Forests and Well-Being – Notes from “The Nature Fix”

Florence Williams’ book, The Nature Fix (Norton, 2017) summarizes some of what we know about how time in nature affects our well-being. It’s a “popular” book, but that’s not to say it is short on substance. Among the endorsements inside the cover is one from famed biologist Edward O. Wilson, whose work includes the biophilia hypothesis which says that evolution has “wired” us to be drawn to nature and all its plants and animals.

Williams is a journalist, and what she writes in this book is woven into a series of interviews, walks, and back country expeditions with experts in the field. It’s the story of her active, “hands-on” research on the subject, and so it is an engaging read. It also lays out some of the evidence and a few of the theories about how nature might decrease our stress hormones, lower our blood pressure, and have other benefits to our well-being. My notes here are part of my effort to understand this better; it seems intuitive to me that being in nature has benefits to our bodies and souls, but I want to look at the science behind it. So here are a few notes from the first section of her book.

In Japan, forest therapy (sometimes referred to as “Forest Bathing”) or “Shinrin yoku” is quite popular. It is based on Shinto and Buddhist practice and seeks to let nature into your body through all five senses. It is also linked to E.O. Wilson’s idea of biophilia, that we have an innate emotional affiliation with other living organisms. In forest therapy, people spend time in forests and become immersed in the sights, sounds, smells, and other experiences there. 

If this sounds a little sketchy, consider the results found by Yoshifumi Miyazaki, a physical anthropologist in Tokyo. He found that leisurely forest walks decreased cortisol, compared to urban walks. (Cortisol is a stress hormone, and with chronic stress cortisol creates problems, from dysregulated blood sugar to heart problems, depression and anxiety, memory and concentration problems, and so on.) Forest walkers had decreased sympathetic nerve activity, lower blood pressure and heart rate. (The constant stimulation and demands of life trigger activity from the sympathetic nervous system, resulting in “fight or flight” reactions. On the other hand, relaxation and feeling at ease are associated with a system that works in opposition to it, the parasympathetic nervous system.) When the walkers completed questionnaires, the nature group report better mood and less anxiety. 

More evidence comes from psychologist Roger Ulrich, who connected subjects to EEG and showed them slides, either of nature or of urban scenes. Those who watched nature slides had greater alpha rhythm, which is associated with relaxation and release of pleasurable endorphins. He also exposed subjects to a stressful activity, and then had them watch 10 minutes of either (a) nature scenes, or (b) urban scenes. Within five minutes, the sympathetic activity of the nature scene group returned to baseline, while the other group only partly recovered. 

Qing Li, an immunologist at the Nippon Medical School in Tokyo, looked at the impact of mood states and stress on the immune system. Li was interested in NK cells, a kind of white blood cell that sends self-destruct messages to tumor cells or virus-infected cells. Stress can decrease the number of these beneficial NK cells. Li took a group into the forest for three days that included hiking in the woods for a couple of hours daily. They had a 40% increase in NK cells. Li wondered if this was due to aromatic volatile substances coming from trees, and so Li had thirteen people spend three nights in a hotel where a humidifier could vaporize oil from hinoki cypress trees (or, for a control group, just water vapor). The cypress oil resulted in a 20% increase in NK cells, compared to controls.

At the Grasslands, With Bug Nerds

I’m seeing more of the LBJ National Grasslands this summer than I have in a while, and it’s been wonderful. The rainfall over the past eight or nine months have resulted in a bonanza of plant life, which leads to a bonanza of bug life, and so on down the food chain. Yesterday, I visited again with a couple of “bug nerd” friends (shorthand for “people who know a lot about invertebrates and other stuff I don’t know”).

Prairies and oak woodlands of the Western Cross Timbers

Actually, Meghan and Paul are all-around fans of the entire natural world, which is just my kind of folks. We talked about the Post Oaks and Blackjack Oaks which are the signature trees for this ecoregion, and Little Bluestem grass and Partridge Pea and what the difference might be between Meadow Pink and Prairie Gentian, and bent over to look at a hundred different plants. Meghan suggested it would be fun to come back and try to inventory all the diversity of grasses and forbs in a one-meter space, which we all agreed would be a long list.


