Ecosystems & Biodiversity
Describe habitat diversity.
the variety of different types of habitats within an ecosystem or pre-established area, contributing to overall biodiversity.
If there are 20,000 Kg of primary producers in the first trophic level, how much biomass can be supported in the second trophic level?
2,000 kg of animals/primary consumers.
Why is e-waste particularly dangerous to human health and the environment?
Contains heavy metals and toxic chemicals that leach into soil and water.
Which layer of the atmosphere contains the ozone layer?
Stratosphere
What farming practice leads directly to desertification when done excessively?
Overgrazing
Many believe more biodiversity always means a healthier ecosystem. What's one situation where that’s not true?
An introduced species may increase biodiversity but disrupt ecosystem function (e.g., invasive species).
OR
Depletion of soil nutrients in tropical rainforests.
Why does eating lower on the food chain reduce environmental impact?
Less energy is lost; more efficient use of primary productivity.
Which type of air pollutant is created from reactions in the atmosphere rather than directly emitted?
Secondary pollutants (e.g., ozone in troposphere, smog)
Name one greenhouse gas that has a higher global warming potential than CO₂.
Methane (CH₄), Nitrous oxide (N₂O), CFCs
Many students confuse urban sprawl with urbanization. What’s the key difference?
Urban sprawl is low-density expansion, populations moving away from cities into the suburbs usually due to poor urban planning.
Urbanization is population shift to cities, increasing population density in urban spaces and often improving efficiency of land use in city limits.
Invasive species are often misunderstood. What makes a species invasive?
NON-NATIVE organisms that harm an environment by establishing, reproducing quickly, and spreading, leading to negative ecological, economic, or human health impacts. They can cause the extinction of native species, destroy biodiversity, and permanently alter habitats.
Which biogeochemical cycle lacks an atmospheric component, leading to misconceptions about its mobility?
The phosphorus cycle
True or false: All biodegradable materials are safe for the environment. Why?
False – some produce methane or use up oxygen as they break down.
Describe the difference between weather and climate.
Weather is short-term, climate is long-term average conditions.
What is the replacement level fertility rate in a population and what number is considered the standard replacement level?
The total fertility rate at which a population exactly replaces itself from one generation to the next. The standard replacement level is generally considered to be 2.1 children per woman. This figure is a standard, but it can vary based on mortality rates and other factors.
Which happens faster, primary succession or secondary succession, and why?
Secondary succession is faster because the soil is already established.
Students often mix up aerobic and anaerobic respiration. What is the main difference between aerobic respiration and anaerobic respiration?
Aerobic respiration uses oxygen and releases carbon dioxide. Anaerobic respiration occurs in a hypoxic environment, where oxygen is not available, and releases methane.
Describe the greenhouse effect.
A natural process where the Earth's atmosphere traps heat, keeping the planet warm enough for life. Some of the infrared radiation from the Sun passes through the atmosphere, but most is absorbed and re-emitted in all directions by greenhouse gas molecules such as carbon dioxide, methane, and water vapor/clouds. The effect of this is to warm the Earth's surface and the lower atmosphere. This process is essential for maintaining a habitable temperature on Earth.
Why do some regions get cooler in the short term even as global temperatures rise?
Disruption in ocean currents and wind patterns can cause increased cloud cover/precipitation can cause regional cooling.
Why can subsidies for agriculture lead to overuse of natural resources?
Encourages overproduction, overuse of water, fertilizer, and land.
Students often forget the major cause of species endangerment. What is it?
habitat destruction - often due to urbanization, expansion of agricultural areas, unsustainable/excessive harvesting of resources such as lumbe, or global climate change causing shifting biome ranges.
What process in the nitrogen cycle releases nitrogen back into the atmosphere, and when this occurs, what nitrogen compound is released?
Denitrification; Nitrous Oxide (N2O)
Describe the type of ecosystem is most commonly affected by non-point source pollution?
Wetlands, bays, aquatic ecosystems at the end of watersheds with extensive urbanization.
What is a major misconception about the role of volcanoes in climate change?
Volcanic eruptions release carbon dioxide (CO₂) but also have a short-term cooling effect primarily due to the reflection of sunlight by sulfate aerosols.
(While volcanoes do emit CO₂, the amount is typically a small percentage of the total global CO₂ emissions from human activities, and the CO₂ released by volcanoes doesn't lead to detectable global warming.
Instead, sulfur dioxide (SO₂) released from volcanoes reacts with water to form sulfate aerosols in the stratosphere, which reflect incoming solar radiation and cause a temporary cooling effect.)
Why is it incorrect to assume deforestation only impacts local ecosystems?
Deforestation contributes to global climate change and biodiversity loss worldwide due to reduced carbon sequestration, and the release of carbon dioxide from the dead organic matter as well as air pollutants from biomass combustion if the deforested material is burned.