Environmental Science
Chapter 8. Human Population Issues
Outline
World Population Characteristics
Factors Influence Population Growth
Standard of Living
Population and Poverty
Environmental Degradation
Conclusion
References
Chapter 8. Human Population Issues
Outline
World Population Characteristics
Factors Influence Population Growth
Standard of Living
Population and Poverty
Environmental Degradation
Conclusion
References
1. World Population Characteristics
The world can be divided into two based on economic development of the countries.
The developed countries have a per capita income that exceeds $US 10,000; the population 1.2 billion people.
The less developed countries have a per capita income of less than $US5000; the population 5.2 billion people, nearly 3 billion of whom live on less than $US2 per day.
More developed countries have stable populations and are expected to grow by about 4 percent by 2050. However, the less developed regions have high population growth rates and are expected to grow by about 55 percent by 2050.
Current population growth has led to:
Famine in areas where food production cannot keep pace with increasing numbers of people;
Political unrest in areas with great disparities in availability of resources;
Environmental degradation by poor agriculture practices;
Water pollution by human and industrial waste.
2. Factors Influence Population Growth
Humans influence by biological, social, and political factors.
Biological Factors: Demographers can predict future growth of a population by looking at several biological indicators. Currently, in almost all countries of the world, the birthrate exceeds the death rate. Therefore, the size of the population must increase.
Social Factors: It is clear that populations in economically developed countries of the world have low fertility rates and low rates of population growth.
Several factors influence the number of children a couple would like have (religious, traditional, social, and economic).
Political Factors:
Two other factors that influence the population growth rate of a country are government policies on population growth and immigration.
Many countries in Europe have official policies to encourage people to have children. In contrast, most countries in the developing world their population growth rates are too high.
China has family-planning policy began in 1971 with:
later marriages and
few children.
These policies resulted in reduction of birthrate by nearly 50 percent between 1970 and 1979.
In addition, one child campaign was begun in 1978-79. The program offered:
free medical care,
cash bonuses for their work,
special housing treatment and
extra old age benefits.
The immigration policies of a country also have a significant impact on the rate at which the population grows. The developed countries are under tremendous pressure to accept immigrant.
In the United States, approximately one-third of the population increase experienced each year is the result of immigration.
3. Standard of living
The standard of living is an abstract concept that attempts to quantify the quality of life of people. Several factors can be included in an analysis of standard of living:
Economic well-being;
Health conditions; and
The ability to changes one’s status in the society.
4. Population and Poverty
The human population is growing most rapidly are those that have the lowest standard of living.
Poverty,
High birthrate,
Poor health, and
Lack of education.
Poor people cannot afford birth control and they are often poorly educated. Therefore, they have more children than they may wish to have.
Poor people need to obtain income in many ways. This includes taking children out of school, so they are able to work on other jobs, but they are less paid.
Poor people have little access to health care.
Women in poor countries are usually poorly educated and not have disposable income. So, they are dependent on their husbands or family unit for their livelihood.
High infant mortality rates result from poor health, but children are desired by parents, because the sons will provide for parents when the parents are old.
At the United Nations International Conference on population and Development held in Cairo, Egypt, in 1994. Several important conclusions raised that:
There was recognition that economic well-being is tied to solving the population problem.
Improving the educational status of women was promoted.
Access to birth control and health care would reduce infant and maternal deaths.
5. Environmental Degradation
At the human population increases, the demand for food rises. People must either grow food themselves or purchase it.
Most people in the developed world purchase what they need and have more than enough food to eat.
Most people in the less-developed world must grow their own food and have very little money to purchase additional food.
When human need food, they convert natural ecosystems to artificially maintained agricultural ecosystems. If these agriculture ecosystems are mismanaged, the region’s total productivity may fall below that of the original ecosystem.
The current situation with respect to world food production and hunger is very complicated, it involves:
land, labor and machines;
appropriate crop selection; and
economic incentive,
political activities often determine food availability.
