Trees for Tomorrow
In this workshop, students will explore what makes up a healthy forest, and how tree and soil health is important for sustaining ecosystems. Students will consider how human actions affect forests, and how forests are important in combatting climate change. Discussions will focus on positive actionable steps students can take to protect plant and soil health in their communities.
During the Introduction, students will be introduced to the elements required for a healthy forest, discuss what climate change is and learn the properties of different soil types using samples. The volunteer will show students how trees use capillary action when interacting with soil through a demonstration. Students are also introduced to Canada’s Boreal forest and will explore different parts of the forest across Canada throughout the workshop. Students will make their own soil model to learn about what soil is made up of and the different types of soil subsections. They will get the chance to compare images of changing landscapes to learn about the effect that losing trees has on the environment through coastal erosion, permafrost melt and landslides. Students will use that context to learn about how wood and roots can help hold soil together while preventing soil erosion. Next, students will learn about the scorching and regenerative effects of wildfires on forests through a hydrophobic water experiment and pinecone experiment. Students will think about the consequences of wildfire to soil using their soil model from the previous activity. Finally, students will learn about how tree rings and pinecones can be used to examine patterns in climate.
What You Need
Introduction
- Celery (optional)
- Straw
- Straw cleaner
- Tissue
- Plastic cup
- Food dye
- Water
- Spray bottle
- Small containers with sand, silt, clay
Activity #1: Soil Model
- Soil packets
- Compartmented containers
- Activity trays
- Laminated soil pictures
- Soil comparison charts
Activity #2: Soil Erosion
- Sponges
- Aluminum pans
- Plastic cup
- Container of wood mulch
- Black soil
- Water
- Laminated soil pictures
Activity #3: Wildfires
- Leaf
- Pinecones
- Plastic jar
- Activity tray
- Eye dropper
- Black soil
- Water
- Laminated pictures
- Container of beeswax
- Gloves
Activity #4: Tree Rings
- Tree rings
- Magnifying glasses
- Activity trays
- Laminated tree ring sheet
Activity guide:
Activity presentation:
What To Do
Introduction
Pre-Activity – Elements of a Forest
Imagine you are a tree in a forest. Place your feet shoulder-width apart, and keep them nice and firm on the ground. Move your arms up and wiggle your fingers like branches, as if you are reaching for the sky! Move your arms side-to-side slowly as the wind blows.
- Ask the students what their fingers represent and discuss the importance of leaves.
- Discuss why trees are important.
- Ask the students what their feet represent and discuss the importance of roots.
- Discuss what dirt is and why dirt / soil is important to trees.
- Describe the 5 components of soil that we can and cannot see very well. Explain new terms, such as minerals, organic matter, and gases using examples.
- Introduce the 3 soil minerals – clay, silt and sand – for the next activity.
Pre-Activity – Soil Texture
- Prepare the 3 small containers with a sample of sand, silt and clay ready in each on the demonstration table at the front of the room.
- Ask the students to describe sand, silt and clay in terms of size and texture.
- Ask the students to think back to a hot summer day at the beach and how the sand feels on their toes.
- Wet each sample with a spray bottle. Ask the students to keep an eye on which sample gets wet more quickly or slowly.
Pre-Activity: Climate Change Discussion
- Ask the students:
- What are some things you can name that make up a healthy forest? Lots of sunlight, rain, healthy soil, organisms
- What is climate change?
- How is climate change different from weather?
- How might trees affected by climate change and extreme weather? How do human actions affect trees?
- How do trees help the environment around them?
Demonstration – Celery Experiment
- Place 8-10 drops of food colouring into the plastic cup with water.
- Place the celery or jumbo straw with the tissue inside in the plastic cup with water.
- Ask students what they think might happen.
- The experiment will take 15-45 minutes to see colour for both the celery and the jumbo straw. You can revisit this activity during the wrap-up session.
In this workshop, you will all be forest detectives for Canada’s Boreal forest. Scientists and conservationists need your help to determine the different ways the trees in Canada’s forests are being affected by both human actions and climate change!
