Observing Closed Loops in Nature

Field Trips for All of Us: Transformative Adventures for Children and Their Adults

Note: This blog is a serialization of a book titled Field Trips for All of Us: Transformative Adventures for Children and Their Adults. Here is the preface. The first field trip is Taking Education Outside.

Introduction

Cycles are a favorite pattern of ours. We think helping people learn about closed-loop systems (my favorite type of cycle) is one of the most important things we can do at this time in Earth’s history. Almost all human-designed factory-style systems are linear, causing massive amounts of waste of material and energy at every step in the linear process, including after manufacturing. This waste and the depletion of natural resources are major contributors to the mess this system has made of our planet. This field trip includes activities to help you and your children begin to make sense of the near-perfect recycling of materials and incredibly efficient reuse of energy that happens in ecosystems. Let your and their curiosity lead the way!

Activity

Looking at Landscape and Nature Photos: Take a look at the above picture with your kids or inner child. Ask them what is happening with the “broken” tree. What is it becoming? Who is making a home in a former tree? Notice the little holes in the tree. Who made them? What will this spot look like in five years?

Exploring the Forest Floor: Take a walk in the woods or any relatively wild ecosystem where fallen leaves, etc. are allowed to accumulate. Find a spot where the soil is well covered in fallen leaves, twigs, etc. This stuff is called duff, or more technically detritus. Lie down face first in the duff and ask any kids you’re with to join you. Smell the duff. Look at it closely. Roll around in it. Maybe even see if you can make yourself invisible by gathering nearby detritus and piling it on yourselves! While experiencing the forest floor, ask your kids (or inner child): What is this duff? Where did it come from? Where will it go?

What Happens When Things Break?: I like to talk with children about what happens to things that break in their homes. They usually get to, “we throw them out” pretty quickly. Then I ask them about what happens when things break in the woods: like branches, twigs, and leaves. If you’ve already done the activities in our Playing in the Dirt field trip, remind them of the crushed leaves, etc. they found in the soil when they looked at it up close and made their soil shake. If not, consider looking at some soil under the duff layer and notice how it contains small bits of organic matter.

Where does Dirt Come From?: While we’re walking and talking and they spot things turning into dirt, I’ll ask them who is turning the dead stuff into dirt. Sometimes we can see rhizomorphs (i.e., white or sometimes orange networks of fungal fibers called mycelium) and/or insects in “rotting” wood, eating away. I’ll also talk with them about where stuff came from and what they think will happen to it next, stuff like water, acorns, pine needles, and pine cones.

Where is Life Living among death?: Look for standing dead trees in the forest. Notice who uses them. Are there bugs using the tree as a home? Do birds perch on their limbs? Have borrowing creatures looked for food or dug homes around its base? Factory-style recycling happens in discrete steps just like factory assembly. A can of soda becomes an empty useless object until it is melted down and reformed. Dead trees, dead twigs, and leaves, are not useless objects waiting to be reformed. They play crucial active roles in ecosystems as food, homes, hiding places, etc. at all stages of their life, including in death.

Closing Loops at Home: If you already compost or deep mulch as described in Composting and Deep Mulching, go take a look at your compost for deep mulch. You ought to be able to observe your yard and kitchen scraps turning into dirt. Ask our favorite cycle questions: Where did the compost come from? Where will it go? What beings are helping you do the work of recycling scraps?

Observing and Discussing the Water Cycle: The water cycle is the first specific material cycle I talk about with kids because it's so visible and fun! I like to ask kids while they’re playing in mud puddles or the snow, “Where did that water/ice/mud come from and where will it go?” When we see rain or snow falling, I ask, “Where did it come from and where will it go?” When we see clouds, I ask, “What are they made of? Where did they come from?” We will share several activities focused on the water cycle in a future blog post!  

Nature Science

The only waste products you will find in any ecosystem are left there by people because it’s easier or cheaper to leave it than clean it up. Products just need to be made and sold. The disposal of the byproducts is far down the list, even in space! In the forest, there is no waste. None! Zero! Nada! Every bit of material that is no longer useful to a living being becomes an input for another: poop, pee, dead bodies, leaves, twigs, etc. all are recycled. For example, trees in the forest take up minerals from the soil through their roots and use those nutrients to grow, including growing leaves. When the leaves fall they contain the perfect mixture of mineral nutrients needed by the tree. The leaves are decomposed by visible and invisible creatures that live in the leaf litter and soil and the nutrients contained from the leaves are ultimately returned to the soil. As the next step in this cycle, those nutrients are taken up by trees and the whole process begins again.