War, payment of foreign debt,
corruption, and
poor management often contribute to hunger and malnutrition.
Methods to increased food production:
Improved plant varieties,
Irrigation, and
Improve agriculture methods.
6. Conclusions
The world can be divided into two segments based on the state of economic development of the countries.
Humans influence by biological, social, and political factors.
Population growth cause environmental degradation.
7. References
Enger, E. D, & Smith, B. F, (10th Edition): Environmental Science: A Study of Interrelationship. Published by McGraw Hill Higher education (2006).
Botkin, D. B, & Keller, E. A : Environmental Science: Earth as a Living Planet. Published by Higher, W. (2004).
QUESTIONS (A)
What is demography?
What is demographic transition? What is it based on?
What is a baby boom?
What does the age distribution of population mean?
List 10 differences between your standard of living and that of someone in a less-developed country.
Why do people who live in overpopulated countries use plants as their main source of food?
Although predicting the future is difficult, describe what you think your life will be like in 10 years. Why?
List five changes you might anticipate if world population were to double in the next 50 years.
QUESTIONS (B)
Which three areas of the world have the highest population growth rate? Which three areas of the world have the lowest standard of living?
How many children per woman would lead to a stable U.S. population?
What role does the status of women play in determining population growth rates?
Describe three reasons why women in the less-developed world might desire more than two children.
Chapter 8. Human Population Issues
By Nam Leng
Environmental Science
Chapter 7. Population Principles
Outline
Population Characteristics
A population Growth Curve
Human Population Growth
Conclusion
References
Chapter 7. Population Principles
Outline
Population Characteristics
A population Growth Curve
Human Population Growth
Conclusion
References
1. Population Characteristics
A population can be defined as a group of individuals of the same species inhabiting an area.
Natality refers to the number of individuals added to the population through reproduction over a particular time period. It is usually described in terms of the birthrate, the number of individuals born per 1000 individuals per year.
The growth of a population is not determined by the birthrate (natality) alone.
Mortality, the number of deaths in a population over a particular time period is also important.
The population growth rate is the birthrate minus the death rate.
The population growth rate is usually expressed as a percentage of the total population.
In human population studies, the population growth rate is usually expressed as a percentage of the total population.
The population growth rate is greatly influenced by sex ratio and age distribution of the population.
The sex ratio refers to the relative numbers of male and female. It is typical in most species that the sex ratio 1:1. However, there are populations in which this is not true. In many social insect population(bees, ants, and wasps), the number of females greatly exceed the number of male at all times.
In humans, about 106 males are born for every 100 females. However, in the United States, by the time people reach their mid-twenties, a higher death rate for males has equalized the sex ratio.
The higher male death rate continues into old age, when women out number men.
The Democratic Republic of Congo’s population has a large prereproductive and reproductive component. This means that it will continue to increase rapidly for some time.
The United States has a very large reproductive component with declining number of prereproductive individuals. Eventually, if there were no immigration, the U.S. population would begin to decline if current trends in birthrates and death rates continued.
Germany has an age distribution with high postreproductive and low prereproductive portions of the population. With low numbers of prereproductive individuals entering their reproductive years, the population of Germany has begun to decline.
Population density is the number of organisms per unit area.
Populations have an inherent tendency to increase in size. At the simplest level, the rate of increase is determined by subtracting the number of individuals leaving the population from the number entering.
2. A Population Growth Curve
Population growth often follows a particular pattern:
Lag phase,
An exponential growth phase, and
A stable equilibrium phase.
During the first portion of the curve, known as the lag phase.
Since more organisms are reproducing, the population begins to increase at an accelerating rate. This stage is known as the exponential growth phase.
The death rate and the birthrate will come to equal one another, the population will stop growing and reach a relatively stable population size. This stage is known as the stable equilibrium phase.
3. Human Population Growth
The human population is increasing at a rapid rate.