- Introduce the Canadian Map of the Boreal Forest
Activity #1: Soil Model
For our first location, we will start in Northern Ontario. You will be provided with randomly assorted packets of soil with different numbers of coloured marbles and beads. How many different marbles can you find? Place all the different marble colours or items you find in the labelled compartments of the stackable container. How many living things do you see in your packet? Place the living things in their labelled compartment.
- Split the students into 6 groups of 4-6 students, and have the 6 packets ready on the demonstration table for them to pick from. Have the corresponding stackable container ready beside each packet.
These 6 packets came from different sections of the soil. Based on the descriptions of each section of soil in a forest, can you find which section your packet came from? Is there anything you found in your packet that was not one of the 5 ingredients of soil we discussed earlier (minerals, soil organic matter, living things, gas and water)?
- Discuss how human actions can affect soil, and the different practices that farmers can use to keep the surrounding soil healthy.
The scientists are also concerned about how the soil in the Boreal Forest may change because of climate change. Remember, that climate change may cause extreme weather such as heavy rainfall, or more heat. Looking at what each coloured marble represents, what elements in the soil could climate change affect and how?
- Discuss how climate change can affect soil based on the components of the soil model.
Each soil sample was taken from a region in the Boreal Forest. Scientists have asked you to figure out which of the soil samples from your packets are related to the following environmental scenarios. How did each soil cause each scenario? Can you explain why based on which subsection of the soil it is, and how many marbles you see?
- Discuss real life scenarios based on the soil model and how they can affect soil health.
Activity #2: Soil Erosion
Now that we have learned a little bit about soil, the scientists need the help of our expert forest detectives to figure out what is happening in 3 different areas of the Boreal Forest. We will visit each one and try to figure out what happened in that region.
- Show students pictures of soil erosion in Newfoundland, a landslide in British Columbia and permafrost in the Yukon. Ask them what they see happening to the soil.
We’ve learned a little bit about how soil can change landscapes. Now let’s learn about how plants can help protect our soil. We will look at 3 different scenarios: one soil sample without anything in it, one soil sample with woodchips and fallen branches from trees on top of it, and one soil sample with the roots of a tree in it.
- At the demonstration table in front of the classroom, place both the large aluminum pan and one small aluminum pan on the table.
- Fill the smaller aluminum pan with soil until 1/2 is filled. Use gloves to push the soil together and make it compact.
- Fill one plastic cup with water.
- At one edge of the large pan, tilt the small pan with soil towards the large pan. You can balance the small pan on one side by using the other small pans in the kit. An example is provided below.
- Ask a student volunteer to pour a 1/4 cup of water into the small pan. How much soil do they see in the water sample?
- Place the large aluminum pan to the side and use the second large aluminum pan from the kit. Alternatively, you can drain the soil into the soil waste bags provided.
- Ask a student volunteer to pour woodchips into the small aluminum pan and cover the entire top section of the soil. Use gloves to push the soil together and make it compact.
- Ask another student volunteer to pour a quarter cup of water into the small aluminum pan. How much soil do they see in the water sample?
- Collect the water in one large aluminum pan, and use the empty large aluminum pan for the next scenario. Alternatively, you can drain the soil into the soil waste bags provided.
- Ask a student volunteer to place 6 sponges deep into the soil of the small aluminum pan in a 2 by 3 arrangement. Use gloves to push the soil together and make it compact around the sponges so they do not fall.
- Ask another student volunteer to pour a quarter cup of water into the small aluminum pan. How much soil do they see in the water sample?
- Discuss the relationship between soil erosion, climate change and plant conservation.
Activity #3: Wildfires
For our next station, we will go to the border between Alberta and Saskatchewan. When we get there, you smell something burning. You look around and you see smoke. Looks like there was a forest fire burning here! You receive information from scientists about what the situation looks like from the air. It seems like there is more than one fire burning, and they are big enough to see from the air. It is difficult for professionals to get them under control.
- Describe the difference between a controlled and uncontrolled fire using a stove analogy.
