Nature & The Nervous System

Nature is life, and nature is rhythm. Co-evolved and co-evolving with plants, animals, fungi, bacteria, weather, water, and all organic elements, humans are inherently part of the symphony of rhythms and relationships.

It’s no surprise, then, that a number of recent scientific studies tackle the problems of modern indoor-centric life and support the assertion that spending a significant amount of time outdoors improves wellbeing. A robust study in 2019 found that exactly two hours of time in nature (outdoor environments like woodlands, beaches, parks, etc.) per week improved health and wellbeing, as reported by the participants. Jim Robbins recently reported on this topic and included findings that time in nature can “lower blood pressure and stress hormone levels, enhance immune function, reduce anxiety, and improve mood.” A 2017 article in the International Journal of Environmental Research and Public Health elucidates how the many benefits of nature experience are most likely related to the variety of sensory inputs combined with particular microbes and chemical compounds our bodies contact and absorb. While vision can be an important sense overall, the article affirms that total lived experiences in the environment full of sounds, smells, tastes, and tactile opportunity are crucial for wellbeing.

A walk in the Wissahickon is a multi-sensory embodied experience

Phytoncides, organic compounds usually emitted by plants for defensive purposes, “permeate the air in natural environments and are ingested by visitors [or inhabitants]…They are a popular topic of study in Japan, and widely believed to contribute to benefits experienced during nature walks known as ‘shinrin-yoku,’ or ‘forest-bathing.’”  Several phytoncides have been found to be antimicrobial, to increase immune system activity, and to decrease stress.

Air ions, charged particles resulting from radiation, cosmic rays, solar waves, waterfalls, thunder, and UV light, are “particularly abundant in natural places…and they have been suggested as one of the potential mechanisms for the physiological and mood benefits of natural places.” The negative air ions found outdoors “stabilize mood and increase vigor, friendliness, and ease of concentration,” while indoor spaces devoid of the ions are associated with depression.

And of course, we must remember that many of the hundred trillion bacteria in our bodies come from soil, water, animal feces, and spores. The “gut microbiota” is crucial for nervous system functioning, and decreased exposure due to a sanitized indoor lifestyle hinders our ability to benefit from those relationships.

Deepening Relationship: Co-regulation

The scientific findings on nature and wellbeing are amplified when we invite in dialogue from psychology and the arts. As someone engaged in body-based healing and therapy, I’ve been studying the Polyvagal Theory, created by Dr. Stephen Porges and referred to by Deb Dana as “the science of feeling safe enough to take the risks of living.” Polyvagal Theory works with the commonly known idea of “fight, flight, or freeze” in regards to human behavior and nervous system activation, and it adds another category: social engagement. The states of nervous system activation could be envisioned as a ladder–if something has signaled to us that our life is in major danger or that we are trapped, we shut down and freeze. That’s the bottom of the ladder, and the oldest part of our nervous system known as the Dorsal Vagus. When we mobilize in order to fight or run away from the stressor or threat, we’re in our sympathetic nervous system. When we perceive safety, largely through the presence of healthy relationships, we enter into the newest part of our nervous system, the Ventral Vagus (VV). Here, at the top of the ladder, we are able to socially engage and communicate with a sense of curiosity. In order to move from shut down to VV, one needs to move through some sympathetic activation on the ladder.

Co-regulation is key for accessing VV energy. In cases of trauma, it can be difficult to self-regulate. Though it may also be difficult to establish enough trust to develop a healthy co-regulation relationship, that relationship built over time is crucial for regaining resilience within the nervous system. Co-regulation is actually a biological need that all humans have for reciprocal regulation; it’s the way our nervous systems talk to each other, connect, mirror, and help each other feel safe enough as we move through the various states of activation and relaxation. It’s for this reason that I love to see “community care” involved in any conversation about “self care.”

Image by Relational Uprising

Essentially, the research on how nature time and health/wellness are interconnected mirrors the finding that spending time in nature helps people reconnect with the VV state. As described in the book Nature-based Therapy by Nevin Harper, Kathryn Rose, and David Segal, “Nature is filled with an abundance of flora and fauna that help engage people in the present moment and embodied exploration. [They] bring out curiosity in people and motivate a further connection with nature…Encounters with beings that can be climbed, tended, and taken in awe or wonder provide a powerful means to engage in the present moment and begin the process of acquainting [people] to their own nature, their own animal bodies, and specifically their mammalian nervous system.” In other words, outdoor environments stimulate curiosity, connection, wonder, and embodied presence that immediately bring us into a Ventral Vagal state.

