How do changes in one environment affect other environments?

Targets

At the end of this Unit you should be able to answer the following questions 

1. What is a wetland ecosystem?

1.1 What are various types of wetlands, and why do they matter?

1.2 What plants and animals may live in a wetland site?

1.3 What adaptations improve plant and animal suitability for life in a wetland?

2. What are the roles of various organisms in a food web?

2.1 Who are the producers, consumers, and decomposers in a wetlands habitat?

2.2 What are food chains and food webs?

What human actions affect wetland ecosystems?

3.1 How do changes in one environment affect other environments?

3.2 What human actions have positive effects or negative effects on wetland habitats?

targets
This activity is about how one small change can have many different effects.  A change to one part of an ecosystem can cause other changes within that ecosystem or possibly even affect other ecosystems.  You will see how these affects can occur when minor changes happen in wetland ecosystems.  Here are some examples of some of these effects:

Draining and filling wetlands to build farms displaces the habitats of many plants and animals.


Smoke and chemicals released into the air can end in water systems when it rains.


Carelessness by people when they are in wetland areas for recreation can sometimes result in wildfires that cause damage to both vegetation and wildlife.

The changes shown in these pictures are big changes, and it is easy to see how an ecosystem can be affected by them. However, smaller changes can have a big effect as well. The loss of even one plant or animal from an ecosystem can threaten the survival of the entire food web.

Sometimes such changes are called a "chain reaction" or a "domino effect". Think of what happens when you tip over a row of dominos: each knocks down another until every domino has fallen. Something very similar happens in ecosystems. You have seen how plants and animals are connected into food webs. These food webs are also affected by anything that changes the quality of the air or water in the environment. In this way, any small change can have a huge effect on an entire ecosystem.