- Describe how a forest fire can start based on 3 requirements: a source of fuel, oxygen and ignition.
Experiment 1 - Pinecones
To learn more about these forest fires, scientists just brought back samples of pinecones from some of the trees at the provincial border that survived the fire. They mention that the pinecones looked different before and after the fire. They give the samples to you and ask you what this means. Let’s perform an experiment to learn more about the behavior of pinecones based on changes in their environment!
- On the demonstration table, place 2 jars. Fill one jar with cold water and leave the other one empty.
- Hand out a pinecone for each group to investigate before the experiment.
- Place one pinecone in each of the jars and close the lid. Ask students to monitor the pinecones.
- Describe what happens to pinecones in water and compare the results to the hot and dry environment of a forest fire.
Experiment 2 – Hydrophobic Drop Test
Sometimes, the effects of forest fires can be positive and allow new trees to grow. Sometimes, the fire can be too hot and the soil can be damaged. To determine how damaged the soil is, scientists perform something called a hydrophobic drop test.
- Describe what a hydrophobic drop test could mean.
- Describe the texture of a leaf or pass a leaf around for the students to feel if you have one available.
- Describe the similarities between a water droplet on a leaf and a water droplet on a hydrophobic layer of soil.
- During the pinecone experiment, on an activity tray, place some black soil and place a thin layer of beeswax strips on top of the soil. An example is shown above.
- When the hydrophobic drop test activity is introduced, prepare an eyedropper with water in it and ask a student volunteer to place the water on the wax.
- Ask students how climate change can affect this process.
- Show students a real photo of a forest 2 years post-fire and discuss the difference between regenerative and scorching forest fires.
- Ask students to describe how their soil model could be affected by regenerative or scorching effects of forest fires.
Activity #4 – Tree Rings
While visiting the Ontario & Quebec border at the end of our tour…we see one of the oldest trees in the Boreal forest fall down naturally. Scientists have asked the Boreal forest detectives to use the information from its tree rings to determine the story of the tree’s life based on the type of climate it survived and thrived in. Let’s start!
- Divide the students into 6 groups with 3-5 students per group. Distribute 3 tree rings and 2 magnifying glasses each.
- Give the students 3 minutes to look at the tree rings closely.
- Put up Slide 30 with instructions on looking at trees rings, or give each group the laminated picture labelled “Tree Ring Guide”.
- Discuss the following questions:
- What do the rings represent?
- Why is there a scar on the tree ring? What event could have caused this?
- Why are the rings different in color (light or dark)?
- Why are the rings not evenly spaced out?
- Based on the number of rings, how old could this tree have been? Count the spaces between the light wood and dark wood as one year, starting from the centre.
- Based on the tree rings, what type of climate did this tree survive in over the years? Is there a pattern you can notice?
- How do trees keep track of the environment around them with these rings, and how can scientists use this information?
Wrap-Up
Let’s go back to our demonstration experiment at the beginning of the workshop.
- For celery:
- Discuss what students notice about the leaves of the celery.
- Cut the celery in half and discuss what students notice about the insides of the celery.
- Based on what we learned about soil, imagine the celery is absorbing things found inside the soil. What could some of these things be?
- For alternative materials:
- Imagine the straw is the stem of the plant, and the tissue represents special things inside of the roots and stem. Imagine the food dye is all the minerals, gases and water inside of the soil. What did you see happen to the tissue? What does this experiment tell us about plants and how they can interact with soil?
- Discuss the following questions:
- Why are trees important and why should we protect them?
- Why is taking care of the soil important for taking care of plants?
- What important things can trees tell us?
- Revisiting our answers to the questions from the introduction (How are trees affected by climate change? How are trees affected by human actions? How do trees help the environment around them?) Have your answers changed after this workshop? Why or why not?
- Discuss possible careers related to the topics covered and what students would need to do (schooling, experience, etc.) to get into those careers.