The Earth’s ultimate carrying capacity for humans is not known.
The causes for human population growth are biological, social, political, philosophical, and theological.
4. Conclusions
A population can be defined as a group of individuals of the same species inhabiting an area.
At the simplest level, the rate of increase is determined by subtracting the number of individuals leaving the population from the number entering.
5. References
Enger, E. D, & Smith, B. F, (10th Edition): Environmental Science: A Study of Interrelationship. Published by McGraw Hill Higher education (2006).
Question
1. How is biotic potential related to the rate at which a population will grow?
2. List three characteristics populations might have.
3. Why do some populations grow? What factors help to determine the rate of this growth?
4. Under what conditions might a death phase occur?
5. List four factors that could determine the carrying capacity of an animal species.
6. How do the concepts of birthrate and population growth differ?
7. How does the population growth cure of humans compare with that of bacteria on a petri dish?
8. How do r-strategists and K-strategists differ?
9. As the human population continues to increase, what might happen to other species?
10. All successful organisms overproduce. What advantage does this provide for the species? What disadvantages may occur?
Chapter 7. Population Principles
By Nam Leng
Environmental Science
Chapter 6: Kinds of Ecosystems and Communities
Chapter 6: Kinds of Ecosystems and Communities
Questions
1. Describe the process of succession. How does primary succession differ from secondary succession?
2. How does a climax community differ from a successional community?
3. List three characteristics typical of each of the following biomes: tropical rainforest, dessert, tundra, taiga, savanna, Mediterranean shrub lands, tropical dry forest, grassland, and temperate deciduous forest.
4. What two primary factors determine the kind of terrestrial biome that will develop in an area?
5. How does height above sea level affect the kind of biome present?
6. What areas of the ocean are the most productive?
7. How does the nature of the substrate affect the kind of the organisms found at the shore?
8. What is the role of each of the following organism in a marine ecosystem: phytoplankton, zooplankton, algae, coral animals, and fish?
9. List three differences between freshwater and marine ecosystems.
10. What is an estuary? Why are estuaries important?
Answer
1. Describe the process of succession. How does primary succession differ from secondary succession?
• Ecosystems are dynamic, changing units. Decomposers recycle the chemical elements that make up the biotic portion of any ecosystem. Abiotic factors also have a major influence on the kind of community that will be established. Since all organisms are linked together in a community, any change in a community affects many organisms within it. Certain conditions within a community are keys to the kinds of organisms that are found associated with one another. Each organism has specific requirements that must be met in the community or it will not survive. Over long time periods, it is possible to see trends in the way the structure of a community changes and to recognize that climate greatly influences the kind of community that become established in an area. This series of changes result in a relatively long-lasting, stable combination of species that is self-perpetuating. The concept that communities proceed through a series of recognizable, predictable changes in structure over time is called succession.
• Primary succession differ from the secondary succession is that
- Primary succession is a succession progression that begins with a total lack of organism and bare mineral surfaces or water. It’s often takes long time, since there is no soil and few rapidly available nutrients for plants to use for growth.
- Secondary succession is much more commonly observed and generally proceeds more rapidly, because it begins with the destruction or disturbance of an existing ecosystem.
2. How does a climax community differ from a successional community?
• The relatively stable, long-lasting community that is result in the succession is called the climax community. The relatively stages is reached calls the climax community. The stages that lead to the climax are called successional stages.
3. List three characteristics typical of each of the following biomes: tropical rainforest, dessert, tundra, taiga, savanna, Mediterranean shrub lands, tropical dry forest, grassland, and temperate deciduous forest.
• Tropical rainforest:
- Temperature is usually warm and relatively constant
- No frost and it rains nearly everyday
- Plants grow rapidly, and many of the trees have extensive root networks.
• Dessert:
- Lack of water
- High evaporation rate
- Windy
• Tundra:
- Lack of trees
- has permanently frozen surface soil
- The plants there are short, less than 20 centimeters.
