Chapter 22 Critical Questions and Learning Objectives

Question 1

What are three provisioning services of biodiversity?

Answer 1

Food, water, materials

Question 2

Why are regulating services considered to be an instrumental value of biodiversity?

Answer 2

It’s considered instrumental because protects against flooding so protects our homes, filters air so our effect on global warming is less. It is instrumental since it serves us an actual purpose, and a monetary value can be assigned to it

Question 3

Why is it difficult to assign an economic value to intrinsic values of biodiversity?

Answer 3

It is difficult to assign an economic value to intrinsic values of biodiversity because it does not technically provide a direct service to humans. Economists have not found a way to capture intrinsic values in a meaningful economic way, so this value has been excluded from any economic determination scheme

Question 4

What data can we use to determine if we are in the midst of a sixth extinction?

Answer 4

at least 75 percent of the existing species go extinct within a 2-million-year period for it to be considered a mass extinction. We can quantify the rates of extinction during the first five mass extinctions and then compare them with the current rate of extinction.

Question 5

Which groups of animals are the most threatened?

Answer 5

Amphibians, they have the most threatened animals. Amphibians are a cold-blooded vertebrate animal of a class that comprises the frogs, toads, newts, and salamanders. Fish are also threatened due to over fishing.

Question 6

Why have we lost the genetic diversity of many crop plants?

Answer 6

Because farmers want to make more of the plant that sells the most. Production favored only the top-producing crop varieties. In addition new varieties have been bred that have improved disease resistance or improved flavor. As a result, many of the older, local varieties of crops are no longer available.

Question 7

How has forested habitat been changing in North America?

Answer 7

The destruction and degradation of habitat have been the largest cause of declining biodiversity. In the United States, for example, most old-growth forests were cut down in the eighteenth century. Now more forests is being planted, but a lot of biodiversity has been lost

Question 8

What evidence indicates that over harvesting animals is not a recent problem?

Answer 8

Overharvesting of animals is not a recent problem and it is evident because For instance, during the past 3 centuries, commercial hunters in North America have hunted to extinction the Steller’s sea cow (Hydrodamalis gigas), great auk (Pinguinus impennis), passenger pigeon (Ectopistes migratorius), and Labrador duck (Camptorhynchus labradorius). Each of these once-abundant species was valued for food or feathers, and they were easily killed. Also years ago a lot of shellfish and stuff was overharvested cuz easy to get.

Question 9

Describe how some pollutants biomagnify through a food web.

Answer 9

DDT in water, plankton absorb, other fish eat plankton, then it goes up the food chain and bioaccumulates. When small fish eat the zooplankton and large fish eat the small fish, DDT is further concentrated, by about 30-fold. Finally, when a fish-eating bird such as an osprey consumes a large fish, DDT becomes concentrated another 10-fold. By the time it reaches the top of the food chain, the insecticide is 276,000 times more concentrated in the body of the fish-eating bird than it was in the water.

Question 10

How has the amount of protected habitat around the world changed over recent decades?

Answer 10

It continually increased over the past 40 years

Question 11

How has the ban on harvesting marine mammals affected populations of northern elephant seals?

Answer 11

Some species can take a long time to recover their population size, but reducing the harvest of a declining species often leads to a return to abundance. Stopping the harvesting caused seals to be from almost extinct to have thousands

Question 12

How can investment in a large, charismatic species also favor the conservation of other species?

Answer 12

Investing in a large charismatic species may allow other species to flourish. Ex. introducing wolves, so more plant species become abundant in the population.

Question 13

Why might different people or groups favor different criteria when prioritizing biodiversity hotspots?

Answer 13

Areas with low species richness can still have high conservation value.

Question 14

Compare and contrast instrumental values versus intrinsic values of species and ecosystems.

Answer 14

Instrumental values represent the value of ecosystems as merely means to an end and are often measured in monetary terms. By contrast, intrinsic values refer to the value of ecosystems as ends to themselves and are often represented as moral duties

Question 15

How can economic benefits of biodiversity be used as an argument to protect biodiversity?

Answer 15

Food production relies on biodiversity for a variety of food plants, pollination, pest control, nutrient provision, genetic diversity, and disease prevention and control. Both medicinal plants and manufactured pharmaceuticals rely on biodiversity.

Question 16

What steps can be taken to slow the sixth mass extinction?

Answer 16

Vote for leaders who recognize the importance of conservation and carbon-neutral energy policies. Also involving local people in the design and management of protected areas has been particularly effective. Protecting habitats and endangered animals can reduce the rate, also limiting deforestation and gas use.

Question 17

Why should we be concerned with preserving both species diversity and genetic diversity?

Answer 17

A wide variety of species will cope better with threats than a limited number of them in large populations. Even if certain species are affected by pollution, climate change or human activities, the ecosystem as a whole may adapt and survive.

Question 18

Why have humans historically overharvested many species of animals?

Answer 18

Each of these once-abundant species was valued for food or feathers, and they were easily killed. Also years ago a lot of shellfish and stuff was overharvested because easy to get. People overhunted and overfished due to how much there was.

Question 19

Why might introduced competitors result in less extinction of native species than introduced predators?

Answer 19

Competitors use the same resources but do not prey on each other. Lack of resources will lead to a decline but not as rapidly as introducing predators who directly feed on the other species.

Question 20

Why do we need to consider the process of biomagnification when assessing the risk of a pesticide to wildlife?

Answer 20

Because by the time it reaches the top of the food chain, the insecticide is 276,000 times more concentrated in the body of the fish-eating bird than it was in the water. Like at plain site it may not be that dangerous but as it goes up the food chain it will.

Question 21

Why is it difficult to predict which species will be driven extinct by global warming?

Answer 21

many endangered species have not been identified or studied yet. Even with advanced computer models, it is difficult to predict how temperature and precipitation will change over future decades. One of the critical factors is how much we continue to increase the amount of CO2 in the atmosphere. Animals can move, it is not easy to predict

Question 22

What are the ecological, economic, and social challenges that can arise when considering a species reintroduction?

Answer 22

Species reintroductions can cost millions of dollars and are usually directed toward species that appeal to the public, such as black- footed ferrets, condors, and wolves. Some people may question the wisdom of spending millions of dollars to save one species. However, efforts made to save a single species o en have positive effects on a large number of species.