Discovery
Introduction
Elements of a Forest
Trees need sunlight and the oxygen in the air to reach their leaves in order to make their own food. Trees provide humans with food, shade, etc. and provide animals with homes and food. Trees are glued to the ground because they need to make strong roots. Trees build these strong roots inside of the soil and grow them overtime. Trees can also use their roots to absorb water in the soil, like drinking straws on your feet! But soil has many more important things in it that can affect trees.
Soil is a made up of five ingredients — some of these we can see with our eyes, and some are not as easy to see. The five parts are minerals, soil organic matter, living organisms, gas, and water.
Humans do not make minerals. They are made naturally over a long period, and they do not come from living things. They can be described by how shiny they are, and what kinds of crystals they can form. An example of a mineral is quartz, which has a mixture of silver and gold in it. There are mines around the world that mine quartz. In soil, minerals are very small, and we cannot see them.
Organic means “from a living thing” while inorganic means “not from a living thing”. The word matter means “things”. Soil contains both inorganic matter, like minerals, and organic matter, like branches, fallen leaves, or even dead worms. These are organic matter that we can see. The organic matter carries nutrients, or things that living things need to survive, that can be stored in the soil for trees to absorb and collect using their roots. These are organic matter that are very small and we cannot see.
Gases are another component of soil we can’t see at all. In fact, gases are all around us in the air we breathe. We can’t see them, but we know they exist! Take a deep breath, that’s a lot of gases that are going into your lungs right now! Just like this, gases from the air can be found and stored in pockets of the soil.
Think of a time when you played in the soil. How many different living things did you see? This is one component of soil we can see very well! What do you do when you want a plant to grow? You water it! Water is another component of soil we can see. When you water the soil, the roots of the plant have an easier time absorbing all the minerals and nutrients in the soil along with the water, to grow stronger. Just like we need to drink water, plants can’t live without water either!
Soil Texture
Let’s learn more about the minerals in soil. Soil minerals can be divided into three groups based on size — clay, silt, and sand. Each grain of sand, silt or clay is different. You can have different amounts of each grain in one soil sample. How much of each grain you have in soil is called soil texture. The soil comparison chart below summarizes the difference between sand, silt and clay.
| 50% SAND | 40% SILT | 10% CLAY | |
| How easily does the soil heat up? | Gets warm/cold very fast | Medium | Very slow |
| How porous (how quickly water passes through) is the soil? | Very fast - the particles have huge spaces between them so they can't hold onto water | Medium (slower than sand, faster than clay) | Very slow |
| What does the soil feel like? | Dry and gritty | Smooth - with wet silty soil, it will make your fingers dirty | Very smooth when dry, sticky when wet |
| How easily can you clump the soil together (sticks together)? | Cannot clump very well (falls apart) | You can squish it into a ball but some of it will fall apart | You can squish it into a ball and it will stay together |
| Particle size (i.e., what does it look like?) | Largest particle size | Medium particle size | Smallest particle size |
Celery Experiment Demonstration
Imagine the straw is the stem of the plant, and the tissue represents special things inside of the roots and stem. Imagine the food dye is all the minerals, gases and water inside of the soil. The food dye was absorbed by tissue in the straw to show that plants can absorb pollution from the environment, and are dependent on the soil around them to survive. The health of the soil that the tree grows in determines the health of the tree.
Soil Model
The top layer of soil is called humus or ground level. This is usually called the organic layer because it has parts of the living tree in it, like fallen leaves or branches in a forest. This layer does is about 5 centimetres deep and only exists in soil that has not been moved in a long time. The second layer is called topsoil, which is almost 10 to 15 centimetres deep, depending on the region. It has many minerals, an almost equal amount of sand and silt, but very little clay. There are also some air pockets that you can find in this layer, but there are usually no additives or rocks. This is the best layer for growing plants. The roots of small plants grow here. The third layer is in-between topsoil and subsoil, which is about 5 to 15 centimetres deep, depending on the region. Many metals or extra additives can be found here, like iron or aluminum, from the topsoil and subsoil layers above and below it. This layer has the highest amount of sand or silt particles. It is usually found in very sandy soils in forests with a lot of rainfall.