But just as I am first and foremost a “herp nerd,” these guys are “bug nerds” and more specifically, Meghan specializes in spiders. It’s an interesting and probably helpful collaboration, as I still have enough residual arachnophobia that I won’t handle spiders (though I can examine and photograph them with no problem). As the sun neared the horizon after 7:00pm, we started noticing lots of the orb-weaving spiders that cast their nets between branches and across the trail. I admire the concentric lines in their webs, but hate running into them.

Gray Treefrog

Then, as we talked about the three-lobed leaves of Blackjack Oak with the little spine at the end of the lobes, I spotted a favorite amphibian, resting quietly on one of those Blackjack leaves and waiting for night to fall. It was a Gray Treefrog, currently showing the mottled green color that they can assume when they are not mottled shades of gray. There was no telling which species of Gray Treefrog we were looking at, as Hyla versicolor (sometimes called the “Eastern Gray Treefrog”) and Hyla chrysoscelis (Cope’s Gray Treefrog) are just about indistinguishable except by their calls and their DNA. H. versicolor has a second set of chromosomes, so that they have twice the number of chromosomes as Cope’s Gray Treefrog. Cope’s also has a more rasping and less musical trill than the Eastern Gray Treefrog.

Little Bluestem in the lengthening shadows of evening

I’ve noticed that I didn’t take photos of the spiders we saw, but I did take a couple of photos of grassland insects. One was a stick insect we came across, and the other was one of the thousands of grasshoppers (and a few katydids) that scattered as we passed through.

Stick insect
Grasshopper, with an ant disappearing behind a leaf at lower left

The grasslands were beautiful as sunset approached and a nearly full moon took its place in the sky. We were privileged to be able to visit this place.

Sunset on the grasslands, near Alvord, TX

But we weren’t done yet. Some evening road-cruising failed to turn up the usual Broad-banded Copperheads, but we were treated to a couple of Western Ratsnakes. These snakes are harmless – or let’s just say that they are “non-venomous.” Completely mild-mannered when left alone, they are pugnacious when picked up. I picked up each one so we could examine these beautiful animals, and Meghan wanted to interact with them, too. Knowing they could not hurt her in any important way, she said that she was unconcerned about being bitten. The second one was more than willing to put that to the test, and promptly bit her. After we admired and then released the snake, we looked at the pattern of little punctures on her arm, and she was delighted to see how these snakes have two rows of palatine teeth (fixed to bones in the area where the palate would be in the upper part of the mouth) between the usual rows of maxillary teeth. Four rows of teeth! And being able to discuss and enjoy that little bit of natural history based on the bleeding evidence of your arm, that’s the sign of a real naturalist!

This Is Our Land

When the sun comes shining, then I was strolling

In wheat fields waving and dust clouds rolling

The voice come chanting as the fog was lifting

This land was made for you and me

– Woody Guthrie

Bang! It’s the Fourth of July.

A day when we might celebrate the founding of this country, and what that meant. We refused to live under a tyrant and were determined to go our own way. What amazing possibilities there were, as expressed in words like, “We hold these truths to be self-evident, that all men are created equal ….” Many of our dreams are noble, even if we stumble sometimes.

 But Jo and I could not stay home and watch on TV as tanks rumbled through Washington, D.C., even if they were our tanks. We decided to celebrate what Woody Guthrie celebrated, that we share a beautiful and extraordinary landscape, some parts of which belong to all of us. It is our collective inheritance, unless we give it away or destroy it. 

We decided to visit the LBJ National Grasslands up above Decatur, mostly in Wise County. It is a patchwork of over twenty thousand acres scattered among small farms, ranches, or homes. Most of it is mixed oak woodlands with little pocket prairies or big open areas where native grasses like Little Bluestem and Indiangrass can flourish. The soil is mostly sand or clay, and in places the loose sand has eroded around the streams and ponds. The Grasslands is located within the Western Cross Timbers ecoregion and seems pretty typical of the Post Oak and Blackjack Oak forests and patches of prairie.

