ESM 300- Exam 2

Worldwide Population Growth Rate

Birth Rate - Death Rate Growth.

Crude Birth Rate

The number of live births in a year per 1000 (using the midyear population).

Regional Population Growth Rate

(Birth Rate + Immigration Rate) - (Death Rate + Emigration Rate).

Exponential Growth Rate

Growth at a constant rate of increase per unit of time. Sequence of numbers where each is a fixed multiple (fraction or exponent) of the previous one. Produces a geometric progression of numbers (ex. 1, 2, 4, 8, 16, 32, 64, …). Forms a J-shaped curve when graphed.

Neo-Malthusian Concepts

1. 850 million starving.

2. Exponential growth.

3. Not enough resources.

Cornucopian Concepts

1. Can feed everyone.

2. Down from 920 million.

3. Demographic transition.

4. Technology; thrive with challenges.

Demographic Transition

It states that as countries become industrialized and economically developed, their per capita incomes rise, poverty declines, and their populations tend to grow more slowly.

Age Structure Profile

Percentage of population (or number of people of each gender) at each age level in the population.

Green Revolution

Involves three steps. First, develop and plant monocultures of selectively bred or genetically engineered varieties of key grain crops such as rice, wheat, and corn. Second, produce high yields by using large inputs of water, synthetic inorganic fertilizers, and pesticides. Third, increase the number of crops grown per year on a plot of land through multiple cropping.

Chronic Undernutrition

Inadequate food energy intake (calories) for a long enough time to cause a harmful effect.

- Calories per person per day:

- Average need: 2200.

- World average: 2800.

- U.S. average: 3600.

Chronic Malnourishment

A nutritional imbalance caused by lack of specific dietary components or inability to absorb or utilize essential nutrients.

- 22 amino acids.

- 21 vitamins.

- 21 minerals.

- fats.

- carbohydrates.

Sustainable Agriculture

(regenerative farming) - goal is to produce food and fiber on a sustainable basis and to repair damage caused by destructive practices. Soil is essential to sustainable agriculture.

Disease

Is an alteration of a living body that impairs its functioning.

Hazard

Is something that can cause injury, disease, economic loss, or environmental damage.

Risk

Is the probability of suffering harm from a hazard that can cause injury, disease, death, economic loss, or damage. A risk is measured by an expression of chance (e.g., 1 in a million chance).

Toxicology

Is the study of the harmful effects of chemicals on humans and other organisms.

Desertification

The process in which the productive potential of topsoil falls by 10% or more because of a combination of prolonged drought and human activities such as overgrazing, deforestation, and excessive plowing, which expose topsoil to erosion.

Aquaculture

It is the practice of raising fish in freshwater ponds, lakes, reservoirs, and rice paddies, and in underwater cages in coastal and deeper ocean waters.

LD50

The dose of a toxin that is lethal to half the test population. Expressed in mg/kg. Less than 50 is a poison.

Bioaccumulation

An increase in the concentration of a chemical in specific organs or tissues at higher levels than normally expected. Involves persistent, fat-soluble chemicals.

Biomagnification

The increase in concentration of slowly degradable (persistent), fat soluble chemicals in organisms at successively higher tropic levels of a food chain or web.

Integrated Pest Management

Combined use of biological, chemical, and cultivation methods in proper sequence and timing to keep the size of the pest population below the size that causes economically unacceptable loss of a crop or livestock animals.

Even-Aged Forest Management

Primarily sun-loving species. To harvest the entire stand in one cut, and to naturally establish an even-aged, sun-loving forest stand.

Uneven-Aged Forest Management

Primarily shade tolerant species. Removal of just the mature and undesirable trees in an uneven-aged stand at relatively short, periodic intervals to produce the continuous establishment of shade tolerant reproduction.

Clearcutting

Clearcutting is the most efficient and sometimes the most cost-effective method for harvesting trees. It also provides profits in the shortest time for landowners and timber companies.

Grasslands

- Grass is Dominant Vegetative Type.

- Cover 29% of the Earth’s Land Surface.

- Offers Grazing and Browsing Opportunities.

- Provide 85% of Ruminant Forage Worldwide; 15% in US.

- Provide Habitat to Many Wildlife Species.

Tragedy of the Commons

An economic theory where individuals, acting in their own self-interest, overuse a shared resource, leading to its depletion and harming the group.

What is the current human population worldwide?

Over 8.3 billion people.

What is the current human population in the US?

333+ million people.