The fourth layer is called subsoil. It is almost 20 to 30 centimetres deep, depending on the region. This layer collects extra materials from the sections above it, like the topsoil. It does not have a lot of organic matter, and it usually has more clay than sand. The roots of tall plants can be found this deep in this soil. The fifth layer is called weathered parent material. It does not look anything like the other sections, and usually includes the main material that the soil formed from geological processes over a long time, such as a lot of dead plants and animals compressed together. The final layer is called bedrock, which is very hard and found deep in the Earth’s surface.
Pesticides and fertilizers were not one of the 5 components of soil discussed earlier (minerals, soil organic matter, living things, gas and water) These extra things in the soil come from nearby farms. Farmers use fertilizers to add minerals and nutrients to the soil to help grow their crops. Farmers can also keep the soil healthy without using fertilizer. Different crops need different nutrients from the soil (e.g., soy beans, wheat, and corn all take different amounts of nutrients from the soil). By changing the crop farmers are growing in a certain field each year, this helps the nutrients stay balanced in each area. This practice is called crop rotation.
Climate change may cause extreme weather such as heavy rainfall, or more heat. Climate change can affect the components of soil in different ways. For example, the amount of moisture can change based on the rain or temperature. Air pockets can change based on the type of gases in the air. Both of these changes would affect the living things in the soil.
Soil Erosion
Water washing up against a cliff can cause erosion. Due to climate change and rising sea levels, this can happen more frequently in coastal areas. Unstable soil can also move away from its original position and can affect infrastructure as well. Similarly, permafrost is a portion of the ground that is completely frozen (0°C or colder) for more than two years. These regions are common at higher elevations, such as on the peak of mountains, or at the North or South poles of the Earth. Permafrost can melt due to rising temperatures and climate change. Melting permafrost can prevent the layers of soil from staying together, making it more unstable. The roots of a tree can help hold the soil together, and the fallen branches or wood help hold the soil in place to prevent it from moving. Protecting our trees will also protect our soil and prevent it from polluting our water sources.
Wildfires
Natural wildfires can happen because of the Sun or a lightning strike. Unattended campfires that are not put out properly are one human activity that can also cause a wildfire. Wildfires require a source of fuel, oxygen and ignition to occur. This is much like when you are trying to start a campfire, but on a much larger scale. The fuel is the logs you are trying to burn, the oxygen is in the air around you, and you can use a fire starter to ignite the fuel. Some factors that determine how intense a wildfire will be in a region are fuel and weather conditions. The source of fuel can be either fast burning or long lasting. Shrubs or dry grasses, like in the prairies, are fast burning because they do not have as many layers of thickness as wooden logs and stumps, like in a large forest, which burn for a longer time. More wind at higher speeds can cause the fire to spread easier. Higher temperatures can cause fuel to be “pre-heated”, taking less time for the fuel to ignite and burn. Precipitation, or rain, can increase the moisture on fuels, and decrease their tendency to ignite.
Trees hold seeds in their pinecones for regrowth. Pinecones close in cold water to protect their seeds. If the seeds get wet and cold, they cannot disperse or grow. The pinecone in the water was in a wet and cold environment compared to the pinecone without the water. Forest fires can get very hot and dry. It is beneficial for a pinecone to stay open during this time to release their seeds and allow new trees to grow in the next generation. Pinecones on the forest floor can help determine what the climate conditions are like in the forest. If it is open – it is likely dry and hot, good conditions for a forest fire. If it is closed – it is likely cold and wet, conditions that will make it less likely for a forest fire to start.
The leaf has a waxy layer on top that protects it from losing water. Just like a candle, the wax on a leaf can melt when it gets very hot. When a forest fire has been burning for a long time, the wax on the leaf can melt and drip to the ground. It can be found on top of the soil. This usually only happens for very severe forest fires. If there was wax from leaves on the soil, this wax does not like water (hydrophobic), so it will form a bead and not soak into the soil. So scientists drop water on the soil to see if it makes a bead or not. If it does, then the fire was probably very severe.
