8. Ecosystems and Habitat
Sustainability by the Numbers
1. Sketch three hypothetical forest habitat patches: a circular patch 2000 feet in diameter, a
square patch 2000 feet on a side, and a rectangular patch 1000 feet by 4000 feet.
a) Calculate the area of interior habitat if the edge effect extends 200 feet into the core from
all sides.
b) Sketch a small road with a 60-foot right-of-way which bisects each patch. Try two
versions of the rectangular patch, one with the road bisecting the long side and one with
the road bisecting the short side. Now calculate the area of the interior habitat in each
patch, assuming that the edge effect extends 200 feet from each side of the road right-ofway.
Research Problems
2. What are the current extinction rates?
3. Explain what is meant by “threatened species” and “endangered species.” Give an example
of each from the region where you live, if possible.
4. Chapter 8 gives examples of invasive species introduced during the twentieth century. Find
as many examples as you can of invasive species introduced by humans in earlier centuries.
5. Research the problem of coral bleaching and write one to two paragraphs describing what
you learn.
6. Write a report on why mangroves are important, why they are threatened, and efforts to
preserve them.
7. Find two examples each of threatened species, endangered species, and species of concern in
your state.
8. Choose one endangered species. Summarize where it lives and how it makes its living.
Report on the threats facing it. If possible, discuss how these threats connect to issues of
environment, economics, and equity, and to larger social and political issues.
9. Investigate the ecosystem services provided by pollinators. What kinds of animals are
pollinators? What types of cultivated and wild plants rely on them? How important is
pollination? What are the current threats facing various pollinators?
© 2014 Margaret Robertson
10. Use information about geology and fossil records to create a timeline for the region where
you live. Indicate the climates, plant communities, and animals which have existed there,
going back as many million years as you can. The timeline format may be written or graphic.
11. How many U.S. animal species are currently listed as Endangered under the Endangered
Species Act? How many are listed as Threatened?
12. In 1971 biologist Barry Commoner proposed “Four Laws of Ecology.” What did they say?
13. Go to Conservation International’s Biodiversity Hotspots website. Select one of the sites;
report on why it was designated as a hotspot and what is being done to protect biodiversity
there.
14. If your library provides an online aerial photography collection, select a neighborhood in
your area developed within the last 70 years for which you can find aerial photographs.
Collect the earliest photographs you can, and see if you can piece together where old river
channels and meander scars were located. Create a display showing images of the area before
and after development, side by side.
15. Find a map of the region where you live. What river’s watershed are you in? Can you find
where the headwaters are? Where does the river’s water go? Find out whether there is a
watershed stewardship group for that river.
16. Obtain a copy of a flood map for the community where you live from the Federal Emergency
Management Agency (FEMA). Locate your residence on the map. Determine whether you
live within a floodplain. If you do, is it a 100-year floodplain? A 500-year floodplain?
Projects and Group Activities
17. Create a diagram that illustrates habitat fragmentation in a way that would be understandable
to a layperson unfamiliar with landscape ecology.
18. Imagine that you work for a nonprofit tree foundation. Create a brochure that could be
distributed in your community explaining the value and benefits of trees.
© 2014 Margaret Robertson
19. Create and label a diagram illustrating a food web. You can draw simplified pictures with
markers, cut and paste images from recycled magazines, or use another graphic method of
your choice. Illustrate a food web from one of the following:
a)
b)
c)
d)
e)
f)
a temperate forest
a mangrove swamp
coastal waters of the ocean
the soil
a river
a prairie.
20. In their book Introduction to Environmental Engineering, authors P. Aarne Vesilind et al. ask
a provocative question: “Would you intentionally run over a box turtle trying to cross a road?
Why or why not?” Write one or several paragraphs in which you answer these questions.
21. Create a timeline graph of the American bison population. Show the population prior to the
arrival of humans in North America, the arrival of humans around 13,000 BP, the
introduction (actually the re-introduction) of the horse, the introduction of the rifle, the
settling of what was called the “frontier” by Europeans, and the conversion of the Great
Plains to agriculture.
22. Pick a previously widespread animal, such as the lion, tiger, camel, or elephant. For example,
lions once lived across Europe and the Middle East, and were featured on ancient Assyrian
carvings. Camels, a type of tiger, and relatives of the elephant once lived in North America.