In “Performing ecologies in a world in crisis,” (an editorial preface to Choreographic Practices) Robert Bingham references choreographer/performer/professor Merián Soto’s outdoor improvisational work Into the Woods: “She urges readers to ‘just go’ outside and feel the heartbeat of nature through their moving, sensing bodies.” To feel a heartbeat is, indeed, a somatic experience. In your own body, you might find that you are aware of your heartbeat and that the awareness is heightened through touch. Touch, colloquially referred to as “the mother of all senses,” is in many ways our most intimate sense and has the greatest co-regulating capabilities. What would it be like to touch the earth with the open intention of feeling the heartbeat of nature, of life itself? What would it be like to garden and grow food with that kind of touch? What would it be like to move through the world still in contact with that rhythm, to make decisions and develop habits from that place of felt-connectedness?

In terms of co-regulating with non-human creatures, we probably most readily understand it with animals, perhaps through relationships with pets. But I propose that even though plants don’t have a nervous system in exactly the way mammals do, we still enter into a dynamic, responsive relationship with them. Studies show that “plants evolved to have between 15 and 20 separate senses including human-like abilities for smell, taste, sight, touch and hearing.” Plants can remember, sense danger, respond with chemical alterations accordingly, and communicate information to their nearby communities. They’re especially intertwined with fungal communication networks. And there may be much more about their rich internal life that we haven’t scientifically explained yet. All this to say: our plant friends are very much alive, and they have a rhythm and intelligence that inevitably resonates in our bodies, helping to balance us as we grow closer to them. Perhaps we can co-regulate with them, just like we co-regulate with friends, partners, pets, or therapists.

Dancing with rocks at the pier, via the Tree Water Land series facilitated by choreographer Esther Baker-Tarpaga

Deepening Relationship: Reciprocity

As we grow closer to nature, spending more time outdoors, getting to know various species, becoming more and more intimate, we may find that we agree with Merián Soto when she asserts that “we are nature.” The authors of Nature-based Therapy agree, emphasizing that their approach to therapy involves supporting a reunion with nature as opposed to an extraction relationship in which humans take benefit from some “thing” that is separate from them. Importantly, the authors also note that outdoor experiences often include an element of risk. Nature isn’t always soothing or tranquil. And from their standpoint, accepting inherent risk is “both restorative and meaningfully disruptive (i.e. burdensome, tiring, challenging).” The risk and therefore inclusion and toning of quick-response survival mechanisms combined with the overall Ventral Vagal support as described earlier in this article actually helps create a more resilient nervous system.

Robin Wall Kimmerer, whose environmental work is grounded in the knowledge systems of First Nations, sees human-plant relationships as that of “kin.” The view of being-family supports an attitude of gratitude and togetherness. Sondra Fraleigh beautifully writes that “as we move our senses out towards the world, and a sense of the world returns to us, there is folding reciprocal play in consciousness.” Reciprocity is real depth of relationship, and what is missing from so much of modern postcolonialist life. While I can appreciate the scientific studies about how being outside in “nature” (for just two hours a week!) improves human health, the studies also perpetuate the problematic view that nature is simply something beautiful/useful for us to feel better, and then we can go on back into the broken bifurcated system keeping us separate from our kin, and essentially, ourselves.

When we come into full reciprocity in relationships, we feel the ebbs and flows of giving and receiving. We feel the innate desire to take care of the earth arise within us. We recognize all the ways we are fed, and we wish to give back equally and frequently. We grieve loss of non-human kin the same way we grieve human loved ones. We ask what we can do to help and support in times of need. We are ready to respond in times of crisis, such as now. Whether the response is shifting the paradigm back to connection, supporting and ushering in political systems that will immediately create large-scale energy and environmental protection reform, supporting indigenous people and returning land to them, caring for regional plants through propagation and stewardship, seed saving, reforesting cleared lands, getting to know local ecology and species, learning wildlife rhythms and needs, taking fewer resources, fighting for regenerative growing practices rather than destructive industrial agriculture, offering material tokens of appreciation, or simply feeding a bird, or a bee, or dancing the spirit of a place— whatever the response, the embodied reciprocity is the heart of healing.

