Course Toolkit

Cumulative Impacts Demonstration

Module 2 - Web of Life Part 2

Contact person: Alain Caissie, Fundy National Park, (506) 887-6105
Submitted by: Southern New Brunswick Field Unit Team

• Alain Caissie
  
• Rod Lutes
  
• Karen Townsend

This demonstration illustrates the lesson on Cumulative Impacts. After you have defined and talked about anthropogenic stressors (under Introduction, Anthropogenic Stressors, Trainer's Manual page 2.13), you are ready to start the demonstration.

Materials Required For Demonstration

• Balloon, small, round shape
  
• 7-8 bricks, labelled (wrapped in paper with name written on) with different (locally pertinent) stressors (from the list on page 2.11 in PW)
  
• A bucket to hold the bricks
  
• A small piece of carpet (12" x 12"), to put under the balloon so it doesn't slide off the table.
  

To do the next activity, I will need a few special items.

• A balloon (take out balloon and inflate); this balloon
  represents our home, our planet, our ecosystem, National Park.
  
  
• A few bricks; these bricks will be stressors; I've labelled this one as "oil spill", "forestry", etc. I didn't make up these stressors; they are well documented to have ecological effects on National Park, and they have been listed in the State of the Park Report, in your Participants Workbook on page 2.11, etc (mention any other documents
  pertinent to your park).
  
  
• What happens if we put a stressor on the park?
  (Put the bucket on the balloon and one or two bricks inside the bucket (naming them as you put them in), support the bucket so that it doesn't tip, but by showing your audience that you are not supporting the weight of the bricks.)
  
  
• The balloon, or the park, is stressed, but it doesn't necessarily break. It simply changes shape; this is what
  first happens when ecosystems are under stress: they
  will show signs of change, but without "bursting" right away.
  
  
• What happens if I remove the stress?
  (Remove the brick(s) from the bucket). The balloon goes back to its original shape. If the stress wasn't too big, ecosystems can bounce back by themselves to the way they were before; this is called resilience. That's why when there is a stress (like an oil spill), often it's not too late to do something to remove the stress because the ecosystems can recover from it. Monitoring programs are aimed at detecting early signs of change, before the "balloon" bursts, while we still have time to reverse the effects.
  
  
• What happens if I put on another, different stressor? Similar effect.
  
  
• What about if I put several stressors at the same time?
  Name each stressor as you put the bricks in the bucket one at a time. As you add on several bricks, some people in the front row may start to anticipate the "Bang." You can ask: "Are you stressed yet?!"
  
  
• The balloon can withstand some stress for a certain period of time, but it will eventually burst when the stress
  is too much and when it is left on for too long.
  
  
• The balloon should eventually burst after 5-7 bricks, depending, of course on the size and inflation of your balloon, and on the weight. The key to being able to anticipate approximately when the balloon will burst is to practice several times before, to get a feel for how much air should be in the balloon, how many bricks it will hold, etc. Still, you must be prepared for things to not go quite as planned. (To make sure that they are not left hanging, some people doing this demonstration have even been known to hide an inverted thumb tack in the carpet and to roll the balloon onto it at the appropriate time!)
  
  
• Once the balloon bursts, follow up with this debriefing, by clearly illustrating at least the following three points:
  
  

1. Which stressor caused the balloon to burst? (The last one?) What if this last one was applied by itself, do you think it would have caused the balloon to break? No. So it often doesn't matter which one was last, or which one was first, what matters is that they were all added together. It is the sum of all the stressors that caused the balloon to break. Ecosystem collapses are not necessarily just the fault of forestry activities, or water pollution, etc. (use whatever stressor examples are pertinent to your park), what makes the difference, and what often causes ecosystems to collapse, is that all the stressors are added together.
2. Could anyone have predicted exactly when the balloon was going to break? (No) Or was it a surprise? (Yes) Cumulative effects sometimes only appear after a time delay. Cumulative effects can appear quite unexpectedly; they are very difficult to predict. This is why we need team work to identify potential cumulative effects. The people who are working on one issue have to make sure that they don't work in isolation, but in conjunction with someone working on another issue. We need to be "better safe than sorry" when reducing the impacts of each stressor to a total level well below what we suspect the ecosystem may be able to withstand.
3. One of Parks Canada's objective is to recognize and identify the potential for cumulative effects, to avoid cumulative effects, and to repair and restore them when they have occurred. Everybody can play a part at every stage of this process.

Ecological Footprint Calculation

You can also follow up this demonstration with another activity, a calculation of our Ecological Footprint, which also serves to illustrate the potential drastic effects of cumulative impacts. There are several organizations that have more information on ecological footprints. The model I used is available from Redefining Progress, a non profit public policy and research organization that develops policies and tools to reorient the economy so it will value people and nature first.

Follow the links to "Calculate Your Own Footprint" and you can also choose to use the metric version adapted by Mountain Equipment Coop, and based on the Redefining Progress Footprint Calculator.

You can do this exercise with the group, by logging onto the website during the course (if your room permits and you have the technical tools required), or you can get an excel spreadsheet of the footprint calculations which lets you simply run the exercise from your hard drive.