Create a map which represents what you are able to learn about the population size and range
of your species over time.
23. Download a copy of the 1972 brief, Should Trees Have Standing? Toward Legal Rights for
Natural Objects by Christopher Stone. Read the brief, then write a two-page summary
including its main points, why it was written, and your comments.
24. Download a copy of the article by medieval historian Lynn White titled “The Historical
Roots of Our Ecological Crisis,” published in the journal Science in 1967. Write one to two
pages in which you summarize the article and then offer your own comments and questions.
25. Select one city block or a 1- to 2-acre patch of land near you. Report in as much detail as you
can what the area looked like 200 years ago. Potential sources may include local geology
research, land use planning bureaus, natural resources surveys, historic aerial photographs,
and records of public land surveys from the nineteenth century. Contact the reference
librarian at your library for suggestions.
© 2014 Margaret Robertson
26. As a class, compile a visual dictionary to help nonscientists understand the issues and causes
of ecosystem change, suitable for your college to distribute to students, or for a city
government to distribute to citizens. For your topic, provide a definition with a brief
explanation, plus an image or images to explain your concept. Images could include
photographs, drawings, or diagrams. Be sure to cite your sources. Each person should choose
one of the following topics: habitat destruction, habitat fragmentation, invasive species,
pollution, population, overharvesting, climate change, extinction, biodiversity. You may also
want to include topics which deal with solutions.
27. If you live in a house or apartment with yard space, prepare a plan for converting your yard
to wildlife habitat that could qualify as Certified Wildlife Habitat under the National Wildlife
Federation program.
28. Write a Bill of Rights for plants, for animals, and for ecosystems. What challenges would
you face if you tried to write a Bill of Rights for bacteria?
29. Write a report on reclamation of pits and quarries. What regulations are involved? What
issues are considered in the planning process? Find a few examples that you think have been
successful. What made them successful?
30. Write a one-page report on Ramsey Creek in South Carolina, an eco-cemetery that is also a
forest restoration project.
31. Obtain a map of your region that shows parks, reserves, wildlife refuges, and other protected
areas. If you received a large grant from a land trust and could protect additional areas, where
would they be? How would you select them? Mark these areas on your map, showing the
sizes and shapes of the areas you would choose. Write a report to the land trust explaining
your choices.
32. Read John McPhee’s 1987 essay “Atchafalaya” about the channeling and control of the
Mississippi River, available in McPhee’s book The Control of Nature or online through the
New Yorker magazine. Write a commentary.
33. Create a poster which illustrates the geometry of stream meander formation.
© 2014 Margaret Robertson
34. Keep a photo record of your local stream or river over the next year. On a map, mark one or
more sites from which you will record photographs of your stream. Take a photo from that
place at least once every 3 months. Take a photo after a rainstorm if possible. Place your
photos in a single document, and label each one with the date and a note about recent
precipitation history. Add other comments, as you choose.
35. Create and label a diagram illustrating a food web within a stream. Include hyporheic and
riparian zones. You can draw simplified pictures with markers, cut and paste images from
recycled magazines, or use another graphic method of your choice.
36. As a group, draw a transect of a stream near you. The stream should be one that you can
wade across. A transect is a straight line across the land. You can mark a line with a length of
string attached to stakes in the ground, or you could envision an imaginary line. The line
should go across the stream, cover the flatter areas on each side, and begin to go up the
slopes above. You can divide the transect, so that one or several students take each section.
Make notes at several points along the line, noting the height of the soil above the stream
surface, type and size of rocks, understory vegetation, trees, and any other habitat elements.
You will notice that all of these features change from point to point along the line. In addition
to your notes, you can take measurements and record locations with photographs. Now use
all this data to draw a long, cross-sectional view of your stream. Try to reproduce the slopes,
vegetation, and other features at the same scale as best you can, so that you can get a realistic
sense of the shape and various features. If you have enough people, you can have another
team draw a transect 100 yards upstream from the first transect.
37. Build a stream table in partnership with a local school class or parks program. A stream table
is a miniature model which lets you see stream dynamics at work. You can find suggestions
and instructions on the websites of a number of university programs. Some science museums
provide stream-building activities; if there is one near you, it can offer useful examples. As a
group, research the size and materials you will use, and divide the tasks to make the project
manageable.
© 2014 Margaret Robertson