What is the current worldwide growth rate? Doubling time? Time to add 1 billion people?

The current worldwide growth rate is 0.85% - 0.87%. The doubling time is 77 to 82 years. The time to add 1 billion people is 14.1 years.

Name several of the elements leading to Demographic Transition.

1. Improved Public Health & Sanitation.

2. Advancements in Medicine.

3. Economic Development & Industrialization.

4. Education of Women & Female Empowerment.

5. Urbanization.

6. Family Planning & Contraception.

7. Lower Infant Mortality.

Is increased birth rate or decreased death rate more important in the expansion of the population now?

Decreased death rate.

How many humans today suffer from food insecurity and/or are chronically underfed?

850 million people.

What is the principal underlying cause of food insecurity worldwide?

Not a problem of too little food, but rather a problem of limited access and distribution due to poverty and social disruption.

How many people worldwide are overfed?

1.6 billion people.

What percentage of the Earth’s land surface is suitable for agriculture?

38% to 50%.

What are the benefits and concerns with using genetically modified organisms in agriculture?

Benefits:

1. Less inputs.

2. Increases yields.

3. Resistant.

Concerns:

1. Initial cost.

2. Trademark an organism.

3. Unknown consequences.

How much of the world’s food supply is produced in the US?

20%.

What percentage of the topsoil in the US has been lost in the last 200 years?

33.33%.

Name and describe the soil horizons.

O horizon- Leaf litter.

A horizon- Topsoil.

B horizon- Subsoil.

C horizon- Parent material.

Name and describe the soil conservation techniques used in agriculture.

1. No-Till or Conservation Tillage: This technique involves reducing or eliminating tillage (plowing) to prevent soil structure disruption and reduce erosion by wind and water.

2. Cover Crops: Crops such as cereal rye, oats, or clover are planted during off-seasons to cover the soil rather than leaving it bare.

3. Contour Farming: Planting crops in rows along the natural contour lines of the land, rather than up and down slopes.

What are the benefits and concerns of using pesticides?

Benefits:

1. Saves human lives.

2. Increases food supply.

3. Increases profit for farmers (versus organic?).

4. When properly used, health risks are very low relative to their benefits.

5. New pesticides are used at lower rates, are safer, and more effective than older ones.

Concerns:

1. Accelerates genetic resistance (natural selection).

2. Can kill natural controlling organisms.

3. Only 0.1% - 5.0% hit the target organisms.

4. Can threaten human health (Some 250,000 household and 300,000 agricultural related poisonings in the US per year).

5. Can harm wildlife (May kill 20% of US honey bee colonies each year).

Are more pesticides used in MDC’s or LDC’s?

MDC’s.

Describe the differences between a logger, a forester, and a silviculturalist.

A logger is an occupation that fells/cuts trees and transports them to a mill for further processing into final consumer products. A forester is a land manager responsible for all the goods, benefits, and services obtainable from forest land. A silviculturalist manipulates forest vegetation to accomplish a specific set of objectives.

Name the dominant woody vegetation found in forests.

Hardwoods such as oak, hickory, maple, beech, and birch, or conifers like pine, spruce, and fir.

List some of the goods, benefits, and services derived from forests.

Timber, paper, medicine, and food.

Describe the past and current level of forest cover on Earth.

Approximately 10,000 years ago, forests covered about 57% of Earth’s habitable land (6 billion hectares). Today, forests cover about 31% of the land surface (around 4 billion hectares).

Describe timber harvest in the US and worldwide.

In the US, it is a highly mechanized, regulated industry (primarily on private lands) that produces roughly 439 million cubic meters of roundwood annually. Globally, it ranges from sustainable, managed operations to deforestation in tropical regions.

In what area does most deforestation occur, and what are the major causes in the US and worldwide.

It mostly occurs in the tropics (Africa, South America). The major causes in the US and worldwide is agricultural expansion.

What are some advantages and some disadvantages to using meat as a food source?

Advantages:

- Nutrient Dense-Protein.

- Tastes good.

- We’re omnivores.

- Supports economy.

- Efficient food production.

- Consume entire planet.

- Make use of grasslands.

- Maintains biodiversity.

- Many grasses thrive under grazing.

Disadvantages:

- High fat content.

- Water use.

- Possible overgrazing.

- Off-site pollution.

- Methane production (CH4).

- Confinement.

- Competing with wildlife.

- Cattle don’t eat too much grain.

- Inefficient.

In what condition are public grasslands in the US?

A fragile, highly altered state.