Kill 2 birds with 1 stone! Here is an easy, one-day project for kids that like the outdoors and photography.
First, find a place with a few trails for hiking. It could be at a school, state park, national park, beach, wetlands, nature center, etc. You will measure how some variable (see list below) changes along the trails – from the parking lot to the furthest point away (or the furthest point you are willing to walk to).
Step 1 Ask a question: How does the amount of trash vary with distance from the parking lot?
Step 2 State a hypothesis (pick one)
1. As the distance from the parking lot increases, the amount of trash decreases (perhaps because the number of people who hike in to a further point decreases).
2. As the distance from the parking lot increases, the amount of trash increases (perhaps because people don’t want to carry their trash all the way back to their car).
3. As the distance from the parking lot increases, the amount of trash stays the same (perhaps because there is trash everywhere or nowhere)
Step 3 Conduct an experiment
Materials: camera, measuring tape, notebook, pencil
Independent variable = distance from parking lot (or trail head)
Dependent variable = amount of trash (or other variable listed below)
1. Starting at the edge of the parking lot (trail head), turn 90 degrees to the right and take a photo, then turn 90 degrees to the left (of center) and take another photo. Count pieces of trash (here you could count each piece as one, or decide to count trash in categories, or just count cans/bottles). Record in your notebook, along with any other interesting observations such as places to sit, number of trash cans, number of people, etc.
2. Move 10 meters down the path (or 100 meters if you are going for a long hike, or 100 steps if you don’t have a way to measure distance) and take 2 photographs: 1, 90 degrees to the right and 1, 90 degrees to the left. Count all the trash you can see in that direction from that point and record in notebook.
3. Continue along the path for as long as you have time, patience, trail, good weather, or whatever, but the more points along the path, the better. Minimum would be 10 points (20 photos).
4. Develop the photographs (or observe on computer). Count pieces of trash in each photograph noting the right and the left pictures.
5. Repeat on three trails in the same area or 3 different areas to evaluate how consistent your results are.
Step 4 Analyze the results
Here you have choices, you could…
• Graph (line graph) the amount of trash (y-axis) as a function of the distance from the parking lot (x-axis) for the right side of the trail (one line) compared to the left side of the trail (another line). Are the lines the same or different (speculate on why)? Do the lines generally go up or down or show no consistent pattern?
• Average the left and right counts for each point along the path and graph the average amount of trash as a function of the distance from the lot. Does the line generally go up or down or show no consistent pattern?
• Calculate the percent change from the starting point (trail head) and use a bar graph to show how the amount of trash changes as distance from the starting point increases (bars might be above and below zero).
How do your photographic results (unbiased) compare to your notebook results (potentially biased because you might look harder in the beginning or at the end). Use the photographs and a map of the area for your backboard display.
Step 5: Make a conclusion
Look at your results and look at your hypothesis. Can you accept your hypothesis (because the results support your prediction) or do you have to reject your hypothesis (results do not agree with your prediction)?
Propose what you could do next. Now that you know where the most trash is, could you conduct another transect-style experiment to determine: Why it is there? Who is most likely leaving it there? How could you reduce the trash?
Make this your own: You could select ANY variable that you can measure along a transect like the one describe above.
• number of trees or ferns or lichens or seashells (biomass)
• number of different type of trees or ferns or lichens (biodiversity)
• number of different leave shapes (biodiversity)
• number of trees with vines, or knotholes, or carvings, or birds nests
• number of insects (more difficult because they might move if they sense you coming)
• number of spider webs, or animal dens, or hermit crab holes
• number of mushrooms, or number of types of mushrooms
• amount of sunlight (would need light meter)
• temperature, humidity, dew point (take a portable weather station with you)
• wind speed (need anemometer)
Note 1: If you are a “Caroline/Carl” type student, then you could use this experimental design and repeat it at many different parks or schools with some measure of the number of visitors, or distance from a major city, or other category, or you could monitor the same trails at different times (every week, or every month, or once each season), or you could measuring many different variables to evaluate which ones correlate.
Note 2: It is difficult to identify the control is this type of experimental design. Technically, because of the way in which the hypothesis is worded, it is the measurement at the first point (trail head) because you are asking how things change from this point. Thus, you are comparing your new results to this “regular” condition.
Have fun and post results and photos from your adventure!