EFTE crews have been restoring native groundcover and shrubs to this woodland space.
A moment in Rittenhouse Square, grieving for loss of kin. Project initiated by Chloe Rossetti.

Dark Night of the Soil: Restoring the Human-Humus Relationship

“‘Imagine a conference not on the Future of the Humanities in the Capitalist Restructuring University, but instead on the Power of the Humusities for a Habitable Multispecies Muddle!

…human beings are with and of the earth, and the biotic and abiotic powers of this earth are the main story. However, the doings of the situated, actual human beings matter. It matters which ways of living and dying we cast our lot rather than others. It matters not just to human beings, but also to those many critters across taxa which and whom we have subjected to exterminations, extinctions, genocides, and prospects of futurelessness.”

Donna J. Haraway, Staying with the Trouble: Making Kin in the Chthulucene

Much of our soil is becoming mere dirt. And if you care about climate change, you need to care about the crucial role that land degradation is playing in global warming, and the crucial role that soil restoration will and does already play in creating real climate solutions.

Healthy soil teems with life beneath our feet. Being land-dwellers, we tend to focus on what’s aboveground. When we observe plants, we’re typically only seeing 30 percent of the overall biomass of that plant! Besides root structures, all sorts of bacteria, organisms, and detritus interact in complex ways in soil. Within a cubic meter of healthy earth, you may find fungal hyphae twice the diameter of the earth! For those who do not know, hyphae are thread-like tubular structures, a mass of which make up the mycelium, which is the true body of a fungus. Hyphae digest externally (by releasing chemicals and enzymes into soil and nearby plant tissues) and form connections that transfer nutrients into itself as well as the nearby plants. The complex subterranean world was designed by nature intelligently; our interference in its wellbeing has had devastating fallout including desertification and global warming.

The number one culprit in degrading and eroding soil is big agriculture. Practices like tilling, no use of cover crops, and heavy use of fertilizers and pesticides all strip nutrients and microbes and destroy what Walter Jehne, Australian climate scientist and soil microbiologist, calls the “soil sponge,” full of fungal hyphae helping to create a porous living material that can sequester carbon. Sue Van Hook, mycologist, naturalist, teacher and healer, explains in this interview with Mushroom Revival that carbon is like the skeleton of the sponge and can hold up to 8x its weight in water. This massively increases the longevity of soil and the ability to continue growing in times of drought. Spores from fungi that grow in soil also trap water vapor, and Walter Jehne notes in this excellent interview how water vapor plays a key role in hydrology and the cooling of the planet. 

Walter Jehne illustrating the soil sponge, largely made by fungi and carbon who make space for voids and space in the soil structure, in which water and roots can proliferate. Jehne also explains how the increased surface area of minerals in a soil sponge like this increases biofertility.

He further explains that, “For the last 8,000 years of ‘human civilization,’ we’ve been very effective at clearing and burning [productive] land, cultivating those soils and building industrial systems. We’ve oxidized the carbon and destroyed the biological cycles that underpin the health of those landscapes. We’ve done that with 5 billion hectares of land, turning 40 percent of the Earth’s land surface into desert and wasteland. As we oxidize the carbon, by definition, those soils can’t infiltrate, retain, or make available water from rain. Invariably, they go to desert. That’s been the history of man on this planet.”

In brief, sequestering carbon in soil has the potential to reverse climate change by firstly drawing down the oxidized atmospheric carbon into the ground where it is stable and beneficial, and by rebalancing the water cycles of planet earth.

OK— so how does humus play into this?

You may be thinking it has something to do with compost? Topsoil? Organic matter? Well, sort of. Let’s start with organic matter. When it decomposes, all kinds of molecules are broken down (protein, sugars, amino acids, etc.) by bacteria/fungi/other organisms in the soil. Eventually usable stuff that’s been broken down as much as is possible is available to plants. Then there’s leftover molecules largely made up of carbon, and this absorbent material that we’ve historically called “humus” is very stable and can persist in soil for hundreds of years. 

Humus is hard to define. In fact, Erhard Jennig writes that “humus is not a real substance, but rather a process.”  The seemingly simple and common definition of humus as “black-brown matter in the topsoil produced by the putrefaction of vegetable and animal matter” does not capture the complexity of formation processes that take place following decomposition processes, which includes binding together with inorganic compounds like fine clay particles. More recent research into soil microbiology by Jehne reveals that “humus” may have more to do with what is secreted by plant roots than we previously realized. 

