APES Unit 5 Review

What is the 'Tragedy of the Commons'?

The tendency for individuals to overexploit shared, public resources for self-interest, leading to their degradation.

What are externalities in the context of resource use?

Unintended negative side-effects of human actions that are not reflected in the market price of a resource.

What is the primary difference between an ecological footprint and a carbon footprint?

Ecological footprint measures land area required (gha), while carbon footprint measures tonnes of CO2 produced.

What does a global hectare (gha) represent?

A biologically productive hectare, equivalent to 2.47 acres.

How does affluence typically affect an individual's ecological footprint?

It increases the footprint due to larger housing, more travel, and higher consumption of material goods.

What is the Green Revolution?

A shift in agriculture from small-scale farming to large-scale industrial agribusiness using mechanization, GMOs, and chemicals.

What is a major negative environmental impact of agricultural mechanization?

Increased reliance on fossil fuels and soil compaction from heavy machinery.

What is the primary benefit of using GMO crops?

Increased profitability and yield through traits like drought tolerance, pest resistance, and faster growth.

What is a significant risk of relying on genetically identical GMO crops?

Reduced genetic diversity, making the crop more susceptible to diseases or pests.

What is the process of eutrophication caused by synthetic fertilizers?

Excess nitrates and phosphates wash into water bodies, causing algae blooms that deplete oxygen.

What is soil salinization?

The increase of salt levels in soil, often caused by overwatering during irrigation.

What are the negative effects of pesticides on non-target species?

Runoff can kill beneficial organisms like bees, thin bird eggshells (e.g., DDT), or cause reproductive issues in amphibians.

What is monocropping?

The agricultural practice of growing a single species of crop over a large area.

Why does tilling increase soil erosion?

It loosens topsoil and breaks up root structures that otherwise hold the soil in place.

What are the environmental consequences of slash and burn agriculture?

Deforestation, loss of biodiversity, and the release of greenhouse gases like CO2 and N2O.

What is the most efficient method of irrigation?

Drip irrigation, which is over 95% efficient.

What is furrow irrigation?

A method where trenches are dug along crops and filled with water; it is approximately 66% efficient.

What is the primary disadvantage of flood irrigation?

It can waterlog the soil, drown plant roots, and is disruptive to the field.

What is the role of the Bureau of Land Management (BLM) in the US?

It manages western rangelands by collecting grazing fees and mitigating overgrazing effects.

What is the current average global ecological footprint in terms of Earths?

1.85 Earths, meaning humanity consumes 1.85 times what the planet can produce annually.

How does a plant-based diet affect an ecological footprint?

It decreases the footprint because meat production requires significantly more land, water, and energy.

What is the purpose of the Clean Air and Clean Water Acts?

To provide regulatory frameworks and penalties to prevent the pollution of shared public resources.

What is 'leaching' in the context of synthetic fertilizers?

The process where water carries excess nutrients through the soil into groundwater or surface runoff.

What is the main difference between synthetic and organic fertilizers regarding soil health?

Synthetic fertilizers do not return organic matter to the soil, whereas organic fertilizers (like manure) do.

What is the primary benefit of using Bt corn?

It is genetically modified to produce a protein that kills specific corn pests, reducing the need for external pesticide application.

What is the primary advantage of spray irrigation over flood or furrow irrigation?

It is more efficient with less water loss.

What is the main cause of waterlogging in soil?

Overwatering fills all soil pore space with water, preventing oxygen from reaching roots.

How does soil salinization occur?

Water used for irrigation contains small amounts of salt; as the water evaporates, the salt remains and builds up in the soil.

What is the difference between unconfined and confined aquifers regarding recharge?

Unconfined aquifers recharge quickly, while confined aquifers are long-term deposits that recharge slowly.

What is saltwater intrusion?

Excessive pumping near the coast lowers water table pressure, allowing saltwater to seep into groundwater.

How does pesticide overuse lead to resistant pest populations?

Pesticides artificially select for resistant individuals by killing non-resistant ones, leaving only those with resistant traits to reproduce.

What is the purpose of Bt corn?

It is genetically modified to contain a bacterial gene that produces crystals toxic to pests.

