Unit 4c. Threats to Biodiversity



Biological diversity has been argued to be the single most direct measure of our planet's health. The goal of this lab is to explore the role of human behavior in threatening biodiversity on Earth. To achieve this, we will discuss four articles relating to biodiversity using the jigsaw puzzle technique.


Figure 4.c.1




One Week Prior to Discussion

In the week prior to this discourse, students should be broken up into four groups to facilitate using the jigsaw puzzle technique. The jigsaw method allows a class to cover a large amount of material, in depth, in a short amount of time. Each group will be assigned one of the following four readings from the WorldWatch Institute.


Before Coming to Class


These articles will help answer questions such as: How many species are there? What are they? Where are they? What is happening to them? We will also explore how the impacts of species loss will affect humans and whether species have intrinsic importance, regardless of the services they provide.


In Class - The Jigsaw Puzzle Technique

The jigsaw puzzle method will then be used in class to explore issues related to biodiversity. Students should come to class having read the article assigned to their group. For the first ~10 minutes of class, students that read the same article should get together and distill the most important themes, concepts and problems in their paper. Once this has been accomplished, mixed groups should be assembled. Make sure that each mixed group has at least one reader from each of the assigned papers. The mixed groups should then compare and contrast the four papers and come to general conclusions about biodiversity based on information provided in the articles.


Action Plans for Protecting Biodiversity

Mixed groups should then be numbered off by five. Mixed groups should each develop an action plan for protecting biological diversity on different scales. Group one should develop an action plan for protecting biodiversity at the local level, such as in your city or area. Group two should develop a plan to protect biodiversity on a state level. Group three should develop an action plan to protect biodiversity on a country or regional scale. Group four should develop an action plan to protect biodiversity on a continent scale and group five should develop an international action plan for the globe. Once groups have developed their action plans, groups should share their plans with the class.


The following questions may be of use to develop action plans and guide a general discussion. In the last 15-20 minutes of the section, the whole class should discuss biodiversity together.




Question 4.c.1

What types of natural goods and services does biological diversity provide?


Question 4.c.2

Why do we study vertebrate population trends if they represent such a small fraction of the species on the planet? Should we be putting more effort into exploring microbial and insect diversity?


Question 4.c.3

What is the status of birds on the planet? How have humans contributed to changes in bird diversity? What is the leading cause of changes in bird diversity?


Question 4.c.4

What types of services do birds provide? Does it matter if bird diversity declines? Are birds intrinsically important, regardless of the services they provide?


Question 4.c.5

One in every four mammals is threatened with extinction. What activities are causing declines in mammals? How is the bushmeat trade affecting mammalian biodiversity? What measures can be implemented to stem the flow of decline?


Question 4.c.6

What ecological services do mammals provide? Should we be concerned about invasive species? What affects do invasive species have on mammalian diversity?


Question 4.c.7

What is the current status of reptile and amphibian diversity on our planet? What are differences in the causes of diversity changes for reptiles versus amphibians? Should measures be implemented to protect reptile and amphibian diversity? If so, what should be done?


Question 4.c.8

What types of human activities are endangering fish diversity? How do human activities on land impact fish populations? How can we decrease our impact on aquatic systems?


Question 4.c.9

What role and responsibility does the fishing industry play in maintaining fish populations and diversity? What policies could be implemented to protect fish diversity in fresh and salt water systems? How do we implement protection of marine organisms, which cross international boarders?


Question 4.c.10

What are the costs and benefits of setting aside protected land areas? What is the best way to assess which areas should be protected?


Question 4.c.11

How do we encourage protection of biodiversity in developing regions like in the tropics, where the majority of Earth's diversity exists? Use Figure 4.c.2 to discuss your answer. This map may be used to show areas in which biodiversity is threatened. Areas where high poverty and high population density coincides with high biodiversity may indicate areas in which poor people likely have no other choice than to unsustainably extract resources, in turn threatening biodiversity.



Global map overlay of poverty and biodiversity


Figure 4.c.2

Map of biodiversity hotspots and population density




Figure 4.c.3





Figure 4.c.2 from FAO 2004, Landscan 2002, Conservation International 2004





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