We can agree that compost is good, and adding organic matter especially to areas in which you frequently harvest seems especially good. But Jehne says that most soil carbon comes from plants’ root exudates. “Nature created soil by growing plants and making sure that potentially up to 60 or 70 percent of the biomass produced can be fixed into stable soil carbon. Currently though, little of it is.” Importantly, fungi are the necessary agents that mediate conversion of these root exudates into humates or glomalin (stable soil carbon). Glomalin is produced from leftover chitin from cell walls of fungi and acts like a glue or bedsprings within our soil sponge. 

These facts illuminate why common agricultural practices that rely on constant soil disturbance through clearing and harvesting end up making the humus process nearly impossible. The humus process generally requires undisturbed land, which is why you’ll find the richest stores of that authentic black topsoil in untouched forests. We need to revise what “commonplace” growing practices are these days—let’s choose practices that support the humus process and the formation of a strong soil sponge that sequesters carbon, retains moisture, and creates nutrient-rich food for everyone. 

Fungal hyphae, an important part of the soil sponge and the humus process. Photo by Jerzy Opioła [CC BY-SA]

What You Can Do

Every bit of carbon that we can re-sequester into soil matters. In reality, restoring the human-humus relationship—restoring our “soil sponge” and recognizing the sacredness of living soil itself— is much more about land management practice than adding awesome compost or other soil amendments.

Van Hook and Jehne note or imply the following basic land management tasks that will restore the soil sponge. Many of these are obviously applicable to farm management, but they can also be adapted for personal backyard growing practices.

  • Don’t till! Tilling breaks up important fungal hyphae, disturbs other processes, exposes soil to radiation, and oxidizes carbon.

  • Use cover crops and groundcover.  Keeping soil covered at all times with plants reduces carbon dioxide off-gassing, provides food and relationships for beneficial fungi, attracts biodiversity and potential pollinators, increases fertility and aeration, and decreases the likelihood of heat domes and runoff. 

  • Diversify crops. Mixed species provide better benefits for everyone below ground as well as aboveground. 

  • Implement appropriate grazing practices, especially in grasslands. Think of grazing animals as “mobile biodigesters” (term coined by Jehne) who help return unharvested vegetation to the earth rather than having it burn. The hooves of these herbivores also break up soil, they help spread seeds, and waste adds fertility. Appropriate grazing means livestock are moved regularly so nothing is overeaten. Atmospheric science has shown that herbivore-maintained grasslands produce an abundance of the kinds of ions needed to break up methane ions, another harmful greenhouse gas.

  • Oppose fracking however you can—the methane exposed from that far outweighs any methane from other sources.

  • Stop using biocides, which whether organic or not, kill life outright in our soils.

  • Plant crops with deep roots like bluestem prairie grass, which pump carbon downwards into the soil.

  • Support regrowth of forests—including urban forests—however you can.

  • Aim to create perennial gardens and food forests rather than gardens full of annual plants. 
Wild Ginger was one of various groundcover plants EFTE Eco-landscaping installed in a woodland reclamation project.

As it goes in this “multispecies muddle,” our human health is directly tied to soil health. Nutrient density depends on fungi converting organic matter into available minerals, and nutrient density and quality of food grown (possibly even the presence of beneficial microbes) affects our gut health. And as we now know, many illnesses can be tied to gut imbalance. Oh, and not to mention the obvious hard truth: loss of productive soil ultimately leads to not only less nutritious food but less food period…many civilizations “plowed themselves out of business,” so to speak. But of course, we only need to worry about food security if we can first secure the habitability of this planet (i.e. mitigating climate change): habitability not only for us humans, but for all our critter friends whose homes and lives are intertwined with our own.

I hope that alongside the abovementioned practices, more humans will feel an inner perspective and awareness shift. The ground beneath our feet is incredibly complex, intelligent, responsive, and alive. We have historically demanded of the ground so much, dominating it with our shovels and machines and flames. What will happen when we recognize that which we stand upon and that which feeds us as sacred and sentient? What if, along with our revision of physical actions and care-taking, we infuse our everyday awareness with deeper sensing and gratitude for the cycles of the underworld?

For visual/auditory learners interested in hearing more details from Walter Jehne and his feasible solutions for literally saving the world, check out this full lecture video. 

A shorter visual illustration of the soil sponge can be found here