What is a major risk of using genetically identical (clone) GM crops?

Lack of genetic diversity makes the entire population vulnerable to a single disease or pest.

What is Integrated Pest Management (IPM)?

A strategy using a variety of pest control methods to minimize environmental disruption and pesticide use.

What is biocontrol in agriculture?

Introducing a natural predator, parasite, or competitor to control pest populations.

How does crop rotation help manage pests?

It disrupts the life cycle of pests that prefer specific crops by changing the food source each season.

What is the 'push-pull' system in intercropping?

Using 'push' plants to repel pests and 'pull' plants to attract pests away from the main crop.

What is a CAFO?

A Concentrated Animal Feeding Operation where animals are densely crowded and fed grain to maximize growth and profit.

What are the environmental risks associated with manure lagoons?

They can overflow during heavy rain, contaminating water with ammonia, hormones, antibiotics, and E. coli.

What is the primary cause of desertification in overgrazed areas?

Removal of vegetation and soil compaction by animals, which prevents the soil from holding water.

Why is meat production considered less efficient than plant production?

It requires significantly more energy, land, and water to produce the same amount of food.

What is a fishery collapse?

When overfishing causes a 90% decline in a fish population, often leading to permanent loss.

What is the 'Tragedy of the Commons' in the context of fishing?

The lack of incentive or penalty to prevent overfishing, leading to the depletion of a shared resource.

What is bycatch?

The unintended capture of non-target species, such as dolphins or turtles, during fishing operations.

Why is bottom trawling considered environmentally harmful?

It destroys coral reef structures, increases turbidity, and results in high levels of bycatch.

What is the main benefit of free-range grazing compared to CAFOs?

Waste is dispersed naturally as fertilizer, and animals grow at a natural rate without needing antibiotics.

What gas is produced by the denitrification of ammonia in manure?

Nitrous oxide (N2O), a powerful greenhouse gas.

How does rotational grazing benefit the land?

It prevents overgrazing and distributes manure evenly, which can stimulate grass growth.

What is the primary drawback of implementing IPM?

It is often more time-consuming and costly than traditional pesticide application.

What is a cone of depression?

A drop in the water table caused by excessive pumping, which can dry out nearby wells.

What is the difference between a herbicide and an insecticide?

Herbicides kill plants (weeds), while insecticides kill insects.

What is the phenomenon of 'fishing down the food web'?

The process of moving to smaller fish species as large, predatory fisheries are depleted.

Define 'ore' in the context of mining.

Commercially valuable deposits of concentrated minerals that can be harvested as raw materials.

What is 'overburden' in mining?

The soil, vegetation, and rocks removed to access an ore deposit below.

What are 'tailings' and 'slag'?

Waste material separated from the valuable metal or mineral within ore.

Why is subsurface mining generally more expensive than surface mining?

Due to higher insurance costs, healthcare costs for workers, and the need for complex ventilation and safety infrastructure.

What is 'acid mine drainage'?

The process where rainwater leaks into abandoned mines and mixes with pyrite to form sulfuric acid.

What is the primary goal of mine reclamation?

To restore land to its original state after mining, including filling shafts, restoring contours, and replanting native vegetation.

How does urbanization affect groundwater?

Impervious surfaces like concrete prevent water infiltration, which stops groundwater recharge.

What causes saltwater intrusion in coastal cities?

Excessive groundwater withdrawal lowering the water table and sea level rise contaminating fresh groundwater.

What is 'urban sprawl'?

The movement of population from dense urban centers to less dense suburban areas.

What is 'mixed land use' in urban planning?

The integration of residential, business, and entertainment buildings in the same area to enable walkability.

What are the primary soil impacts of clearcutting?

Increased soil erosion, loss of organic matter, and compaction from heavy machinery.

How does clearcutting affect stream temperature?

Loss of tree shade along rivers and increased sediment turbidity both lead to warmer water temperatures.

What is a major disadvantage of tree plantations compared to natural forests?

Lower biodiversity and reduced resilience due to the presence of only a single species of the same age.

What role do tree stomata play in air quality?

They remove air pollutants like VOCs, NO2, and particulate matter from the atmosphere.

