A region plants one genetically identical corn variety across thousands of hectares. Which type of biodiversity is especially low?

After a pesticide spill, two native fish species disappear from a river while the remaining fish population sizes are unchanged. What has directly decreased?

A county replaces wetlands, deciduous forest, and grassland with one large shopping complex. Which level of biodiversity declines most directly?

A conservation hatchery breeds only a few closely related California condors for several generations. What kind of diversity is the program most at risk of reducing?

A highway divides a landscape containing prairie, riparian forest, and marsh into paved lots. What biodiversity measure best describes the lost variety of habitats?

A fungal disease extirpates one endemic frog species from a mountain valley, but other frog species remain. Which component of biodiversity has declined?

Several salmon populations use the same river, but a dam leaves only one breeding run. Which biodiversity loss is most directly represented?

A reef still has the same coral species, but warming eliminates several species of reef fish. What has changed?

A watershed once included alpine tundra, conifer forest, and freshwater marsh; development leaves only conifer forest. Which level of biodiversity is reduced?

Two grassland plots each contain eight plant species. In Plot A, each species has 25 individuals; in Plot B, one species has 170 of 200 individuals. How do the plots compare?

A reclaimed mine plot has 12 plant species with equal abundances, while an adjacent unmanaged plot has 7 plant species with equal abundances. What comparison is accurate?

Before restoration, a marsh has three bird species with 20 individuals each. After restoration, it has six bird species with 20 individuals each. What changed?

Site A contains five insect species with 20 individuals each. Site B contains the same five species, but one species has 80 individuals and each other species has 5. Which site has greater evenness?

A stream survey finds 10 macroinvertebrate species both before and after construction. After construction, one tolerant species makes up 91% of individuals. What measure changed?

Orchard A supports four pollinator species, each equally common. Orchard B supports eight pollinator species, each equally common. What does Orchard B have more of?

Plot A has six plant species, with one making up half the individuals. Plot B has four plant species with equal abundances. How does Plot B compare with Plot A?

Why can low genetic diversity make a crop vulnerable when a new plant disease arrives?

A lake loses several predator species but retains the same total number of individual organisms. Why can this species loss still matter?

Why does ecosystem diversity across a watershed matter to human communities downstream?

Plant breeders conserve wild relatives of wheat in seed banks. Why can genetic diversity in those relatives be valuable?

A forest contains many tree species instead of one dominant plantation species. Why can this species diversity matter after an insect outbreak?

A coast contains mangroves, seagrass beds, and coral reefs. Why is this ecosystem diversity important for many fish populations?

Why do ecologists measure evenness as well as species richness after a disturbance?

Wild bees and other insects visit apple blossoms throughout spring. What ecosystem service do they provide to the orchard?

A city preserves a wetland upstream of its drinking-water intake. As water flows through, wetland plants and soils trap sediments and process nutrients. What service is supplied?

Farmers retain a forested riparian buffer beside a stream. Tree roots hold soil during heavy rain. What ecosystem service does the buffer provide?

A coastal community keeps mangrove forests intact near homes. During storms, the forests reduce wave energy reaching shore. What service do the mangroves provide?

A forested watershed supplies a reservoir with cleaner water than a heavily paved watershed. Which service is most directly supplied by the forest ecosystem?

Soil fungi and bacteria decompose crop residues, returning nutrients that plants can use. What ecosystem service is illustrated?

Researchers collect seeds from wild bean populations with many inherited traits. A breeder later uses one trait to develop disease-resistant beans. What benefit did biodiversity supply?