My visits to the Grasslands started in 2001, with an afternoon and evening spent finding reptiles and amphibians with Steve Campbell. Multiple kingsnakes, ratsnakes, watersnakes, greensnakes, copperheads, turtles, frogs and toads later (all in one day!) the place was a favorite. Over the years since that first trip, I have tried to educate myself about some of the other plants and animals there. It is a work in progress, and I have a lot still to learn – and what a pleasant task that is! “Which juniper is that? Is that a Gulf Fritillary butterfly? What is that flower?” The questions just keep coming, along with a few answers.

One trip to the Grasslands happened on a really hot day in late May last year when I led some members of the Friends of the Fort Worth Nature Center & Refuge in search of herps. The first part, which we will call the “heat exhaustion” portion of the trip, failed to turn up the Texas Spiny Lizards and Western Coachwhips that Clint and I anticipated. However, at 7:30pm (with the sun low and late afternoon shading into evening) we spotted an Ornate Box Turtle, a species that is no longer seen nearly as often as it once was. Then, exploring around a small pond just after dark, we saw a couple of ribbonsnakes, a watersnake, and we watched a baby Northern Cottonmouth swim across the water to avoid us. My attempts to get a good photograph of it clearly demonstrated how nonaggressive these snakes usually are, as it kept trying to get away without ever attempting to bite. Finally, at the end of our visit, we were able to gather around a beautiful Broad-banded Copperhead on the road, another potentially dangerous snake that really just wants to be left alone.

Today there were no box turtles, although I did think about that possibility when we arrived early enough in the morning that the temperatures were very moderate. We didn’t see any snakes, either, but there were plenty of flowers, and the landscape was green and lush after all the rain we have had this spring and early summer. The season of basketflowers and thistles is winding down, though we did see some in places. A metallic green bee was visiting one of them.

We both love Little Bluestem, and today there were plenty of pocket prairies and fields with the blue-green clumps of this native grass among the other grasses. The little bunches of bluish leaves are gorgeous, but as they send up those straight, tall stalks they really stand out. 

White Rosinweed

In one of those bluestem prairies I spotted a few White Rosinweed, a species of compass-plant. This one is a Texas endemic – that is, found nowhere else but in the central part of Texas, in prairies from near the Red River down to Austin. Its leaves are big, with long and narrow lobes, with a stiff, sandpapery feel. The white flowers are beautiful.

We also saw lots of Spotted Horsemint (aka Spotted Beebalm).  Jo is a particular fan of this plant, which is taller and less colorful than Lemon Beebalm, but its whorls of tiny-spotted flowers (in layers alternating with leaf-like bracts that may be tinged purple) are beautiful when examined close up. 

Spotted Horsemint

There were also patches of what I imagine were Black-eyed Susan and Meadow Pink, making a beautiful carpet of yellow and pink in some open areas. We saw them at roadside and in open areas near stands of oak, and the flowers made a gorgeous tapestry.

Silverleaf Nightshade

We are also both big fans of Silverleaf Nightshade, a plant with beautiful violet flowers with yellow stamens. The stems and leaves are somewhat hairy, making them look rather pale. They are related to the tomato plant, but the Lady Bird Johnson Wildflower Center describes Silverleaf Nightshade as an “aggressive, poisonous weed.” That doesn’t discourage us in the slightest in our appreciation of this plant. In one location, we found several beetles crawling on these plants, a sort of velvety-tan insect with little or no markings on the wing covers or elytra, but black antennae, legs, and black-bordered segments of the abdomen. Best I can tell, these may have been some sort of blister beetle in the genus Epicauta (thanks, Meghan Rose, for suggesting this identification).

Grasshoppers were everywhere, ranging from the slender, slant-faced grasshoppers to big lubbers. I took a photo of a beautiful katydid, which iNaturalist suggests was one of the round-headed katydids. 

In one little roadside puddle, I spotted a young bullfrog with his head angled up out of the water, but he retreated before I could get out of the car and I didn’t dig through the caliche mud to try to find where he was hiding. The same little spot had several cricket frogs. We weren’t sure where these frogs will go when the puddle dries, but I’m confident they will find their way. We were just grateful that they provided a few sightings of herpetofauna while we were out.

Blanchard’s Cricket Frog

And that was our Fourth of July celebration. No fireworks, no “blowing stuff up,” and no parades. Just an appreciation of one spot among the public lands shared by all of us.