• Taiga:
- Short cool summer and long winter with abundant snowfall
- The trees are having needle-shape leaves
- Few animals
• Savanna:
- Prolonged drought
- The predominant plants are grasses
- The animal that live there are grazers
• Mediterranean Shrubland:
- Wet, cool winters and hot, dry summer
- Near the ocean
- The vegetation is dominated by woody shrubs
• Tropical dry forest:
- Monsoon climate
- Plants can enduring the drought
- The trees drop their leaves during the dry period
• Grassland
- Windy with hot summer and cold-to-mild winter
- Grass make 60 to 90 percent of vegetation
- Many grazer animals
• Temperate deciduous forest
- Winter-summer change of seasons
- Have trees that lose their leaves during the winter and replace the following spring
- Home to great variety of insects
4. What two primary factors determine the kind of terrestrial biome that will develop in an area?
• The two primary factors that determine the kind of terrestrial biomes that will develop in an area are temperature and precipitation.
5. How does height above sea level affect the kind of biome present?
• Biomes are terrestrial climax communities with wide geographic distribution. The distribution of terrestrial ecosystem is primarily related to precipitation and temperature. The temperature is warmest near the equator, and become colder toward the poles. Similarly, as the height above sea level increases, the average temperature decreases. This means that even at the equator, it is possible to have cold temperatures on the peak of tall mountains.
6. What areas of the ocean are the most productive?
• The area of the oceans that are most productive is the upper layer of the ocean known as euphotic zone.
7. How does the nature of the substrate affect the kind of the organisms found at the shore?
• The kind of the substrate determines the kinds of organisms that live near the shore. For example, rocks provide area for the attachment, that sand do not, since sand is constantly moving. Mud usually has little oxygen for the construction of new living organisms. In water, these are often in short supply.
8. What is the role of each of the following organism in a marine ecosystem: phytoplankton, zooplankton, algae, coral animals, and fish?
• Phytoplankton: is the planktonic organism that carries on photosynthesis.
• Zooplankton: It feeds on the large population of phytoplankton.
• Algae: provide both themselves and the coral animals with the nutrient for growth
• Coral animals: eat zooplanktons and algae as primary food source
• Fish eat the zooplankton and it is eaten by large fish such as shark, salmon, or tuna.
9. List three differences between freshwater and marine ecosystems.
• The nature of the bottom substrate
• The water temperature
• The amount of dissolved salt
10. What is an estuary? Why are estuaries important?
• An estuary is a special category of aquatic ecosystem that consists of shallow, partially enclosed areas where freshwater enters the ocean. Because the estuary is shallow that allows the sunlight to penetrate to most of the water in the basin. And the photosynthesis activity support many kinds of organisms in the estuary. Also, estuary is a nursery sites for fish and crustaceans such as flounder and shrimp. The adult enter these productive sheltered areas to reproduce and then return to the ocean.
Environmental Science Chapter 6: Kinds of Ecosystems and Communities
By Nam Leng
Environmental Science Chapter 5: Interactions: Environments and Organisms
Questions
1. Define environment.
2. Describe, in detail, the niche of human.
3. How is natural selection related to the concept of niche?
4. List five predators and their prey organism.
5. How is ecosystem different for a community?
6. Humans raising cattle for food is what kind of relationship?
7. Give examples of organisms that are herbivores, carnivores, and omnivores.
8. What are some different trophic levels in an ecosystem?
9. Describe the carbon cycle, the nitrogen cycle, and the phosphorus cycle.
10. Analyze an aquarium as an ecosystem. Identify the major abiotic and biotic factors. List members of the producer, primary consumer, secondary consumer, and decomposer trophic levels.
Answer
1. Define environment.
• The environment of an organism can be divided into living (biotic) and nonliving (abiotic).
- Living (biotic factors) of an organism’s environment include all forms of life with which it interacts.
- Nonliving (abiotic factors): energy, nonliving matter, and processes that involve the interactions of nonliving matter and energy.
