Two forest stands are harvested. One has bare soil and heavy runoff, while the other retains scattered mature trees and little runoff. Which harvest methods were used, in order?

A new four-lane road divides one continuous forest into small patches. What land-use effect is most likely to increase?

After repeated cattle grazing, a semiarid grassland has sparse vegetation and exposed soil. Which process is the greatest long-term risk?

A tropical forest is cut, burned, and planted for a few years before farmers move to another plot. What practice is described?

A city replaces a wet meadow with parking lots and rooftops. During storms, what change is most likely downstream?

A developer builds houses along the edge of a forest rather than in its interior. Which ecological condition most increases near the development?

A timber company harvests narrow strips while leaving uncut strips between them to provide seed sources and cover. Which method is this?

A hillside subdivision is built without retaining vegetation or sediment barriers. What pollutant is most likely to rise in the stream after rain?

An abandoned mine is graded, covered with topsoil, and planted with native grasses. What is the main purpose of this reclamation?

A county rezones farmland for scattered low-density housing, roads, and stores. This conversion is best described as what?

On a sloping field, which practice most directly keeps soil in place between harvest and the next cash crop?

A farmer plows across a hillside along lines of equal elevation. What loss does this contour farming most directly reduce?

A field has repeated identical crop plantings and increasing insect damage despite more pesticide use. Which management change best slows selection for pesticide resistance?

A soil test shows a field is low in the nutrient plants need to build amino acids, proteins, and chlorophyll. Which fertilizer nutrient addresses that result?

Irrigation water evaporates from a field in a dry climate, leaving dissolved salts near the soil surface. What soil problem is developing?

A grower adds compost to sandy soil. Which change most directly helps the soil retain water and nutrients?

A farmer replaces annual plowing with no-till planting and leaves crop residues on the surface. What outcome is most likely?

A field borders a stream. Which feature most directly intercepts fertilizer runoff before it enters the water?

A farmer releases lady beetles after aphids exceed a threshold, then uses a targeted pesticide only if needed. What approach is being used?

A field is converted from one crop planted every year to alternating legumes and corn. What benefit can legumes provide to the rotation?

A feedlot stores manure in an uncovered pile beside a stream before a heavy rain. Which water-quality problem is most likely?

On a steep field, terraces are built into level steps. What is the main soil-conservation benefit?

A well field withdraws groundwater faster than its aquifer recharges for many years. What happens to the local water table?

A coastal town pumps heavily from freshwater wells. What can occur if the freshwater pressure falls below seawater pressure?

A city pumps a well and nearby wells must be drilled deeper because groundwater slopes toward the pumping location. What feature has formed?

Rainwater passes rapidly through coarse sand but slowly through clay. Which material has greater permeability?

A wastewater pipe discharges warm water into a river downstream of a power plant. Which immediate change most threatens fish?

A lake receives excess nitrogen and phosphorus after spring rain. Which sequence is most likely?

A factory releases effluent from one identifiable pipe into a river. How is this pollution source classified?

Rain washes oil, fertilizer, and sediment from many streets and lawns into a creek. How is this source best classified?

A town replaces a drained wetland with buildings. Which water-service is most directly lost?

A stream sample has high turbidity after a storm. What does the measurement indicate?

Which U.S. law is most directly associated with regulating pollutant discharges into surface waters?

A dam's reservoir traps sediment that once reached a river delta. What change to the delta is most likely over time?

Before coal is reached in a surface mine, workers remove the soil and rock above the seam. What is this material called?

After ore is crushed and processed, fine waste rock and processing residue are stored in a pond. What are these wastes called?

Water draining from a sulfide-rich mine has a very low pH and dissolves metals from surrounding rock. What pollution problem is this?

A company removes a mountain summit to expose a coal seam and places excess rock in nearby valleys. Which mining method is described?

Workers remove long horizontal layers of coal near the surface, creating parallel trenches. Which method is being used?

Gold-bearing sediment is separated from stream gravel using flowing water. Which extraction method is this?

A copper deposit is spread through rock near Earth's surface, so miners excavate a broad, deep terraced hole. What mine type fits this deposit?

A mine operator restores drainage patterns, replaces topsoil, and establishes vegetation after extraction ends. What practice is this?

For the same amount of energy produced, which fossil fuel generally emits the most carbon dioxide when burned?

A utility replaces a coal plant with a natural-gas plant producing the same useful energy. Which direct combustion change is expected?

Coal with a high sulfur content is burned without sulfur controls. Which air pollutant is most directly increased?

A power station uses uranium fission to heat water and turn turbines. During normal operation, which of these does the plant not produce?

A natural-gas system leaks methane before the gas reaches customers. Why can this reduce its climate advantage over coal?

A dam generates electricity by releasing stored water through turbines. Which trade-off can occur downstream?

A biomass plant burns wood waste to generate electricity. Which statement correctly describes this fuel?

A geothermal plant is proposed where hot underground water is available. What energy source would the turbines use?

A solar photovoltaic array produces no electricity after sunset. Which system addition most directly helps supply electricity then?

A wind farm is planned on a migratory bird route. Which site study most directly addresses a potential ecological impact?

A school uses 800 kilowatt-hours per day. An efficiency retrofit reduces use by 25%. How many kilowatt-hours does the school use per day afterward?

A household uses 12,000 kilowatt-hours each year. Rooftop solar supplies 3,000 kilowatt-hours. What percentage of the household's annual electricity use does solar supply?

Use the energy pyramid. If 10% transfers between trophic levels, how much energy would be available to tertiary consumers?

A farm harvests 4,000 kilograms of wheat from 2 hectares. What is its yield?

A town's population grows at 2% per year. Using the rule of 70, its approximate doubling time is how many years?

A water utility repairs leaks and reduces daily withdrawals from 40 million liters to 30 million liters. What percentage reduction occurred?

A household replaces ten 60-watt bulbs with ten 10-watt LED bulbs for 5 hours each day. How much less electricity do the LEDs use each day?

A city compares two electricity contracts: Plan A costs $0.12 per kilowatt-hour and Plan B costs $0.15 per kilowatt-hour. For 1,000 kilowatt-hours, which plan costs less and by how much?