranks the use of most other natural resources

Monoculture Forestry

(aka Plantation Forestry) 

type of reforestation  - only one species grown

example: Brazil

2% of forests (monoculture) produces approx. 50% of demanded product

*Criticized for extracting wood from native land (drastically less efficient) 

Intensive Forestry

more efficient

Ideal: Sustainable Efficiency

protects natural land;

still producing demand but effieciently

Causes of Tropical Deforestation

Logging for valuable hardwoods (Mahogany)

Clearing land (Cattle ranch & exported crops)

ie: bananas & pineapples 

burning of vegetation to release natural resources which assist growth of farm productivity 

(worked with low population)

Now the amount of people using land rises, so Slash and Burn could lead to deforestation

Major problem : changing area to non-forest for people

Destruction of habitat : leads to increased soil erosion from rain (namely tropical rainforest)

Waste of resources : could have been valuable exported somewhere instead of burned

Too much Poor-quality food

(issue in malnutrition)

Greatest Threats to "Food Security"

(ability to obtain enough food daily)

Poverty

Lack of Social Status 

55% of the 12 million child deaths(per year)

More than 800 million (200million = children) are chronically undernourished

- receive < 90% minimum caloric intake

Most Hungry: East/South Asia

- also in Africa:  Tanzania & Ehiopia

Large-scale food shortages

Massive Starvation

Social Disruption

Economic Chaos 

Causes of Famines

Economic

 -price gouging

-landlessness

Environmental

-drought

-insects

-natural disasters

Political

-war

-oppression using famine as weapon

Nutritional imbalance caused by:

- a lack of specific dietary components

or 

- inability to utilize essential nutrients

Iron deficiency (India)

- anemia. (little oxygen in blood)

affects physical and mental development 

- most common dietary deficiency in world

-most extreme in India

 Iodine Deficiency

- hyperthyroidism / goiter

Protein Deficiency:

Kwashioker 

-inflated belly disease occuring from lack of protein

Marasmus

"wasting away" sunken eyes, shriveledness, extreme thinness

Most common dietary problem in Wealthy Countries

US:

61% adults

Russia:

54% adults

United Kingdom:

51% adults

Germany:

50% adults 

THREE

rice, corn, wheat

these 3 produce > 50% world's food

Rice

this deficiency in poor countries causes blindness and a million child deaths each year

Genetic engineering - Europe

found "cure" in daffodils 

Animal Protein

Milk, Meat, Seafood

provides smaller amount of world food supply

90% grain produced is used to feed animals for Milk and Meat, but 20% of world consume 80% of meat/milk

important source of protein

overharvesting / habitat destruction has resulted

Southeast Asia - destruction of wetlands for shrimp dependency

Environmental Issues Raising cattle

Loss of food from feeding cattle

Feedlots: 

Manure

- produces methane

Scrap meat in food: Cannibalism

- spread of Prions (proteins which lead to neurological disease and spreading of TSE

leading to TSE or Mad Cow Disease 

Complete Mixture of:

*Weathered minerals *partially decomposed organic matter and a  *host of living organisms

Non-renewable resource

Complex living substance

20,000 types of soil

topsoil = most fertile part of the soil 

 rate lost > rate to replace

Land Resources

Average of 0.7 acres of cropland per person

 in 25 years estimated to be 0.42acres/person

land conversion = ecological trade off

refuges/reserves/etc 

Most serious threat to soil degradation

-topsoil removed & transported elsewhere

reduces crop production by 1% each year

Natural Process

gravity,wind,water

 Wind and Water

1) Sheet Erosion

Thin, uniform layer of soil removed

* 2) Rill Erosion *

                                    most common                                        small rivulets of water cut small channels into soil

3) Gully Erosion

Rills enlarge and forme small stream (torrent) and moves water deeper into the profile.  These channels are too large to remove through tillage

4) Streambank Erosion

Washing away the soil from an established stream bank

US and Canada have high erosion rates

leave soil exposed to wind (erosion)

intensive farming practice

**US and Canada 

important agricultural resource

Huge costs - irrigation

80% water drawn never reaches intended destination

Extremely important in Northwest (apples) 

important and Limited agricultural resource

Over-fertilization can harm or pollute

Three essential elements:

Nitrogen

Phosphorous

Potassium

90% never reach target  area

Precision agriculture

exciting new area of research

Crops w/o pesticides have lower yield, but also lower costs and eco damage 

Genetic Engineering

Splicing of a gene

from one organism into the gene of another

produces a GMO aka transgenic

GMOs Currently:

1/3 soy beans & corn 

60% all processed foods

increase costs could hurt small farmers 

Sustainable agriculture

"Regenerative Farming"

*Soil is essential

Goal: Produce food and fiber  w/o destructive agricultural processes

Important elements in conservation: 

