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The Human Factor
Greetings naturalists, welcome to day three of our week exploring the forces of nature! So far, we’ve discovered some of the more familiar forces of the natural world such as water and fire. Today we are going to explore a force of nature that most people don’t even realize is one: ourselves.
Wait...ourselves? You might be asking, but we’re humans, not a force of nature. Well, you are absolutely right; we are humans! However, it’s important to remember that just like any other species, we are still a part of Earth’s systems (bonus points if you can remember which sphere is made up of living things)! Likewise, our actions as a whole can change the rest of the planet in a big way. Just like a fire can burn thousands of acres of forest, or flooding can permanently change the flow of a river, our actions also have impacts beyond what we immediately see. Humans are unique in that we are able to quickly and drastically change conditions across the globe. Take some time to look at your window, or step outside. What do you think your town looked like before humans moved in and changed things? Start with the most obvious things, and then narrow your focus. How detailed can your observations get? To get more involved, draw a picture, or (with your parents’ permission) see if your town has old pictures posted online! For example, the City of Fayetteville has several online historical photo albums online at https://www.fayettevillehistory.org/photo-albums.html .
Speaking of things we can’t easily see, let’s start today by talking about air. How do we affect the air? One of the most obvious ways is through air pollution. When you think of air pollution, you probably think of giant power plants burning fossil fuels like coal and oil. For several hundreds of years we’ve been burning these resources (why?), but it also produces a large amount of air pollution.
There are other sources of air pollution, too. Decomposing garbage in landfills and fumes from aerosols (liquid particles held up by air) like paint and hairspray also cause air pollution. What other sources of air pollution can you think of? Take a minute or two to write these down.
Air pollution releases dust and other particles along with toxic gases into the air, junk that isn’t good for anyone to be breathing in. Yuck! Exposure to air pollution over time can lead to health problems like asthma, heart disease, stroke, and lung cancer. Remember, it’s not just people who rely on clean air to stay healthy. How might animals be affected by air pollution? Plants?
Air pollution has a major effect on life on this planet. Lichens like this one, for example, are very sensitive to dirty air and will die if pollution levels are too high. If you see lichen in your neighborhood, that’s a sign of clean air!
Human actions can also have significant impacts on the world’s water as well. Water flowing across farmland or pavement often picks up pollutants like plastic, oil, and fertilizer along the way. This runoff often ends up in nearby rivers and lakes which spreads the pollution further.
The good news for us is that we can treat some water pollution fairly easily through wastewater treatment plants. After treatment, the water is released into nearby lakes or rivers. However, do you think that all of the polluted water finds its way to a treatment plant? What happens to the rest of that polluted water? When a river or stream becomes polluted, how are people and ecosystems many miles away still affected by it?
Have you ever looked into where your pollution might end up, you can use a map to track the path of water from your local stream all the way out to the ocean. For a starting point for most of Northwest Arkansas, you can start at Beaver Lake. What river does Beaver lake eventually flow into? From there, where does the water go? Just as a flood affects everything downstream, so does pollution!
Polluted water can lead to us being exposed to things like toxic chemicals, raw sewage, and disease-causing bacteria and parasites. Do you want raw sewage or polluted storm water going into the water you drink or the lake/river you swim in? Yeah, me neither. How might water pollution affect animals? Plants?
So you can see, human activity can have a significant negative impact on nature. But fear not, it isn't all bad news. Just like water and fire can help natural ecosystems, humans can also be a significant positive force of nature. One example of humans acting as a force of nature, both negative and positive, is the history of the American bison. Scientists believe that in the late 1700’s there were over 60 million bison in North America. However, intense hunting of the bison reduced their number to under 300 by 1900. However, people began to realize that if nothing was done these large animals would soon go extinct. Soon after major conservation efforts began to try and save the bison and today it is estimated there are now roughly 500,000 bison found in North America. Thank you Chyna Pei for the Bison photo!