Earth Systems Science is the exploration of how the Earth functions from a systems perspective. You may recall from The Build a System Game field trip that the basic idea of systems thinking is that any system, in addition to being explained in terms of the behavior of its parts, can also be described in terms of how its subsystems are interrelated. The major subsystems of the Earth System are air, land, water, and life. Earth system scientists call these subsystems, spheres: the atmosphere, lithosphere, hydrosphere, and biosphere, respectively. The major relationships between the spheres are called material cycles. The most important material cycles for maintaining life on Earth are the water cycle, the carbon cycle, the nitrogen cycle, and to a lesser degree, the phosphorus and sulfur cycles. Earth Systems Science also includes the study of how energy flows through Earth systems and how feedback systems serve to maintain homeostasis (ie., a relatively steady internal state) on Earth in terms of temperature and the proportion of various elements and compounds in the various Earth spheres.

When I work with kids of any age I introduce the idea of material cycles with only occasional reference to the specific materials (e.g., water, carbon, nitrogen, carbon dioxide) involved. What I hope for them to understand is that water (the substrate in which all life processes happen) and nutrients (other materials required to sustain life) move through the Earth’s spheres with a big assist from life itself. The materials I do mention occasionally to younger children, and older kids just getting started with making sense of material cycles are water, oxygen, carbon, carbon dioxide, and sugars.

During this introductory phase, I tell two cycle stories. The first is about how plants and animals give each other the gift of life breath in a very small cycle. The second is how nutrients move from soil, to plant, to animal, to soil in an endless cycle.

I tell the first story in a variety of contexts (including as they breathe into a bush as described in greater detail in our future field trip introducing photosynthesis and respiration). The story is that plants use the energy of the sun and the carbon from carbon dioxide to produce sugar they use to store the sun’s energy and as building blocks to make materials (cellulose and starches), they build themselves from. As a byproduct of using carbon from carbon dioxide (carbon atoms stuck to pairs of oxygen atoms) to make sugars, they release the oxygen atoms into the air. I usually tell this story after we have worked with fire and mention that just like fire uses fuel and oxygen, our cells use sugar that we get from plants we eat and oxygen we get from plants by breathing to burn sugars very slowly and at low temperatures inside our cells and release carbon dioxide into the air. 

I also tell the second story in a variety of contexts including when we see signs of decomposition. The story is that plants contain all the nutrients they need to survive. When they die and shed parts of themselves, those nutrients are returned to the soil. When animals eat plants those nutrients are taken in by the animal. When those animals poop, pee, and die, those nutrients are returned to the soil in the form of organic matter (i.e., plant and animal remains). After plants and animals return their matter to the soil, decomposers break those nutrients down into a form that plants can take them in and the whole cycle begins again.

Forests and other ecosystems have evolved to produce no long-lasting eco-toxins or other waste by maximizing diversity and the recycling of materials and reuse of energy. Factories are designed to maximize profit while minimizing cost per unit of time without regard to leaking toxins into surrounding ecosystems. For a great 25-minute video about the problems with profit-driven designed linear systems suitable for folks aged 3-99, please watch The Story of Stuff.

Educational Suggestion

In factories, things are assembled one piece at a time in a linear fashion. Factory-like education works the same way. Learn about atoms, check. Learn about molecules, check. In the forest, beings learn through repeated encounters in different contexts. In forest-like learning, environments and community participants encounter the same phenomena, skills, and big ideas over and over again in different contexts. Each encounter enriches our understanding and our abilities. Observing closed loops in nature and making sense of them is a great example of this kind of learning. This is not a do-once-master-and-never-look-back lesson. Talking and looking for cycles in your environment will become just as natural as a regular walk in the woods!

Wrap Up

Cycles are central to how ecosystems do what they do. And, what do ecosystems do? They continuously regenerate themselves! Human-designed systems tend to be linear and produce lots of toxic waste. Knowing how ecosystems recycle and reuse everything is an important step in understanding how ecosystems sustain themselves and how forests differ from factories. Closing Loops at Home (the subject of a soon-to-be-published post) is one thing we can do to live more ecologically.