Pinecones like dry and hot conditions. Some will open during a forest fire to disperse their seeds. Depending on how severe a fire is, the soil can be covered with the melted wax from the leaves of the plant. Scientists can use this information to determine whether the conditions for a forest fire are likely (if the pinecone is open), or how long it will take for the forest to recover from the fire (if the soil is hydrophobic).
Tree Rings
As trees grow, they make new wood, which we see as rings on the tree ring. The difference in colour depends on the season that the tree grew its wood. Light wood is made during the spring, and dark wood is made during the summer. The difference between the light wood and dark wood is considered one growth year for the tree. Scars can be caused from disturbances in the environment of the tree, like wildfires and insect bites. When the tree grows new wood over the old one, it leaves a scar on the tree ring. Trees that grow in good conditions, such as in good temperatures and rainfall, they can grow wood more than trees that did not grow in good conditions. The wider the growth ring, the better the conditions for the tree. Wider growth rings represent good climate conditions, while shorter growth rings do not represent ideal climate conditions. The width of the growth rings gives scientists important information about the climate around the tree. Wider growth rings means the climate was good for a tree to live in, while consistently shorter growth rings may mean the climate around the tree may be getting less ideal. Scientists can use this information from the past to predict future climate in that area and plan for the future.
The impacts of climate change spread across Canada and around the world. Climate change endangers global ecosystems, human health, Indigenous ways of life, coastal communities, global transportation systems and much more. Learning about how plant and soil health interact with each other to protect our communities is important for limiting our impact on the environment and preparing our communities for a changing landscape.
This workshop discusses topics which can lead to feelings of eco-anxiety among volunteers, educators and youth if not presented in a thoughtful manner. The most important things to remember are to be honest, hopeful, developmentally-appropriate, and action-oriented. This workshop was created with these guidelines in mind. For more details, refer to the volunteer resource, Being Conscious of Eco-Anxiety.
Use the resources in the Activity Manual to discuss how Indigenous communities use land management strategies to mitigate the effects of climate change.
What's Happening?
Introduction
Elements of a Forest
Trees need sunlight and the oxygen in the air to reach their leaves in order to make their own food. Trees provide humans with food, shade, etc. and provide animals with homes and food. Trees are glued to the ground because they need to make strong roots. Trees build these strong roots inside of the soil and grow them overtime. Trees can also use their roots to absorb water in the soil, like drinking straws on your feet! But soil has many more important things in it that can affect trees.
Soil is a made up of five ingredients — some of these we can see with our eyes, and some are not as easy to see. The five parts are minerals, soil organic matter, living organisms, gas, and water.
Humans do not make minerals. They are made naturally over a long period, and they do not come from living things. They can be described by how shiny they are, and what kinds of crystals they can form. An example of a mineral is quartz, which has a mixture of silver and gold in it. There are mines around the world that mine quartz. In soil, minerals are very small, and we cannot see them.
Organic means “from a living thing” while inorganic means “not from a living thing”. The word matter means “things”. Soil contains both inorganic matter, like minerals, and organic matter, like branches, fallen leaves, or even dead worms. These are organic matter that we can see. The organic matter carries nutrients, or things that living things need to survive, that can be stored in the soil for trees to absorb and collect using their roots. These are organic matter that are very small and we cannot see.
Gases are another component of soil we can’t see at all. In fact, gases are all around us in the air we breathe. We can’t see them, but we know they exist! Take a deep breath, that’s a lot of gases that are going into your lungs right now! Just like this, gases from the air can be found and stored in pockets of the soil.
Think of a time when you played in the soil. How many different living things did you see? This is one component of soil we can see very well! What do you do when you want a plant to grow? You water it! Water is another component of soil we can see. When you water the soil, the roots of the plant have an easier time absorbing all the minerals and nutrients in the soil along with the water, to grow stronger. Just like we need to drink water, plants can’t live without water either!
