5A4 Humans and Ecosystems

Question 1

What is an ecosystem?

Answer 1

It consists of the living and non-living things that interact with one another in a particular location.

Question 2

What is a balanced ecosystem?

Answer 2

An ecosystem that maintains:

• stable population sizes.
• efficient nutrient cycling.
• consistent energy flow between organisms and their environment.

Question 3

Define an unbalanced ecosystem.

Answer 3

When the stability of an ecosystem is disrupted by natural or human disturbances.

Question 4

What are natural disturbances?

Answer 4

Disturbances with natural forces, such as hurricanes, wildfires, floods, or droughts—that disrupt the structure or function of an ecosystem.

Effects are usually temporary and the ecosystem will eventually recover.

Examples Include:

• Fires
• Diseases
• Severe storms
• Insects
• Volcanic activity
• Earthquakes
• Long-term freezing

Question 5

What are human disturbances?

Answer 5

Disturbances caused by people, such as chemical pollution and urbanization.

Examples include:

• Deforestation
• Mining
• Light or noise pollution

Question 6

How do human disturbances affect ecosystems?

Answer 6

They can introduce non-native species, disrupt ecosystems, and cause pollution and climate change, placing undue pressure on ecosystems to adapt.

Question 7

What are the three categories of habitat destruction caused by human activities?

Answer 7

• Destruction
• Degradation
• Fragmentation

Destruction: Occurs when the ecosystem is completely transformed over a short period of time.

Degradation: Human activities cause gradual loss of wild species.

Fragmentation: Artificial barriers are placed in an ecosystem preventing the movement of organisms.

Question 8

What are the causes of habitat destruction by human activities?

Answer 8

• Conversion of land for agriculture and livestock.
• Infrastructure development.
• Urbanization.
• Harvesting of natural resources.
• Industrial installations.

Question 9

What are the effects of animal habitat loss?

Answer 9

• Loss of vegetal cover.
• Displacement of species.
• Uncontrolled reproduction of exotic species.
• Climate change impacts.

Question 10

What are effects of habitat destruction?

Answer 10

• Alters populations of plant and animal species.
• Causes loss of biodiversity.
• Increases pollution.
• Influences Earth’s climate change.

Question 11

What is pollution?

Answer 11

The act of a harmful or damaging substance being released into the environment.

Question 12

What are the five recognized categories of pollution?

Answer 12

• Air
• Land
• Water
• Noise
• Light

Question 13

Define physical pollution.

Answer 13

When materials or objects are introduced into the environment, causing toxicity or harm.

Primary type of physical pollution is litter.

Question 14

Define:

chemical pollution

Answer 14

The release of harmful chemicals into soil, air, or water due to human activity.

Examples include:

• Mercury
• Volatile organic compounds (VOCs)
• Carbon Monoxide
• Sulfur Dioxide

Question 15

Define:

biological pollution

Answer 15

Naturally occurring biological substances that negatively impact human health

Examples: allergens or pathogens

Question 16

What is biological pollution of water?

Answer 16

The buildup of biologically derived substances in water, such as bacteria or fungus.

Question 17

What is environmental pollution?

Answer 17

Anything released into the environment that can cause harm.

Question 18

What is acid precipitation?

Answer 18

Precipitation that has increased in acidity caused by environmental factors and can cause damage to buildings and living creatures over time.

Question 19

What are the main culprits in the formation of acid precipitation?

Answer 19

Sulfuric and nitric acids.

Question 20

How can acid precipitation affect human health?

Answer 20

Exposure to acid precipitation can contribute to respiratory illnesses such as bronchitis and asthma.

Question 21

What is the ozone layer?

Answer 21

A protective gaseous layer in the atmosphere.

Human life on Earth is made possible in part by the ozone layer.

Question 22

How is the ozone layer protective?

Answer 22

It plays an important part in filtering the sun’s radiation.

Without the ozone layer, the UV rays from the sun would be too strong for human and plant life to thrive.

The sun’s radiation is known as ultraviolet (UV) rays.

Question 23

What are some potential health risks associated with too much exposure to UV rays?

Answer 23

• Sunburn
• Skin cancer
• Glaucoma

Question 24

What is the chemical composition of ozone?

Answer 24

Three oxygen atoms.

(O-O-O)

This is reflected as 𝑂3.

Question 25

Where is the **ozone layer located**?

Answer 25

About **10-30 miles from Earth's surface** in the stratosphere. ## Footnote 90% of the Earth's ozone is found here.

Question 26

How is **ozone distributed globally** in the stratosphere?

Answer 26

* Lower densities near the tropics. * Higher densities as you travel toward higher latitudes near the poles.

Question 27

What can **destroy atmospheric ozone**?

Answer 27

Reactions with **chloro-fluoro-carbons (CFCs)** or nitrogen dioxide (NO₂).

Question 28

How long do **CFCs** remain in the atmosphere?

Answer 28

About 30-150 years.

Question 29

Is **ground-level ozone** harmful?

Answer 29

Yes ## Footnote Too much ozone is harmful to the human body leading to increased respiratory issues, cancer, etc.

Question 30

What can **ozone gas** near a factory create in the air?

Answer 30

Smog

Question 31

What is a good way to **assess ozone levels** and other environmental pollutants before going outside?

