Page 323 - Environment: The Science Behind the Stories

Testing Your Comprehension

1. What is biodiversity? Describe three levels of biodiversity. 7. What is the Endangered Species Act? Describe one of its
2. What are the five primary causes of biodiversity loss? successes.
Give one specific example of each. 8. Explain how captive breeding can help with endangered
3. List three invasive species, and describe their impacts. species recovery, and give an example. Now explain why
cloning could never be, in itself, an effective response to
4. Define the term ecosystem services. Give three examples species loss.
of ecosystem services that people would have a hard time
replacing if their natural sources were eliminated. 9. What is a biodiversity hotspot? What role does it play in
the protection of global biodiversity?
5. What is the relationship between biodiversity and food
security? Between biodiversity and pharmaceuticals? 10. Explain the notion of community-based conservation.
Give three examples of potential benefits of biodiversity Why have conservation advocates been turning to this
conservation for food supplies and medicine. approach? What challenges exist in implementing it?
6. Provide several reasons why our estimates of species
numbers are incomplete.

Seeking Solutions

1. Many arguments have been advanced for the importance 5. ThINK IT ThROUGh You are an influential legislator
of preserving biodiversity. Which argument do you think in a nation that has no endangered species act, and you
is most compelling, and why? Which argument do you want to introduce legislation to protect your nation’s van-
think is least compelling, and why? ishing biodiversity. Consider the U.S. Endangered Spe-
2. Some people declare that we shouldn’t worry about endan- cies Act and Canada’s Species At Risk Act, as well as
gered species because extinction has always occurred. international efforts such as CITES and the Convention
How would you respond to this view? on Biological Diversity. What strategies would you write
into your legislation? How would your law be similar to
3. Conservation advocates from industrialized nations have and different from each of these efforts?
long pushed to set aside land in biodiversity-rich regions
of developing nations. Leaders of developing nations have 6. ThINK IT ThROUGh As a resident of your commu-
accused them of neocolonialism. “Your nations attained nity and a parent of two young children, you attend a
prosperity and power by overexploiting your environ- town meeting called to discuss the proposed develop-
ments decades or centuries ago,” these leaders ask, “so ment of a shopping mall and condominium complex.
why should we now sacrifice our development by setting The development would eliminate a 100-acre stand of
aside our land and resources?” What would you say to forest, the last sizeable forest stand in your town. The
these leaders? What would you say to the conservation developers say the forest loss will not matter because
advocates? Do you see ways that both preservation and plenty of 1-acre stands still exist scattered throughout
development goals might be reached? the area. Consider the development’s possible impacts
on the community’s biodiversity, children, and quality
4. Compare the approach of setting aside protected areas of life. What will you choose to tell your fellow citi-
with the approach of community-based conservation. zens and the town’s decision-makers at this meeting,
What are the advantages and disadvantages of each? Can and why?
we—and should we—follow both approaches?

Calculating Ecological Footprints

Research shows that much of humanity’s footprint on biodiversity When footprints are equal to or below biocapacity, then resources
comes from our use of grasslands for livestock grazing and forests are being used sustainably. When footprints surpass biocapacity,
for timber and other resources. Grasslands and forests contrib- then resources are being used unsustainably.
ute different amounts to each nation’s biocapacity (pp. 23, 226) In the table, fill in the proportion of each nation’s per
depending on how much of these habitats each nation has. Like- capita footprint accounted for by use of grazing land and for-
wise, the per capita biocapacity and per capita ecological foot- est land. Then fill in the proportion of each nation’s per capita
322 prints of each nation vary further according to their populations. biocapacity provided by grazing land and forest land.

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