Land management

Ground Cover

Climate

Soil Type

Tillage Systems 

*Dependent on maintaining groundcover

Contour

plowing/planting with contour across slope

slows water flow

Strip-farming

planting different crops in alternating strips along the contours

Terracing

Shaping land to create level shelves

also with contour to hold water

*Also planting perennials (live>2years) 

1960 famine China - Great Leap Forward

-plowed terraces

*no longer held water

food productivity didn't restablize until terraces were  rebuilt

Most important Factor of 

Long-term Sustainable Agriculture

Keeping area vegetative

(bare soil has higher erosion rates)

**Also need water availability

Reduced tillage methods

one of the greatest advances in

sustainable agriculture

dead vegetation is left on ground

acts as mulch

Reduces:

efforts of plowing

runoff (soil erosion)

Ground Cover

holds & protects soil

ie: Alfalfa and clover fix nitrogen in soil

can be harvested for hay 

 ie: Mulching - can prevent erosion and insulate plants

Reduced Tillage:requires more pesticides

1) Minimum Tillage - reduces #times soil is turned 

chisel plow/ridge tilling

2) Conserv-tilling - sharp blade "Coulter"

very little soil disruption 

3) No-tilling - drilled directly through mulch/ground cover 

Environmental Health Hazards

Involve Introduction of pollutants to:

Air, water, soil, & food

**Air pollution has received much attention

-US Clean Air Act (decent job) 

state of well-being

physical, mental, social 

deleterious change in the bodies condition

therefore cannot deal with some

environmental factor(s)

presence of illness

(in a population) 

presence of death

(in a population) 

#1 Worldwide:

Cardiovascular disease

-failure of heart to move blood through body 

Others:

*Cancer(s)

*AIDS

*Malaria

*Diarrhea

(among infants) 

Ebola (Africa)

Buruli Ulcer (W.Africa)

West Nile

Factor that contribute to the

Spread of Contagious Disease

High population densities

-easier to move from person to person

Isolated Groups

-haven't developed basic immunities to othe diseases
 -native americans

Environmental Change

global warming

Speed of travel

stress decreases resistance

travel allows disease to pass geographical barriers

Contamination of Food & Water 

Penicillin

not as effective anymore 

Disease-causing protozoa 

*Malaria

now resistant to most antibiotics

Pesticide Resistance:

Malaria-carrying mosquitos

resistance developed against pesticides

PCBs

chemicals that affect immune system

 -reduce ability to fight disease

Hazardous chemical substance

cause mutations (affecting fetus)

ie: alcohol

Fetal Alcohol Syndrome

substances that cause/aggravate cancer

1) Arsenic

2) Lead

weights in fishing lures 

3) Mercury 

Study of Toxins

how they may harm humans/organisms 

dilute toxins in the environment

-can reach dangerous levels inside cells & tissues

Effects of toxins

*seen through food web

small concentration of toxins increase as we move up through the food chain

ex - DDT and the American Bald Eagle 

LD 50 Factor (lethal dose)

measures toxicity of substance

lethal = 50% population dies

DDT's LD 50 = 50mg/kg

*wont be immediate lethal impact, but we can see from historical evidence DDT effected humans 

Measuring Toxicity

Animal Testing

*can be quite inhumane

*can be unreasonable to compare

-animals & humans have different immunities 

 *can be time consuming

- toxic effects can take years to appear 

Y-axis

#individuals first responding

X-axis

Dose 

Bell shaped 

Acute Effect

immediate health effect

caused by single exposure to toxin

Can be reversible

ie: You swallow Rat Poison but you're okay 

long lasting or permanent effect

caused by:

1) single exposure to very toxic substance

2) continuous or repeated sub lethal exposure to a toxin 

Probability of

Harm x Exposure

*Biggest daily Risk = Driving

Risks change with perception

-therefore difficult to measure 

Earth's Lower Atmosphere: 

Nitrogen - 78%

Oxygen - 21%

Argon - <1%

*Carbon Dioxide extremely important, but low concentration

Troposphere

Humans live

Stratosphere

Ozone Layer

Mesosphere

&

Thermosphere 

*divided by absorbtion of solar energy

50% Sun's energy reaches Earth

Energy absorbed by Earth's surface:

-changed into lower quality heat energy which is re-emitted as infrared energy

*because of Cloud Cover,

- this infrared energy is reflected back to surface to repeat same step

*cause of greenhouse effect / warming

Vertical Convection Currents

causes variation in temperature

occurs because of shift in Earth's tilt, change in orbit, and wobble along axis.

Kyoto Protocol

Treaty setting limits on greenhouse gases for individual nations

*Based on output before 1990 

Secondary pollutants

reduce local air quality

physically separates large solids from waste stream

(sewage treatment) 

(sewage treatment)

aerobic bacteria breakdown dissolved

organic compounds 

(sewage treatment)

removal of plan nutrients

(such as nitrates and phosphates) 

from the secondary effluent

(chemicals, or natural wetlands)