2. Describe, in detail, the niche of human.
• Humans are the dominant organisms on Earth. Our niche is very broad and we interact in many ways with the organisms with which we share the planet. We can see that we have complicated interactions with other organism, and these interactions can be places into the same categories we use to describe relationships between nonhuman organisms. Human is a predator as we use animals as food. Humans are also relying on many kinds of plants as their primary source of food. Also many times, humans are raising the animals, feed the animals by using other sources found in nature such as plants or other animals as food to feed their live stocks. And humans are also plant the trees, or do farming. It is the concept that humans raise the animals or plants as a primary food source.
3. How is natural selection related to the concept of niche?
• Since the most the structural, physiological, and behavioral characteristics organisms display are determined by the genes they possess. As in the niche of an organism is the functional role it has in its surrounding. In the niche concept of the organisms is how it modifies its physical surrounding and how it is affect to the organism. So that is what it says in the natural selection. The species have to produce their next generation by passing the genes. And that genes which pass to the next generation has something to do with the niche of the organism which it has to adapt and to knows its surrounding and its profession.
4. List five predators and their prey organism.
• Lions eat zebra
• Wolves eat moose
• Toads eat flies
• Pelicans eat fish
• Snakes eat mouse
5. How is ecosystem different for a community?
• Two concepts that focus on relationships that involve many different kinds of interactions are community and ecosystem. A community is assemblage of all the interacting populations of different species of organisms in an area. Some species play minor roles, while others play major roles, but all are part of the community. Community consists of interacting populations of different species, but these species interact with their physical world as well. Ecosystem is defined space in which interactions take place between a community, with its entire complex interrelationship, and the physical environment. Many communities create an ecosystem of the Earth.
6. Humans raising cattle for food is what kind of relationship?
• A human is raising cattle for food is a Mutualism relationship.
7. Give examples of organisms that are herbivores, carnivores, and omnivores.
• Primary consumers also known as herbivores are animals that eat producers as a source of food such as leaf-eating insects, and seed-eating birds.
• Secondary consumers known as carnivores are animals that eat other animals such as eagles primarily eat fish, or lions primarily eat zebras.
• Omnivores are animals that eat both plants and other animals in their diet, such as bears, foxes, chickens. Etc.
8. What are some different trophic levels in an ecosystem?
• Each step in the flow of energy through an ecosystem is known as a tropic level. Producers (plants, algae, and phytoplankton) constitute the first trophic level.
• Herbivores constitute the second tropic level.
• Carnivores that eat herbivores constitute the third trophic level.
• Carnivores that eat other carnivores are the fourth trophic level.
9. Describe the carbon cycle, the nitrogen cycle, and the phosphorus cycle.
• Carbon Cycle: The carbon cycle includes the processes and pathways involved in capturing inorganic carbon-containing molecules, converting them into organic molecules that are used by organisms, and the ultimate release of inorganic carbon molecules back to the abiotic environment.
Nitrogen Cycle: involves the cycling of nitrogen atoms between the abiotic and biotic components and among the organisms in an ecosystem. Seventy-eight percent of the gas in the air we breathe is made up of molecules of nitrogen gas. However, the two nitrogen atoms are bound very tightly to each other, and very few organisms are able to use nitrogen in the form.
• Phosphorus Cycle: is different from the carbon and nitrogen cycles in one important respect. The ultimate source of phosphorus atoms is rock and release in nature by the erosion of rock and become dissolved in water. Plants use the dissolved phosphorus compounds to construct the molecules they need. Animal obtain the phosphorus they need when they consume plants or other animals. When the organism dies or excretes waste products, decomposer organisms recycle the phosphorus compound back into the soil.
10. Analyze an aquarium as an ecosystem. Identify the major abiotic and biotic factors. List members of the producer, primary consumer, secondary consumer, and decomposer trophic levels.