Soil Texture
Let’s learn more about the minerals in soil. Soil minerals can be divided into three groups based on size — clay, silt, and sand. Each grain of sand, silt or clay is different. You can have different amounts of each grain in one soil sample. How much of each grain you have in soil is called soil texture. The soil comparison chart below summarizes the difference between sand, silt and clay.
| 50% SAND | 40% SILT | 10% CLAY | |
| How easily does the soil heat up? | Gets warm/cold very fast | Medium | Very slow |
| How porous (how quickly water passes through) is the soil? | Very fast - the particles have huge spaces between them so they can't hold onto water | Medium (slower than sand, faster than clay) | Very slow |
| What does the soil feel like? | Dry and gritty | Smooth - with wet silty soil, it will make your fingers dirty | Very smooth when dry, sticky when wet |
| How easily can you clump the soil together (sticks together)? | Cannot clump very well (falls apart) | You can squish it into a ball but some of it will fall apart | You can squish it into a ball and it will stay together |
| Particle size (i.e., what does it look like?) | Largest particle size | Medium particle size | Smallest particle size |
Celery Experiment Demonstration
Imagine the straw is the stem of the plant, and the tissue represents special things inside of the roots and stem. Imagine the food dye is all the minerals, gases and water inside of the soil. The food dye was absorbed by tissue in the straw to show that plants can absorb pollution from the environment, and are dependent on the soil around them to survive. The health of the soil that the tree grows in determines the health of the tree.
Soil Model
The top layer of soil is called humus or ground level. This is usually called the organic layer because it has parts of the living tree in it, like fallen leaves or branches in a forest. This layer does is about 5 centimetres deep and only exists in soil that has not been moved in a long time. The second layer is called topsoil, which is almost 10 to 15 centimetres deep, depending on the region. It has many minerals, an almost equal amount of sand and silt, but very little clay. There are also some air pockets that you can find in this layer, but there are usually no additives or rocks. This is the best layer for growing plants. The roots of small plants grow here. The third layer is in-between topsoil and subsoil, which is about 5 to 15 centimetres deep, depending on the region. Many metals or extra additives can be found here, like iron or aluminum, from the topsoil and subsoil layers above and below it. This layer has the highest amount of sand or silt particles. It is usually found in very sandy soils in forests with a lot of rainfall.
The fourth layer is called subsoil. It is almost 20 to 30 centimetres deep, depending on the region. This layer collects extra materials from the sections above it, like the topsoil. It does not have a lot of organic matter, and it usually has more clay than sand. The roots of tall plants can be found this deep in this soil. The fifth layer is called weathered parent material. It does not look anything like the other sections, and usually includes the main material that the soil formed from geological processes over a long time, such as a lot of dead plants and animals compressed together. The final layer is called bedrock, which is very hard and found deep in the Earth’s surface.
Pesticides and fertilizers were not one of the 5 components of soil discussed earlier (minerals, soil organic matter, living things, gas and water) These extra things in the soil come from nearby farms. Farmers use fertilizers to add minerals and nutrients to the soil to help grow their crops. Farmers can also keep the soil healthy without using fertilizer. Different crops need different nutrients from the soil (e.g., soy beans, wheat, and corn all take different amounts of nutrients from the soil). By changing the crop farmers are growing in a certain field each year, this helps the nutrients stay balanced in each area. This practice is called crop rotation.
Climate change may cause extreme weather such as heavy rainfall, or more heat. Climate change can affect the components of soil in different ways. For example, the amount of moisture can change based on the rain or temperature. Air pockets can change based on the type of gases in the air. Both of these changes would affect the living things in the soil.
Soil Erosion
Water washing up against a cliff can cause erosion. Due to climate change and rising sea levels, this can happen more frequently in coastal areas. Unstable soil can also move away from its original position and can affect infrastructure as well. Similarly, permafrost is a portion of the ground that is completely frozen (0°C or colder) for more than two years. These regions are common at higher elevations, such as on the peak of mountains, or at the North or South poles of the Earth. Permafrost can melt due to rising temperatures and climate change. Melting permafrost can prevent the layers of soil from staying together, making it more unstable. The roots of a tree can help hold the soil together, and the fallen branches or wood help hold the soil in place to prevent it from moving. Protecting our trees will also protect our soil and prevent it from polluting our water sources.