What is 'sustainability'?

Consuming a resource in a way that does not deplete or degrade it for future generations.

What is 'Maximum Sustainable Yield'?

The maximum amount of a renewable resource that can be harvested without reducing the resource for future use.

What is the relationship between biodiversity and ecosystem health?

Higher biodiversity generally indicates a healthier, more resilient ecosystem.

What are the major threats to global food production?

Climate change, soil degradation, and groundwater depletion.

Why does coal mining release methane?

Methane is trapped in the rock around coal and is vented during mining to prevent explosions.

What is the 'albedo' effect of soil compared to trees?

Soil has a lower albedo than leaves, meaning it absorbs more heat.

What is the 'slash and burn' method?

A technique of clearing land for agriculture by cutting and burning trees, which releases GHGs like CO2 and N2O.

What are 'urban growth boundaries'?

Zoning laws set by cities to prevent development beyond a specific geographic limit.

What is the primary cause of blight in urban centers?

The decline in tax revenue and loss of businesses as residents move to suburbs.

How does mining impact water pH?

Acid drainage lowers the pH of water, making toxic metals like mercury and aluminum more soluble.

What is the global extinction rate used for?

It serves as a strong environmental indicator of ecosystem health and biodiversity loss.

What is the primary cause of soil erosion in the US compared to its formation rate?

The US is losing topsoil 10 times faster than it forms.

How does contour plowing prevent soil erosion?

By plowing parallel to natural slopes, it creates mini-terraces that catch water runoff.

What is the primary benefit of using perennial crops?

They live year-round with established roots, preventing bare soil between harvests.

How does the 'no-till' method improve soil health?

It leaves crop remains in the soil, which adds organic matter and prevents erosion.

What is the purpose of strip cropping?

To alternate rows of dense and less dense crops, preventing runoff from eroding the less dense rows.

Why are legumes like peas and beans used in crop rotation?

They have nitrogen-fixing bacteria in their root nodules that return nitrogen to the soil.

How does limestone improve soil fertility?

It releases calcium carbonate, which neutralizes acidic soil and provides calcium as a nutrient.

What are the benefits of rotational grazing?

It prevents overgrazing, promotes faster pasture growth, and encourages deeper root development.

What is a major drawback of high-density aquaculture?

It produces high concentrations of waste, leading to eutrophication and increased disease risk.

What is the goal of ecologically sustainable forestry?

To minimize ecosystem damage through methods like selective cutting and using animal labor to reduce soil compaction.

Why is fire suppression considered potentially harmful to forests?

It leads to a buildup of dry biomass, which makes future forest fires significantly worse.

What are the benefits of prescribed burns?

They remove dead biomass (fuel), prevent large fires, and promote nutrient recycling.

What determines the boundaries of a watershed?

The slope of the land, with ridges acting as dividers for runoff direction.

How does vegetation density affect a watershed?

More vegetation increases infiltration and groundwater recharge.

What is the process of eutrophication in the Chesapeake Bay?

Nutrient pollution causes algae blooms, which block sunlight, kill plants, and lead to hypoxia during decomposition.

What are the primary sources of nitrogen and phosphorus pollution in the Chesapeake Bay?

Sewage treatment plants, animal waste from CAFOs, and synthetic fertilizers.

What are the environmental consequences of urban runoff?

Decreased groundwater recharge and the transport of pollutants like salt, sediment, and oil into surface waters.

How does permeable pavement mitigate urban runoff?

It allows stormwater to infiltrate the ground, reducing runoff volume and pollutant transport.

What is the function of a rain garden?

It is planted near storm drains to soak up runoff and reduce flooding.

How does public transit help reduce water pollution?

It reduces the number of cars, thereby decreasing the amount of oil, tire pieces, and gasoline on roads.

What is the benefit of building vertically instead of horizontally in urban planning?

It decreases impervious surfaces, which reduces urban runoff.

What are the benefits of a 'green roof'?

They reduce runoff, sequester CO2, and filter air pollutants.

What is the relationship between CO2 and Earth's temperature?

CO2 is a greenhouse gas that traps infrared radiation, causing the atmosphere to warm.