• Abiotic factors (nonliving) can be organized into several categories: energy, nonliving, matter, and process that involve the interactions on nonliving and energy.
• Biotic factors (living) of an organism’s environment include all forms of life and with which it interact.
- Producer: grass, algae, phytoplankton
- Primary consumer: grasshopper, larva, zooplankton
- Secondary consumer: rat, fish
- Decomposer: fungi, bacteria, insects, worms
Environmental Science Chapter 5: Interactions: Environments and Organisms
By Nam Leng
Women’s Studies
Chapter 3: Intersectionality and difference
Race, Class, and Gender
Contents
I. Introduction
II. Contest Over Difference
III. Race and the Birth of Intersectionality
IV. Ethnicity and Intersectionality
V. Conclusion
What is Intersectionality?
Intersectionality is the idea that multiple identities intersect to create a whole that is different from the component identities. These identities that can intersect include gender, race, social class, ethnicity, nationality, sexual orientation, religion, age, mental disability, physical disability, mental illness, and physical illness as well as other forms of identity
Women’s studies began with other unifying themes
Women share the same life stories of oppression
They simply lacked the rich individuality and wide-ranging capacities of men.
Women’s movement, it is now seen merely reverse the evaluation, making it positive.
What is the idea of “Difference”?
“Some differnces are playful; some are poles of world historical system of dominationFeminist theorist, Donna Haraway
Difference is the key to building coalitions across various interest groups.
II. Contests Over Difference
Difference means a point or way in which people or things are not the same.
In 1974 to 1980, the Combahee River Collective pointed the different of sexuality.
The problem by those of different sexualities, races, and the ethnic groups may be said to be superficial in comparison with the oppression of women generally.
II. CONTESTS OVER DIFFERENCE (Continued)
Contests over difference between men and women in United and Western
African had fewer rights in the new world that one advocated and one not advocated
In the West women wanted to be judge when men against to local tradition
The concepts of differences allowed women studies to examine issue of race, class, and gender from an integrated set of perspectives and thus fostered interdisciplinarity’s progress.
III. Race and the Birth of Intersectionality
Race is powerful in politics, economy, and society
In our modern age, geniticnists find only the tiniest difference so-called race.
o Skin color is indicating “race” and inescapable diffrence.
III. Race and the Birth of Intersectionality (Continued)
The awareness of race has become enriched with the use of “Critical theory”
Intersectionality is an idea initially devised by Kimberlé Crenshaw, a professor of law in the U.S. she explain how the intersectionality was born:
Different race conflict
Racial harm and gender harm
When the law does not recognize the interaction of exclusionary positions and identities, it is called Intersectionality.
Intersectionality is at work in everyday life.
A recognision of intersectioality allows for the crafting unique solutions to the variety of intersecting condition.
IV. Ethnicity and Intersectionality
Ethnic: referring to the origin, classification, characteristics, etc., of such groups.
- Many Africans maintain that ethnicity is far more powerful maker among African people.
- In European Balkhans, a mixture among people is difficult to tell on ethnic group from another.
- Ethnic cleansing is the distinct of one racial group.
IV. Ethnicity and Intersectionality (Continued)
The Botswana-born feminist author Bessie Head wrote movingly about ethnicity, race, and gender in her novel Maru (1971)
This novel intersectionality is at work as a mixture of race, ethnicity, and gender determines the outcome of the story and the fate of its characters.
Raping is consider as a “Normal” condition in women’s lives in the Western hemisphere.
Intersectionality has added to the understanding of such atrocities of the ethnicity.
V. Conclusion
Contest over difference
- Different point of views of women’s life
- needs challenged the mainstream scientific principle that there were universal laws and truths.
Race, birth of Intersectionality
- Different race conflict
- Racial harm and gender harm
Ethnicity
- Mixture of people from different ethnic groups
- Ethnic cleansing
Women’s Studies: Intersectionality and difference: Race, Class, and Gender
By Nam Leng
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