Answer 31

Checking the **EPA Air Quality Index**. | (AQI)

Question 32

What is the goal of the **Montreal Protocol**?

Answer 32

To **reduce CFC production** by at least 50%. ## Footnote Use and production of CFCs has decreased by 95% since the 1980s.

Question 33

What is **climate change**?

Answer 33

**Long-term changes in Earth’s temperature and weather patterns**, largely driven by human activities such as fossil fuel use and deforestation.

Question 34

What are some examples of the **effects of climate change**?

Answer 34

* Increases in ocean temperatures. * Reduction in ice sheets found in the Antarctic and Greenland. * Rising ocean levels. * Loss of biodiversity.

Question 35

What is the **greenhouse effect**?

Answer 35

A natural process essential for maintaining warmth on the planet.

Question 36

What are **greenhouse gases**?

Answer 36

* Fluorinated gases * Methane * Carbon dioxide * Nitrous oxide

Question 37

What has led to a **significant increase in greenhouse gases** trapped in the Earth's atmosphere?

Answer 37

Human activity and the use of fossil fuels such as coal, natural gas, and oil.

Question 38

What is **global warming**?

Answer 38

Refers to the **increases in temperature** observed on Earth since the start of the Industrial Revolution during the mid-nineteenth century, representing a long-term warming trend primarily attributed to human activities such as the use of fossil fuels. ## Footnote Over the past 40 years, Earth’s average temperature has increased by approximately 1°C (2°F).

Question 39

What are some of the **negative effects** of global warming?

Answer 39

* 2°F or 1°C increase in global temperatures. * Melting of polar ice caps and glaciers. * Extinction of various plant and animal species due to habitat loss. * Increases in natural disasters and the strength of storms. * Nearly 7-inch increase in sea levels over the past 100 years.

Question 40

What is the process called when carbon dioxide dissolves in seawater and **forms carbonic acid, lowering the pH of the seawater**?

Answer 40

Ocean acidification ## Footnote The natural pH of the ocean is approximately 8.2.

Question 41

What is the ocean's role in the **carbon cycle**?

Answer 41

A **sink** for atmospheric carbon dioxide. ## Footnote Atmospheric carbon dioxide is absorbed by the ocean.

Question 42

What is the ocean's way of regaining equilibrium when more carbonic acid and H+ ions are formed due to increased carbon dioxide dissolved in seawater?

Answer 42

Dissolving the calcium carbonate in the shells of sea creatures therefore weakening their shells.

Question 43

What is an **introduced species**?

Answer 43

Also called alien species, they are those that have been **moved by humans to an environment where they didn't occur naturally**. ## Footnote Introduction of a species can be accidental or deliberate. Examples: brown rats, kudzu, zebra mussels.

Question 44

What are some reasons for **deliberate** species introduction by humans?

Answer 44

* Conservation efforts. * Population control of native species. * Boosting agriculture and fisheries. * Human enjoyment.

Question 45

What are some ways of **accidental** introductions of species?

Answer 45

* Black rat spreading through ship cellars. * Species introduced through water discharged by cruise ships and tankers. * Species stuck to travelers' clothes and shoes. * Species introduced in imported wood and food.

Question 46

What makes a species **invasive**?

Answer 46

A species introduced to a **non-native environment** that causes harm by **outcompeting native species for resources**. ## Footnote Examples of invasive species include: * Lionsfish * Zebra Mussels * Quagga Mussels * Purple loosestrife

Question 47

What is one of the most **important solutions** to the invasive species problem?

Answer 47

**Preventing** the introduction of new invasive species into the environment.

Question 48

What is **overconsumption**?

Answer 48

The use of a region's resources to such an extent that they **cease to be replenishable** and eventually depleting Earth’s supply of oil and natural gas. ## Footnote These resources can include food, water, natural minerals, natural gas, and clean air. An example of overconsumption is the consistently increasing human need to consume oil and natural gas. If the rate continues to increase, eventually the Earth's supply of oil and natural gas will run out and not be available to anyone.

Question 49

What is an **ecological footprint**?

Answer 49

A measure of the environmental impact of an individual or population based on **resource consumption and waste production**.

Question 50

What is **environmental remediation**?

Answer 50

Refers to the processes involved in **reducing contaminants in the environment**. ## Footnote This includes air, water, and soil contaminants.

Question 51

What are the **benefits** of environmental remediation?

Answer 51

* Improvements in human health. * Enhanced water systems. * Increased land productivity. * Effective pollution control. * Overall ecosystem health.

Question 52

What is one method of environmental remediation that involves **allowing forests to regrow**?

Answer 52

Reforestation ## Footnote This occurs when efforts are put in place to allow forests to regrow, either by replanting or setting restrictions to prevent complete removal.

Question 53

What is a **movement corridor** in the context of environmental remediation?

Answer 53

An area that **connects isolated wildlife habitats** to allow inhabitants to move between areas and provide necessary resources.

Question 54

How do **captive breeding programs** contribute to environmental remediation?

Answer 54

They create controlled environments to **preserve species facing decline or extinction**, helping to increase populations and balance ecosystems.

Question 55

What is **biotechnology's** role in environmental remediation?

Answer 55

The use of molecular biology can aid in the removal of contaminants and provide insights into environmental processes.