People and Planet - Changing Ecosystems

All ecosystems are made up of abiotic and biotic factors. In ecosystems, the living things depend on their environment and each other for the things they need to live. One of the best ways to study interactions within ecosystems is to watch what happens when something changes or goes wrong.

In this activity you will research ecosystems at risk and write a summary of relationships that are suffering or are causing problems in some of Earth's best known ecosystems.

Throughout the United States wetlands ecosystems are in danger. For example, wetlands are areas where land and water meet. These areas may include ponds, swamps, marshes or bogs. These lands are important because they provide a great deal of plant matter for food chains, they provide food and shelter for millions of migratory birds and other organisms, they provide flood and erosion control, they help purify and store groundwater, they are useful for hunting, fishing and bird watching activities, and in many places in the world they provide areas for growing major food crops like rice or cranberries.

In the past, wetlands were viewed as useless lands - sources of mosquitoes, flies, bad smells and diseases. Because of this kind of thinking, more than half of the wetlands in the lower 48 United States have been drained and used for other purposes. President George Bush (the first one) established a policy of "No net loss of wetlands." We now spend hundreds of millions of dollars each year on protecting and developing wetlands. Where wetlands must be destroyed in the building process, they must be replaced by creating new wetlands in other areas. Wetlands that were once drained are sometimes now being reclaimed as wetlands.

Wetlands are just one example of ecosystems that have been used and abused. As human populations grow, ecosystems everywhere will be affected. Your job is to become aware of how organisms, including humans, interact to make ecosystems that will last forever. If we don't understand and do the things that are necessary, our days on planet Earth may be numbered.


  1. Search the Internet with the phrase "Ecosystems at Risk." Find at least three sites that describe ecosystems in places you think are important.
  2. Read and discover the critical organisms that are at risk in each ecosystem.
  3. Describe the changes that have caused the ecosystems to be at risk.
  4. Prepare a report on the ecosystem that is of most interest to you.
  5. Share your report with your teacher, your parent or guardian, friends, or classmates.

Interactions between organisms and their environment can be studied by monitoring the final stages of the nitrogen cycle (denitrification) in a small marine environment. During these stages of the nitrogen cycle ammonia from animal wastes and decay is converted to nitrogen gas and released into the atmosphere. Instructions for an experiment to study this phenomenon.