So you can see, human activity can have a significant negative impact on nature. But fear not, it isn't all bad news. Just like water and fire can help natural ecosystems, humans can also be a significant positive force of nature. One example of humans acting as a force of nature, both negative and positive, is the history of the American bison. Scientists believe that in the late 1700’s there were over 60 million bison in North America. However, intense hunting of the bison reduced their number to under 300 by 1900. However, people began to realize that if nothing was done these large animals would soon go extinct. Soon after major conservation efforts began to try and save the bison and today it is estimated there are now roughly 500,000 bison found in North America.
Kaweha, a Californai condor from the Oregon Zoo. Thank you to Travis Koons for letting us feature your picture!
What are some other ways humans can be a positive force of nature? What are some ways you can be a positive force of nature?
So, while water and fire may be some of the more familiar forces of nature, we humans can have just as much impact on the earth as the other forces can. Now it’s time for us to conduct an experiment on how our actions can change the planet for the better or the worse. This experiment will compare the ability of a parking lot and a wetland to filter polluted water. This experiment requires two disposable bottles (such as soda bottles), something to cut the bottles, a rock, “pollution” items such as food coloring, cooking oil, and soil, and items around your house that you might use to filter water.
If pollution were dumped in each of these locations, what would happen to it?
With your parents’ assistance, carefully cut the two bottles in half, separating the top and bottom half of the bottle. Take the top half of the bottle and remove the cap (if not already removed) and place the top half upside down in the bottom half of the bottle. Now we need to make up a batch of “polluted” water. In a separate container, get some water from the sink and add your “pollution” that you created. As in our other online experiments make sure you get your parents’ permission before you start turning household items into science tools.
Now that we’ve created pollution, we need to make a filter to put in our soda bottle. Think about what items you have around your house that might “catch” your pollution. This might include things like coffee filters, grass clippings, gravel, sand, and cotton balls. You will be placing them in your “wetland” water bottle to show the effects of these important ecosystems. Think about which items you should add to the filter first and which ones you should add last.
For the second bottle, we are going to imagine that humans have cleared that swamp and built a shopping mall. Place one large rock in the bottle. If you do not have a rock, a waterproof ball or other simple toy will work too.
Now we’re going to make some predictions about what will happen. Which water do you think will be cleaner? Which one will drain faster? Overall, which one will provide cleaner water? Why? Write your hypothesis down in the chart below. Remember that a hypothesis is an educated guess, so remember to write down your reasoning!
Once you have written your hypothesis, it is time to perform the experiment! Separate your pollution into two separate halves, making sure they look about the same. Now it’s time to mimic a heavy rainstorm by pouring the polluted water into each of the bottles. Using your watch, phone, or a stopwatch, time how long it takes for the water to filter through. The filter you have created is like a sponge, holding the water in one place and slowly releasing it.
How long did it take? Does the water look different now than when it started? Even if the water comes out “clean”, it is unsafe for humans to drink. Why? How have we changed our environment that makes this the case?
As a final thought, imagine you live along the edge of a river. Your town is seeing record rainfall, and flash flooding is occurring along much of the river’s path.
Thinking about your experiment, decide where you would want to live, considering that at some point you may have to quickly evacuate. Where would you be safer, downstream from a wetland or a parking lot? Where is the water going to be moving fastest? Slowest? Which areas will see the most erosion? Take some time to journal your thoughts.
Bonus: Clean out the bottle and you can try again putting the layers in different order from last time, challenging yourself to make the best filter possible. Did the water drip through the filter faster this time? Slower? The same? Was the water dripping into the bottle cleaner than last time? Dirtier? The same?
Every action that we take can change the planet around us. Let’s take a quick look at one more: invasive species. Whether a species is large or small, cute or terrifying, it may take over if given the opportunity. Let’s learn about an invasive species out here in the Ozarks!
These past three days, we’ve been discussing many things that can quickly change a natural ecosystem. Tomorrow, we will be examining how those ecosystems recover from damage, and what a healthy forest looks like. Make sure you’re sending us any nature related questions, comments, or pictures over the week and then tune in to our Find-Out Fridays where we will answer those questions live for you. Questions can be sent to our Facebook page or to Socialmedia@onsc.us and don’t forget Find-Out Fridays air at 11:00AM CST. Until next time, happy exploring.
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