Wildfires
Natural wildfires can happen because of the Sun or a lightning strike. Unattended campfires that are not put out properly are one human activity that can also cause a wildfire. Wildfires require a source of fuel, oxygen and ignition to occur. This is much like when you are trying to start a campfire, but on a much larger scale. The fuel is the logs you are trying to burn, the oxygen is in the air around you, and you can use a fire starter to ignite the fuel. Some factors that determine how intense a wildfire will be in a region are fuel and weather conditions. The source of fuel can be either fast burning or long lasting. Shrubs or dry grasses, like in the prairies, are fast burning because they do not have as many layers of thickness as wooden logs and stumps, like in a large forest, which burn for a longer time. More wind at higher speeds can cause the fire to spread easier. Higher temperatures can cause fuel to be “pre-heated”, taking less time for the fuel to ignite and burn. Precipitation, or rain, can increase the moisture on fuels, and decrease their tendency to ignite.
Trees hold seeds in their pinecones for regrowth. Pinecones close in cold water to protect their seeds. If the seeds get wet and cold, they cannot disperse or grow. The pinecone in the water was in a wet and cold environment compared to the pinecone without the water. Forest fires can get very hot and dry. It is beneficial for a pinecone to stay open during this time to release their seeds and allow new trees to grow in the next generation. Pinecones on the forest floor can help determine what the climate conditions are like in the forest. If it is open – it is likely dry and hot, good conditions for a forest fire. If it is closed – it is likely cold and wet, conditions that will make it less likely for a forest fire to start.
The leaf has a waxy layer on top that protects it from losing water. Just like a candle, the wax on a leaf can melt when it gets very hot. When a forest fire has been burning for a long time, the wax on the leaf can melt and drip to the ground. It can be found on top of the soil. This usually only happens for very severe forest fires. If there was wax from leaves on the soil, this wax does not like water (hydrophobic), so it will form a bead and not soak into the soil. So scientists drop water on the soil to see if it makes a bead or not. If it does, then the fire was probably very severe.
Pinecones like dry and hot conditions. Some will open during a forest fire to disperse their seeds. Depending on how severe a fire is, the soil can be covered with the melted wax from the leaves of the plant. Scientists can use this information to determine whether the conditions for a forest fire are likely (if the pinecone is open), or how long it will take for the forest to recover from the fire (if the soil is hydrophobic).
Tree Rings
As trees grow, they make new wood, which we see as rings on the tree ring. The difference in colour depends on the season that the tree grew its wood. Light wood is made during the spring, and dark wood is made during the summer. The difference between the light wood and dark wood is considered one growth year for the tree. Scars can be caused from disturbances in the environment of the tree, like wildfires and insect bites. When the tree grows new wood over the old one, it leaves a scar on the tree ring. Trees that grow in good conditions, such as in good temperatures and rainfall, they can grow wood more than trees that did not grow in good conditions. The wider the growth ring, the better the conditions for the tree. Wider growth rings represent good climate conditions, while shorter growth rings do not represent ideal climate conditions. The width of the growth rings gives scientists important information about the climate around the tree. Wider growth rings means the climate was good for a tree to live in, while consistently shorter growth rings may mean the climate around the tree may be getting less ideal. Scientists can use this information from the past to predict future climate in that area and plan for the future.
Why Does It Matter?
The impacts of climate change spread across Canada and around the world. Climate change endangers global ecosystems, human health, Indigenous ways of life, coastal communities, global transportation systems and much more. Learning about how plant and soil health interact with each other to protect our communities is important for limiting our impact on the environment and preparing our communities for a changing landscape.
Investigate Further
This workshop discusses topics which can lead to feelings of eco-anxiety among volunteers, educators and youth if not presented in a thoughtful manner. The most important things to remember are to be honest, hopeful, developmentally-appropriate, and action-oriented. This workshop was created with these guidelines in mind. For more details, refer to the volunteer resource, Being Conscious of Eco-Anxiety.
Use the resources in the Activity Manual to discuss how Indigenous communities use land management strategies to mitigate the effects of climate change.
